jiangzhikang

os/os/linux/.vscode/settings.json

@@ -0,0 +1,9 @@
+{
+    "files.associations": {
+        "*.json": "c",
+        "*.o": "plaintext",
+        "new.h": "c",
+        "new0.h": "c",
+        "errno.h": "c"
+    }
+}

os/os/linux/Makefile

@@ -0,0 +1,125 @@
+#
+# if you want the ram-disk device, define this to be the
+# size in blocks.
+#
+RAMDISK = #-DRAMDISK=512
+
+AS86	=as86 -0 -a
+LD86	=ld86 -0
+
+AS	=as
+LD	=ld
+LDFLAGS	=-m elf_i386 -Ttext 0 -e startup_32 -Map=System.map.2 -N
+CC	=gcc -march=i386 $(RAMDISK)
+CFLAGS	=-w -g -fstrength-reduce -fomit-frame-pointer -fno-stack-protector -mcld
+CPP	=cpp -nostdinc -Iinclude
+
+#
+# ROOT_DEV specifies the default root-device when making the image.
+# This can be either FLOPPY, /dev/xxxx or empty, in which case the
+# default of /dev/hd6 is used by 'build'.
+#
+ROOT_DEV=
+
+ARCHIVES=kernel/kernel.o mm/mm.o fs/fs.o
+DRIVERS =kernel/blk_drv/blk_drv.a kernel/chr_drv/chr_drv.a
+MATH	=kernel/math/math.a
+LIBS	=lib/lib.a
+
+.c.s:
+	$(CC) $(CFLAGS) \
+	-nostdinc -Iinclude -S -o $*.s $<
+.s.o:
+	$(AS) -o $*.o $<
+.c.o:
+	$(CC) $(CFLAGS) \
+	-nostdinc -Iinclude -c -o $*.o $<
+
+all:	Image
+
+Image: boot/bootsect boot/setup tools/system tools/build
+	cp -f tools/system system.tmp
+	strip system.tmp
+	tools/build boot/bootsect boot/setup system.tmp $(ROOT_DEV) > Image
+	rm -f system.tmp
+	sync
+
+disk: Image
+	dd bs=8192 if=Image of=/dev/PS0
+
+tools/build: tools/build.c
+	$(CC) $(CFLAGS) \
+	-o tools/build tools/build.c
+
+boot/head.o: boot/head.s
+
+tools/system:	boot/head.o init/main.o \
+		$(ARCHIVES) $(DRIVERS) $(MATH) $(LIBS)
+	$(LD) $(LDFLAGS) boot/head.o init/main.o \
+	$(ARCHIVES) \
+	$(DRIVERS) \
+	$(MATH) \
+	$(LIBS) \
+	-o tools/system
+	nm tools/system | grep -v '\(compiled\)\|\(\.o$$\)\|\( [aUw]\)\|\(\.\.ng$$\)\|\(LASH[RL]DI\)' | sort >System.map
+
+kernel/math/math.a: FORCE
+	(cd kernel/math; make)
+
+kernel/blk_drv/blk_drv.a: FORCE
+	(cd kernel/blk_drv; make)
+
+kernel/chr_drv/chr_drv.a: FORCE
+	(cd kernel/chr_drv; make)
+
+kernel/kernel.o: FORCE
+	(cd kernel; make)
+
+mm/mm.o: FORCE
+	(cd mm; make)
+
+fs/fs.o: FORCE
+	(cd fs; make)
+
+lib/lib.a: FORCE
+	(cd lib; make)
+
+FORCE:
+
+boot/setup: boot/setup.s
+	$(AS86) -o boot/setup.o boot/setup.s
+	$(LD86) -s -o boot/setup boot/setup.o
+
+boot/bootsect:	boot/bootsect.s
+	$(AS86) -o boot/bootsect.o boot/bootsect.s
+	$(LD86) -s -o boot/bootsect boot/bootsect.o
+
+tmp.s:	boot/bootsect.s tools/system
+	(echo -n "SYSSIZE = (";ls -l tools/system | grep system \
+		| cut -c25-31 | tr '\012' ' '; echo "+ 15 ) / 16") > tmp.s
+	cat boot/bootsect.s >> tmp.s
+
+clean:
+	rm -f Image System.map tmp_make core System.map.2
+	rm -f boot/bootsect boot/setup
+	rm -f init/*.o tools/system tools/build boot/*.o
+	(cd mm;make clean)
+	(cd fs;make clean)
+	(cd kernel;make clean)
+	(cd lib;make clean)
+
+dep:
+	sed '/\#\#\# Dependencies/q' < Makefile > tmp_make
+	(for i in init/*.c;do echo -n "init/";$(CPP) -M $$i;done) >> tmp_make
+	cp tmp_make Makefile
+	(cd fs; make dep)
+	(cd kernel; make dep)
+	(cd mm; make dep)
+
+### Dependencies:
+init/main.o : init/main.c include/unistd.h include/sys/stat.h \
+  include/sys/types.h include/sys/times.h include/sys/utsname.h \
+  include/utime.h include/time.h include/linux/tty.h include/termios.h \
+  include/linux/sched.h include/linux/head.h include/linux/fs.h \
+  include/linux/mm.h include/signal.h include/asm/system.h include/asm/io.h \
+  include/stddef.h include/stdarg.h include/fcntl.h 

os/os/linux/System.map

@@ -0,0 +1,598 @@
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+000234c0 b ques
+000234c4 b saved_x
+000234c8 b saved_y
+000234e0 B drive_info
+00023500 B user_stack
+00024500 B hash_table
+000249e0 B super_block
+00024d40 B file_table
+00025140 B request
+000255c0 B rd_start
+000255c4 B _ctmp
+000255c8 B errno
+000255cc B ___strtok
+000255d0 B end
+000255d0 B _end

os/os/linux/boot/bootsect.s

@@ -0,0 +1,260 @@
+!
+! SYS_SIZE is the number of clicks (16 bytes) to be loaded.
+! 0x3000 is 0x30000 bytes = 196kB, more than enough for current
+! versions of linux
+!
+SYSSIZE = 0x3000
+!
+!	bootsect.s		(C) 1991 Linus Torvalds
+!
+! bootsect.s is loaded at 0x7c00 by the bios-startup routines, and moves
+! iself out of the way to address 0x90000, and jumps there.
+!
+! It then loads 'setup' directly after itself (0x90200), and the system
+! at 0x10000, using BIOS interrupts. 
+!
+! NOTE! currently system is at most 8*65536 bytes long. This should be no
+! problem, even in the future. I want to keep it simple. This 512 kB
+! kernel size should be enough, especially as this doesn't contain the
+! buffer cache as in minix
+!
+! The loader has been made as simple as possible, and continuos
+! read errors will result in a unbreakable loop. Reboot by hand. It
+! loads pretty fast by getting whole sectors at a time whenever possible.
+
+.globl begtext, begdata, begbss, endtext, enddata, endbss
+.text
+begtext:
+.data
+begdata:
+.bss
+begbss:
+.text
+
+SETUPLEN = 4				! nr of setup-sectors
+BOOTSEG  = 0x07c0			! original address of boot-sector
+INITSEG  = 0x9000			! we move boot here - out of the way
+SETUPSEG = 0x9020			! setup starts here
+SYSSEG   = 0x1000			! system loaded at 0x10000 (65536).
+ENDSEG   = SYSSEG + SYSSIZE		! where to stop loading
+
+! ROOT_DEV:	0x000 - same type of floppy as boot.
+!		0x301 - first partition on first drive etc
+ROOT_DEV = 0x306
+
+entry start
+start:
+	mov	ax,#BOOTSEG
+	mov	ds,ax
+	mov	ax,#INITSEG
+	mov	es,ax
+	mov	cx,#256
+	sub	si,si
+	sub	di,di
+	rep
+	movw
+	jmpi	go,INITSEG
+go:	mov	ax,cs
+	mov	ds,ax
+	mov	es,ax
+! put stack at 0x9ff00.
+	mov	ss,ax
+	mov	sp,#0xFF00		! arbitrary value >>512
+
+! load the setup-sectors directly after the bootblock.
+! Note that 'es' is already set up.
+
+load_setup:
+	mov	dx,#0x0000		! drive 0, head 0
+	mov	cx,#0x0002		! sector 2, track 0
+	mov	bx,#0x0200		! address = 512, in INITSEG
+	mov	ax,#0x0200+SETUPLEN	! service 2, nr of sectors
+	int	0x13			! read it
+	jnc	ok_load_setup		! ok - continue
+	mov	dx,#0x0000
+	mov	ax,#0x0000		! reset the diskette
+	int	0x13
+	j	load_setup
+
+ok_load_setup:
+
+! Get disk drive parameters, specifically nr of sectors/track
+
+	mov	dl,#0x00
+	mov	ax,#0x0800		! AH=8 is get drive parameters
+	int	0x13
+	mov	ch,#0x00
+	seg cs
+	mov	sectors,cx
+	mov	ax,#INITSEG
+	mov	es,ax
+
+! Print some inane message
+
+	mov	ah,#0x03		! read cursor pos
+	xor	bh,bh
+	int	0x10
+	
+	mov	cx,#24
+	mov	bx,#0x0007		! page 0, attribute 7 (normal)
+	mov	bp,#msg1
+	mov	ax,#0x1301		! write string, move cursor
+	int	0x10
+
+! ok, we've written the message, now
+! we want to load the system (at 0x10000)
+
+	mov	ax,#SYSSEG
+	mov	es,ax		! segment of 0x010000
+	call	read_it
+	call	kill_motor
+
+! After that we check which root-device to use. If the device is
+! defined (!= 0), nothing is done and the given device is used.
+! Otherwise, either /dev/PS0 (2,28) or /dev/at0 (2,8), depending
+! on the number of sectors that the BIOS reports currently.
+
+	seg cs
+	mov	ax,root_dev
+	cmp	ax,#0
+	jne	root_defined
+	seg cs
+	mov	bx,sectors
+	mov	ax,#0x0208		! /dev/ps0 - 1.2Mb
+	cmp	bx,#15
+	je	root_defined
+	mov	ax,#0x021c		! /dev/PS0 - 1.44Mb
+	cmp	bx,#18
+	je	root_defined
+undef_root:
+	jmp undef_root
+root_defined:
+	seg cs
+	mov	root_dev,ax
+
+! after that (everyting loaded), we jump to
+! the setup-routine loaded directly after
+! the bootblock:
+
+	jmpi	0,SETUPSEG
+
+! This routine loads the system at address 0x10000, making sure
+! no 64kB boundaries are crossed. We try to load it as fast as
+! possible, loading whole tracks whenever we can.
+!
+! in:	es - starting address segment (normally 0x1000)
+!
+sread:	.word 1+SETUPLEN	! sectors read of current track
+head:	.word 0			! current head
+track:	.word 0			! current track
+
+read_it:
+	mov ax,es
+	test ax,#0x0fff
+die:	jne die			! es must be at 64kB boundary
+	xor bx,bx		! bx is starting address within segment
+rp_read:
+	mov ax,es
+	cmp ax,#ENDSEG		! have we loaded all yet?
+	jb ok1_read
+	ret
+ok1_read:
+	seg cs
+	mov ax,sectors
+	sub ax,sread
+	mov cx,ax
+	shl cx,#9
+	add cx,bx
+	jnc ok2_read
+	je ok2_read
+	xor ax,ax
+	sub ax,bx
+	shr ax,#9
+ok2_read:
+	call read_track
+	mov cx,ax
+	add ax,sread
+	seg cs
+	cmp ax,sectors
+	jne ok3_read
+	mov ax,#1
+	sub ax,head
+	jne ok4_read
+	inc track
+ok4_read:
+	mov head,ax
+	xor ax,ax
+ok3_read:
+	mov sread,ax
+	shl cx,#9
+	add bx,cx
+	jnc rp_read
+	mov ax,es
+	add ax,#0x1000
+	mov es,ax
+	xor bx,bx
+	jmp rp_read
+
+read_track:
+	push ax
+	push bx
+	push cx
+	push dx
+	mov dx,track
+	mov cx,sread
+	inc cx
+	mov ch,dl
+	mov dx,head
+	mov dh,dl
+	mov dl,#0
+	and dx,#0x0100
+	mov ah,#2
+	int 0x13
+	jc bad_rt
+	pop dx
+	pop cx
+	pop bx
+	pop ax
+	ret
+bad_rt:	mov ax,#0
+	mov dx,#0
+	int 0x13
+	pop dx
+	pop cx
+	pop bx
+	pop ax
+	jmp read_track
+
+/*
+ * This procedure turns off the floppy drive motor, so
+ * that we enter the kernel in a known state, and
+ * don't have to worry about it later.
+ */
+kill_motor:
+	push dx
+	mov dx,#0x3f2
+	mov al,#0
+	outb
+	pop dx
+	ret
+
+sectors:
+	.word 0
+
+msg1:
+	.byte 13,10
+	.ascii "Loading system ..."
+	.byte 13,10,13,10
+
+.org 508
+root_dev:
+	.word ROOT_DEV
+boot_flag:
+	.word 0xAA55
+
+.text
+endtext:
+.data
+enddata:
+.bss
+endbss:

os/os/linux/boot/head.s

@@ -0,0 +1,240 @@
+/*
+ *  linux/boot/head.s
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+/*
+ *  head.s contains the 32-bit startup code.
+ *
+ * NOTE!!! Startup happens at absolute address 0x00000000, which is also where
+ * the page directory will exist. The startup code will be overwritten by
+ * the page directory.
+ */
+.text
+.globl idt,gdt,pg_dir,tmp_floppy_area
+pg_dir:
+.globl startup_32
+startup_32:
+	movl $0x10,%eax
+	mov %ax,%ds
+	mov %ax,%es
+	mov %ax,%fs
+	mov %ax,%gs
+	lss stack_start,%esp
+	call setup_idt
+	call setup_gdt
+	movl $0x10,%eax		# reload all the segment registers
+	mov %ax,%ds		# after changing gdt. CS was already
+	mov %ax,%es		# reloaded in 'setup_gdt'
+	mov %ax,%fs
+	mov %ax,%gs
+	lss stack_start,%esp
+	xorl %eax,%eax
+1:	incl %eax		# check that A20 really IS enabled
+	movl %eax,0x000000	# loop forever if it isn't
+	cmpl %eax,0x100000
+	je 1b
+/*
+ * NOTE! 486 should set bit 16, to check for write-protect in supervisor
+ * mode. Then it would be unnecessary with the "verify_area()"-calls.
+ * 486 users probably want to set the NE (#5) bit also, so as to use
+ * int 16 for math errors.
+ */
+	movl %cr0,%eax		# check math chip
+	andl $0x80000011,%eax	# Save PG,PE,ET
+/* "orl $0x10020,%eax" here for 486 might be good */
+	orl $2,%eax		# set MP
+	movl %eax,%cr0
+	call check_x87
+	jmp after_page_tables
+
+/*
+ * We depend on ET to be correct. This checks for 287/387.
+ */
+check_x87:
+	fninit
+	fstsw %ax
+	cmpb $0,%al
+	je 1f			/* no coprocessor: have to set bits */
+	movl %cr0,%eax
+	xorl $6,%eax		/* reset MP, set EM */
+	movl %eax,%cr0
+	ret
+.align 4
+1:	.byte 0xDB,0xE4		/* fsetpm for 287, ignored by 387 */
+	ret
+
+/*
+ *  setup_idt
+ *
+ *  sets up a idt with 256 entries pointing to
+ *  ignore_int, interrupt gates. It then loads
+ *  idt. Everything that wants to install itself
+ *  in the idt-table may do so themselves. Interrupts
+ *  are enabled elsewhere, when we can be relatively
+ *  sure everything is ok. This routine will be over-
+ *  written by the page tables.
+ */
+setup_idt:
+	lea ignore_int,%edx
+	movl $0x00080000,%eax
+	movw %dx,%ax		/* selector = 0x0008 = cs */
+	movw $0x8E00,%dx	/* interrupt gate - dpl=0, present */
+
+	lea idt,%edi
+	mov $256,%ecx
+rp_sidt:
+	movl %eax,(%edi)
+	movl %edx,4(%edi)
+	addl $8,%edi
+	dec %ecx
+	jne rp_sidt
+	lidt idt_descr
+	ret
+
+/*
+ *  setup_gdt
+ *
+ *  This routines sets up a new gdt and loads it.
+ *  Only two entries are currently built, the same
+ *  ones that were built in init.s. The routine
+ *  is VERY complicated at two whole lines, so this
+ *  rather long comment is certainly needed :-).
+ *  This routine will beoverwritten by the page tables.
+ */
+setup_gdt:
+	lgdt gdt_descr
+	ret
+
+/*
+ * I put the kernel page tables right after the page directory,
+ * using 4 of them to span 16 Mb of physical memory. People with
+ * more than 16MB will have to expand this.
+ */
+.org 0x1000
+pg0:
+
+.org 0x2000
+pg1:
+
+.org 0x3000
+pg2:
+
+.org 0x4000
+pg3:
+
+.org 0x5000
+/*
+ * tmp_floppy_area is used by the floppy-driver when DMA cannot
+ * reach to a buffer-block. It needs to be aligned, so that it isn't
+ * on a 64kB border.
+ */
+tmp_floppy_area:
+	.fill 1024,1,0
+
+after_page_tables:
+	pushl $0		# These are the parameters to main :-)
+	pushl $0
+	pushl $0
+	pushl $L6		# return address for main, if it decides to.
+	pushl $main
+	jmp setup_paging
+L6:
+	jmp L6			# main should never return here, but
+				# just in case, we know what happens.
+
+/* This is the default interrupt "handler" :-) */
+int_msg:
+	.asciz "Unknown interrupt\n\r"
+.align 4
+ignore_int:
+	pushl %eax
+	pushl %ecx
+	pushl %edx
+	push %ds
+	push %es
+	push %fs
+	movl $0x10,%eax
+	mov %ax,%ds
+	mov %ax,%es
+	mov %ax,%fs
+	pushl $int_msg
+	call printk
+	popl %eax
+	pop %fs
+	pop %es
+	pop %ds
+	popl %edx
+	popl %ecx
+	popl %eax
+	iret
+
+
+/*
+ * Setup_paging
+ *
+ * This routine sets up paging by setting the page bit
+ * in cr0. The page tables are set up, identity-mapping
+ * the first 16MB. The pager assumes that no illegal
+ * addresses are produced (ie >4Mb on a 4Mb machine).
+ *
+ * NOTE! Although all physical memory should be identity
+ * mapped by this routine, only the kernel page functions
+ * use the >1Mb addresses directly. All "normal" functions
+ * use just the lower 1Mb, or the local data space, which
+ * will be mapped to some other place - mm keeps track of
+ * that.
+ *
+ * For those with more memory than 16 Mb - tough luck. I've
+ * not got it, why should you :-) The source is here. Change
+ * it. (Seriously - it shouldn't be too difficult. Mostly
+ * change some constants etc. I left it at 16Mb, as my machine
+ * even cannot be extended past that (ok, but it was cheap :-)
+ * I've tried to show which constants to change by having
+ * some kind of marker at them (search for "16Mb"), but I
+ * won't guarantee that's all :-( )
+ */
+.align 4
+setup_paging:
+	movl $1024*5,%ecx		/* 5 pages - pg_dir+4 page tables */
+	xorl %eax,%eax
+	xorl %edi,%edi			/* pg_dir is at 0x000 */
+	cld;rep;stosl
+	movl $pg0+7,pg_dir		/* set present bit/user r/w */
+	movl $pg1+7,pg_dir+4		/*  --------- " " --------- */
+	movl $pg2+7,pg_dir+8		/*  --------- " " --------- */
+	movl $pg3+7,pg_dir+12		/*  --------- " " --------- */
+	movl $pg3+4092,%edi
+	movl $0xfff007,%eax		/*  16Mb - 4096 + 7 (r/w user,p) */
+	std
+1:	stosl			/* fill pages backwards - more efficient :-) */
+	subl $0x1000,%eax
+	jge 1b
+	xorl %eax,%eax		/* pg_dir is at 0x0000 */
+	movl %eax,%cr3		/* cr3 - page directory start */
+	movl %cr0,%eax
+	orl $0x80000000,%eax
+	movl %eax,%cr0		/* set paging (PG) bit */
+	cld         /* by wyj */
+	ret			/* this also flushes prefetch-queue */
+
+.align 4
+.word 0
+idt_descr:
+	.word 256*8-1		# idt contains 256 entries
+	.long idt
+.align 4
+.word 0
+gdt_descr:
+	.word 256*8-1		# so does gdt (not that that's any
+	.long gdt		# magic number, but it works for me :^)
+
+	.align 8
+idt:	.fill 256,8,0		# idt is uninitialized
+
+gdt:	.quad 0x0000000000000000	/* NULL descriptor */
+	.quad 0x00c09a0000000fff	/* 16Mb */
+	.quad 0x00c0920000000fff	/* 16Mb */
+	.quad 0x0000000000000000	/* TEMPORARY - don't use */
+	.fill 252,8,0			/* space for LDT's and TSS's etc */

os/os/linux/boot/setup.s

@@ -0,0 +1,231 @@
+!
+!	setup.s		(C) 1991 Linus Torvalds
+!
+! setup.s is responsible for getting the system data from the BIOS,
+! and putting them into the appropriate places in system memory.
+! both setup.s and system has been loaded by the bootblock.
+!
+! This code asks the bios for memory/disk/other parameters, and
+! puts them in a "safe" place: 0x90000-0x901FF, ie where the
+! boot-block used to be. It is then up to the protected mode
+! system to read them from there before the area is overwritten
+! for buffer-blocks.
+!
+
+! NOTE! These had better be the same as in bootsect.s!
+
+INITSEG  = 0x9000	! we move boot here - out of the way
+SYSSEG   = 0x1000	! system loaded at 0x10000 (65536).
+SETUPSEG = 0x9020	! this is the current segment
+
+.globl begtext, begdata, begbss, endtext, enddata, endbss
+.text
+begtext:
+.data
+begdata:
+.bss
+begbss:
+.text
+
+entry start
+start:
+
+! ok, the read went well so we get current cursor position and save it for
+! posterity.
+
+	mov	ax,#INITSEG	! this is done in bootsect already, but...
+	mov	ds,ax
+	mov	ah,#0x03	! read cursor pos
+	xor	bh,bh
+	int	0x10		! save it in known place, con_init fetches
+	mov	[0],dx		! it from 0x90000.
+
+! Get memory size (extended mem, kB)
+
+	mov	ah,#0x88
+	int	0x15
+	mov	[2],ax
+
+! Get video-card data:
+
+	mov	ah,#0x0f
+	int	0x10
+	mov	[4],bx		! bh = display page
+	mov	[6],ax		! al = video mode, ah = window width
+
+! check for EGA/VGA and some config parameters
+
+	mov	ah,#0x12
+	mov	bl,#0x10
+	int	0x10
+	mov	[8],ax
+	mov	[10],bx
+	mov	[12],cx
+
+! Get hd0 data
+
+	mov	ax,#0x0000
+	mov	ds,ax
+	lds	si,[4*0x41]
+	mov	ax,#INITSEG
+	mov	es,ax
+	mov	di,#0x0080
+	mov	cx,#0x10
+	rep
+	movsb
+
+! Get hd1 data
+
+	mov	ax,#0x0000
+	mov	ds,ax
+	lds	si,[4*0x46]
+	mov	ax,#INITSEG
+	mov	es,ax
+	mov	di,#0x0090
+	mov	cx,#0x10
+	rep
+	movsb
+
+! Check that there IS a hd1 :-)
+
+	mov	ax,#0x01500
+	mov	dl,#0x81
+	int	0x13
+	jc	no_disk1
+	cmp	ah,#3
+	je	is_disk1
+no_disk1:
+	mov	ax,#INITSEG
+	mov	es,ax
+	mov	di,#0x0090
+	mov	cx,#0x10
+	mov	ax,#0x00
+	rep
+	stosb
+is_disk1:
+
+! now we want to move to protected mode ...
+
+	cli			! no interrupts allowed !
+
+! first we move the system to it's rightful place
+
+	mov	ax,#0x0000
+	cld			! 'direction'=0, movs moves forward
+do_move:
+	mov	es,ax		! destination segment
+	add	ax,#0x1000
+	cmp	ax,#0x9000
+	jz	end_move
+	mov	ds,ax		! source segment
+	sub	di,di
+	sub	si,si
+	mov 	cx,#0x8000
+	rep
+	movsw
+	jmp	do_move
+
+! then we load the segment descriptors
+
+end_move:
+	mov	ax,#SETUPSEG	! right, forgot this at first. didn't work :-)
+	mov	ds,ax
+	lidt	idt_48		! load idt with 0,0
+	lgdt	gdt_48		! load gdt with whatever appropriate
+
+! that was painless, now we enable A20
+
+	call	empty_8042
+	mov	al,#0xD1		! command write
+	out	#0x64,al
+	call	empty_8042
+	mov	al,#0xDF		! A20 on
+	out	#0x60,al
+	call	empty_8042
+
+! well, that went ok, I hope. Now we have to reprogram the interrupts :-(
+! we put them right after the intel-reserved hardware interrupts, at
+! int 0x20-0x2F. There they won't mess up anything. Sadly IBM really
+! messed this up with the original PC, and they haven't been able to
+! rectify it afterwards. Thus the bios puts interrupts at 0x08-0x0f,
+! which is used for the internal hardware interrupts as well. We just
+! have to reprogram the 8259's, and it isn't fun.
+
+	mov	al,#0x11		! initialization sequence
+	out	#0x20,al		! send it to 8259A-1
+	.word	0x00eb,0x00eb		! jmp $+2, jmp $+2
+	out	#0xA0,al		! and to 8259A-2
+	.word	0x00eb,0x00eb
+	mov	al,#0x20		! start of hardware int's (0x20)
+	out	#0x21,al
+	.word	0x00eb,0x00eb
+	mov	al,#0x28		! start of hardware int's 2 (0x28)
+	out	#0xA1,al
+	.word	0x00eb,0x00eb
+	mov	al,#0x04		! 8259-1 is master
+	out	#0x21,al
+	.word	0x00eb,0x00eb
+	mov	al,#0x02		! 8259-2 is slave
+	out	#0xA1,al
+	.word	0x00eb,0x00eb
+	mov	al,#0x01		! 8086 mode for both
+	out	#0x21,al
+	.word	0x00eb,0x00eb
+	out	#0xA1,al
+	.word	0x00eb,0x00eb
+	mov	al,#0xFF		! mask off all interrupts for now
+	out	#0x21,al
+	.word	0x00eb,0x00eb
+	out	#0xA1,al
+
+! well, that certainly wasn't fun :-(. Hopefully it works, and we don't
+! need no steenking BIOS anyway (except for the initial loading :-).
+! The BIOS-routine wants lots of unnecessary data, and it's less
+! "interesting" anyway. This is how REAL programmers do it.
+!
+! Well, now's the time to actually move into protected mode. To make
+! things as simple as possible, we do no register set-up or anything,
+! we let the gnu-compiled 32-bit programs do that. We just jump to
+! absolute address 0x00000, in 32-bit protected mode.
+
+	mov	ax,#0x0001	! protected mode (PE) bit
+	lmsw	ax		! This is it!
+	jmpi	0,8		! jmp offset 0 of segment 8 (cs)
+
+! This routine checks that the keyboard command queue is empty
+! No timeout is used - if this hangs there is something wrong with
+! the machine, and we probably couldn't proceed anyway.
+empty_8042:
+	.word	0x00eb,0x00eb
+	in	al,#0x64	! 8042 status port
+	test	al,#2		! is input buffer full?
+	jnz	empty_8042	! yes - loop
+	ret
+
+gdt:
+	.word	0,0,0,0		! dummy
+
+	.word	0x07FF		! 8Mb - limit=2047 (2048*4096=8Mb)
+	.word	0x0000		! base address=0
+	.word	0x9A00		! code read/exec
+	.word	0x00C0		! granularity=4096, 386
+
+	.word	0x07FF		! 8Mb - limit=2047 (2048*4096=8Mb)
+	.word	0x0000		! base address=0
+	.word	0x9200		! data read/write
+	.word	0x00C0		! granularity=4096, 386
+
+idt_48:
+	.word	0			! idt limit=0
+	.word	0,0			! idt base=0L
+
+gdt_48:
+	.word	0x800		! gdt limit=2048, 256 GDT entries
+	.word	512+gdt,0x9	! gdt base = 0X9xxxx
+	
+.text
+endtext:
+.data
+enddata:
+.bss
+endbss:

os/os/linux/execve2.patch

@@ -0,0 +1,41 @@
+diff -Naur 0/linux/init/main.c 4/linux/init/main.c
+--- 0/linux/init/main.c	2016-08-08 09:40:13.000000000 +0800
++++ 4/linux/init/main.c	2021-07-06 14:16:56.000000000 +0800
+@@ -208,3 +208,9 @@
+ 	}
+ 	_exit(0);	/* NOTE! _exit, not exit() */
+ }
++
++void print_nr(int sid)
++{
++	if (sid > 86)
++		printk(" --syscall: sid=%d, pid=%d\n", sid, current->pid);
++}
+diff -Naur 0/linux/kernel/system_call.s 4/linux/kernel/system_call.s
+--- 0/linux/kernel/system_call.s	2015-09-03 20:21:09.000000000 +0800
++++ 4/linux/kernel/system_call.s	2021-07-06 14:18:56.000000000 +0800
+@@ -91,6 +91,11 @@
+ 	mov %dx,%es
+ 	movl $0x17,%edx		# fs points to local data space
+ 	mov %dx,%fs
++
++	pushl %eax   #by wyj
++	call print_nr
++	popl %eax
++
+ 	call sys_call_table(,%eax,4)
+ 	pushl %eax
+ 	movl current,%eax
+diff -Naur 0/linux/mm/memory.c 4/linux/mm/memory.c
+--- 0/linux/mm/memory.c	2015-09-04 15:24:20.000000000 +0800
++++ 4/linux/mm/memory.c	2021-07-06 14:21:45.000000000 +0800
+@@ -370,6 +370,9 @@
+ 	unsigned long page;
+ 	int block,i;
+ 
++	if (current->pid > 5)
++		printk(" --do_no_page: address=%x, pid=%d\n", address, current->pid);
++		
+ 	address &= 0xfffff000;
+ 	tmp = address - current->start_code;
+ 	if (!current->executable || tmp >= current->end_data) {

os/os/linux/fs/Makefile

@@ -0,0 +1,101 @@
+AR	=ar
+AS	=as
+LD	=ld
+LDFLAGS	=-s -x
+CC	=gcc -march=i386
+CFLAGS	=-w -g -fstrength-reduce -fomit-frame-pointer -mcld \
+	-finline-functions -nostdinc -fno-stack-protector -I../include
+CPP	=gcc -E -nostdinc -I../include
+
+.c.s:
+	$(CC) $(CFLAGS) \
+	-S -o $*.s $<
+.c.o:
+	$(CC) $(CFLAGS) \
+	-c -o $*.o $<
+.s.o:
+	$(AS) -o $*.o $<
+
+OBJS=	open.o read_write.o inode.o file_table.o buffer.o super.o \
+	block_dev.o char_dev.o file_dev.o stat.o exec.o pipe.o namei.o \
+	bitmap.o fcntl.o ioctl.o truncate.o select.o
+
+fs.o: $(OBJS)
+	$(LD) -r -o fs.o $(OBJS)
+
+clean:
+	rm -f core *.o *.a tmp_make
+	for i in *.c;do rm -f `basename $$i .c`.s;done
+
+dep:
+	sed '/\#\#\# Dependencies/q' < Makefile > tmp_make
+	(for i in *.c;do $(CPP) -M $$i;done) >> tmp_make
+	cp tmp_make Makefile
+
+### Dependencies:
+bitmap.o : bitmap.c ../include/string.h ../include/linux/sched.h \
+  ../include/linux/head.h ../include/linux/fs.h ../include/sys/types.h \
+  ../include/linux/mm.h ../include/signal.h ../include/linux/kernel.h 
+block_dev.o : block_dev.c ../include/errno.h ../include/linux/sched.h \
+  ../include/linux/head.h ../include/linux/fs.h ../include/sys/types.h \
+  ../include/linux/mm.h ../include/signal.h ../include/linux/kernel.h \
+  ../include/asm/segment.h ../include/asm/system.h 
+buffer.o : buffer.c ../include/stdarg.h ../include/linux/config.h \
+  ../include/linux/sched.h ../include/linux/head.h ../include/linux/fs.h \
+  ../include/sys/types.h ../include/linux/mm.h ../include/signal.h \
+  ../include/linux/kernel.h ../include/asm/system.h ../include/asm/io.h 
+char_dev.o : char_dev.c ../include/errno.h ../include/sys/types.h \
+  ../include/linux/sched.h ../include/linux/head.h ../include/linux/fs.h \
+  ../include/linux/mm.h ../include/signal.h ../include/linux/kernel.h \
+  ../include/asm/segment.h ../include/asm/io.h 
+exec.o : exec.c ../include/errno.h ../include/string.h \
+  ../include/sys/stat.h ../include/sys/types.h ../include/a.out.h \
+  ../include/linux/fs.h ../include/linux/sched.h ../include/linux/head.h \
+  ../include/linux/mm.h ../include/signal.h ../include/linux/kernel.h \
+  ../include/asm/segment.h 
+fcntl.o : fcntl.c ../include/string.h ../include/errno.h \
+  ../include/linux/sched.h ../include/linux/head.h ../include/linux/fs.h \
+  ../include/sys/types.h ../include/linux/mm.h ../include/signal.h \
+  ../include/linux/kernel.h ../include/asm/segment.h ../include/fcntl.h \
+  ../include/sys/stat.h 
+file_dev.o : file_dev.c ../include/errno.h ../include/fcntl.h \
+  ../include/sys/types.h ../include/linux/sched.h ../include/linux/head.h \
+  ../include/linux/fs.h ../include/linux/mm.h ../include/signal.h \
+  ../include/linux/kernel.h ../include/asm/segment.h 
+file_table.o : file_table.c ../include/linux/fs.h ../include/sys/types.h 
+inode.o : inode.c ../include/string.h ../include/sys/stat.h \
+  ../include/sys/types.h ../include/linux/sched.h ../include/linux/head.h \
+  ../include/linux/fs.h ../include/linux/mm.h ../include/signal.h \
+  ../include/linux/kernel.h ../include/asm/system.h 
+ioctl.o : ioctl.c ../include/string.h ../include/errno.h \
+  ../include/sys/stat.h ../include/sys/types.h ../include/linux/sched.h \
+  ../include/linux/head.h ../include/linux/fs.h ../include/linux/mm.h \
+  ../include/signal.h 
+namei.o : namei.c ../include/linux/sched.h ../include/linux/head.h \
+  ../include/linux/fs.h ../include/sys/types.h ../include/linux/mm.h \
+  ../include/signal.h ../include/linux/kernel.h ../include/asm/segment.h \
+  ../include/string.h ../include/fcntl.h ../include/errno.h \
+  ../include/const.h ../include/sys/stat.h 
+open.o : open.c ../include/string.h ../include/errno.h ../include/fcntl.h \
+  ../include/sys/types.h ../include/utime.h ../include/sys/stat.h \
+  ../include/linux/sched.h ../include/linux/head.h ../include/linux/fs.h \
+  ../include/linux/mm.h ../include/signal.h ../include/linux/tty.h \
+  ../include/termios.h ../include/linux/kernel.h ../include/asm/segment.h 
+pipe.o : pipe.c ../include/signal.h ../include/sys/types.h \
+  ../include/linux/sched.h ../include/linux/head.h ../include/linux/fs.h \
+  ../include/linux/mm.h ../include/asm/segment.h 
+read_write.o : read_write.c ../include/sys/stat.h ../include/sys/types.h \
+  ../include/errno.h ../include/linux/kernel.h ../include/linux/sched.h \
+  ../include/linux/head.h ../include/linux/fs.h ../include/linux/mm.h \
+  ../include/signal.h ../include/asm/segment.h 
+stat.o : stat.c ../include/errno.h ../include/sys/stat.h \
+  ../include/sys/types.h ../include/linux/fs.h ../include/linux/sched.h \
+  ../include/linux/head.h ../include/linux/mm.h ../include/signal.h \
+  ../include/linux/kernel.h ../include/asm/segment.h 
+super.o : super.c ../include/linux/config.h ../include/linux/sched.h \
+  ../include/linux/head.h ../include/linux/fs.h ../include/sys/types.h \
+  ../include/linux/mm.h ../include/signal.h ../include/linux/kernel.h \
+  ../include/asm/system.h ../include/errno.h ../include/sys/stat.h 
+truncate.o : truncate.c ../include/linux/sched.h ../include/linux/head.h \
+  ../include/linux/fs.h ../include/sys/types.h ../include/linux/mm.h \
+  ../include/signal.h ../include/sys/stat.h 

os/os/linux/fs/bitmap.c

@@ -0,0 +1,168 @@
+/*
+ *  linux/fs/bitmap.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+/* bitmap.c contains the code that handles the inode and block bitmaps */
+#include <string.h>
+
+#include <linux/sched.h>
+#include <linux/kernel.h>
+
+#define clear_block(addr) \
+__asm__ __volatile__ ("cld\n\t" \
+	"rep\n\t" \
+	"stosl" \
+	::"a" (0),"c" (BLOCK_SIZE/4),"D" ((long) (addr)))
+
+#define set_bit(nr,addr) ({\
+register int res __asm__("ax"); \
+__asm__ __volatile__("btsl %2,%3\n\tsetb %%al": \
+"=a" (res):"0" (0),"r" (nr),"m" (*(addr))); \
+res;})
+
+#define clear_bit(nr,addr) ({\
+register int res __asm__("ax"); \
+__asm__ __volatile__("btrl %2,%3\n\tsetnb %%al": \
+"=a" (res):"0" (0),"r" (nr),"m" (*(addr))); \
+res;})
+
+#define find_first_zero(addr) ({ \
+int __res; \
+__asm__ __volatile__ ("cld\n" \
+	"1:\tlodsl\n\t" \
+	"notl %%eax\n\t" \
+	"bsfl %%eax,%%edx\n\t" \
+	"je 2f\n\t" \
+	"addl %%edx,%%ecx\n\t" \
+	"jmp 3f\n" \
+	"2:\taddl $32,%%ecx\n\t" \
+	"cmpl $8192,%%ecx\n\t" \
+	"jl 1b\n" \
+	"3:" \
+	:"=c" (__res):"c" (0),"S" (addr)); \
+__res;})
+
+void free_block(int dev, int block)
+{
+	struct super_block * sb;
+	struct buffer_head * bh;
+
+	if (!(sb = get_super(dev)))
+		panic("trying to free block on nonexistent device");
+	if (block < sb->s_firstdatazone || block >= sb->s_nzones)
+		panic("trying to free block not in datazone");
+	bh = get_hash_table(dev,block);
+	if (bh) {
+		if (bh->b_count != 1) {
+			printk("trying to free block (%04x:%d), count=%d\n",
+				dev,block,bh->b_count);
+			return;
+		}
+		bh->b_dirt=0;
+		bh->b_uptodate=0;
+		brelse(bh);
+	}
+	block -= sb->s_firstdatazone - 1 ;
+	if (clear_bit(block&8191,sb->s_zmap[block/8192]->b_data)) {
+		printk("block (%04x:%d) ",dev,block+sb->s_firstdatazone-1);
+		panic("free_block: bit already cleared");
+	}
+	sb->s_zmap[block/8192]->b_dirt = 1;
+}
+
+int new_block(int dev)
+{
+	struct buffer_head * bh;
+	struct super_block * sb;
+	int i,j;
+
+	if (!(sb = get_super(dev)))
+		panic("trying to get new block from nonexistant device");
+	j = 8192;
+	for (i=0 ; i<8 ; i++)
+		if (bh=sb->s_zmap[i])
+			if ((j=find_first_zero(bh->b_data))<8192)
+				break;
+	if (i>=8 || !bh || j>=8192)
+		return 0;
+	if (set_bit(j,bh->b_data))
+		panic("new_block: bit already set");
+	bh->b_dirt = 1;
+	j += i*8192 + sb->s_firstdatazone-1;
+	if (j >= sb->s_nzones)
+		return 0;
+	if (!(bh=getblk(dev,j)))
+		panic("new_block: cannot get block");
+	if (bh->b_count != 1)
+		panic("new block: count is != 1");
+	clear_block(bh->b_data);
+	bh->b_uptodate = 1;
+	bh->b_dirt = 1;
+	brelse(bh);
+	return j;
+}
+
+void free_inode(struct m_inode * inode)
+{
+	struct super_block * sb;
+	struct buffer_head * bh;
+
+	if (!inode)
+		return;
+	if (!inode->i_dev) {
+		memset(inode,0,sizeof(*inode));
+		return;
+	}
+	if (inode->i_count>1) {
+		printk("trying to free inode with count=%d\n",inode->i_count);
+		panic("free_inode");
+	}
+	if (inode->i_nlinks)
+		panic("trying to free inode with links");
+	if (!(sb = get_super(inode->i_dev)))
+		panic("trying to free inode on nonexistent device");
+	if (inode->i_num < 1 || inode->i_num > sb->s_ninodes)
+		panic("trying to free inode 0 or nonexistant inode");
+	if (!(bh=sb->s_imap[inode->i_num>>13]))
+		panic("nonexistent imap in superblock");
+	if (clear_bit(inode->i_num&8191,bh->b_data))
+		printk("free_inode: bit already cleared.\n\r");
+	bh->b_dirt = 1;
+	memset(inode,0,sizeof(*inode));
+}
+
+struct m_inode * new_inode(int dev)
+{
+	struct m_inode * inode;
+	struct super_block * sb;
+	struct buffer_head * bh;
+	int i,j;
+
+	if (!(inode=get_empty_inode()))
+		return NULL;
+	if (!(sb = get_super(dev)))
+		panic("new_inode with unknown device");
+	j = 8192;
+	for (i=0 ; i<8 ; i++)
+		if (bh=sb->s_imap[i])
+			if ((j=find_first_zero(bh->b_data))<8192)
+				break;
+	if (!bh || j >= 8192 || j+i*8192 > sb->s_ninodes) {
+		iput(inode);
+		return NULL;
+	}
+	if (set_bit(j,bh->b_data))
+		panic("new_inode: bit already set");
+	bh->b_dirt = 1;
+	inode->i_count=1;
+	inode->i_nlinks=1;
+	inode->i_dev=dev;
+	inode->i_uid=current->euid;
+	inode->i_gid=current->egid;
+	inode->i_dirt=1;
+	inode->i_num = j + i*8192;
+	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
+	return inode;
+}

os/os/linux/fs/block_dev.c

@@ -0,0 +1,73 @@
+/*
+ *  linux/fs/block_dev.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+#include <errno.h>
+
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <asm/segment.h>
+#include <asm/system.h>
+
+int block_write(int dev, long * pos, char * buf, int count)
+{
+	int block = *pos >> BLOCK_SIZE_BITS;
+	int offset = *pos & (BLOCK_SIZE-1);
+	int chars;
+	int written = 0;
+	struct buffer_head * bh;
+	register char * p;
+
+	while (count>0) {
+		chars = BLOCK_SIZE - offset;
+		if (chars > count)
+			chars=count;
+		if (chars == BLOCK_SIZE)
+			bh = getblk(dev,block);
+		else
+			bh = breada(dev,block,block+1,block+2,-1);
+		block++;
+		if (!bh)
+			return written?written:-EIO;
+		p = offset + bh->b_data;
+		offset = 0;
+		*pos += chars;
+		written += chars;
+		count -= chars;
+		while (chars-->0)
+			*(p++) = get_fs_byte(buf++);
+		bh->b_dirt = 1;
+		brelse(bh);
+	}
+	return written;
+}
+
+int block_read(int dev, unsigned long * pos, char * buf, int count)
+{
+	int block = *pos >> BLOCK_SIZE_BITS;
+	int offset = *pos & (BLOCK_SIZE-1);
+	int chars;
+	int read = 0;
+	struct buffer_head * bh;
+	register char * p;
+
+	while (count>0) {
+		chars = BLOCK_SIZE-offset;
+		if (chars > count)
+			chars = count;
+		if (!(bh = breada(dev,block,block+1,block+2,-1)))
+			return read?read:-EIO;
+		block++;
+		p = offset + bh->b_data;
+		offset = 0;
+		*pos += chars;
+		read += chars;
+		count -= chars;
+		while (chars-->0)
+			put_fs_byte(*(p++),buf++);
+		brelse(bh);
+	}
+	return read;
+}

os/os/linux/fs/buffer.c

@@ -0,0 +1,384 @@
+/*
+ *  linux/fs/buffer.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+/*
+ *  'buffer.c' implements the buffer-cache functions. Race-conditions have
+ * been avoided by NEVER letting a interrupt change a buffer (except for the
+ * data, of course), but instead letting the caller do it. NOTE! As interrupts
+ * can wake up a caller, some cli-sti sequences are needed to check for
+ * sleep-on-calls. These should be extremely quick, though (I hope).
+ */
+
+/*
+ * NOTE! There is one discordant note here: checking floppies for
+ * disk change. This is where it fits best, I think, as it should
+ * invalidate changed floppy-disk-caches.
+ */
+
+#include <stdarg.h>
+ 
+#include <linux/config.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <asm/system.h>
+#include <asm/io.h>
+
+extern void put_super(int dev);
+extern void invalidate_inodes(int dev);
+
+extern int end;
+struct buffer_head * start_buffer = (struct buffer_head *) &end;
+struct buffer_head * hash_table[NR_HASH];
+static struct buffer_head * free_list;
+static struct task_struct * buffer_wait = NULL;
+int NR_BUFFERS = 0;
+
+static inline void wait_on_buffer(struct buffer_head * bh)
+{
+	cli();
+	while (bh->b_lock)
+		sleep_on(&bh->b_wait);
+	sti();
+}
+
+int sys_sync(void)
+{
+	int i;
+	struct buffer_head * bh;
+
+	sync_inodes();		/* write out inodes into buffers */
+	bh = start_buffer;
+	for (i=0 ; i<NR_BUFFERS ; i++,bh++) {
+		wait_on_buffer(bh);
+		if (bh->b_dirt)
+			ll_rw_block(WRITE,bh);
+	}
+	return 0;
+}
+
+int sync_dev(int dev)
+{
+	int i;
+	struct buffer_head * bh;
+
+	bh = start_buffer;
+	for (i=0 ; i<NR_BUFFERS ; i++,bh++) {
+		if (bh->b_dev != dev)
+			continue;
+		wait_on_buffer(bh);
+		if (bh->b_dev == dev && bh->b_dirt)
+			ll_rw_block(WRITE,bh);
+	}
+	sync_inodes();
+	bh = start_buffer;
+	for (i=0 ; i<NR_BUFFERS ; i++,bh++) {
+		if (bh->b_dev != dev)
+			continue;
+		wait_on_buffer(bh);
+		if (bh->b_dev == dev && bh->b_dirt)
+			ll_rw_block(WRITE,bh);
+	}
+	return 0;
+}
+
+void inline invalidate_buffers(int dev)
+{
+	int i;
+	struct buffer_head * bh;
+
+	bh = start_buffer;
+	for (i=0 ; i<NR_BUFFERS ; i++,bh++) {
+		if (bh->b_dev != dev)
+			continue;
+		wait_on_buffer(bh);
+		if (bh->b_dev == dev)
+			bh->b_uptodate = bh->b_dirt = 0;
+	}
+}
+
+/*
+ * This routine checks whether a floppy has been changed, and
+ * invalidates all buffer-cache-entries in that case. This
+ * is a relatively slow routine, so we have to try to minimize using
+ * it. Thus it is called only upon a 'mount' or 'open'. This
+ * is the best way of combining speed and utility, I think.
+ * People changing diskettes in the middle of an operation deserve
+ * to loose :-)
+ *
+ * NOTE! Although currently this is only for floppies, the idea is
+ * that any additional removable block-device will use this routine,
+ * and that mount/open needn't know that floppies/whatever are
+ * special.
+ */
+void check_disk_change(int dev)
+{
+	int i;
+
+	if (MAJOR(dev) != 2)
+		return;
+	if (!floppy_change(dev & 0x03))
+		return;
+	for (i=0 ; i<NR_SUPER ; i++)
+		if (super_block[i].s_dev == dev)
+			put_super(super_block[i].s_dev);
+	invalidate_inodes(dev);
+	invalidate_buffers(dev);
+}
+
+#define _hashfn(dev,block) (((unsigned)(dev^block))%NR_HASH)
+#define hash(dev,block) hash_table[_hashfn(dev,block)]
+
+static inline void remove_from_queues(struct buffer_head * bh)
+{
+/* remove from hash-queue */
+	if (bh->b_next)
+		bh->b_next->b_prev = bh->b_prev;
+	if (bh->b_prev)
+		bh->b_prev->b_next = bh->b_next;
+	if (hash(bh->b_dev,bh->b_blocknr) == bh)
+		hash(bh->b_dev,bh->b_blocknr) = bh->b_next;
+/* remove from free list */
+	if (!(bh->b_prev_free) || !(bh->b_next_free))
+		panic("Free block list corrupted");
+	bh->b_prev_free->b_next_free = bh->b_next_free;
+	bh->b_next_free->b_prev_free = bh->b_prev_free;
+	if (free_list == bh)
+		free_list = bh->b_next_free;
+}
+
+static inline void insert_into_queues(struct buffer_head * bh)
+{
+/* put at end of free list */
+	bh->b_next_free = free_list;
+	bh->b_prev_free = free_list->b_prev_free;
+	free_list->b_prev_free->b_next_free = bh;
+	free_list->b_prev_free = bh;
+/* put the buffer in new hash-queue if it has a device */
+	bh->b_prev = NULL;
+	bh->b_next = NULL;
+	if (!bh->b_dev)
+		return;
+	bh->b_next = hash(bh->b_dev,bh->b_blocknr);
+	hash(bh->b_dev,bh->b_blocknr) = bh;
+	bh->b_next->b_prev = bh;
+}
+
+static struct buffer_head * find_buffer(int dev, int block)
+{		
+	struct buffer_head * tmp;
+
+	for (tmp = hash(dev,block) ; tmp != NULL ; tmp = tmp->b_next)
+		if (tmp->b_dev==dev && tmp->b_blocknr==block)
+			return tmp;
+	return NULL;
+}
+
+/*
+ * Why like this, I hear you say... The reason is race-conditions.
+ * As we don't lock buffers (unless we are readint them, that is),
+ * something might happen to it while we sleep (ie a read-error
+ * will force it bad). This shouldn't really happen currently, but
+ * the code is ready.
+ */
+struct buffer_head * get_hash_table(int dev, int block)
+{
+	struct buffer_head * bh;
+
+	for (;;) {
+		if (!(bh=find_buffer(dev,block)))
+			return NULL;
+		bh->b_count++;
+		wait_on_buffer(bh);
+		if (bh->b_dev == dev && bh->b_blocknr == block)
+			return bh;
+		bh->b_count--;
+	}
+}
+
+/*
+ * Ok, this is getblk, and it isn't very clear, again to hinder
+ * race-conditions. Most of the code is seldom used, (ie repeating),
+ * so it should be much more efficient than it looks.
+ *
+ * The algoritm is changed: hopefully better, and an elusive bug removed.
+ */
+#define BADNESS(bh) (((bh)->b_dirt<<1)+(bh)->b_lock)
+struct buffer_head * getblk(int dev,int block)
+{
+	struct buffer_head * tmp, * bh;
+
+repeat:
+	if (bh = get_hash_table(dev,block))
+		return bh;
+	tmp = free_list;
+	do {
+		if (tmp->b_count)
+			continue;
+		if (!bh || BADNESS(tmp)<BADNESS(bh)) {
+			bh = tmp;
+			if (!BADNESS(tmp))
+				break;
+		}
+/* and repeat until we find something good */
+	} while ((tmp = tmp->b_next_free) != free_list);
+	if (!bh) {
+		sleep_on(&buffer_wait);
+		goto repeat;
+	}
+	wait_on_buffer(bh);
+	if (bh->b_count)
+		goto repeat;
+	while (bh->b_dirt) {
+		sync_dev(bh->b_dev);
+		wait_on_buffer(bh);
+		if (bh->b_count)
+			goto repeat;
+	}
+/* NOTE!! While we slept waiting for this block, somebody else might */
+/* already have added "this" block to the cache. check it */
+	if (find_buffer(dev,block))
+		goto repeat;
+/* OK, FINALLY we know that this buffer is the only one of it's kind, */
+/* and that it's unused (b_count=0), unlocked (b_lock=0), and clean */
+	bh->b_count=1;
+	bh->b_dirt=0;
+	bh->b_uptodate=0;
+	remove_from_queues(bh);
+	bh->b_dev=dev;
+	bh->b_blocknr=block;
+	insert_into_queues(bh);
+	return bh;
+}
+
+void brelse(struct buffer_head * buf)
+{
+	if (!buf)
+		return;
+	wait_on_buffer(buf);
+	if (!(buf->b_count--))
+		panic("Trying to free free buffer");
+	wake_up(&buffer_wait);
+}
+
+/*
+ * bread() reads a specified block and returns the buffer that contains
+ * it. It returns NULL if the block was unreadable.
+ */
+struct buffer_head * bread(int dev,int block)
+{
+	struct buffer_head * bh;
+
+	if (!(bh=getblk(dev,block)))
+		panic("bread: getblk returned NULL\n");
+	if (bh->b_uptodate)
+		return bh;
+	ll_rw_block(READ,bh);
+	wait_on_buffer(bh);
+	if (bh->b_uptodate)
+		return bh;
+	brelse(bh);
+	return NULL;
+}
+
+#define COPYBLK(from,to) \
+__asm__("cld\n\t" \
+	"rep\n\t" \
+	"movsl\n\t" \
+	::"c" (BLOCK_SIZE/4),"S" (from),"D" (to) \
+	)
+
+/*
+ * bread_page reads four buffers into memory at the desired address. It's
+ * a function of its own, as there is some speed to be got by reading them
+ * all at the same time, not waiting for one to be read, and then another
+ * etc.
+ */
+void bread_page(unsigned long address,int dev,int b[4])
+{
+	struct buffer_head * bh[4];
+	int i;
+
+	for (i=0 ; i<4 ; i++)
+		if (b[i]) {
+			if (bh[i] = getblk(dev,b[i]))
+				if (!bh[i]->b_uptodate)
+					ll_rw_block(READ,bh[i]);
+		} else
+			bh[i] = NULL;
+	for (i=0 ; i<4 ; i++,address += BLOCK_SIZE)
+		if (bh[i]) {
+			wait_on_buffer(bh[i]);
+			if (bh[i]->b_uptodate)
+				COPYBLK((unsigned long) bh[i]->b_data,address);
+			brelse(bh[i]);
+		}
+}
+
+/*
+ * Ok, breada can be used as bread, but additionally to mark other
+ * blocks for reading as well. End the argument list with a negative
+ * number.
+ */
+struct buffer_head * breada(int dev,int first, ...)
+{
+	va_list args;
+	struct buffer_head * bh, *tmp;
+
+	va_start(args,first);
+	if (!(bh=getblk(dev,first)))
+		panic("bread: getblk returned NULL\n");
+	if (!bh->b_uptodate)
+		ll_rw_block(READ,bh);
+	while ((first=va_arg(args,int))>=0) {
+		tmp=getblk(dev,first);
+		if (tmp) {
+			if (!tmp->b_uptodate)
+				ll_rw_block(READA,bh);
+			tmp->b_count--;
+		}
+	}
+	va_end(args);
+	wait_on_buffer(bh);
+	if (bh->b_uptodate)
+		return bh;
+	brelse(bh);
+	return (NULL);
+}
+
+void buffer_init(long buffer_end)
+{
+	struct buffer_head * h = start_buffer;
+	void * b;
+	int i;
+
+	if (buffer_end == 1<<20)
+		b = (void *) (640*1024);
+	else
+		b = (void *) buffer_end;
+	while ( (b -= BLOCK_SIZE) >= ((void *) (h+1)) ) {
+		h->b_dev = 0;
+		h->b_dirt = 0;
+		h->b_count = 0;
+		h->b_lock = 0;
+		h->b_uptodate = 0;
+		h->b_wait = NULL;
+		h->b_next = NULL;
+		h->b_prev = NULL;
+		h->b_data = (char *) b;
+		h->b_prev_free = h-1;
+		h->b_next_free = h+1;
+		h++;
+		NR_BUFFERS++;
+		if (b == (void *) 0x100000)
+			b = (void *) 0xA0000;
+	}
+	h--;
+	free_list = start_buffer;
+	free_list->b_prev_free = h;
+	h->b_next_free = free_list;
+	for (i=0;i<NR_HASH;i++)
+		hash_table[i]=NULL;
+}	

os/os/linux/fs/char_dev.c

@@ -0,0 +1,104 @@
+/*
+ *  linux/fs/char_dev.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+#include <errno.h>
+#include <sys/types.h>
+
+#include <linux/sched.h>
+#include <linux/kernel.h>
+
+#include <asm/segment.h>
+#include <asm/io.h>
+
+extern int tty_read(unsigned minor,char * buf,int count);
+extern int tty_write(unsigned minor,char * buf,int count);
+
+typedef (*crw_ptr)(int rw,unsigned minor,char * buf,int count,off_t * pos);
+
+static int rw_ttyx(int rw,unsigned minor,char * buf,int count,off_t * pos)
+{
+	return ((rw==READ)?tty_read(minor,buf,count):
+		tty_write(minor,buf,count));
+}
+
+static int rw_tty(int rw,unsigned minor,char * buf,int count, off_t * pos)
+{
+	if (current->tty<0)
+		return -EPERM;
+	return rw_ttyx(rw,current->tty,buf,count,pos);
+}
+
+static int rw_ram(int rw,char * buf, int count, off_t *pos)
+{
+	return -EIO;
+}
+
+static int rw_mem(int rw,char * buf, int count, off_t * pos)
+{
+	return -EIO;
+}
+
+static int rw_kmem(int rw,char * buf, int count, off_t * pos)
+{
+	return -EIO;
+}
+
+static int rw_port(int rw,char * buf, int count, off_t * pos)
+{
+	int i=*pos;
+
+	while (count-->0 && i<65536) {
+		if (rw==READ)
+			put_fs_byte(inb(i),buf++);
+		else
+			outb(get_fs_byte(buf++),i);
+		i++;
+	}
+	i -= *pos;
+	*pos += i;
+	return i;
+}
+
+static int rw_memory(int rw, unsigned minor, char * buf, int count, off_t * pos)
+{
+	switch(minor) {
+		case 0:
+			return rw_ram(rw,buf,count,pos);
+		case 1:
+			return rw_mem(rw,buf,count,pos);
+		case 2:
+			return rw_kmem(rw,buf,count,pos);
+		case 3:
+			return (rw==READ)?0:count;	/* rw_null */
+		case 4:
+			return rw_port(rw,buf,count,pos);
+		default:
+			return -EIO;
+	}
+}
+
+#define NRDEVS ((sizeof (crw_table))/(sizeof (crw_ptr)))
+
+static crw_ptr crw_table[]={
+	NULL,		/* nodev */
+	rw_memory,	/* /dev/mem etc */
+	NULL,		/* /dev/fd */
+	NULL,		/* /dev/hd */
+	rw_ttyx,	/* /dev/ttyx */
+	rw_tty,		/* /dev/tty */
+	NULL,		/* /dev/lp */
+	NULL};		/* unnamed pipes */
+
+int rw_char(int rw,int dev, char * buf, int count, off_t * pos)
+{
+	crw_ptr call_addr;
+
+	if (MAJOR(dev)>=NRDEVS)
+		return -ENODEV;
+	if (!(call_addr=crw_table[MAJOR(dev)]))
+		return -ENODEV;
+	return call_addr(rw,MINOR(dev),buf,count,pos);
+}

os/os/linux/fs/exec.c

@@ -0,0 +1,359 @@
+/*
+ *  linux/fs/exec.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+/*
+ * #!-checking implemented by tytso.
+ */
+
+/*
+ * Demand-loading implemented 01.12.91 - no need to read anything but
+ * the header into memory. The inode of the executable is put into
+ * "current->executable", and page faults do the actual loading. Clean.
+ *
+ * Once more I can proudly say that linux stood up to being changed: it
+ * was less than 2 hours work to get demand-loading completely implemented.
+ */
+
+#include <errno.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <a.out.h>
+
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <asm/segment.h>
+
+extern int sys_exit(int exit_code);
+extern int sys_close(int fd);
+
+/*
+ * MAX_ARG_PAGES defines the number of pages allocated for arguments
+ * and envelope for the new program. 32 should suffice, this gives
+ * a maximum env+arg of 128kB !
+ */
+#define MAX_ARG_PAGES 32
+
+
+int sys_uselib()
+{
+	return -ENOSYS;
+}
+
+/*
+ * create_tables() parses the env- and arg-strings in new user
+ * memory and creates the pointer tables from them, and puts their
+ * addresses on the "stack", returning the new stack pointer value.
+ */
+static unsigned long * create_tables(char * p,int argc,int envc)
+{
+	unsigned long *argv,*envp;
+	unsigned long * sp;
+
+	sp = (unsigned long *) (0xfffffffc & (unsigned long) p);
+	sp -= envc+1;
+	envp = sp;
+	sp -= argc+1;
+	argv = sp;
+	put_fs_long((unsigned long)envp,--sp);
+	put_fs_long((unsigned long)argv,--sp);
+	put_fs_long((unsigned long)argc,--sp);
+	while (argc-->0) {
+		put_fs_long((unsigned long) p,argv++);
+		while (get_fs_byte(p++)) /* nothing */ ;
+	}
+	put_fs_long(0,argv);
+	while (envc-->0) {
+		put_fs_long((unsigned long) p,envp++);
+		while (get_fs_byte(p++)) /* nothing */ ;
+	}
+	put_fs_long(0,envp);
+	return sp;
+}
+
+/*
+ * count() counts the number of arguments/envelopes
+ */
+static int count(char ** argv)
+{
+	int i=0;
+	char ** tmp;
+
+	if (tmp = argv)
+		while (get_fs_long((unsigned long *) (tmp++)))
+			i++;
+
+	return i;
+}
+
+/*
+ * 'copy_string()' copies argument/envelope strings from user
+ * memory to free pages in kernel mem. These are in a format ready
+ * to be put directly into the top of new user memory.
+ *
+ * Modified by TYT, 11/24/91 to add the from_kmem argument, which specifies
+ * whether the string and the string array are from user or kernel segments:
+ * 
+ * from_kmem     argv *        argv **
+ *    0          user space    user space
+ *    1          kernel space  user space
+ *    2          kernel space  kernel space
+ * 
+ * We do this by playing games with the fs segment register.  Since it
+ * it is expensive to load a segment register, we try to avoid calling
+ * set_fs() unless we absolutely have to.
+ */
+static unsigned long copy_strings(int argc,char ** argv,unsigned long *page,
+		unsigned long p, int from_kmem)
+{
+	char *tmp, *pag;
+	int len, offset = 0;
+	unsigned long old_fs, new_fs;
+
+	if (!p)
+		return 0;	/* bullet-proofing */
+	new_fs = get_ds();
+	old_fs = get_fs();
+	if (from_kmem==2)
+		set_fs(new_fs);
+	while (argc-- > 0) {
+		if (from_kmem == 1)
+			set_fs(new_fs);
+		if (!(tmp = (char *)get_fs_long(((unsigned long *)argv)+argc)))
+			panic("argc is wrong");
+		if (from_kmem == 1)
+			set_fs(old_fs);
+		len=0;		/* remember zero-padding */
+		do {
+			len++;
+		} while (get_fs_byte(tmp++));
+		if (p-len < 0) {	/* this shouldn't happen - 128kB */
+			set_fs(old_fs);
+			return 0;
+		}
+		while (len) {
+			--p; --tmp; --len;
+			if (--offset < 0) {
+				offset = p % PAGE_SIZE;
+				if (from_kmem==2)
+					set_fs(old_fs);
+				if (!(pag = (char *) page[p/PAGE_SIZE]) &&
+				    !(pag = (char *) (page[p/PAGE_SIZE] =
+				      (unsigned long *) get_free_page()))) 
+					return 0;
+				if (from_kmem==2)
+					set_fs(new_fs);
+
+			}
+			*(pag + offset) = get_fs_byte(tmp);
+		}
+	}
+	if (from_kmem==2)
+		set_fs(old_fs);
+	return p;
+}
+
+static unsigned long change_ldt(unsigned long text_size,unsigned long * page)
+{
+	unsigned long code_limit,data_limit,code_base,data_base;
+	int i;
+
+	code_limit = text_size+PAGE_SIZE -1;
+	code_limit &= 0xFFFFF000;
+	data_limit = 0x4000000;
+	code_base = get_base(current->ldt[1]);
+	data_base = code_base;
+	set_base(current->ldt[1],code_base);
+	set_limit(current->ldt[1],code_limit);
+	set_base(current->ldt[2],data_base);
+	set_limit(current->ldt[2],data_limit);
+/* make sure fs points to the NEW data segment */
+	__asm__("pushl $0x17\n\tpop %%fs"::);
+	data_base += data_limit;
+	for (i=MAX_ARG_PAGES-1 ; i>=0 ; i--) {
+		data_base -= PAGE_SIZE;
+		if (page[i])
+			put_page(page[i],data_base);
+	}
+	return data_limit;
+}
+
+/*
+ * 'do_execve()' executes a new program.
+ */
+int do_execve(unsigned long * eip,long tmp,char * filename,
+	char ** argv, char ** envp)
+{
+	struct m_inode * inode;
+	struct buffer_head * bh;
+	struct exec ex;
+	unsigned long page[MAX_ARG_PAGES];
+	int i,argc,envc;
+	int e_uid, e_gid;
+	int retval;
+	int sh_bang = 0;
+	unsigned long p=PAGE_SIZE*MAX_ARG_PAGES-4;
+
+	if ((0xffff & eip[1]) != 0x000f)
+		panic("execve called from supervisor mode");
+	for (i=0 ; i<MAX_ARG_PAGES ; i++)	/* clear page-table */
+		page[i]=0;
+	if (!(inode=namei(filename)))		/* get executables inode */
+		return -ENOENT;
+	argc = count(argv);
+	envc = count(envp);
+	
+restart_interp:
+	if (!S_ISREG(inode->i_mode)) {	/* must be regular file */
+		retval = -EACCES;
+		goto exec_error2;
+	}
+	i = inode->i_mode;
+	e_uid = (i & S_ISUID) ? inode->i_uid : current->euid;
+	e_gid = (i & S_ISGID) ? inode->i_gid : current->egid;
+	if (current->euid == inode->i_uid)
+		i >>= 6;
+	else if (current->egid == inode->i_gid)
+		i >>= 3;
+	if (!(i & 1) &&
+	    !((inode->i_mode & 0111) && suser())) {
+		retval = -ENOEXEC;
+		goto exec_error2;
+	}
+	if (!(bh = bread(inode->i_dev,inode->i_zone[0]))) {
+		retval = -EACCES;
+		goto exec_error2;
+	}
+	ex = *((struct exec *) bh->b_data);	/* read exec-header */
+	if ((bh->b_data[0] == '#') && (bh->b_data[1] == '!') && (!sh_bang)) {
+		/*
+		 * This section does the #! interpretation.
+		 * Sorta complicated, but hopefully it will work.  -TYT
+		 */
+
+		char buf[1023], *cp, *interp, *i_name, *i_arg;
+		unsigned long old_fs;
+
+		strncpy(buf, bh->b_data+2, 1022);
+		brelse(bh);
+		iput(inode);
+		buf[1022] = '\0';
+		if (cp = strchr(buf, '\n')) {
+			*cp = '\0';
+			for (cp = buf; (*cp == ' ') || (*cp == '\t'); cp++);
+		}
+		if (!cp || *cp == '\0') {
+			retval = -ENOEXEC; /* No interpreter name found */
+			goto exec_error1;
+		}
+		interp = i_name = cp;
+		i_arg = 0;
+		for ( ; *cp && (*cp != ' ') && (*cp != '\t'); cp++) {
+ 			if (*cp == '/')
+				i_name = cp+1;
+		}
+		if (*cp) {
+			*cp++ = '\0';
+			i_arg = cp;
+		}
+		/*
+		 * OK, we've parsed out the interpreter name and
+		 * (optional) argument.
+		 */
+		if (sh_bang++ == 0) {
+			p = copy_strings(envc, envp, page, p, 0);
+			p = copy_strings(--argc, argv+1, page, p, 0);
+		}
+		/*
+		 * Splice in (1) the interpreter's name for argv[0]
+		 *           (2) (optional) argument to interpreter
+		 *           (3) filename of shell script
+		 *
+		 * This is done in reverse order, because of how the
+		 * user environment and arguments are stored.
+		 */
+		p = copy_strings(1, &filename, page, p, 1);
+		argc++;
+		if (i_arg) {
+			p = copy_strings(1, &i_arg, page, p, 2);
+			argc++;
+		}
+		p = copy_strings(1, &i_name, page, p, 2);
+		argc++;
+		if (!p) {
+			retval = -ENOMEM;
+			goto exec_error1;
+		}
+		/*
+		 * OK, now restart the process with the interpreter's inode.
+		 */
+		old_fs = get_fs();
+		set_fs(get_ds());
+		if (!(inode=namei(interp))) { /* get executables inode */
+			set_fs(old_fs);
+			retval = -ENOENT;
+			goto exec_error1;
+		}
+		set_fs(old_fs);
+		goto restart_interp;
+	}
+	brelse(bh);
+	if (N_MAGIC(ex) != ZMAGIC || ex.a_trsize || ex.a_drsize ||
+		ex.a_text+ex.a_data+ex.a_bss>0x3000000 ||
+		inode->i_size < ex.a_text+ex.a_data+ex.a_syms+N_TXTOFF(ex)) {
+		retval = -ENOEXEC;
+		goto exec_error2;
+	}
+	if (N_TXTOFF(ex) != BLOCK_SIZE) {
+		printk("%s: N_TXTOFF != BLOCK_SIZE. See a.out.h.", filename);
+		retval = -ENOEXEC;
+		goto exec_error2;
+	}
+	if (!sh_bang) {
+		p = copy_strings(envc,envp,page,p,0);
+		p = copy_strings(argc,argv,page,p,0);
+		if (!p) {
+			retval = -ENOMEM;
+			goto exec_error2;
+		}
+	}
+/* OK, This is the point of no return */
+	if (current->executable)
+		iput(current->executable);
+	current->executable = inode;
+	for (i=0 ; i<32 ; i++)
+		current->sigaction[i].sa_handler = NULL;
+	for (i=0 ; i<NR_OPEN ; i++)
+		if ((current->close_on_exec>>i)&1)
+			sys_close(i);
+	current->close_on_exec = 0;
+	free_page_tables(get_base(current->ldt[1]),get_limit(0x0f));
+	free_page_tables(get_base(current->ldt[2]),get_limit(0x17));
+	if (last_task_used_math == current)
+		last_task_used_math = NULL;
+	current->used_math = 0;
+	p += change_ldt(ex.a_text,page)-MAX_ARG_PAGES*PAGE_SIZE;
+	p = (unsigned long) create_tables((char *)p,argc,envc);
+	current->brk = ex.a_bss +
+		(current->end_data = ex.a_data +
+		(current->end_code = ex.a_text));
+	current->start_stack = p & 0xfffff000;
+	current->euid = e_uid;
+	current->egid = e_gid;
+	i = ex.a_text+ex.a_data;
+	while (i&0xfff)
+		put_fs_byte(0,(char *) (i++));
+	eip[0] = ex.a_entry;		/* eip, magic happens :-) */
+	eip[3] = p;			/* stack pointer */
+	return 0;
+exec_error2:
+	iput(inode);
+exec_error1:
+	for (i=0 ; i<MAX_ARG_PAGES ; i++)
+		free_page(page[i]);
+	return(retval);
+}

os/os/linux/fs/fcntl.c

@@ -0,0 +1,75 @@
+/*
+ *  linux/fs/fcntl.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+#include <string.h>
+#include <errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <asm/segment.h>
+
+#include <fcntl.h>
+#include <sys/stat.h>
+
+extern int sys_close(int fd);
+
+static int dupfd(unsigned int fd, unsigned int arg)
+{
+	if (fd >= NR_OPEN || !current->filp[fd])
+		return -EBADF;
+	if (arg >= NR_OPEN)
+		return -EINVAL;
+	while (arg < NR_OPEN)
+		if (current->filp[arg])
+			arg++;
+		else
+			break;
+	if (arg >= NR_OPEN)
+		return -EMFILE;
+	current->close_on_exec &= ~(1<<arg);
+	(current->filp[arg] = current->filp[fd])->f_count++;
+	return arg;
+}
+
+int sys_dup2(unsigned int oldfd, unsigned int newfd)
+{
+	sys_close(newfd);
+	return dupfd(oldfd,newfd);
+}
+
+int sys_dup(unsigned int fildes)
+{
+	return dupfd(fildes,0);
+}
+
+int sys_fcntl(unsigned int fd, unsigned int cmd, unsigned long arg)
+{	
+	struct file * filp;
+
+	if (fd >= NR_OPEN || !(filp = current->filp[fd]))
+		return -EBADF;
+	switch (cmd) {
+		case F_DUPFD:
+			return dupfd(fd,arg);
+		case F_GETFD:
+			return (current->close_on_exec>>fd)&1;
+		case F_SETFD:
+			if (arg&1)
+				current->close_on_exec |= (1<<fd);
+			else
+				current->close_on_exec &= ~(1<<fd);
+			return 0;
+		case F_GETFL:
+			return filp->f_flags;
+		case F_SETFL:
+			filp->f_flags &= ~(O_APPEND | O_NONBLOCK);
+			filp->f_flags |= arg & (O_APPEND | O_NONBLOCK);
+			return 0;
+		case F_GETLK:	case F_SETLK:	case F_SETLKW:
+			return -1;
+		default:
+			return -1;
+	}
+}

os/os/linux/fs/file_dev.c

@@ -0,0 +1,90 @@
+/*
+ *  linux/fs/file_dev.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <asm/segment.h>
+
+#define MIN(a,b) (((a)<(b))?(a):(b))
+#define MAX(a,b) (((a)>(b))?(a):(b))
+
+int file_read(struct m_inode * inode, struct file * filp, char * buf, int count)
+{
+	int left,chars,nr;
+	struct buffer_head * bh;
+
+	if ((left=count)<=0)
+		return 0;
+	while (left) {
+		if (nr = bmap(inode,(filp->f_pos)/BLOCK_SIZE)) {
+			if (!(bh=bread(inode->i_dev,nr)))
+				break;
+		} else
+			bh = NULL;
+		nr = filp->f_pos % BLOCK_SIZE;
+		chars = MIN( BLOCK_SIZE-nr , left );
+		filp->f_pos += chars;
+		left -= chars;
+		if (bh) {
+			char * p = nr + bh->b_data;
+			while (chars-->0)
+				put_fs_byte(*(p++),buf++);
+			brelse(bh);
+		} else {
+			while (chars-->0)
+				put_fs_byte(0,buf++);
+		}
+	}
+	inode->i_atime = CURRENT_TIME;
+	return (count-left)?(count-left):-ERROR;
+}
+
+int file_write(struct m_inode * inode, struct file * filp, char * buf, int count)
+{
+	off_t pos;
+	int block,c;
+	struct buffer_head * bh;
+	char * p;
+	int i=0;
+
+/*
+ * ok, append may not work when many processes are writing at the same time
+ * but so what. That way leads to madness anyway.
+ */
+	if (filp->f_flags & O_APPEND)
+		pos = inode->i_size;
+	else
+		pos = filp->f_pos;
+	while (i<count) {
+		if (!(block = create_block(inode,pos/BLOCK_SIZE)))
+			break;
+		if (!(bh=bread(inode->i_dev,block)))
+			break;
+		c = pos % BLOCK_SIZE;
+		p = c + bh->b_data;
+		bh->b_dirt = 1;
+		c = BLOCK_SIZE-c;
+		if (c > count-i) c = count-i;
+		pos += c;
+		if (pos > inode->i_size) {
+			inode->i_size = pos;
+			inode->i_dirt = 1;
+		}
+		i += c;
+		while (c-->0)
+			*(p++) = get_fs_byte(buf++);
+		brelse(bh);
+	}
+	inode->i_mtime = CURRENT_TIME;
+	if (!(filp->f_flags & O_APPEND)) {
+		filp->f_pos = pos;
+		inode->i_ctime = CURRENT_TIME;
+	}
+	return (i?i:-1);
+}

os/os/linux/fs/file_table.c

@@ -0,0 +1,9 @@
+/*
+ *  linux/fs/file_table.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+#include <linux/fs.h>
+
+struct file file_table[NR_FILE];

os/os/linux/fs/inode.c

@@ -0,0 +1,340 @@
+/*
+ *  linux/fs/inode.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+#include <string.h>
+#include <sys/stat.h>
+
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <asm/system.h>
+
+struct m_inode inode_table[NR_INODE]={{0,},};
+
+static void read_inode(struct m_inode * inode);
+static void write_inode(struct m_inode * inode);
+
+static inline void wait_on_inode(struct m_inode * inode)
+{
+	cli();
+	while (inode->i_lock)
+		sleep_on(&inode->i_wait);
+	sti();
+}
+
+static inline void lock_inode(struct m_inode * inode)
+{
+	cli();
+	while (inode->i_lock)
+		sleep_on(&inode->i_wait);
+	inode->i_lock=1;
+	sti();
+}
+
+static inline void unlock_inode(struct m_inode * inode)
+{
+	inode->i_lock=0;
+	wake_up(&inode->i_wait);
+}
+
+void invalidate_inodes(int dev)
+{
+	int i;
+	struct m_inode * inode;
+
+	inode = 0+inode_table;
+	for(i=0 ; i<NR_INODE ; i++,inode++) {
+		wait_on_inode(inode);
+		if (inode->i_dev == dev) {
+			if (inode->i_count)
+				printk("inode in use on removed disk\n\r");
+			inode->i_dev = inode->i_dirt = 0;
+		}
+	}
+}
+
+void sync_inodes(void)
+{
+	int i;
+	struct m_inode * inode;
+
+	inode = 0+inode_table;
+	for(i=0 ; i<NR_INODE ; i++,inode++) {
+		wait_on_inode(inode);
+		if (inode->i_dirt && !inode->i_pipe)
+			write_inode(inode);
+	}
+}
+
+static int _bmap(struct m_inode * inode,int block,int create)
+{
+	struct buffer_head * bh;
+	int i;
+
+	if (block<0)
+		panic("_bmap: block<0");
+	if (block >= 7+512+512*512)
+		panic("_bmap: block>big");
+	if (block<7) {
+		if (create && !inode->i_zone[block])
+			if (inode->i_zone[block]=new_block(inode->i_dev)) {
+				inode->i_ctime=CURRENT_TIME;
+				inode->i_dirt=1;
+			}
+		return inode->i_zone[block];
+	}
+	block -= 7;
+	if (block<512) {
+		if (create && !inode->i_zone[7])
+			if (inode->i_zone[7]=new_block(inode->i_dev)) {
+				inode->i_dirt=1;
+				inode->i_ctime=CURRENT_TIME;
+			}
+		if (!inode->i_zone[7])
+			return 0;
+		if (!(bh = bread(inode->i_dev,inode->i_zone[7])))
+			return 0;
+		i = ((unsigned short *) (bh->b_data))[block];
+		if (create && !i)
+			if (i=new_block(inode->i_dev)) {
+				((unsigned short *) (bh->b_data))[block]=i;
+				bh->b_dirt=1;
+			}
+		brelse(bh);
+		return i;
+	}
+	block -= 512;
+	if (create && !inode->i_zone[8])
+		if (inode->i_zone[8]=new_block(inode->i_dev)) {
+			inode->i_dirt=1;
+			inode->i_ctime=CURRENT_TIME;
+		}
+	if (!inode->i_zone[8])
+		return 0;
+	if (!(bh=bread(inode->i_dev,inode->i_zone[8])))
+		return 0;
+	i = ((unsigned short *)bh->b_data)[block>>9];
+	if (create && !i)
+		if (i=new_block(inode->i_dev)) {
+			((unsigned short *) (bh->b_data))[block>>9]=i;
+			bh->b_dirt=1;
+		}
+	brelse(bh);
+	if (!i)
+		return 0;
+	if (!(bh=bread(inode->i_dev,i)))
+		return 0;
+	i = ((unsigned short *)bh->b_data)[block&511];
+	if (create && !i)
+		if (i=new_block(inode->i_dev)) {
+			((unsigned short *) (bh->b_data))[block&511]=i;
+			bh->b_dirt=1;
+		}
+	brelse(bh);
+	return i;
+}
+
+int bmap(struct m_inode * inode,int block)
+{
+	return _bmap(inode,block,0);
+}
+
+int create_block(struct m_inode * inode, int block)
+{
+	return _bmap(inode,block,1);
+}
+		
+void iput(struct m_inode * inode)
+{
+	if (!inode)
+		return;
+	wait_on_inode(inode);
+	if (!inode->i_count)
+		panic("iput: trying to free free inode");
+	if (inode->i_pipe) {
+		wake_up(&inode->i_wait);
+		if (--inode->i_count)
+			return;
+		free_page(inode->i_size);
+		inode->i_count=0;
+		inode->i_dirt=0;
+		inode->i_pipe=0;
+		return;
+	}
+	if (!inode->i_dev) {
+		inode->i_count--;
+		return;
+	}
+	if (S_ISBLK(inode->i_mode)) {
+		sync_dev(inode->i_zone[0]);
+		wait_on_inode(inode);
+	}
+repeat:
+	if (inode->i_count>1) {
+		inode->i_count--;
+		return;
+	}
+	if (!inode->i_nlinks) {
+		truncate(inode);
+		free_inode(inode);
+		return;
+	}
+	if (inode->i_dirt) {
+		write_inode(inode);	/* we can sleep - so do again */
+		wait_on_inode(inode);
+		goto repeat;
+	}
+	inode->i_count--;
+	return;
+}
+
+struct m_inode * get_empty_inode(void)
+{
+	struct m_inode * inode;
+	static struct m_inode * last_inode = inode_table;
+	int i;
+
+	do {
+		inode = NULL;
+		for (i = NR_INODE; i ; i--) {
+			if (++last_inode >= inode_table + NR_INODE)
+				last_inode = inode_table;
+			if (!last_inode->i_count) {
+				inode = last_inode;
+				if (!inode->i_dirt && !inode->i_lock)
+					break;
+			}
+		}
+		if (!inode) {
+			for (i=0 ; i<NR_INODE ; i++)
+				printk("%04x: %6d\t",inode_table[i].i_dev,
+					inode_table[i].i_num);
+			panic("No free inodes in mem");
+		}
+		wait_on_inode(inode);
+		while (inode->i_dirt) {
+			write_inode(inode);
+			wait_on_inode(inode);
+		}
+	} while (inode->i_count);
+	memset(inode,0,sizeof(*inode));
+	inode->i_count = 1;
+	return inode;
+}
+
+struct m_inode * get_pipe_inode(void)
+{
+	struct m_inode * inode;
+
+	if (!(inode = get_empty_inode()))
+		return NULL;
+	if (!(inode->i_size=get_free_page())) {
+		inode->i_count = 0;
+		return NULL;
+	}
+	inode->i_count = 2;	/* sum of readers/writers */
+	PIPE_HEAD(*inode) = PIPE_TAIL(*inode) = 0;
+	inode->i_pipe = 1;
+	return inode;
+}
+
+struct m_inode * iget(int dev,int nr)
+{
+	struct m_inode * inode, * empty;
+
+	if (!dev)
+		panic("iget with dev==0");
+	empty = get_empty_inode();
+	inode = inode_table;
+	while (inode < NR_INODE+inode_table) {
+		if (inode->i_dev != dev || inode->i_num != nr) {
+			inode++;
+			continue;
+		}
+		wait_on_inode(inode);
+		if (inode->i_dev != dev || inode->i_num != nr) {
+			inode = inode_table;
+			continue;
+		}
+		inode->i_count++;
+		if (inode->i_mount) {
+			int i;
+
+			for (i = 0 ; i<NR_SUPER ; i++)
+				if (super_block[i].s_imount==inode)
+					break;
+			if (i >= NR_SUPER) {
+				printk("Mounted inode hasn't got sb\n");
+				if (empty)
+					iput(empty);
+				return inode;
+			}
+			iput(inode);
+			dev = super_block[i].s_dev;
+			nr = ROOT_INO;
+			inode = inode_table;
+			continue;
+		}
+		if (empty)
+			iput(empty);
+		return inode;
+	}
+	if (!empty)
+		return (NULL);
+	inode=empty;
+	inode->i_dev = dev;
+	inode->i_num = nr;
+	read_inode(inode);
+	return inode;
+}
+
+static void read_inode(struct m_inode * inode)
+{
+	struct super_block * sb;
+	struct buffer_head * bh;
+	int block;
+
+	lock_inode(inode);
+	if (!(sb=get_super(inode->i_dev)))
+		panic("trying to read inode without dev");
+	block = 2 + sb->s_imap_blocks + sb->s_zmap_blocks +
+		(inode->i_num-1)/INODES_PER_BLOCK;
+	if (!(bh=bread(inode->i_dev,block)))
+		panic("unable to read i-node block");
+	__asm__ volatile ("cld");   /* by wyj */
+	*(struct d_inode *)inode =
+		((struct d_inode *)bh->b_data)
+			[(inode->i_num-1)%INODES_PER_BLOCK];
+	brelse(bh);
+	unlock_inode(inode);
+}
+
+static void write_inode(struct m_inode * inode)
+{
+	struct super_block * sb;
+	struct buffer_head * bh;
+	int block;
+
+	lock_inode(inode);
+	if (!inode->i_dirt || !inode->i_dev) {
+		unlock_inode(inode);
+		return;
+	}
+	if (!(sb=get_super(inode->i_dev)))
+		panic("trying to write inode without device");
+	block = 2 + sb->s_imap_blocks + sb->s_zmap_blocks +
+		(inode->i_num-1)/INODES_PER_BLOCK;
+	if (!(bh=bread(inode->i_dev,block)))
+		panic("unable to read i-node block");
+	__asm__ volatile ("cld");   /* by wyj */
+	((struct d_inode *)bh->b_data)
+		[(inode->i_num-1)%INODES_PER_BLOCK] =
+			*(struct d_inode *)inode;
+	bh->b_dirt=1;
+	inode->i_dirt=0;
+	brelse(bh);
+	unlock_inode(inode);
+}

os/os/linux/fs/ioctl.c

@@ -0,0 +1,46 @@
+/*
+ *  linux/fs/ioctl.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+#include <string.h>
+#include <errno.h>
+#include <sys/stat.h>
+
+#include <linux/sched.h>
+
+extern int tty_ioctl(int dev, int cmd, int arg);
+
+typedef int (*ioctl_ptr)(int dev,int cmd,int arg);
+
+#define NRDEVS ((sizeof (ioctl_table))/(sizeof (ioctl_ptr)))
+
+static ioctl_ptr ioctl_table[]={
+	NULL,		/* nodev */
+	NULL,		/* /dev/mem */
+	NULL,		/* /dev/fd */
+	NULL,		/* /dev/hd */
+	tty_ioctl,	/* /dev/ttyx */
+	tty_ioctl,	/* /dev/tty */
+	NULL,		/* /dev/lp */
+	NULL};		/* named pipes */
+	
+
+int sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
+{	
+	struct file * filp;
+	int dev,mode;
+
+	if (fd >= NR_OPEN || !(filp = current->filp[fd]))
+		return -EBADF;
+	mode=filp->f_inode->i_mode;
+	if (!S_ISCHR(mode) && !S_ISBLK(mode))
+		return -EINVAL;
+	dev = filp->f_inode->i_zone[0];
+	if (MAJOR(dev) >= NRDEVS)
+		return -ENODEV;
+	if (!ioctl_table[MAJOR(dev)])
+		return -ENOTTY;
+	return ioctl_table[MAJOR(dev)](dev,cmd,arg);
+}

os/os/linux/fs/namei.c

@@ -0,0 +1,783 @@
+/*
+ *  linux/fs/namei.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+/*
+ * Some corrections by tytso.
+ */
+
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <asm/segment.h>
+
+#include <string.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <const.h>
+#include <sys/stat.h>
+
+#define ACC_MODE(x) ("\004\002\006\377"[(x)&O_ACCMODE])
+
+/*
+ * comment out this line if you want names > NAME_LEN chars to be
+ * truncated. Else they will be disallowed.
+ */
+/* #define NO_TRUNCATE */
+
+#define MAY_EXEC 1
+#define MAY_WRITE 2
+#define MAY_READ 4
+
+/*
+ *	permission()
+ *
+ * is used to check for read/write/execute permissions on a file.
+ * I don't know if we should look at just the euid or both euid and
+ * uid, but that should be easily changed.
+ */
+static int permission(struct m_inode * inode,int mask)
+{
+	int mode = inode->i_mode;
+
+/* special case: not even root can read/write a deleted file */
+	if (inode->i_dev && !inode->i_nlinks)
+		return 0;
+	else if (current->euid==inode->i_uid)
+		mode >>= 6;
+	else if (current->egid==inode->i_gid)
+		mode >>= 3;
+	if (((mode & mask & 0007) == mask) || suser())
+		return 1;
+	return 0;
+}
+
+/*
+ * ok, we cannot use strncmp, as the name is not in our data space.
+ * Thus we'll have to use match. No big problem. Match also makes
+ * some sanity tests.
+ *
+ * NOTE! unlike strncmp, match returns 1 for success, 0 for failure.
+ */
+static int match(int len,const char * name,struct dir_entry * de)
+{
+	register int same __asm__("ax");
+
+	if (!de || !de->inode || len > NAME_LEN)
+		return 0;
+	if (len < NAME_LEN && de->name[len])
+		return 0;
+	__asm__("cld\n\t"
+		"fs ; repe ; cmpsb\n\t"
+		"setz %%al"
+		:"=a" (same)
+		:"0" (0),"S" ((long) name),"D" ((long) de->name),"c" (len)
+		);
+	return same;
+}
+
+/*
+ *	find_entry()
+ *
+ * finds an entry in the specified directory with the wanted name. It
+ * returns the cache buffer in which the entry was found, and the entry
+ * itself (as a parameter - res_dir). It does NOT read the inode of the
+ * entry - you'll have to do that yourself if you want to.
+ *
+ * This also takes care of the few special cases due to '..'-traversal
+ * over a pseudo-root and a mount point.
+ */
+static struct buffer_head * find_entry(struct m_inode ** dir,
+	const char * name, int namelen, struct dir_entry ** res_dir)
+{
+	int entries;
+	int block,i;
+	struct buffer_head * bh;
+	struct dir_entry * de;
+	struct super_block * sb;
+
+#ifdef NO_TRUNCATE
+	if (namelen > NAME_LEN)
+		return NULL;
+#else
+	if (namelen > NAME_LEN)
+		namelen = NAME_LEN;
+#endif
+	entries = (*dir)->i_size / (sizeof (struct dir_entry));
+	*res_dir = NULL;
+	if (!namelen)
+		return NULL;
+/* check for '..', as we might have to do some "magic" for it */
+	if (namelen==2 && get_fs_byte(name)=='.' && get_fs_byte(name+1)=='.') {
+/* '..' in a pseudo-root results in a faked '.' (just change namelen) */
+		if ((*dir) == current->root)
+			namelen=1;
+		else if ((*dir)->i_num == ROOT_INO) {
+/* '..' over a mount-point results in 'dir' being exchanged for the mounted
+   directory-inode. NOTE! We set mounted, so that we can iput the new dir */
+			sb=get_super((*dir)->i_dev);
+			if (sb->s_imount) {
+				iput(*dir);
+				(*dir)=sb->s_imount;
+				(*dir)->i_count++;
+			}
+		}
+	}
+	if (!(block = (*dir)->i_zone[0]))
+		return NULL;
+	if (!(bh = bread((*dir)->i_dev,block)))
+		return NULL;
+	i = 0;
+	de = (struct dir_entry *) bh->b_data;
+	while (i < entries) {
+		if ((char *)de >= BLOCK_SIZE+bh->b_data) {
+			brelse(bh);
+			bh = NULL;
+			if (!(block = bmap(*dir,i/DIR_ENTRIES_PER_BLOCK)) ||
+			    !(bh = bread((*dir)->i_dev,block))) {
+				i += DIR_ENTRIES_PER_BLOCK;
+				continue;
+			}
+			de = (struct dir_entry *) bh->b_data;
+		}
+		if (match(namelen,name,de)) {
+			*res_dir = de;
+			return bh;
+		}
+		de++;
+		i++;
+	}
+	brelse(bh);
+	return NULL;
+}
+
+/*
+ *	add_entry()
+ *
+ * adds a file entry to the specified directory, using the same
+ * semantics as find_entry(). It returns NULL if it failed.
+ *
+ * NOTE!! The inode part of 'de' is left at 0 - which means you
+ * may not sleep between calling this and putting something into
+ * the entry, as someone else might have used it while you slept.
+ */
+static struct buffer_head * add_entry(struct m_inode * dir,
+	const char * name, int namelen, struct dir_entry ** res_dir)
+{
+	int block,i;
+	struct buffer_head * bh;
+	struct dir_entry * de;
+
+	*res_dir = NULL;
+#ifdef NO_TRUNCATE
+	if (namelen > NAME_LEN)
+		return NULL;
+#else
+	if (namelen > NAME_LEN)
+		namelen = NAME_LEN;
+#endif
+	if (!namelen)
+		return NULL;
+	if (!(block = dir->i_zone[0]))
+		return NULL;
+	if (!(bh = bread(dir->i_dev,block)))
+		return NULL;
+	i = 0;
+	de = (struct dir_entry *) bh->b_data;
+	while (1) {
+		if ((char *)de >= BLOCK_SIZE+bh->b_data) {
+			brelse(bh);
+			bh = NULL;
+			block = create_block(dir,i/DIR_ENTRIES_PER_BLOCK);
+			if (!block)
+				return NULL;
+			if (!(bh = bread(dir->i_dev,block))) {
+				i += DIR_ENTRIES_PER_BLOCK;
+				continue;
+			}
+			de = (struct dir_entry *) bh->b_data;
+		}
+		if (i*sizeof(struct dir_entry) >= dir->i_size) {
+			de->inode=0;
+			dir->i_size = (i+1)*sizeof(struct dir_entry);
+			dir->i_dirt = 1;
+			dir->i_ctime = CURRENT_TIME;
+		}
+		if (!de->inode) {
+			dir->i_mtime = CURRENT_TIME;
+			for (i=0; i < NAME_LEN ; i++)
+				de->name[i]=(i<namelen)?get_fs_byte(name+i):0;
+			bh->b_dirt = 1;
+			*res_dir = de;
+			return bh;
+		}
+		de++;
+		i++;
+	}
+	brelse(bh);
+	return NULL;
+}
+
+/*
+ *	get_dir()
+ *
+ * Getdir traverses the pathname until it hits the topmost directory.
+ * It returns NULL on failure.
+ */
+static struct m_inode * get_dir(const char * pathname)
+{
+	char c;
+	const char * thisname;
+	struct m_inode * inode;
+	struct buffer_head * bh;
+	int namelen,inr,idev;
+	struct dir_entry * de;
+
+	if (!current->root || !current->root->i_count)
+		panic("No root inode");
+	if (!current->pwd || !current->pwd->i_count)
+		panic("No cwd inode");
+	if ((c=get_fs_byte(pathname))=='/') {
+		inode = current->root;
+		pathname++;
+	} else if (c)
+		inode = current->pwd;
+	else
+		return NULL;	/* empty name is bad */
+	inode->i_count++;
+	while (1) {
+		thisname = pathname;
+		if (!S_ISDIR(inode->i_mode) || !permission(inode,MAY_EXEC)) {
+			iput(inode);
+			return NULL;
+		}
+		for(namelen=0;(c=get_fs_byte(pathname++))&&(c!='/');namelen++)
+			/* nothing */ ;
+		if (!c)
+			return inode;
+		if (!(bh = find_entry(&inode,thisname,namelen,&de))) {
+			iput(inode);
+			return NULL;
+		}
+		inr = de->inode;
+		idev = inode->i_dev;
+		brelse(bh);
+		iput(inode);
+		if (!(inode = iget(idev,inr)))
+			return NULL;
+	}
+}
+
+/*
+ *	dir_namei()
+ *
+ * dir_namei() returns the inode of the directory of the
+ * specified name, and the name within that directory.
+ */
+static struct m_inode * dir_namei(const char * pathname,
+	int * namelen, const char ** name)
+{
+	char c;
+	const char * basename;
+	struct m_inode * dir;
+
+	if (!(dir = get_dir(pathname)))
+		return NULL;
+	basename = pathname;
+	while (c=get_fs_byte(pathname++))
+		if (c=='/')
+			basename=pathname;
+	*namelen = pathname-basename-1;
+	*name = basename;
+	return dir;
+}
+
+/*
+ *	namei()
+ *
+ * is used by most simple commands to get the inode of a specified name.
+ * Open, link etc use their own routines, but this is enough for things
+ * like 'chmod' etc.
+ */
+struct m_inode * namei(const char * pathname)
+{
+	const char * basename;
+	int inr,dev,namelen;
+	struct m_inode * dir;
+	struct buffer_head * bh;
+	struct dir_entry * de;
+
+	if (!(dir = dir_namei(pathname,&namelen,&basename)))
+		return NULL;
+	if (!namelen)			/* special case: '/usr/' etc */
+		return dir;
+	bh = find_entry(&dir,basename,namelen,&de);
+	if (!bh) {
+		iput(dir);
+		return NULL;
+	}
+	inr = de->inode;
+	dev = dir->i_dev;
+	brelse(bh);
+	iput(dir);
+	dir=iget(dev,inr);
+	if (dir) {
+		dir->i_atime=CURRENT_TIME;
+		dir->i_dirt=1;
+	}
+	return dir;
+}
+
+/*
+ *	open_namei()
+ *
+ * namei for open - this is in fact almost the whole open-routine.
+ */
+int open_namei(const char * pathname, int flag, int mode,
+	struct m_inode ** res_inode)
+{
+	const char * basename;
+	int inr,dev,namelen;
+	struct m_inode * dir, *inode;
+	struct buffer_head * bh;
+	struct dir_entry * de;
+
+	if ((flag & O_TRUNC) && !(flag & O_ACCMODE))
+		flag |= O_WRONLY;
+	mode &= 0777 & ~current->umask;
+	mode |= I_REGULAR;
+	if (!(dir = dir_namei(pathname,&namelen,&basename)))
+		return -ENOENT;
+	if (!namelen) {			/* special case: '/usr/' etc */
+		if (!(flag & (O_ACCMODE|O_CREAT|O_TRUNC))) {
+			*res_inode=dir;
+			return 0;
+		}
+		iput(dir);
+		return -EISDIR;
+	}
+	bh = find_entry(&dir,basename,namelen,&de);
+	if (!bh) {
+		if (!(flag & O_CREAT)) {
+			iput(dir);
+			return -ENOENT;
+		}
+		if (!permission(dir,MAY_WRITE)) {
+			iput(dir);
+			return -EACCES;
+		}
+		inode = new_inode(dir->i_dev);
+		if (!inode) {
+			iput(dir);
+			return -ENOSPC;
+		}
+		inode->i_uid = current->euid;
+		inode->i_mode = mode;
+		inode->i_dirt = 1;
+		bh = add_entry(dir,basename,namelen,&de);
+		if (!bh) {
+			inode->i_nlinks--;
+			iput(inode);
+			iput(dir);
+			return -ENOSPC;
+		}
+		de->inode = inode->i_num;
+		bh->b_dirt = 1;
+		brelse(bh);
+		iput(dir);
+		*res_inode = inode;
+		return 0;
+	}
+	inr = de->inode;
+	dev = dir->i_dev;
+	brelse(bh);
+	iput(dir);
+	if (flag & O_EXCL)
+		return -EEXIST;
+	if (!(inode=iget(dev,inr)))
+		return -EACCES;
+	if ((S_ISDIR(inode->i_mode) && (flag & O_ACCMODE)) ||
+	    !permission(inode,ACC_MODE(flag))) {
+		iput(inode);
+		return -EPERM;
+	}
+	inode->i_atime = CURRENT_TIME;
+	if (flag & O_TRUNC)
+		truncate(inode);
+	*res_inode = inode;
+	return 0;
+}
+
+int sys_mknod(const char * filename, int mode, int dev)
+{
+	const char * basename;
+	int namelen;
+	struct m_inode * dir, * inode;
+	struct buffer_head * bh;
+	struct dir_entry * de;
+	
+	if (!suser())
+		return -EPERM;
+	if (!(dir = dir_namei(filename,&namelen,&basename)))
+		return -ENOENT;
+	if (!namelen) {
+		iput(dir);
+		return -ENOENT;
+	}
+	if (!permission(dir,MAY_WRITE)) {
+		iput(dir);
+		return -EPERM;
+	}
+	bh = find_entry(&dir,basename,namelen,&de);
+	if (bh) {
+		brelse(bh);
+		iput(dir);
+		return -EEXIST;
+	}
+	inode = new_inode(dir->i_dev);
+	if (!inode) {
+		iput(dir);
+		return -ENOSPC;
+	}
+	inode->i_mode = mode;
+	if (S_ISBLK(mode) || S_ISCHR(mode))
+		inode->i_zone[0] = dev;
+	inode->i_mtime = inode->i_atime = CURRENT_TIME;
+	inode->i_dirt = 1;
+	bh = add_entry(dir,basename,namelen,&de);
+	if (!bh) {
+		iput(dir);
+		inode->i_nlinks=0;
+		iput(inode);
+		return -ENOSPC;
+	}
+	de->inode = inode->i_num;
+	bh->b_dirt = 1;
+	iput(dir);
+	iput(inode);
+	brelse(bh);
+	return 0;
+}
+
+int sys_mkdir(const char * pathname, int mode)
+{
+	const char * basename;
+	int namelen;
+	struct m_inode * dir, * inode;
+	struct buffer_head * bh, *dir_block;
+	struct dir_entry * de;
+
+	if (!suser())
+		return -EPERM;
+	if (!(dir = dir_namei(pathname,&namelen,&basename)))
+		return -ENOENT;
+	if (!namelen) {
+		iput(dir);
+		return -ENOENT;
+	}
+	if (!permission(dir,MAY_WRITE)) {
+		iput(dir);
+		return -EPERM;
+	}
+	bh = find_entry(&dir,basename,namelen,&de);
+	if (bh) {
+		brelse(bh);
+		iput(dir);
+		return -EEXIST;
+	}
+	inode = new_inode(dir->i_dev);
+	if (!inode) {
+		iput(dir);
+		return -ENOSPC;
+	}
+	inode->i_size = 32;
+	inode->i_dirt = 1;
+	inode->i_mtime = inode->i_atime = CURRENT_TIME;
+	if (!(inode->i_zone[0]=new_block(inode->i_dev))) {
+		iput(dir);
+		inode->i_nlinks--;
+		iput(inode);
+		return -ENOSPC;
+	}
+	inode->i_dirt = 1;
+	if (!(dir_block=bread(inode->i_dev,inode->i_zone[0]))) {
+		iput(dir);
+		free_block(inode->i_dev,inode->i_zone[0]);
+		inode->i_nlinks--;
+		iput(inode);
+		return -ERROR;
+	}
+	de = (struct dir_entry *) dir_block->b_data;
+	de->inode=inode->i_num;
+	strcpy(de->name,".");
+	de++;
+	de->inode = dir->i_num;
+	strcpy(de->name,"..");
+	inode->i_nlinks = 2;
+	dir_block->b_dirt = 1;
+	brelse(dir_block);
+	inode->i_mode = I_DIRECTORY | (mode & 0777 & ~current->umask);
+	inode->i_dirt = 1;
+	bh = add_entry(dir,basename,namelen,&de);
+	if (!bh) {
+		iput(dir);
+		free_block(inode->i_dev,inode->i_zone[0]);
+		inode->i_nlinks=0;
+		iput(inode);
+		return -ENOSPC;
+	}
+	de->inode = inode->i_num;
+	bh->b_dirt = 1;
+	dir->i_nlinks++;
+	dir->i_dirt = 1;
+	iput(dir);
+	iput(inode);
+	brelse(bh);
+	return 0;
+}
+
+/*
+ * routine to check that the specified directory is empty (for rmdir)
+ */
+static int empty_dir(struct m_inode * inode)
+{
+	int nr,block;
+	int len;
+	struct buffer_head * bh;
+	struct dir_entry * de;
+
+	len = inode->i_size / sizeof (struct dir_entry);
+	if (len<2 || !inode->i_zone[0] ||
+	    !(bh=bread(inode->i_dev,inode->i_zone[0]))) {
+	    	printk("warning - bad directory on dev %04x\n",inode->i_dev);
+		return 0;
+	}
+	de = (struct dir_entry *) bh->b_data;
+	if (de[0].inode != inode->i_num || !de[1].inode || 
+	    strcmp(".",de[0].name) || strcmp("..",de[1].name)) {
+	    	printk("warning - bad directory on dev %04x\n",inode->i_dev);
+		return 0;
+	}
+	nr = 2;
+	de += 2;
+	while (nr<len) {
+		if ((void *) de >= (void *) (bh->b_data+BLOCK_SIZE)) {
+			brelse(bh);
+			block=bmap(inode,nr/DIR_ENTRIES_PER_BLOCK);
+			if (!block) {
+				nr += DIR_ENTRIES_PER_BLOCK;
+				continue;
+			}
+			if (!(bh=bread(inode->i_dev,block)))
+				return 0;
+			de = (struct dir_entry *) bh->b_data;
+		}
+		if (de->inode) {
+			brelse(bh);
+			return 0;
+		}
+		de++;
+		nr++;
+	}
+	brelse(bh);
+	return 1;
+}
+
+int sys_rmdir(const char * name)
+{
+	const char * basename;
+	int namelen;
+	struct m_inode * dir, * inode;
+	struct buffer_head * bh;
+	struct dir_entry * de;
+
+	if (!suser())
+		return -EPERM;
+	if (!(dir = dir_namei(name,&namelen,&basename)))
+		return -ENOENT;
+	if (!namelen) {
+		iput(dir);
+		return -ENOENT;
+	}
+	if (!permission(dir,MAY_WRITE)) {
+		iput(dir);
+		return -EPERM;
+	}
+	bh = find_entry(&dir,basename,namelen,&de);
+	if (!bh) {
+		iput(dir);
+		return -ENOENT;
+	}
+	if (!(inode = iget(dir->i_dev, de->inode))) {
+		iput(dir);
+		brelse(bh);
+		return -EPERM;
+	}
+	if ((dir->i_mode & S_ISVTX) && current->euid &&
+	    inode->i_uid != current->euid) {
+		iput(dir);
+		iput(inode);
+		brelse(bh);
+		return -EPERM;
+	}
+	if (inode->i_dev != dir->i_dev || inode->i_count>1) {
+		iput(dir);
+		iput(inode);
+		brelse(bh);
+		return -EPERM;
+	}
+	if (inode == dir) {	/* we may not delete ".", but "../dir" is ok */
+		iput(inode);
+		iput(dir);
+		brelse(bh);
+		return -EPERM;
+	}
+	if (!S_ISDIR(inode->i_mode)) {
+		iput(inode);
+		iput(dir);
+		brelse(bh);
+		return -ENOTDIR;
+	}
+	if (!empty_dir(inode)) {
+		iput(inode);
+		iput(dir);
+		brelse(bh);
+		return -ENOTEMPTY;
+	}
+	if (inode->i_nlinks != 2)
+		printk("empty directory has nlink!=2 (%d)",inode->i_nlinks);
+	de->inode = 0;
+	bh->b_dirt = 1;
+	brelse(bh);
+	inode->i_nlinks=0;
+	inode->i_dirt=1;
+	dir->i_nlinks--;
+	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+	dir->i_dirt=1;
+	iput(dir);
+	iput(inode);
+	return 0;
+}
+
+int sys_unlink(const char * name)
+{
+	const char * basename;
+	int namelen;
+	struct m_inode * dir, * inode;
+	struct buffer_head * bh;
+	struct dir_entry * de;
+
+	if (!(dir = dir_namei(name,&namelen,&basename)))
+		return -ENOENT;
+	if (!namelen) {
+		iput(dir);
+		return -ENOENT;
+	}
+	if (!permission(dir,MAY_WRITE)) {
+		iput(dir);
+		return -EPERM;
+	}
+	bh = find_entry(&dir,basename,namelen,&de);
+	if (!bh) {
+		iput(dir);
+		return -ENOENT;
+	}
+	if (!(inode = iget(dir->i_dev, de->inode))) {
+		iput(dir);
+		brelse(bh);
+		return -ENOENT;
+	}
+	if ((dir->i_mode & S_ISVTX) && !suser() &&
+	    current->euid != inode->i_uid &&
+	    current->euid != dir->i_uid) {
+		iput(dir);
+		iput(inode);
+		brelse(bh);
+		return -EPERM;
+	}
+	if (S_ISDIR(inode->i_mode)) {
+		iput(inode);
+		iput(dir);
+		brelse(bh);
+		return -EPERM;
+	}
+	if (!inode->i_nlinks) {
+		printk("Deleting nonexistent file (%04x:%d), %d\n",
+			inode->i_dev,inode->i_num,inode->i_nlinks);
+		inode->i_nlinks=1;
+	}
+	de->inode = 0;
+	bh->b_dirt = 1;
+	brelse(bh);
+	inode->i_nlinks--;
+	inode->i_dirt = 1;
+	inode->i_ctime = CURRENT_TIME;
+	iput(inode);
+	iput(dir);
+	return 0;
+}
+
+int sys_symlink()
+{
+	return -ENOSYS;
+}
+
+int sys_link(const char * oldname, const char * newname)
+{
+	struct dir_entry * de;
+	struct m_inode * oldinode, * dir;
+	struct buffer_head * bh;
+	const char * basename;
+	int namelen;
+
+	oldinode=namei(oldname);
+	if (!oldinode)
+		return -ENOENT;
+	if (S_ISDIR(oldinode->i_mode)) {
+		iput(oldinode);
+		return -EPERM;
+	}
+	dir = dir_namei(newname,&namelen,&basename);
+	if (!dir) {
+		iput(oldinode);
+		return -EACCES;
+	}
+	if (!namelen) {
+		iput(oldinode);
+		iput(dir);
+		return -EPERM;
+	}
+	if (dir->i_dev != oldinode->i_dev) {
+		iput(dir);
+		iput(oldinode);
+		return -EXDEV;
+	}
+	if (!permission(dir,MAY_WRITE)) {
+		iput(dir);
+		iput(oldinode);
+		return -EACCES;
+	}
+	bh = find_entry(&dir,basename,namelen,&de);
+	if (bh) {
+		brelse(bh);
+		iput(dir);
+		iput(oldinode);
+		return -EEXIST;
+	}
+	bh = add_entry(dir,basename,namelen,&de);
+	if (!bh) {
+		iput(dir);
+		iput(oldinode);
+		return -ENOSPC;
+	}
+	de->inode = oldinode->i_num;
+	bh->b_dirt = 1;
+	brelse(bh);
+	iput(dir);
+	oldinode->i_nlinks++;
+	oldinode->i_ctime = CURRENT_TIME;
+	oldinode->i_dirt = 1;
+	iput(oldinode);
+	return 0;
+}

os/os/linux/fs/open.c

@@ -0,0 +1,208 @@
+/*
+ *  linux/fs/open.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <utime.h>
+#include <sys/stat.h>
+
+#include <linux/sched.h>
+#include <linux/tty.h>
+#include <linux/kernel.h>
+#include <asm/segment.h>
+
+int sys_ustat(int dev, struct ustat * ubuf)
+{
+	return -ENOSYS;
+}
+
+int sys_utime(char * filename, struct utimbuf * times)
+{
+	struct m_inode * inode;
+	long actime,modtime;
+
+	if (!(inode=namei(filename)))
+		return -ENOENT;
+	if (times) {
+		actime = get_fs_long((unsigned long *) &times->actime);
+		modtime = get_fs_long((unsigned long *) &times->modtime);
+	} else
+		actime = modtime = CURRENT_TIME;
+	inode->i_atime = actime;
+	inode->i_mtime = modtime;
+	inode->i_dirt = 1;
+	iput(inode);
+	return 0;
+}
+
+/*
+ * XXX should we use the real or effective uid?  BSD uses the real uid,
+ * so as to make this call useful to setuid programs.
+ */
+int sys_access(const char * filename,int mode)
+{
+	struct m_inode * inode;
+	int res, i_mode;
+
+	mode &= 0007;
+	if (!(inode=namei(filename)))
+		return -EACCES;
+	i_mode = res = inode->i_mode & 0777;
+	iput(inode);
+	if (current->uid == inode->i_uid)
+		res >>= 6;
+	else if (current->gid == inode->i_gid)
+		res >>= 6;
+	if ((res & 0007 & mode) == mode)
+		return 0;
+	/*
+	 * XXX we are doing this test last because we really should be
+	 * swapping the effective with the real user id (temporarily),
+	 * and then calling suser() routine.  If we do call the
+	 * suser() routine, it needs to be called last. 
+	 */
+	if ((!current->uid) &&
+	    (!(mode & 1) || (i_mode & 0111)))
+		return 0;
+	return -EACCES;
+}
+
+int sys_chdir(const char * filename)
+{
+	struct m_inode * inode;
+
+	if (!(inode = namei(filename)))
+		return -ENOENT;
+	if (!S_ISDIR(inode->i_mode)) {
+		iput(inode);
+		return -ENOTDIR;
+	}
+	iput(current->pwd);
+	current->pwd = inode;
+	return (0);
+}
+
+int sys_chroot(const char * filename)
+{
+	struct m_inode * inode;
+
+	if (!(inode=namei(filename)))
+		return -ENOENT;
+	if (!S_ISDIR(inode->i_mode)) {
+		iput(inode);
+		return -ENOTDIR;
+	}
+	iput(current->root);
+	current->root = inode;
+	return (0);
+}
+
+int sys_chmod(const char * filename,int mode)
+{
+	struct m_inode * inode;
+
+	if (!(inode=namei(filename)))
+		return -ENOENT;
+	if ((current->euid != inode->i_uid) && !suser()) {
+		iput(inode);
+		return -EACCES;
+	}
+	inode->i_mode = (mode & 07777) | (inode->i_mode & ~07777);
+	inode->i_dirt = 1;
+	iput(inode);
+	return 0;
+}
+
+int sys_chown(const char * filename,int uid,int gid)
+{
+	struct m_inode * inode;
+
+	if (!(inode=namei(filename)))
+		return -ENOENT;
+	if (!suser()) {
+		iput(inode);
+		return -EACCES;
+	}
+	inode->i_uid=uid;
+	inode->i_gid=gid;
+	inode->i_dirt=1;
+	iput(inode);
+	return 0;
+}
+
+int sys_open(const char * filename,int flag,int mode)
+{
+	struct m_inode * inode;
+	struct file * f;
+	int i,fd;
+
+	mode &= 0777 & ~current->umask;
+	for(fd=0 ; fd<NR_OPEN ; fd++)
+		if (!current->filp[fd])
+			break;
+	if (fd>=NR_OPEN)
+		return -EINVAL;
+	current->close_on_exec &= ~(1<<fd);
+	f=0+file_table;
+	for (i=0 ; i<NR_FILE ; i++,f++)
+		if (!f->f_count) break;
+	if (i>=NR_FILE)
+		return -EINVAL;
+	(current->filp[fd]=f)->f_count++;
+	if ((i=open_namei(filename,flag,mode,&inode))<0) {
+		current->filp[fd]=NULL;
+		f->f_count=0;
+		return i;
+	}
+/* ttys are somewhat special (ttyxx major==4, tty major==5) */
+	if (S_ISCHR(inode->i_mode))
+		if (MAJOR(inode->i_zone[0])==4) {
+			if (current->leader && current->tty<0) {
+				current->tty = MINOR(inode->i_zone[0]);
+				tty_table[current->tty].pgrp = current->pgrp;
+			}
+		} else if (MAJOR(inode->i_zone[0])==5)
+			if (current->tty<0) {
+				iput(inode);
+				current->filp[fd]=NULL;
+				f->f_count=0;
+				return -EPERM;
+			}
+/* Likewise with block-devices: check for floppy_change */
+	if (S_ISBLK(inode->i_mode))
+		check_disk_change(inode->i_zone[0]);
+	f->f_mode = inode->i_mode;
+	f->f_flags = flag;
+	f->f_count = 1;
+	f->f_inode = inode;
+	f->f_pos = 0;
+	return (fd);
+}
+
+int sys_creat(const char * pathname, int mode)
+{
+	return sys_open(pathname, O_CREAT | O_TRUNC, mode);
+}
+
+int sys_close(unsigned int fd)
+{	
+	struct file * filp;
+
+	if (fd >= NR_OPEN)
+		return -EINVAL;
+	current->close_on_exec &= ~(1<<fd);
+	if (!(filp = current->filp[fd]))
+		return -EINVAL;
+	current->filp[fd] = NULL;
+	if (filp->f_count == 0)
+		panic("Close: file count is 0");
+	if (--filp->f_count)
+		return (0);
+	iput(filp->f_inode);
+	return (0);
+}

os/os/linux/fs/pipe.c

@@ -0,0 +1,111 @@
+/*
+ *  linux/fs/pipe.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+#include <signal.h>
+
+#include <linux/sched.h>
+#include <linux/mm.h>	/* for get_free_page */
+#include <asm/segment.h>
+
+int read_pipe(struct m_inode * inode, char * buf, int count)
+{
+	int chars, size, read = 0;
+
+	while (count>0) {
+		while (!(size=PIPE_SIZE(*inode))) {
+			wake_up(&inode->i_wait);
+			if (inode->i_count != 2) /* are there any writers? */
+				return read;
+			sleep_on(&inode->i_wait);
+		}
+		chars = PAGE_SIZE-PIPE_TAIL(*inode);
+		if (chars > count)
+			chars = count;
+		if (chars > size)
+			chars = size;
+		count -= chars;
+		read += chars;
+		size = PIPE_TAIL(*inode);
+		PIPE_TAIL(*inode) += chars;
+		PIPE_TAIL(*inode) &= (PAGE_SIZE-1);
+		while (chars-->0)
+			put_fs_byte(((char *)inode->i_size)[size++],buf++);
+	}
+	wake_up(&inode->i_wait);
+	return read;
+}
+	
+int write_pipe(struct m_inode * inode, char * buf, int count)
+{
+	int chars, size, written = 0;
+
+	while (count>0) {
+		while (!(size=(PAGE_SIZE-1)-PIPE_SIZE(*inode))) {
+			wake_up(&inode->i_wait);
+			if (inode->i_count != 2) { /* no readers */
+				current->signal |= (1<<(SIGPIPE-1));
+				return written?written:-1;
+			}
+			sleep_on(&inode->i_wait);
+		}
+		chars = PAGE_SIZE-PIPE_HEAD(*inode);
+		if (chars > count)
+			chars = count;
+		if (chars > size)
+			chars = size;
+		count -= chars;
+		written += chars;
+		size = PIPE_HEAD(*inode);
+		PIPE_HEAD(*inode) += chars;
+		PIPE_HEAD(*inode) &= (PAGE_SIZE-1);
+		while (chars-->0)
+			((char *)inode->i_size)[size++]=get_fs_byte(buf++);
+	}
+	wake_up(&inode->i_wait);
+	return written;
+}
+
+int sys_pipe(unsigned long * fildes)
+{
+	struct m_inode * inode;
+	struct file * f[2];
+	int fd[2];
+	int i,j;
+
+	j=0;
+	for(i=0;j<2 && i<NR_FILE;i++)
+		if (!file_table[i].f_count)
+			(f[j++]=i+file_table)->f_count++;
+	if (j==1)
+		f[0]->f_count=0;
+	if (j<2)
+		return -1;
+	j=0;
+	for(i=0;j<2 && i<NR_OPEN;i++)
+		if (!current->filp[i]) {
+			current->filp[ fd[j]=i ] = f[j];
+			j++;
+		}
+	if (j==1)
+		current->filp[fd[0]]=NULL;
+	if (j<2) {
+		f[0]->f_count=f[1]->f_count=0;
+		return -1;
+	}
+	if (!(inode=get_pipe_inode())) {
+		current->filp[fd[0]] =
+			current->filp[fd[1]] = NULL;
+		f[0]->f_count = f[1]->f_count = 0;
+		return -1;
+	}
+	f[0]->f_inode = f[1]->f_inode = inode;
+	f[0]->f_pos = f[1]->f_pos = 0;
+	f[0]->f_mode = 1;		/* read */
+	f[1]->f_mode = 2;		/* write */
+	put_fs_long(fd[0],0+fildes);
+	put_fs_long(fd[1],1+fildes);
+	return 0;
+}

os/os/linux/fs/read_write.c

@@ -0,0 +1,103 @@
+/*
+ *  linux/fs/read_write.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+#include <sys/stat.h>
+#include <errno.h>
+#include <sys/types.h>
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <asm/segment.h>
+
+extern int rw_char(int rw,int dev, char * buf, int count, off_t * pos);
+extern int read_pipe(struct m_inode * inode, char * buf, int count);
+extern int write_pipe(struct m_inode * inode, char * buf, int count);
+extern int block_read(int dev, off_t * pos, char * buf, int count);
+extern int block_write(int dev, off_t * pos, char * buf, int count);
+extern int file_read(struct m_inode * inode, struct file * filp,
+		char * buf, int count);
+extern int file_write(struct m_inode * inode, struct file * filp,
+		char * buf, int count);
+
+int sys_lseek(unsigned int fd,off_t offset, int origin)
+{
+	struct file * file;
+	int tmp;
+
+	if (fd >= NR_OPEN || !(file=current->filp[fd]) || !(file->f_inode)
+	   || !IS_SEEKABLE(MAJOR(file->f_inode->i_dev)))
+		return -EBADF;
+	if (file->f_inode->i_pipe)
+		return -ESPIPE;
+	switch (origin) {
+		case 0:
+			if (offset<0) return -EINVAL;
+			file->f_pos=offset;
+			break;
+		case 1:
+			if (file->f_pos+offset<0) return -EINVAL;
+			file->f_pos += offset;
+			break;
+		case 2:
+			if ((tmp=file->f_inode->i_size+offset) < 0)
+				return -EINVAL;
+			file->f_pos = tmp;
+			break;
+		default:
+			return -EINVAL;
+	}
+	return file->f_pos;
+}
+
+int sys_read(unsigned int fd,char * buf,int count)
+{
+	struct file * file;
+	struct m_inode * inode;
+
+	if (fd>=NR_OPEN || count<0 || !(file=current->filp[fd]))
+		return -EINVAL;
+	if (!count)
+		return 0;
+	verify_area(buf,count);
+	inode = file->f_inode;
+	if (inode->i_pipe)
+		return (file->f_mode&1)?read_pipe(inode,buf,count):-EIO;
+	if (S_ISCHR(inode->i_mode))
+		return rw_char(READ,inode->i_zone[0],buf,count,&file->f_pos);
+	if (S_ISBLK(inode->i_mode))
+		return block_read(inode->i_zone[0],&file->f_pos,buf,count);
+	if (S_ISDIR(inode->i_mode) || S_ISREG(inode->i_mode)) {
+		if (count+file->f_pos > inode->i_size)
+			count = inode->i_size - file->f_pos;
+		if (count<=0)
+			return 0;
+		return file_read(inode,file,buf,count);
+	}
+	printk("(Read)inode->i_mode=%06o\n\r",inode->i_mode);
+	return -EINVAL;
+}
+
+int sys_write(unsigned int fd,char * buf,int count)
+{
+	struct file * file;
+	struct m_inode * inode;
+	
+	if (fd>=NR_OPEN || count <0 || !(file=current->filp[fd]))
+		return -EINVAL;
+	if (!count)
+		return 0;
+	inode=file->f_inode;
+	if (inode->i_pipe)
+		return (file->f_mode&2)?write_pipe(inode,buf,count):-EIO;
+	if (S_ISCHR(inode->i_mode))
+		return rw_char(WRITE,inode->i_zone[0],buf,count,&file->f_pos);
+	if (S_ISBLK(inode->i_mode))
+		return block_write(inode->i_zone[0],&file->f_pos,buf,count);
+	if (S_ISREG(inode->i_mode))
+		return file_write(inode,file,buf,count);
+	printk("(Write)inode->i_mode=%06o\n\r",inode->i_mode);
+	return -EINVAL;
+}

os/os/linux/fs/select.c

@@ -0,0 +1,10 @@
+/* nothing , only the stub */
+/* gohigh */
+
+#include <errno.h>
+
+int sys_select()
+{
+	return -ENOSYS;
+}
+

os/os/linux/fs/stat.c

@@ -0,0 +1,66 @@
+/*
+ *  linux/fs/stat.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+#include <errno.h>
+#include <sys/stat.h>
+
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <asm/segment.h>
+
+static void cp_stat(struct m_inode * inode, struct stat * statbuf)
+{
+	struct stat tmp;
+	int i;
+
+	verify_area(statbuf,sizeof (* statbuf));
+	tmp.st_dev = inode->i_dev;
+	tmp.st_ino = inode->i_num;
+	tmp.st_mode = inode->i_mode;
+	tmp.st_nlink = inode->i_nlinks;
+	tmp.st_uid = inode->i_uid;
+	tmp.st_gid = inode->i_gid;
+	tmp.st_rdev = inode->i_zone[0];
+	tmp.st_size = inode->i_size;
+	tmp.st_atime = inode->i_atime;
+	tmp.st_mtime = inode->i_mtime;
+	tmp.st_ctime = inode->i_ctime;
+	for (i=0 ; i<sizeof (tmp) ; i++)
+		put_fs_byte(((char *) &tmp)[i],&((char *) statbuf)[i]);
+}
+
+int sys_stat(char * filename, struct stat * statbuf)
+{
+	struct m_inode * inode;
+
+	if (!(inode=namei(filename)))
+		return -ENOENT;
+	cp_stat(inode,statbuf);
+	iput(inode);
+	return 0;
+}
+
+int sys_lstat(char * filename, struct stat * statbuf)
+{
+	return sys_stat(filename, statbuf);
+}
+
+int sys_fstat(unsigned int fd, struct stat * statbuf)
+{
+	struct file * f;
+	struct m_inode * inode;
+
+	if (fd >= NR_OPEN || !(f=current->filp[fd]) || !(inode=f->f_inode))
+		return -EBADF;
+	cp_stat(inode,statbuf);
+	return 0;
+}
+
+int sys_readlink()
+{
+	return -ENOSYS;
+}

os/os/linux/fs/super.c

@@ -0,0 +1,282 @@
+/*
+ *  linux/fs/super.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+/*
+ * super.c contains code to handle the super-block tables.
+ */
+#include <linux/config.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <asm/system.h>
+
+#include <errno.h>
+#include <sys/stat.h>
+
+int sync_dev(int dev);
+void wait_for_keypress(void);
+
+/* set_bit uses setb, as gas doesn't recognize setc */
+#define set_bit(bitnr,addr) ({ \
+register int __res __asm__("ax"); \
+__asm__("bt %2,%3;setb %%al":"=a" (__res):"a" (0),"r" (bitnr),"m" (*(addr))); \
+__res; })
+
+struct super_block super_block[NR_SUPER];
+/* this is initialized in init/main.c */
+int ROOT_DEV = 0;
+
+static void lock_super(struct super_block * sb)
+{
+	cli();
+	while (sb->s_lock)
+		sleep_on(&(sb->s_wait));
+	sb->s_lock = 1;
+	sti();
+}
+
+static void free_super(struct super_block * sb)
+{
+	cli();
+	sb->s_lock = 0;
+	wake_up(&(sb->s_wait));
+	sti();
+}
+
+static void wait_on_super(struct super_block * sb)
+{
+	cli();
+	while (sb->s_lock)
+		sleep_on(&(sb->s_wait));
+	sti();
+}
+
+struct super_block * get_super(int dev)
+{
+	struct super_block * s;
+
+	if (!dev)
+		return NULL;
+	s = 0+super_block;
+	while (s < NR_SUPER+super_block)
+		if (s->s_dev == dev) {
+			wait_on_super(s);
+			if (s->s_dev == dev)
+				return s;
+			s = 0+super_block;
+		} else
+			s++;
+	return NULL;
+}
+
+void put_super(int dev)
+{
+	struct super_block * sb;
+/*	struct m_inode * inode; */
+	int i;
+
+	if (dev == ROOT_DEV) {
+		printk("root diskette changed: prepare for armageddon\n\r");
+		return;
+	}
+	if (!(sb = get_super(dev)))
+		return;
+	if (sb->s_imount) {
+		printk("Mounted disk changed - tssk, tssk\n\r");
+		return;
+	}
+	lock_super(sb);
+	sb->s_dev = 0;
+	for(i=0;i<I_MAP_SLOTS;i++)
+		brelse(sb->s_imap[i]);
+	for(i=0;i<Z_MAP_SLOTS;i++)
+		brelse(sb->s_zmap[i]);
+	free_super(sb);
+	return;
+}
+
+static struct super_block * read_super(int dev)
+{
+	struct super_block * s;
+	struct buffer_head * bh;
+	int i,block;
+
+	if (!dev)
+		return NULL;
+	check_disk_change(dev);
+	if (s = get_super(dev))
+		return s;
+	for (s = 0+super_block ;; s++) {
+		if (s >= NR_SUPER+super_block)
+			return NULL;
+		if (!s->s_dev)
+			break;
+	}
+	s->s_dev = dev;
+	s->s_isup = NULL;
+	s->s_imount = NULL;
+	s->s_time = 0;
+	s->s_rd_only = 0;
+	s->s_dirt = 0;
+	lock_super(s);
+	if (!(bh = bread(dev,1))) {
+		s->s_dev=0;
+		free_super(s);
+		return NULL;
+	}
+	__asm__ volatile ("cld");   /* by wyj */	
+	*((struct d_super_block *) s) =
+		*((struct d_super_block *) bh->b_data);
+	brelse(bh);
+	if (s->s_magic != SUPER_MAGIC) {
+		s->s_dev = 0;
+		free_super(s);
+		return NULL;
+	}
+	for (i=0;i<I_MAP_SLOTS;i++)
+		s->s_imap[i] = NULL;
+	for (i=0;i<Z_MAP_SLOTS;i++)
+		s->s_zmap[i] = NULL;
+	block=2;
+	for (i=0 ; i < s->s_imap_blocks ; i++)
+		if (s->s_imap[i]=bread(dev,block))
+			block++;
+		else
+			break;
+	for (i=0 ; i < s->s_zmap_blocks ; i++)
+		if (s->s_zmap[i]=bread(dev,block))
+			block++;
+		else
+			break;
+	if (block != 2+s->s_imap_blocks+s->s_zmap_blocks) {
+		for(i=0;i<I_MAP_SLOTS;i++)
+			brelse(s->s_imap[i]);
+		for(i=0;i<Z_MAP_SLOTS;i++)
+			brelse(s->s_zmap[i]);
+		s->s_dev=0;
+		free_super(s);
+		return NULL;
+	}
+	s->s_imap[0]->b_data[0] |= 1;
+	s->s_zmap[0]->b_data[0] |= 1;
+	free_super(s);
+	return s;
+}
+
+int sys_umount(char * dev_name)
+{
+	struct m_inode * inode;
+	struct super_block * sb;
+	int dev;
+
+	if (!(inode=namei(dev_name)))
+		return -ENOENT;
+	dev = inode->i_zone[0];
+	if (!S_ISBLK(inode->i_mode)) {
+		iput(inode);
+		return -ENOTBLK;
+	}
+	iput(inode);
+	if (dev==ROOT_DEV)
+		return -EBUSY;
+	if (!(sb=get_super(dev)) || !(sb->s_imount))
+		return -ENOENT;
+	if (!sb->s_imount->i_mount)
+		printk("Mounted inode has i_mount=0\n");
+	for (inode=inode_table+0 ; inode<inode_table+NR_INODE ; inode++)
+		if (inode->i_dev==dev && inode->i_count)
+				return -EBUSY;
+	sb->s_imount->i_mount=0;
+	iput(sb->s_imount);
+	sb->s_imount = NULL;
+	iput(sb->s_isup);
+	sb->s_isup = NULL;
+	put_super(dev);
+	sync_dev(dev);
+	return 0;
+}
+
+int sys_mount(char * dev_name, char * dir_name, int rw_flag)
+{
+	struct m_inode * dev_i, * dir_i;
+	struct super_block * sb;
+	int dev;
+
+	if (!(dev_i=namei(dev_name)))
+		return -ENOENT;
+	dev = dev_i->i_zone[0];
+	if (!S_ISBLK(dev_i->i_mode)) {
+		iput(dev_i);
+		return -EPERM;
+	}
+	iput(dev_i);
+	if (!(dir_i=namei(dir_name)))
+		return -ENOENT;
+	if (dir_i->i_count != 1 || dir_i->i_num == ROOT_INO) {
+		iput(dir_i);
+		return -EBUSY;
+	}
+	if (!S_ISDIR(dir_i->i_mode)) {
+		iput(dir_i);
+		return -EPERM;
+	}
+	if (!(sb=read_super(dev))) {
+		iput(dir_i);
+		return -EBUSY;
+	}
+	if (sb->s_imount) {
+		iput(dir_i);
+		return -EBUSY;
+	}
+	if (dir_i->i_mount) {
+		iput(dir_i);
+		return -EPERM;
+	}
+	sb->s_imount=dir_i;
+	dir_i->i_mount=1;
+	dir_i->i_dirt=1;		/* NOTE! we don't iput(dir_i) */
+	return 0;			/* we do that in umount */
+}
+
+void mount_root(void)
+{
+	int i,free;
+	struct super_block * p;
+	struct m_inode * mi;
+
+	if (32 != sizeof (struct d_inode))
+		panic("bad i-node size");
+	for(i=0;i<NR_FILE;i++)
+		file_table[i].f_count=0;
+	if (MAJOR(ROOT_DEV) == 2) {
+		printk("Insert root floppy and press ENTER");
+		wait_for_keypress();
+	}
+	for(p = &super_block[0] ; p < &super_block[NR_SUPER] ; p++) {
+		p->s_dev = 0;
+		p->s_lock = 0;
+		p->s_wait = NULL;
+	}
+	if (!(p=read_super(ROOT_DEV)))
+		panic("Unable to mount root");
+	if (!(mi=iget(ROOT_DEV,ROOT_INO)))
+		panic("Unable to read root i-node");
+	mi->i_count += 3 ;	/* NOTE! it is logically used 4 times, not 1 */
+	p->s_isup = p->s_imount = mi;
+	current->pwd = mi;
+	current->root = mi;
+	free=0;
+	i=p->s_nzones;
+	while (-- i >= 0)
+		if (!set_bit(i&8191,p->s_zmap[i>>13]->b_data))
+			free++;
+	printk("%d/%d free blocks\n\r",free,p->s_nzones);
+	free=0;
+	i=p->s_ninodes+1;
+	while (-- i >= 0)
+		if (!set_bit(i&8191,p->s_imap[i>>13]->b_data))
+			free++;
+	printk("%d/%d free inodes\n\r",free,p->s_ninodes);
+}

os/os/linux/fs/truncate.c

@@ -0,0 +1,65 @@
+/*
+ *  linux/fs/truncate.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+#include <linux/sched.h>
+
+#include <sys/stat.h>
+
+static void free_ind(int dev,int block)
+{
+	struct buffer_head * bh;
+	unsigned short * p;
+	int i;
+
+	if (!block)
+		return;
+	if (bh=bread(dev,block)) {
+		p = (unsigned short *) bh->b_data;
+		for (i=0;i<512;i++,p++)
+			if (*p)
+				free_block(dev,*p);
+		brelse(bh);
+	}
+	free_block(dev,block);
+}
+
+static void free_dind(int dev,int block)
+{
+	struct buffer_head * bh;
+	unsigned short * p;
+	int i;
+
+	if (!block)
+		return;
+	if (bh=bread(dev,block)) {
+		p = (unsigned short *) bh->b_data;
+		for (i=0;i<512;i++,p++)
+			if (*p)
+				free_ind(dev,*p);
+		brelse(bh);
+	}
+	free_block(dev,block);
+}
+
+void truncate(struct m_inode * inode)
+{
+	int i;
+
+	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)))
+		return;
+	for (i=0;i<7;i++)
+		if (inode->i_zone[i]) {
+			free_block(inode->i_dev,inode->i_zone[i]);
+			inode->i_zone[i]=0;
+		}
+	free_ind(inode->i_dev,inode->i_zone[7]);
+	free_dind(inode->i_dev,inode->i_zone[8]);
+	inode->i_zone[7] = inode->i_zone[8] = 0;
+	inode->i_size = 0;
+	inode->i_dirt = 1;
+	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+}
+

os/os/linux/include/a.out.h

@@ -0,0 +1,220 @@
+#ifndef _A_OUT_H
+#define _A_OUT_H
+
+#define __GNU_EXEC_MACROS__
+
+struct exec {
+  unsigned long a_magic;	/* Use macros N_MAGIC, etc for access */
+  unsigned a_text;		/* length of text, in bytes */
+  unsigned a_data;		/* length of data, in bytes */
+  unsigned a_bss;		/* length of uninitialized data area for file, in bytes */
+  unsigned a_syms;		/* length of symbol table data in file, in bytes */
+  unsigned a_entry;		/* start address */
+  unsigned a_trsize;		/* length of relocation info for text, in bytes */
+  unsigned a_drsize;		/* length of relocation info for data, in bytes */
+};
+
+#ifndef N_MAGIC
+#define N_MAGIC(exec) ((exec).a_magic)
+#endif
+
+#ifndef OMAGIC
+/* Code indicating object file or impure executable.  */
+#define OMAGIC 0407
+/* Code indicating pure executable.  */
+#define NMAGIC 0410
+/* Code indicating demand-paged executable.  */
+#define ZMAGIC 0413
+#endif /* not OMAGIC */
+
+#ifndef N_BADMAG
+#define N_BADMAG(x)					\
+ (N_MAGIC(x) != OMAGIC && N_MAGIC(x) != NMAGIC		\
+  && N_MAGIC(x) != ZMAGIC)
+#endif
+
+#define _N_BADMAG(x)					\
+ (N_MAGIC(x) != OMAGIC && N_MAGIC(x) != NMAGIC		\
+  && N_MAGIC(x) != ZMAGIC)
+
+#define _N_HDROFF(x) (SEGMENT_SIZE - sizeof (struct exec))
+
+#ifndef N_TXTOFF
+#define N_TXTOFF(x) \
+ (N_MAGIC(x) == ZMAGIC ? _N_HDROFF((x)) + sizeof (struct exec) : sizeof (struct exec))
+#endif
+
+#ifndef N_DATOFF
+#define N_DATOFF(x) (N_TXTOFF(x) + (x).a_text)
+#endif
+
+#ifndef N_TRELOFF
+#define N_TRELOFF(x) (N_DATOFF(x) + (x).a_data)
+#endif
+
+#ifndef N_DRELOFF
+#define N_DRELOFF(x) (N_TRELOFF(x) + (x).a_trsize)
+#endif
+
+#ifndef N_SYMOFF
+#define N_SYMOFF(x) (N_DRELOFF(x) + (x).a_drsize)
+#endif
+
+#ifndef N_STROFF
+#define N_STROFF(x) (N_SYMOFF(x) + (x).a_syms)
+#endif
+
+/* Address of text segment in memory after it is loaded.  */
+#ifndef N_TXTADDR
+#define N_TXTADDR(x) 0
+#endif
+
+/* Address of data segment in memory after it is loaded.
+   Note that it is up to you to define SEGMENT_SIZE
+   on machines not listed here.  */
+#if defined(vax) || defined(hp300) || defined(pyr)
+#define SEGMENT_SIZE PAGE_SIZE
+#endif
+#ifdef	hp300
+#define	PAGE_SIZE	4096
+#endif
+#ifdef	sony
+#define	SEGMENT_SIZE	0x2000
+#endif	/* Sony.  */
+#ifdef is68k
+#define SEGMENT_SIZE 0x20000
+#endif
+#if defined(m68k) && defined(PORTAR)
+#define PAGE_SIZE 0x400
+#define SEGMENT_SIZE PAGE_SIZE
+#endif
+
+#define PAGE_SIZE 4096
+#define SEGMENT_SIZE 1024
+
+#define _N_SEGMENT_ROUND(x) (((x) + SEGMENT_SIZE - 1) & ~(SEGMENT_SIZE - 1))
+
+#define _N_TXTENDADDR(x) (N_TXTADDR(x)+(x).a_text)
+
+#ifndef N_DATADDR
+#define N_DATADDR(x) \
+    (N_MAGIC(x)==OMAGIC? (_N_TXTENDADDR(x)) \
+     : (_N_SEGMENT_ROUND (_N_TXTENDADDR(x))))
+#endif
+
+/* Address of bss segment in memory after it is loaded.  */
+#ifndef N_BSSADDR
+#define N_BSSADDR(x) (N_DATADDR(x) + (x).a_data)
+#endif
+
+#ifndef N_NLIST_DECLARED
+struct nlist {
+  union {
+    char *n_name;
+    struct nlist *n_next;
+    long n_strx;
+  } n_un;
+  unsigned char n_type;
+  char n_other;
+  short n_desc;
+  unsigned long n_value;
+};
+#endif
+
+#ifndef N_UNDF
+#define N_UNDF 0
+#endif
+#ifndef N_ABS
+#define N_ABS 2
+#endif
+#ifndef N_TEXT
+#define N_TEXT 4
+#endif
+#ifndef N_DATA
+#define N_DATA 6
+#endif
+#ifndef N_BSS
+#define N_BSS 8
+#endif
+#ifndef N_COMM
+#define N_COMM 18
+#endif
+#ifndef N_FN
+#define N_FN 15
+#endif
+
+#ifndef N_EXT
+#define N_EXT 1
+#endif
+#ifndef N_TYPE
+#define N_TYPE 036
+#endif
+#ifndef N_STAB
+#define N_STAB 0340
+#endif
+
+/* The following type indicates the definition of a symbol as being
+   an indirect reference to another symbol.  The other symbol
+   appears as an undefined reference, immediately following this symbol.
+
+   Indirection is asymmetrical.  The other symbol's value will be used
+   to satisfy requests for the indirect symbol, but not vice versa.
+   If the other symbol does not have a definition, libraries will
+   be searched to find a definition.  */
+#define N_INDR 0xa
+
+/* The following symbols refer to set elements.
+   All the N_SET[ATDB] symbols with the same name form one set.
+   Space is allocated for the set in the text section, and each set
+   element's value is stored into one word of the space.
+   The first word of the space is the length of the set (number of elements).
+
+   The address of the set is made into an N_SETV symbol
+   whose name is the same as the name of the set.
+   This symbol acts like a N_DATA global symbol
+   in that it can satisfy undefined external references.  */
+
+/* These appear as input to LD, in a .o file.  */
+#define	N_SETA	0x14		/* Absolute set element symbol */
+#define	N_SETT	0x16		/* Text set element symbol */
+#define	N_SETD	0x18		/* Data set element symbol */
+#define	N_SETB	0x1A		/* Bss set element symbol */
+
+/* This is output from LD.  */
+#define N_SETV	0x1C		/* Pointer to set vector in data area.  */
+
+#ifndef N_RELOCATION_INFO_DECLARED
+
+/* This structure describes a single relocation to be performed.
+   The text-relocation section of the file is a vector of these structures,
+   all of which apply to the text section.
+   Likewise, the data-relocation section applies to the data section.  */
+
+struct relocation_info
+{
+  /* Address (within segment) to be relocated.  */
+  int r_address;
+  /* The meaning of r_symbolnum depends on r_extern.  */
+  unsigned int r_symbolnum:24;
+  /* Nonzero means value is a pc-relative offset
+     and it should be relocated for changes in its own address
+     as well as for changes in the symbol or section specified.  */
+  unsigned int r_pcrel:1;
+  /* Length (as exponent of 2) of the field to be relocated.
+     Thus, a value of 2 indicates 1<<2 bytes.  */
+  unsigned int r_length:2;
+  /* 1 => relocate with value of symbol.
+          r_symbolnum is the index of the symbol
+	  in file's the symbol table.
+     0 => relocate with the address of a segment.
+          r_symbolnum is N_TEXT, N_DATA, N_BSS or N_ABS
+	  (the N_EXT bit may be set also, but signifies nothing).  */
+  unsigned int r_extern:1;
+  /* Four bits that aren't used, but when writing an object file
+     it is desirable to clear them.  */
+  unsigned int r_pad:4;
+};
+#endif /* no N_RELOCATION_INFO_DECLARED.  */
+
+
+#endif /* __A_OUT_GNU_H__ */

os/os/linux/include/asm/io.h

@@ -0,0 +1,24 @@
+#define outb(value,port) \
+__asm__ ("outb %%al,%%dx"::"a" (value),"d" (port))
+
+
+#define inb(port) ({ \
+unsigned char _v; \
+__asm__ volatile ("inb %%dx,%%al":"=a" (_v):"d" (port)); \
+_v; \
+})
+
+#define outb_p(value,port) \
+__asm__ ("outb %%al,%%dx\n" \
+		"\tjmp 1f\n" \
+		"1:\tjmp 1f\n" \
+		"1:"::"a" (value),"d" (port))
+
+#define inb_p(port) ({ \
+unsigned char _v; \
+__asm__ volatile ("inb %%dx,%%al\n" \
+	"\tjmp 1f\n" \
+	"1:\tjmp 1f\n" \
+	"1:":"=a" (_v):"d" (port)); \
+_v; \
+})

os/os/linux/include/asm/memory.h

@@ -0,0 +1,15 @@
+/*
+ *  NOTE!!! memcpy(dest,src,n) assumes ds=es=normal data segment. This
+ *  goes for all kernel functions (ds=es=kernel space, fs=local data,
+ *  gs=null), as well as for all well-behaving user programs (ds=es=
+ *  user data space). This is NOT a bug, as any user program that changes
+ *  es deserves to die if it isn't careful.
+ */
+#define memcpy(dest,src,n) ({ \
+void * _res = dest; \
+__asm__ ("cld;rep;movsb" \
+	::"D" ((long)(_res)),"S" ((long)(src)),"c" ((long) (n)) \
+	); \
+_res; \
+})
+

os/os/linux/include/asm/segment.h

@@ -0,0 +1,65 @@
+static inline unsigned char get_fs_byte(const char * addr)
+{
+	unsigned register char _v;
+
+	__asm__ ("movb %%fs:%1,%0":"=r" (_v):"m" (*addr));
+	return _v;
+}
+
+static inline unsigned short get_fs_word(const unsigned short *addr)
+{
+	unsigned short _v;
+
+	__asm__ ("movw %%fs:%1,%0":"=r" (_v):"m" (*addr));
+	return _v;
+}
+
+static inline unsigned long get_fs_long(const unsigned long *addr)
+{
+	unsigned long _v;
+
+	__asm__ ("movl %%fs:%1,%0":"=r" (_v):"m" (*addr)); \
+	return _v;
+}
+
+static inline void put_fs_byte(char val,char *addr)
+{
+__asm__ ("movb %0,%%fs:%1"::"r" (val),"m" (*addr));
+}
+
+static inline void put_fs_word(short val,short * addr)
+{
+__asm__ ("movw %0,%%fs:%1"::"r" (val),"m" (*addr));
+}
+
+static inline void put_fs_long(unsigned long val,unsigned long * addr)
+{
+__asm__ ("movl %0,%%fs:%1"::"r" (val),"m" (*addr));
+}
+
+/*
+ * Someone who knows GNU asm better than I should double check the followig.
+ * It seems to work, but I don't know if I'm doing something subtly wrong.
+ * --- TYT, 11/24/91
+ * [ nothing wrong here, Linus ]
+ */
+
+static inline unsigned long get_fs() 
+{
+	unsigned short _v;
+	__asm__("mov %%fs,%%ax":"=a" (_v):);
+	return _v;
+}
+
+static inline unsigned long get_ds() 
+{
+	unsigned short _v;
+	__asm__("mov %%ds,%%ax":"=a" (_v):);
+	return _v;
+}
+
+static inline void set_fs(unsigned long val)
+{
+	__asm__("mov %0,%%fs"::"a" ((unsigned short) val));
+}
+

os/os/linux/include/asm/system.h

@@ -0,0 +1,66 @@
+#define move_to_user_mode() \
+__asm__ ("movl %%esp,%%eax\n\t" \
+	"pushl $0x17\n\t" \
+	"pushl %%eax\n\t" \
+	"pushfl\n\t" \
+	"pushl $0x0f\n\t" \
+	"pushl $1f\n\t" \
+	"iret\n" \
+	"1:\tmovl $0x17,%%eax\n\t" \
+	"movw %%ax,%%ds\n\t" \
+	"movw %%ax,%%es\n\t" \
+	"movw %%ax,%%fs\n\t" \
+	"movw %%ax,%%gs" \
+	:::"ax")
+
+#define sti() __asm__ ("sti"::)
+#define cli() __asm__ ("cli"::)
+#define nop() __asm__ ("nop"::)
+
+#define iret() __asm__ ("iret"::)
+
+#define _set_gate(gate_addr,type,dpl,addr) \
+__asm__ ("movw %%dx,%%ax\n\t" \
+	"movw %0,%%dx\n\t" \
+	"movl %%eax,%1\n\t" \
+	"movl %%edx,%2" \
+	: \
+	: "i" ((short) (0x8000+(dpl<<13)+(type<<8))), \
+	"o" (*((char *) (gate_addr))), \
+	"o" (*(4+(char *) (gate_addr))), \
+	"d" ((char *) (addr)),"a" (0x00080000))
+
+#define set_intr_gate(n,addr) \
+	_set_gate(&idt[n],14,0,addr)
+
+#define set_trap_gate(n,addr) \
+	_set_gate(&idt[n],15,0,addr)
+
+#define set_system_gate(n,addr) \
+	_set_gate(&idt[n],15,3,addr)
+
+#define _set_seg_desc(gate_addr,type,dpl,base,limit) {\
+	*(gate_addr) = ((base) & 0xff000000) | \
+		(((base) & 0x00ff0000)>>16) | \
+		((limit) & 0xf0000) | \
+		((dpl)<<13) | \
+		(0x00408000) | \
+		((type)<<8); \
+	*((gate_addr)+1) = (((base) & 0x0000ffff)<<16) | \
+		((limit) & 0x0ffff); }
+
+#define _set_tssldt_desc(n,addr,type) \
+__asm__ ("movw $104,%1\n\t" \
+	"movw %%ax,%2\n\t" \
+	"rorl $16,%%eax\n\t" \
+	"movb %%al,%3\n\t" \
+	"movb $" type ",%4\n\t" \
+	"movb $0x00,%5\n\t" \
+	"movb %%ah,%6\n\t" \
+	"rorl $16,%%eax" \
+	::"a" (addr), "m" (*(n)), "m" (*(n+2)), "m" (*(n+4)), \
+	 "m" (*(n+5)), "m" (*(n+6)), "m" (*(n+7)) \
+	)
+
+#define set_tss_desc(n,addr) _set_tssldt_desc(((char *) (n)),addr,"0x89")
+#define set_ldt_desc(n,addr) _set_tssldt_desc(((char *) (n)),addr,"0x82")

os/os/linux/include/const.h

@@ -0,0 +1,15 @@
+#ifndef _CONST_H
+#define _CONST_H
+
+#define BUFFER_END 0x200000
+
+#define I_TYPE          0170000
+#define I_DIRECTORY	0040000
+#define I_REGULAR       0100000
+#define I_BLOCK_SPECIAL 0060000
+#define I_CHAR_SPECIAL  0020000
+#define I_NAMED_PIPE	0010000
+#define I_SET_UID_BIT   0004000
+#define I_SET_GID_BIT   0002000
+
+#endif

os/os/linux/include/ctype.h

@@ -0,0 +1,34 @@
+#ifndef _CTYPE_H
+#define _CTYPE_H
+
+#define _U	0x01	/* upper */
+#define _L	0x02	/* lower */
+#define _D	0x04	/* digit */
+#define _C	0x08	/* cntrl */
+#define _P	0x10	/* punct */
+#define _S	0x20	/* white space (space/lf/tab) */
+#define _X	0x40	/* hex digit */
+#define _SP	0x80	/* hard space (0x20) */
+
+extern unsigned char _ctype[];
+extern char _ctmp;
+
+#define isalnum(c) ((_ctype+1)[c]&(_U|_L|_D))
+#define isalpha(c) ((_ctype+1)[c]&(_U|_L))
+#define iscntrl(c) ((_ctype+1)[c]&(_C))
+#define isdigit(c) ((_ctype+1)[c]&(_D))
+#define isgraph(c) ((_ctype+1)[c]&(_P|_U|_L|_D))
+#define islower(c) ((_ctype+1)[c]&(_L))
+#define isprint(c) ((_ctype+1)[c]&(_P|_U|_L|_D|_SP))
+#define ispunct(c) ((_ctype+1)[c]&(_P))
+#define isspace(c) ((_ctype+1)[c]&(_S))
+#define isupper(c) ((_ctype+1)[c]&(_U))
+#define isxdigit(c) ((_ctype+1)[c]&(_D|_X))
+
+#define isascii(c) (((unsigned) c)<=0x7f)
+#define toascii(c) (((unsigned) c)&0x7f)
+
+#define tolower(c) (_ctmp=c,isupper(_ctmp)?_ctmp-('A'-'a'):_ctmp)
+#define toupper(c) (_ctmp=c,islower(_ctmp)?_ctmp-('a'-'A'):_ctmp)
+
+#endif

os/os/linux/include/errno.h

@@ -0,0 +1,60 @@
+#ifndef _ERRNO_H
+#define _ERRNO_H
+
+/*
+ * ok, as I hadn't got any other source of information about
+ * possible error numbers, I was forced to use the same numbers
+ * as minix.
+ * Hopefully these are posix or something. I wouldn't know (and posix
+ * isn't telling me - they want $$$ for their f***ing standard).
+ *
+ * We don't use the _SIGN cludge of minix, so kernel returns must
+ * see to the sign by themselves.
+ *
+ * NOTE! Remember to change strerror() if you change this file!
+ */
+
+extern int errno;
+
+#define ERROR		99
+#define EPERM		 1
+#define ENOENT		 2
+#define ESRCH		 3
+#define EINTR		 4
+#define EIO		 5
+#define ENXIO		 6
+#define E2BIG		 7
+#define ENOEXEC		 8
+#define EBADF		 9
+#define ECHILD		10
+#define EAGAIN		11
+#define ENOMEM		12
+#define EACCES		13
+#define EFAULT		14
+#define ENOTBLK		15
+#define EBUSY		16
+#define EEXIST		17
+#define EXDEV		18
+#define ENODEV		19
+#define ENOTDIR		20
+#define EISDIR		21
+#define EINVAL		22
+#define ENFILE		23
+#define EMFILE		24
+#define ENOTTY		25
+#define ETXTBSY		26
+#define EFBIG		27
+#define ENOSPC		28
+#define ESPIPE		29
+#define EROFS		30
+#define EMLINK		31
+#define EPIPE		32
+#define EDOM		33
+#define ERANGE		34
+#define EDEADLK		35
+#define ENAMETOOLONG	36
+#define ENOLCK		37
+#define ENOSYS		38
+#define ENOTEMPTY	39
+
+#endif

os/os/linux/include/fcntl.h

@@ -0,0 +1,55 @@
+#ifndef _FCNTL_H
+#define _FCNTL_H
+
+#include <sys/types.h>
+
+/* open/fcntl - NOCTTY, NDELAY isn't implemented yet */
+#define O_ACCMODE	00003
+#define O_RDONLY	   00
+#define O_WRONLY	   01
+#define O_RDWR		   02
+#define O_CREAT		00100	/* not fcntl */
+#define O_EXCL		00200	/* not fcntl */
+#define O_NOCTTY	00400	/* not fcntl */
+#define O_TRUNC		01000	/* not fcntl */
+#define O_APPEND	02000
+#define O_NONBLOCK	04000	/* not fcntl */
+#define O_NDELAY	O_NONBLOCK
+
+/* Defines for fcntl-commands. Note that currently
+ * locking isn't supported, and other things aren't really
+ * tested.
+ */
+#define F_DUPFD		0	/* dup */
+#define F_GETFD		1	/* get f_flags */
+#define F_SETFD		2	/* set f_flags */
+#define F_GETFL		3	/* more flags (cloexec) */
+#define F_SETFL		4
+#define F_GETLK		5	/* not implemented */
+#define F_SETLK		6
+#define F_SETLKW	7
+
+/* for F_[GET|SET]FL */
+#define FD_CLOEXEC	1	/* actually anything with low bit set goes */
+
+/* Ok, these are locking features, and aren't implemented at any
+ * level. POSIX wants them.
+ */
+#define F_RDLCK		0
+#define F_WRLCK		1
+#define F_UNLCK		2
+
+/* Once again - not implemented, but ... */
+struct flock {
+	short l_type;
+	short l_whence;
+	off_t l_start;
+	off_t l_len;
+	pid_t l_pid;
+};
+
+extern int creat(const char * filename,mode_t mode);
+extern int fcntl(int fildes,int cmd, ...);
+extern int open(const char * filename, int flags, ...);
+
+#endif

os/os/linux/include/linux/config.h

@@ -0,0 +1,48 @@
+#ifndef _CONFIG_H
+#define _CONFIG_H
+
+/*
+ * The root-device is no longer hard-coded. You can change the default
+ * root-device by changing the line ROOT_DEV = XXX in boot/bootsect.s
+ */
+
+/*
+ * define your keyboard here -
+ * KBD_FINNISH for Finnish keyboards
+ * KBD_US for US-type
+ * KBD_GR for German keyboards
+ * KBD_FR for Frech keyboard
+ */
+#define KBD_US 
+/*#define KBD_GR */
+/*#define KBD_FR */
+/*#define KBD_FINNISH */
+
+/*
+ * Normally, Linux can get the drive parameters from the BIOS at
+ * startup, but if this for some unfathomable reason fails, you'd
+ * be left stranded. For this case, you can define HD_TYPE, which
+ * contains all necessary info on your harddisk.
+ *
+ * The HD_TYPE macro should look like this:
+ *
+ * #define HD_TYPE { head, sect, cyl, wpcom, lzone, ctl}
+ *
+ * In case of two harddisks, the info should be sepatated by
+ * commas:
+ *
+ * #define HD_TYPE { h,s,c,wpcom,lz,ctl },{ h,s,c,wpcom,lz,ctl }
+ */
+/*
+ This is an example, two drives, first is type 2, second is type 3:
+
+#define HD_TYPE { 4,17,615,300,615,8 }, { 6,17,615,300,615,0 }
+
+ NOTE: ctl is 0 for all drives with heads<=8, and ctl=8 for drives
+ with more than 8 heads.
+
+ If you want the BIOS to tell what kind of drive you have, just
+ leave HD_TYPE undefined. This is the normal thing to do.
+*/
+
+#endif

os/os/linux/include/linux/fdreg.h

@@ -0,0 +1,71 @@
+/*
+ * This file contains some defines for the floppy disk controller.
+ * Various sources. Mostly "IBM Microcomputers: A Programmers
+ * Handbook", Sanches and Canton.
+ */
+#ifndef _FDREG_H
+#define _FDREG_H
+
+extern int ticks_to_floppy_on(unsigned int nr);
+extern void floppy_on(unsigned int nr);
+extern void floppy_off(unsigned int nr);
+extern void floppy_select(unsigned int nr);
+extern void floppy_deselect(unsigned int nr);
+
+/* Fd controller regs. S&C, about page 340 */
+#define FD_STATUS	0x3f4
+#define FD_DATA		0x3f5
+#define FD_DOR		0x3f2		/* Digital Output Register */
+#define FD_DIR		0x3f7		/* Digital Input Register (read) */
+#define FD_DCR		0x3f7		/* Diskette Control Register (write)*/
+
+/* Bits of main status register */
+#define STATUS_BUSYMASK	0x0F		/* drive busy mask */
+#define STATUS_BUSY	0x10		/* FDC busy */
+#define STATUS_DMA	0x20		/* 0- DMA mode */
+#define STATUS_DIR	0x40		/* 0- cpu->fdc */
+#define STATUS_READY	0x80		/* Data reg ready */
+
+/* Bits of FD_ST0 */
+#define ST0_DS		0x03		/* drive select mask */
+#define ST0_HA		0x04		/* Head (Address) */
+#define ST0_NR		0x08		/* Not Ready */
+#define ST0_ECE		0x10		/* Equipment chech error */
+#define ST0_SE		0x20		/* Seek end */
+#define ST0_INTR	0xC0		/* Interrupt code mask */
+
+/* Bits of FD_ST1 */
+#define ST1_MAM		0x01		/* Missing Address Mark */
+#define ST1_WP		0x02		/* Write Protect */
+#define ST1_ND		0x04		/* No Data - unreadable */
+#define ST1_OR		0x10		/* OverRun */
+#define ST1_CRC		0x20		/* CRC error in data or addr */
+#define ST1_EOC		0x80		/* End Of Cylinder */
+
+/* Bits of FD_ST2 */
+#define ST2_MAM		0x01		/* Missing Addess Mark (again) */
+#define ST2_BC		0x02		/* Bad Cylinder */
+#define ST2_SNS		0x04		/* Scan Not Satisfied */
+#define ST2_SEH		0x08		/* Scan Equal Hit */
+#define ST2_WC		0x10		/* Wrong Cylinder */
+#define ST2_CRC		0x20		/* CRC error in data field */
+#define ST2_CM		0x40		/* Control Mark = deleted */
+
+/* Bits of FD_ST3 */
+#define ST3_HA		0x04		/* Head (Address) */
+#define ST3_TZ		0x10		/* Track Zero signal (1=track 0) */
+#define ST3_WP		0x40		/* Write Protect */
+
+/* Values for FD_COMMAND */
+#define FD_RECALIBRATE	0x07		/* move to track 0 */
+#define FD_SEEK		0x0F		/* seek track */
+#define FD_READ		0xE6		/* read with MT, MFM, SKip deleted */
+#define FD_WRITE	0xC5		/* write with MT, MFM */
+#define FD_SENSEI	0x08		/* Sense Interrupt Status */
+#define FD_SPECIFY	0x03		/* specify HUT etc */
+
+/* DMA commands */
+#define DMA_READ	0x46
+#define DMA_WRITE	0x4A
+
+#endif

os/os/linux/include/linux/fs.h

@@ -0,0 +1,202 @@
+/*
+ * This file has definitions for some important file table
+ * structures etc.
+ */
+
+#ifndef _FS_H
+#define _FS_H
+
+#include <sys/types.h>
+
+/* devices are as follows: (same as minix, so we can use the minix
+ * file system. These are major numbers.)
+ *
+ * 0 - unused (nodev)
+ * 1 - /dev/mem
+ * 2 - /dev/fd
+ * 3 - /dev/hd
+ * 4 - /dev/ttyx
+ * 5 - /dev/tty
+ * 6 - /dev/lp
+ * 7 - unnamed pipes
+ */
+
+#define IS_SEEKABLE(x) ((x)>=1 && (x)<=3)
+
+#define READ 0
+#define WRITE 1
+#define READA 2		/* read-ahead - don't pause */
+#define WRITEA 3	/* "write-ahead" - silly, but somewhat useful */
+
+void buffer_init(long buffer_end);
+
+#define MAJOR(a) (((unsigned)(a))>>8)
+#define MINOR(a) ((a)&0xff)
+
+#define NAME_LEN 14
+#define ROOT_INO 1
+
+#define I_MAP_SLOTS 8
+#define Z_MAP_SLOTS 8
+#define SUPER_MAGIC 0x137F
+
+#define NR_OPEN 20
+#define NR_INODE 32
+#define NR_FILE 64
+#define NR_SUPER 8
+#define NR_HASH 307
+#define NR_BUFFERS nr_buffers
+#define BLOCK_SIZE 1024
+#define BLOCK_SIZE_BITS 10
+#ifndef NULL
+#define NULL ((void *) 0)
+#endif
+
+#define INODES_PER_BLOCK ((BLOCK_SIZE)/(sizeof (struct d_inode)))
+#define DIR_ENTRIES_PER_BLOCK ((BLOCK_SIZE)/(sizeof (struct dir_entry)))
+
+#define PIPE_HEAD(inode) ((inode).i_zone[0])
+#define PIPE_TAIL(inode) ((inode).i_zone[1])
+#define PIPE_SIZE(inode) ((PIPE_HEAD(inode)-PIPE_TAIL(inode))&(PAGE_SIZE-1))
+#define PIPE_EMPTY(inode) (PIPE_HEAD(inode)==PIPE_TAIL(inode))
+#define PIPE_FULL(inode) (PIPE_SIZE(inode)==(PAGE_SIZE-1))
+#define INC_PIPE(head) \
+__asm__("incl %0\n\tandl $4095,%0"::"m" (head))
+
+typedef char buffer_block[BLOCK_SIZE];
+
+struct buffer_head {
+	char * b_data;			/* pointer to data block (1024 bytes) */
+	unsigned long b_blocknr;	/* block number */
+	unsigned short b_dev;		/* device (0 = free) */
+	unsigned char b_uptodate;
+	unsigned char b_dirt;		/* 0-clean,1-dirty */
+	unsigned char b_count;		/* users using this block */
+	unsigned char b_lock;		/* 0 - ok, 1 -locked */
+	struct task_struct * b_wait;
+	struct buffer_head * b_prev;
+	struct buffer_head * b_next;
+	struct buffer_head * b_prev_free;
+	struct buffer_head * b_next_free;
+};
+
+struct d_inode {
+	unsigned short i_mode;
+	unsigned short i_uid;
+	unsigned long i_size;
+	unsigned long i_time;
+	unsigned char i_gid;
+	unsigned char i_nlinks;
+	unsigned short i_zone[9];
+};
+
+struct m_inode {
+	unsigned short i_mode;
+	unsigned short i_uid;
+	unsigned long i_size;
+	unsigned long i_mtime;
+	unsigned char i_gid;
+	unsigned char i_nlinks;
+	unsigned short i_zone[9];
+/* these are in memory also */
+	struct task_struct * i_wait;
+	unsigned long i_atime;
+	unsigned long i_ctime;
+	unsigned short i_dev;
+	unsigned short i_num;
+	unsigned short i_count;
+	unsigned char i_lock;
+	unsigned char i_dirt;
+	unsigned char i_pipe;
+	unsigned char i_mount;
+	unsigned char i_seek;
+	unsigned char i_update;
+};
+
+struct file {
+	unsigned short f_mode;
+	unsigned short f_flags;
+	unsigned short f_count;
+	struct m_inode * f_inode;
+	off_t f_pos;
+};
+
+struct super_block {
+	unsigned short s_ninodes;
+	unsigned short s_nzones;
+	unsigned short s_imap_blocks;
+	unsigned short s_zmap_blocks;
+	unsigned short s_firstdatazone;
+	unsigned short s_log_zone_size;
+	unsigned long s_max_size;
+	unsigned short s_magic;
+/* These are only in memory */
+	struct buffer_head * s_imap[8];
+	struct buffer_head * s_zmap[8];
+	unsigned short s_dev;
+	struct m_inode * s_isup;
+	struct m_inode * s_imount;
+	unsigned long s_time;
+	struct task_struct * s_wait;
+	unsigned char s_lock;
+	unsigned char s_rd_only;
+	unsigned char s_dirt;
+};
+
+struct d_super_block {
+	unsigned short s_ninodes;
+	unsigned short s_nzones;
+	unsigned short s_imap_blocks;
+	unsigned short s_zmap_blocks;
+	unsigned short s_firstdatazone;
+	unsigned short s_log_zone_size;
+	unsigned long s_max_size;
+	unsigned short s_magic;
+};
+
+struct dir_entry {
+	unsigned short inode;
+	char name[NAME_LEN];
+};
+
+extern struct m_inode inode_table[NR_INODE];
+extern struct file file_table[NR_FILE];
+extern struct super_block super_block[NR_SUPER];
+extern struct buffer_head * start_buffer;
+extern int nr_buffers;
+
+extern void check_disk_change(int dev);
+extern int floppy_change(unsigned int nr);
+extern int ticks_to_floppy_on(unsigned int dev);
+extern void floppy_on(unsigned int dev);
+extern void floppy_off(unsigned int dev);
+extern void truncate(struct m_inode * inode);
+extern void sync_inodes(void);
+extern void wait_on(struct m_inode * inode);
+extern int bmap(struct m_inode * inode,int block);
+extern int create_block(struct m_inode * inode,int block);
+extern struct m_inode * namei(const char * pathname);
+extern int open_namei(const char * pathname, int flag, int mode,
+	struct m_inode ** res_inode);
+extern void iput(struct m_inode * inode);
+extern struct m_inode * iget(int dev,int nr);
+extern struct m_inode * get_empty_inode(void);
+extern struct m_inode * get_pipe_inode(void);
+extern struct buffer_head * get_hash_table(int dev, int block);
+extern struct buffer_head * getblk(int dev, int block);
+extern void ll_rw_block(int rw, struct buffer_head * bh);
+extern void brelse(struct buffer_head * buf);
+extern struct buffer_head * bread(int dev,int block);
+extern void bread_page(unsigned long addr,int dev,int b[4]);
+extern struct buffer_head * breada(int dev,int block,...);
+extern int new_block(int dev);
+extern void free_block(int dev, int block);
+extern struct m_inode * new_inode(int dev);
+extern void free_inode(struct m_inode * inode);
+extern int sync_dev(int dev);
+extern struct super_block * get_super(int dev);
+extern int ROOT_DEV;
+
+extern void mount_root(void);
+
+#endif

os/os/linux/include/linux/hdreg.h

@@ -0,0 +1,65 @@
+/*
+ * This file contains some defines for the AT-hd-controller.
+ * Various sources. Check out some definitions (see comments with
+ * a ques).
+ */
+#ifndef _HDREG_H
+#define _HDREG_H
+
+/* Hd controller regs. Ref: IBM AT Bios-listing */
+#define HD_DATA		0x1f0	/* _CTL when writing */
+#define HD_ERROR	0x1f1	/* see err-bits */
+#define HD_NSECTOR	0x1f2	/* nr of sectors to read/write */
+#define HD_SECTOR	0x1f3	/* starting sector */
+#define HD_LCYL		0x1f4	/* starting cylinder */
+#define HD_HCYL		0x1f5	/* high byte of starting cyl */
+#define HD_CURRENT	0x1f6	/* 101dhhhh , d=drive, hhhh=head */
+#define HD_STATUS	0x1f7	/* see status-bits */
+#define HD_PRECOMP HD_ERROR	/* same io address, read=error, write=precomp */
+#define HD_COMMAND HD_STATUS	/* same io address, read=status, write=cmd */
+
+#define HD_CMD		0x3f6
+
+/* Bits of HD_STATUS */
+#define ERR_STAT	0x01
+#define INDEX_STAT	0x02
+#define ECC_STAT	0x04	/* Corrected error */
+#define DRQ_STAT	0x08
+#define SEEK_STAT	0x10
+#define WRERR_STAT	0x20
+#define READY_STAT	0x40
+#define BUSY_STAT	0x80
+
+/* Values for HD_COMMAND */
+#define WIN_RESTORE		0x10
+#define WIN_READ		0x20
+#define WIN_WRITE		0x30
+#define WIN_VERIFY		0x40
+#define WIN_FORMAT		0x50
+#define WIN_INIT		0x60
+#define WIN_SEEK 		0x70
+#define WIN_DIAGNOSE		0x90
+#define WIN_SPECIFY		0x91
+
+/* Bits for HD_ERROR */
+#define MARK_ERR	0x01	/* Bad address mark ? */
+#define TRK0_ERR	0x02	/* couldn't find track 0 */
+#define ABRT_ERR	0x04	/* ? */
+#define ID_ERR		0x10	/* ? */
+#define ECC_ERR		0x40	/* ? */
+#define	BBD_ERR		0x80	/* ? */
+
+struct partition {
+	unsigned char boot_ind;		/* 0x80 - active (unused) */
+	unsigned char head;		/* ? */
+	unsigned char sector;		/* ? */
+	unsigned char cyl;		/* ? */
+	unsigned char sys_ind;		/* ? */
+	unsigned char end_head;		/* ? */
+	unsigned char end_sector;	/* ? */
+	unsigned char end_cyl;		/* ? */
+	unsigned int start_sect;	/* starting sector counting from 0 */
+	unsigned int nr_sects;		/* nr of sectors in partition */
+};
+
+#endif

os/os/linux/include/linux/head.h

@@ -0,0 +1,20 @@
+#ifndef _HEAD_H
+#define _HEAD_H
+
+typedef struct desc_struct {
+	unsigned long a,b;
+} desc_table[256];
+
+extern unsigned long pg_dir[1024];
+extern desc_table idt,gdt;
+
+#define GDT_NUL 0
+#define GDT_CODE 1
+#define GDT_DATA 2
+#define GDT_TMP 3
+
+#define LDT_NUL 0
+#define LDT_CODE 1
+#define LDT_DATA 2
+
+#endif

os/os/linux/include/linux/kernel.h

@@ -0,0 +1,22 @@
+/*
+ * 'kernel.h' contains some often-used function prototypes etc
+ */
+void verify_area(void * addr,int count);
+volatile void panic(const char * str);
+int printf(const char * fmt, ...);
+int printk(const char * fmt, ...);
+int tty_write(unsigned ch,char * buf,int count);
+void * malloc(unsigned int size);
+void free_s(void * obj, int size);
+
+#define free(x) free_s((x), 0)
+
+/*
+ * This is defined as a macro, but at some point this might become a
+ * real subroutine that sets a flag if it returns true (to do
+ * BSD-style accounting where the process is flagged if it uses root
+ * privs).  The implication of this is that you should do normal
+ * permissions checks first, and check suser() last.
+ */
+#define suser() (current->euid == 0)
+

os/os/linux/include/linux/mm.h

@@ -0,0 +1,10 @@
+#ifndef _MM_H
+#define _MM_H
+
+#define PAGE_SIZE 4096
+
+extern unsigned long get_free_page(void);
+extern unsigned long put_page(unsigned long page,unsigned long address);
+extern void free_page(unsigned long addr);
+
+#endif

os/os/linux/include/linux/sched.h

@@ -0,0 +1,239 @@
+#ifndef _SCHED_H
+#define _SCHED_H
+
+#define NR_TASKS 64
+#define HZ 100
+
+#define FIRST_TASK task[0]
+#define LAST_TASK task[NR_TASKS-1]
+
+#include <linux/head.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <signal.h>
+
+#if (NR_OPEN > 32)
+#error "Currently the close-on-exec-flags are in one word, max 32 files/proc"
+#endif
+
+#define TASK_RUNNING		0
+#define TASK_INTERRUPTIBLE	1
+#define TASK_UNINTERRUPTIBLE	2
+#define TASK_ZOMBIE		3
+#define TASK_STOPPED		4
+
+#ifndef NULL
+#define NULL ((void *) 0)
+#endif
+
+extern int copy_page_tables(unsigned long from, unsigned long to, long size);
+extern int free_page_tables(unsigned long from, unsigned long size);
+
+extern void sched_init(void);
+extern void schedule(void);
+extern void trap_init(void);
+extern void panic(const char * str);
+extern int tty_write(unsigned minor,char * buf,int count);
+
+typedef int (*fn_ptr)();
+
+struct i387_struct {
+	long	cwd;
+	long	swd;
+	long	twd;
+	long	fip;
+	long	fcs;
+	long	foo;
+	long	fos;
+	long	st_space[20];	/* 8*10 bytes for each FP-reg = 80 bytes */
+};
+
+struct tss_struct {
+	long	back_link;	/* 16 high bits zero */
+	long	esp0;
+	long	ss0;		/* 16 high bits zero */
+	long	esp1;
+	long	ss1;		/* 16 high bits zero */
+	long	esp2;
+	long	ss2;		/* 16 high bits zero */
+	long	cr3;
+	long	eip;
+	long	eflags;
+	long	eax,ecx,edx,ebx;
+	long	esp;
+	long	ebp;
+	long	esi;
+	long	edi;
+	long	es;		/* 16 high bits zero */
+	long	cs;		/* 16 high bits zero */
+	long	ss;		/* 16 high bits zero */
+	long	ds;		/* 16 high bits zero */
+	long	fs;		/* 16 high bits zero */
+	long	gs;		/* 16 high bits zero */
+	long	ldt;		/* 16 high bits zero */
+	long	trace_bitmap;	/* bits: trace 0, bitmap 16-31 */
+	struct i387_struct i387;
+};
+
+struct task_struct {
+/* these are hardcoded - don't touch */
+	long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
+	long counter;
+	long priority;
+	long signal;
+	struct sigaction sigaction[32];
+	long blocked;	/* bitmap of masked signals */
+/* various fields */
+	int exit_code;
+	unsigned long start_code,end_code,end_data,brk,start_stack;
+	long pid,father,pgrp,session,leader;
+	unsigned short uid,euid,suid;
+	unsigned short gid,egid,sgid;
+	long alarm;
+	long utime,stime,cutime,cstime,start_time;
+	unsigned short used_math;
+/* file system info */
+	int tty;		/* -1 if no tty, so it must be signed */
+	unsigned short umask;
+	struct m_inode * pwd;
+	struct m_inode * root;
+	struct m_inode * executable;
+	unsigned long close_on_exec;
+	struct file * filp[NR_OPEN];
+/* ldt for this task 0 - zero 1 - cs 2 - ds&ss */
+	struct desc_struct ldt[3];
+/* tss for this task */
+	struct tss_struct tss;
+};
+
+/*
+ *  INIT_TASK is used to set up the first task table, touch at
+ * your own risk!. Base=0, limit=0x9ffff (=640kB)
+ */
+#define INIT_TASK \
+/* state etc */	{ 0,15,15, \
+/* signals */	0,{{},},0, \
+/* ec,brk... */	0,0,0,0,0,0, \
+/* pid etc.. */	0,-1,0,0,0, \
+/* uid etc */	0,0,0,0,0,0, \
+/* alarm */	0,0,0,0,0,0, \
+/* math */	0, \
+/* fs info */	-1,0022,NULL,NULL,NULL,0, \
+/* filp */	{NULL,}, \
+	{ \
+		{0,0}, \
+/* ldt */	{0x9f,0xc0fa00}, \
+		{0x9f,0xc0f200}, \
+	}, \
+/*tss*/	{0,PAGE_SIZE+(long)&init_task,0x10,0,0,0,0,(long)&pg_dir,\
+	 0,0,0,0,0,0,0,0, \
+	 0,0,0x17,0x17,0x17,0x17,0x17,0x17, \
+	 _LDT(0),0x80000000, \
+		{} \
+	}, \
+}
+
+extern struct task_struct *task[NR_TASKS];
+extern struct task_struct *last_task_used_math;
+extern struct task_struct *current;
+extern long volatile jiffies;
+extern long startup_time;
+
+#define CURRENT_TIME (startup_time+jiffies/HZ)
+
+extern void add_timer(long jiffies, void (*fn)(void));
+extern void sleep_on(struct task_struct ** p);
+extern void interruptible_sleep_on(struct task_struct ** p);
+extern void wake_up(struct task_struct ** p);
+
+/*
+ * Entry into gdt where to find first TSS. 0-nul, 1-cs, 2-ds, 3-syscall
+ * 4-TSS0, 5-LDT0, 6-TSS1 etc ...
+ */
+#define FIRST_TSS_ENTRY 4
+#define FIRST_LDT_ENTRY (FIRST_TSS_ENTRY+1)
+#define _TSS(n) ((((unsigned long) n)<<4)+(FIRST_TSS_ENTRY<<3))
+#define _LDT(n) ((((unsigned long) n)<<4)+(FIRST_LDT_ENTRY<<3))
+#define ltr(n) __asm__("ltr %%ax"::"a" (_TSS(n)))
+#define lldt(n) __asm__("lldt %%ax"::"a" (_LDT(n)))
+#define str(n) \
+__asm__("str %%ax\n\t" \
+	"subl %2,%%eax\n\t" \
+	"shrl $4,%%eax" \
+	:"=a" (n) \
+	:"a" (0),"i" (FIRST_TSS_ENTRY<<3))
+/*
+ *	switch_to(n) should switch tasks to task nr n, first
+ * checking that n isn't the current task, in which case it does nothing.
+ * This also clears the TS-flag if the task we switched to has used
+ * tha math co-processor latest.
+ */
+#define switch_to(n) {\
+struct {long a,b;} __tmp; \
+__asm__("cmpl %%ecx,current\n\t" \
+	"je 1f\n\t" \
+	"movw %%dx,%1\n\t" \
+	"xchgl %%ecx,current\n\t" \
+	"ljmp *%0\n\t" \
+	"cmpl %%ecx,last_task_used_math\n\t" \
+	"jne 1f\n\t" \
+	"clts\n" \
+	"1:" \
+	::"m" (*&__tmp.a),"m" (*&__tmp.b), \
+	"d" (_TSS(n)),"c" ((long) task[n])); \
+}
+
+#define PAGE_ALIGN(n) (((n)+0xfff)&0xfffff000)
+
+#define _set_base(addr,base)  \
+__asm__ ("push %%edx\n\t" \
+	"movw %%dx,%0\n\t" \
+	"rorl $16,%%edx\n\t" \
+	"movb %%dl,%1\n\t" \
+	"movb %%dh,%2\n\t" \
+	"pop %%edx" \
+	::"m" (*((addr)+2)), \
+	 "m" (*((addr)+4)), \
+	 "m" (*((addr)+7)), \
+	 "d" (base) \
+	)
+
+#define _set_limit(addr,limit) \
+__asm__ ("push %%edx\n\t" \
+	"movw %%dx,%0\n\t" \
+	"rorl $16,%%edx\n\t" \
+	"movb %1,%%dh\n\t" \
+	"andb $0xf0,%%dh\n\t" \
+	"orb %%dh,%%dl\n\t" \
+	"movb %%dl,%1\n\t" \
+	"pop %%edx" \
+	::"m" (*(addr)), \
+	 "m" (*((addr)+6)), \
+	 "d" (limit) \
+	)
+
+#define set_base(ldt,base) _set_base( ((char *)&(ldt)) , (base) )
+#define set_limit(ldt,limit) _set_limit( ((char *)&(ldt)) , (limit-1)>>12 )
+
+static inline unsigned long _get_base(char * addr)
+{
+         unsigned long __base;
+         __asm__("movb %3,%%dh\n\t"
+                 "movb %2,%%dl\n\t"
+                 "shll $16,%%edx\n\t"
+                 "movw %1,%%dx"
+                 :"=&d" (__base)
+                 :"m" (*((addr)+2)),
+                  "m" (*((addr)+4)),
+                  "m" (*((addr)+7)));
+         return __base;
+}
+
+#define get_base(ldt) _get_base( ((char *)&(ldt)) )
+
+#define get_limit(segment) ({ \
+unsigned long __limit; \
+__asm__("lsll %1,%0\n\tincl %0":"=r" (__limit):"r" (segment)); \
+__limit;})
+
+#endif

os/os/linux/include/linux/sys.h

@@ -0,0 +1,116 @@
+/*
+ * Why isn't this a .c file?  Enquiring minds....
+ */
+
+extern int sys_setup();
+extern int sys_exit();
+extern int sys_fork();
+extern int sys_read();
+extern int sys_write();
+extern int sys_open();
+extern int sys_close();
+extern int sys_waitpid();
+extern int sys_creat();
+extern int sys_link();
+extern int sys_unlink();
+extern int sys_execve();
+extern int sys_chdir();
+extern int sys_time();
+extern int sys_mknod();
+extern int sys_chmod();
+extern int sys_chown();
+extern int sys_break();
+extern int sys_stat();
+extern int sys_lseek();
+extern int sys_getpid();
+extern int sys_mount();
+extern int sys_umount();
+extern int sys_setuid();
+extern int sys_getuid();
+extern int sys_stime();
+extern int sys_ptrace();
+extern int sys_alarm();
+extern int sys_fstat();
+extern int sys_pause();
+extern int sys_utime();
+extern int sys_stty();
+extern int sys_gtty();
+extern int sys_access();
+extern int sys_nice();
+extern int sys_ftime();
+extern int sys_sync();
+extern int sys_kill();
+extern int sys_rename();
+extern int sys_mkdir();
+extern int sys_rmdir();
+extern int sys_dup();
+extern int sys_pipe();
+extern int sys_times();
+extern int sys_prof();
+extern int sys_brk();
+extern int sys_setgid();
+extern int sys_getgid();
+extern int sys_signal();
+extern int sys_geteuid();
+extern int sys_getegid();
+extern int sys_acct();
+extern int sys_phys();
+extern int sys_lock();
+extern int sys_ioctl();
+extern int sys_fcntl();
+extern int sys_mpx();
+extern int sys_setpgid();
+extern int sys_ulimit();
+extern int sys_uname();
+extern int sys_umask();
+extern int sys_chroot();
+extern int sys_ustat();
+extern int sys_dup2();
+extern int sys_getppid();
+extern int sys_getpgrp();
+extern int sys_setsid();
+extern int sys_sigaction();
+extern int sys_sgetmask();
+extern int sys_ssetmask();
+extern int sys_setreuid();
+extern int sys_setregid();
+extern int sys_sigpending();
+extern int sys_sigsuspend();
+extern int sys_sethostname();
+extern int sys_setrlimit();
+extern int sys_getrlimit();
+extern int sys_getrusage();
+extern int sys_gettimeofday();
+extern int sys_settimeofday();
+extern int sys_getgroups();
+extern int sys_setgroups();
+extern int sys_select();
+extern int sys_symlink();
+extern int sys_lstat();
+extern int sys_readlink();
+extern int sys_uselib();
+extern int sys_execve2();
+extern int sys_getdents();
+extern int sys_pipe2();
+extern int sys_sleep();
+extern int sys_getcwd();
+fn_ptr sys_call_table[] = { sys_setup, sys_exit, sys_fork, sys_read,
+sys_write, sys_open, sys_close, sys_waitpid, sys_creat, sys_link,
+sys_unlink, sys_execve, sys_chdir, sys_time, sys_mknod, sys_chmod,
+sys_chown, sys_break, sys_stat, sys_lseek, sys_getpid, sys_mount,
+sys_umount, sys_setuid, sys_getuid, sys_stime, sys_ptrace, sys_alarm,
+sys_fstat, sys_pause, sys_utime, sys_stty, sys_gtty, sys_access,
+sys_nice, sys_ftime, sys_sync, sys_kill, sys_rename, sys_mkdir,
+sys_rmdir, sys_dup, sys_pipe, sys_times, sys_prof, sys_brk, sys_setgid,
+sys_getgid, sys_signal, sys_geteuid, sys_getegid, sys_acct, sys_phys,
+sys_lock, sys_ioctl, sys_fcntl, sys_mpx, sys_setpgid, sys_ulimit,
+sys_uname, sys_umask, sys_chroot, sys_ustat, sys_dup2, sys_getppid,
+sys_getpgrp, sys_setsid, sys_sigaction, sys_sgetmask, sys_ssetmask,
+sys_setreuid,sys_setregid, sys_sigsuspend, sys_sigpending, sys_sethostname,
+sys_setrlimit, sys_getrlimit, sys_getrusage, sys_gettimeofday, 
+sys_settimeofday, sys_getgroups, sys_setgroups, sys_select, sys_symlink,
+sys_lstat, sys_readlink, sys_uselib, sys_execve2, sys_getdents, sys_pipe2,
+sys_sleep, sys_getcwd};
+
+/* So we don't have to do any more manual updating.... */
+int NR_syscalls = sizeof(sys_call_table)/sizeof(fn_ptr);

os/os/linux/include/linux/tty.h

@@ -0,0 +1,77 @@
+/*
+ * 'tty.h' defines some structures used by tty_io.c and some defines.
+ *
+ * NOTE! Don't touch this without checking that nothing in rs_io.s or
+ * con_io.s breaks. Some constants are hardwired into the system (mainly
+ * offsets into 'tty_queue'
+ */
+
+#ifndef _TTY_H
+#define _TTY_H
+
+#include <termios.h>
+
+#define TTY_BUF_SIZE 1024
+
+struct tty_queue {
+	unsigned long data;
+	unsigned long head;
+	unsigned long tail;
+	struct task_struct * proc_list;
+	char buf[TTY_BUF_SIZE];
+};
+
+#define INC(a) ((a) = ((a)+1) & (TTY_BUF_SIZE-1))
+#define DEC(a) ((a) = ((a)-1) & (TTY_BUF_SIZE-1))
+#define EMPTY(a) ((a).head == (a).tail)
+#define LEFT(a) (((a).tail-(a).head-1)&(TTY_BUF_SIZE-1))
+#define LAST(a) ((a).buf[(TTY_BUF_SIZE-1)&((a).head-1)])
+#define FULL(a) (!LEFT(a))
+#define CHARS(a) (((a).head-(a).tail)&(TTY_BUF_SIZE-1))
+#define GETCH(queue,c) \
+(void)({c=(queue).buf[(queue).tail];INC((queue).tail);})
+#define PUTCH(c,queue) \
+(void)({(queue).buf[(queue).head]=(c);INC((queue).head);})
+
+#define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR])
+#define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT])
+#define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE])
+#define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL])
+#define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF])
+#define START_CHAR(tty) ((tty)->termios.c_cc[VSTART])
+#define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP])
+#define SUSPEND_CHAR(tty) ((tty)->termios.c_cc[VSUSP])
+
+struct tty_struct {
+	struct termios termios;
+	int pgrp;
+	int stopped;
+	void (*write)(struct tty_struct * tty);
+	struct tty_queue read_q;
+	struct tty_queue write_q;
+	struct tty_queue secondary;
+	};
+
+extern struct tty_struct tty_table[];
+
+/*	intr=^C		quit=^|		erase=del	kill=^U
+	eof=^D		vtime=\0	vmin=\1		sxtc=\0
+	start=^Q	stop=^S		susp=^Z		eol=\0
+	reprint=^R	discard=^U	werase=^W	lnext=^V
+	eol2=\0
+*/
+#define INIT_C_CC "\003\034\177\025\004\0\1\0\021\023\032\0\022\017\027\026\0"
+
+void rs_init(void);
+void con_init(void);
+void tty_init(void);
+
+int tty_read(unsigned c, char * buf, int n);
+int tty_write(unsigned c, char * buf, int n);
+
+void rs_write(struct tty_struct * tty);
+void con_write(struct tty_struct * tty);
+
+void copy_to_cooked(struct tty_struct * tty);
+
+#endif

os/os/linux/include/new0.h

@@ -0,0 +1,30 @@
+#ifndef _NEW_H
+#define _NEW_H
+
+#include <sys/types.h>
+
+struct linux_dirent {
+	long           d_ino;
+	off_t          d_off;
+	unsigned short d_reclen;
+	char           d_name[14];
+};
+
+/* Return value of `mmap' in case of an error.  */
+#define MAP_FAILED	((void *) -1)
+
+#define PROT_READ	0x1		/* page can be read */
+#define PROT_WRITE	0x2		/* page can be written */
+#define PROT_EXEC	0x4		/* page can be executed */
+#define PROT_SEM	0x8		/* page may be used for atomic ops */
+#define PROT_NONE	0x0		/* page can not be accessed */
+
+/* compatibility flags */
+#define MAP_FILE	0
+
+#define MAP_SHARED	0x01		/* Share changes */
+#define MAP_PRIVATE	0x02		/* Changes are private */
+
+#define CLONE_VM	0x00000100	/* set if VM shared between processes */
+
+#endif

os/os/linux/include/signal.h

@@ -0,0 +1,68 @@
+#ifndef _SIGNAL_H
+#define _SIGNAL_H
+
+#include <sys/types.h>
+
+typedef int sig_atomic_t;
+typedef unsigned int sigset_t;		/* 32 bits */
+
+#define _NSIG             32
+#define NSIG		_NSIG
+
+#define SIGHUP		 1
+#define SIGINT		 2
+#define SIGQUIT		 3
+#define SIGILL		 4
+#define SIGTRAP		 5
+#define SIGABRT		 6
+#define SIGIOT		 6
+#define SIGUNUSED	 7
+#define SIGFPE		 8
+#define SIGKILL		 9
+#define SIGUSR1		10
+#define SIGSEGV		11
+#define SIGUSR2		12
+#define SIGPIPE		13
+#define SIGALRM		14
+#define SIGTERM		15
+#define SIGSTKFLT	16
+#define SIGCHLD		17
+#define SIGCONT		18
+#define SIGSTOP		19
+#define SIGTSTP		20
+#define SIGTTIN		21
+#define SIGTTOU		22
+
+/* Ok, I haven't implemented sigactions, but trying to keep headers POSIX */
+#define SA_NOCLDSTOP	1
+#define SA_NOMASK	0x40000000
+#define SA_ONESHOT	0x80000000
+
+#define SIG_BLOCK          0	/* for blocking signals */
+#define SIG_UNBLOCK        1	/* for unblocking signals */
+#define SIG_SETMASK        2	/* for setting the signal mask */
+
+#define SIG_DFL		((void (*)(int))0)	/* default signal handling */
+#define SIG_IGN		((void (*)(int))1)	/* ignore signal */
+
+struct sigaction {
+	void (*sa_handler)(int);
+	sigset_t sa_mask;
+	int sa_flags;
+	void (*sa_restorer)(void);
+};
+
+void (*signal(int _sig, void (*_func)(int)))(int);
+int raise(int sig);
+int kill(pid_t pid, int sig);
+int sigaddset(sigset_t *mask, int signo);
+int sigdelset(sigset_t *mask, int signo);
+int sigemptyset(sigset_t *mask);
+int sigfillset(sigset_t *mask);
+int sigismember(sigset_t *mask, int signo); /* 1 - is, 0 - not, -1 error */
+int sigpending(sigset_t *set);
+int sigprocmask(int how, sigset_t *set, sigset_t *oldset);
+int sigsuspend(sigset_t *sigmask);
+int sigaction(int sig, struct sigaction *act, struct sigaction *oldact);
+
+#endif /* _SIGNAL_H */

os/os/linux/include/stdarg.h

@@ -0,0 +1,28 @@
+#ifndef _STDARG_H
+#define _STDARG_H
+
+typedef char *va_list;
+
+/* Amount of space required in an argument list for an arg of type TYPE.
+   TYPE may alternatively be an expression whose type is used.  */
+
+#define __va_rounded_size(TYPE)  \
+  (((sizeof (TYPE) + sizeof (int) - 1) / sizeof (int)) * sizeof (int))
+
+#ifndef __sparc__
+#define va_start(AP, LASTARG) 						\
+ (AP = ((char *) &(LASTARG) + __va_rounded_size (LASTARG)))
+#else
+#define va_start(AP, LASTARG) 						\
+ (__builtin_saveregs (),						\
+  AP = ((char *) &(LASTARG) + __va_rounded_size (LASTARG)))
+#endif
+
+void va_end (va_list);		/* Defined in gnulib */
+#define va_end(AP)
+
+#define va_arg(AP, TYPE)						\
+ (AP += __va_rounded_size (TYPE),					\
+  *((TYPE *) (AP - __va_rounded_size (TYPE))))
+
+#endif /* _STDARG_H */

os/os/linux/include/stddef.h

@@ -0,0 +1,19 @@
+#ifndef _STDDEF_H
+#define _STDDEF_H
+
+#ifndef _PTRDIFF_T
+#define _PTRDIFF_T
+typedef long ptrdiff_t;
+#endif
+
+#ifndef _SIZE_T
+#define _SIZE_T
+typedef unsigned long size_t;
+#endif
+
+#undef NULL
+#define NULL ((void *)0)
+
+#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
+
+#endif

os/os/linux/include/string.h

@@ -0,0 +1,405 @@
+#ifndef _STRING_H_
+#define _STRING_H_
+
+#ifndef NULL
+#define NULL ((void *) 0)
+#endif
+
+#ifndef _SIZE_T
+#define _SIZE_T
+typedef unsigned int size_t;
+#endif
+
+extern char * strerror(int errno);
+
+/*
+ * This string-include defines all string functions as inline
+ * functions. Use gcc. It also assumes ds=es=data space, this should be
+ * normal. Most of the string-functions are rather heavily hand-optimized,
+ * see especially strtok,strstr,str[c]spn. They should work, but are not
+ * very easy to understand. Everything is done entirely within the register
+ * set, making the functions fast and clean. String instructions have been
+ * used through-out, making for "slightly" unclear code :-)
+ *
+ *		(C) 1991 Linus Torvalds
+ */
+ 
+extern inline char * strcpy(char * dest,const char *src)
+{
+__asm__("cld\n"
+	"1:\tlodsb\n\t"
+	"stosb\n\t"
+	"testb %%al,%%al\n\t"
+	"jne 1b"
+	::"S" (src),"D" (dest));
+return dest;
+}
+
+extern inline char * strncpy(char * dest,const char *src,int count)
+{
+__asm__("cld\n"
+	"1:\tdecl %2\n\t"
+	"js 2f\n\t"
+	"lodsb\n\t"
+	"stosb\n\t"
+	"testb %%al,%%al\n\t"
+	"jne 1b\n\t"
+	"rep\n\t"
+	"stosb\n"
+	"2:"
+	::"S" (src),"D" (dest),"c" (count));
+return dest;
+}
+
+extern inline char * strcat(char * dest,const char * src)
+{
+__asm__("cld\n\t"
+	"repne\n\t"
+	"scasb\n\t"
+	"decl %1\n"
+	"1:\tlodsb\n\t"
+	"stosb\n\t"
+	"testb %%al,%%al\n\t"
+	"jne 1b"
+	::"S" (src),"D" (dest),"a" (0),"c" (0xffffffff));
+return dest;
+}
+
+extern inline char * strncat(char * dest,const char * src,int count)
+{
+__asm__("cld\n\t"
+	"repne\n\t"
+	"scasb\n\t"
+	"decl %1\n\t"
+	"movl %4,%3\n"
+	"1:\tdecl %3\n\t"
+	"js 2f\n\t"
+	"lodsb\n\t"
+	"stosb\n\t"
+	"testb %%al,%%al\n\t"
+	"jne 1b\n"
+	"2:\txorl %2,%2\n\t"
+	"stosb"
+	::"S" (src),"D" (dest),"a" (0),"c" (0xffffffff),"g" (count)
+	);
+return dest;
+}
+
+extern inline int strcmp(const char * cs,const char * ct)
+{
+register int __res __asm__("ax");
+__asm__("cld\n"
+	"1:\tlodsb\n\t"
+	"scasb\n\t"
+	"jne 2f\n\t"
+	"testb %%al,%%al\n\t"
+	"jne 1b\n\t"
+	"xorl %%eax,%%eax\n\t"
+	"jmp 3f\n"
+	"2:\tmovl $1,%%eax\n\t"
+	"jl 3f\n\t"
+	"negl %%eax\n"
+	"3:"
+	:"=a" (__res):"D" (cs),"S" (ct));
+return __res;
+}
+
+extern inline int strncmp(const char * cs,const char * ct,int count)
+{
+register int __res __asm__("ax");
+__asm__("cld\n"
+	"1:\tdecl %3\n\t"
+	"js 2f\n\t"
+	"lodsb\n\t"
+	"scasb\n\t"
+	"jne 3f\n\t"
+	"testb %%al,%%al\n\t"
+	"jne 1b\n"
+	"2:\txorl %%eax,%%eax\n\t"
+	"jmp 4f\n"
+	"3:\tmovl $1,%%eax\n\t"
+	"jl 4f\n\t"
+	"negl %%eax\n"
+	"4:"
+	:"=a" (__res):"D" (cs),"S" (ct),"c" (count));
+return __res;
+}
+
+extern inline char * strchr(const char * s,char c)
+{
+register char * __res __asm__("ax");
+__asm__("cld\n\t"
+	"movb %%al,%%ah\n"
+	"1:\tlodsb\n\t"
+	"cmpb %%ah,%%al\n\t"
+	"je 2f\n\t"
+	"testb %%al,%%al\n\t"
+	"jne 1b\n\t"
+	"movl $1,%1\n"
+	"2:\tmovl %1,%0\n\t"
+	"decl %0"
+	:"=a" (__res):"S" (s),"0" (c));
+return __res;
+}
+
+extern inline char * strrchr(const char * s,char c)
+{
+register char * __res __asm__("dx");
+__asm__("cld\n\t"
+	"movb %%al,%%ah\n"
+	"1:\tlodsb\n\t"
+	"cmpb %%ah,%%al\n\t"
+	"jne 2f\n\t"
+	"movl %%esi,%0\n\t"
+	"decl %0\n"
+	"2:\ttestb %%al,%%al\n\t"
+	"jne 1b"
+	:"=d" (__res):"0" (0),"S" (s),"a" (c));
+return __res;
+}
+
+extern inline int strspn(const char * cs, const char * ct)
+{
+register char * __res __asm__("si");
+__asm__("cld\n\t"
+	"movl %4,%%edi\n\t"
+	"repne\n\t"
+	"scasb\n\t"
+	"notl %%ecx\n\t"
+	"decl %%ecx\n\t"
+	"movl %%ecx,%%edx\n"
+	"1:\tlodsb\n\t"
+	"testb %%al,%%al\n\t"
+	"je 2f\n\t"
+	"movl %4,%%edi\n\t"
+	"movl %%edx,%%ecx\n\t"
+	"repne\n\t"
+	"scasb\n\t"
+	"je 1b\n"
+	"2:\tdecl %0"
+	:"=S" (__res):"a" (0),"c" (0xffffffff),"0" (cs),"g" (ct)
+	);
+return __res-cs;
+}
+
+extern inline int strcspn(const char * cs, const char * ct)
+{
+register char * __res __asm__("si");
+__asm__("cld\n\t"
+	"movl %4,%%edi\n\t"
+	"repne\n\t"
+	"scasb\n\t"
+	"notl %%ecx\n\t"
+	"decl %%ecx\n\t"
+	"movl %%ecx,%%edx\n"
+	"1:\tlodsb\n\t"
+	"testb %%al,%%al\n\t"
+	"je 2f\n\t"
+	"movl %4,%%edi\n\t"
+	"movl %%edx,%%ecx\n\t"
+	"repne\n\t"
+	"scasb\n\t"
+	"jne 1b\n"
+	"2:\tdecl %0"
+	:"=S" (__res):"a" (0),"c" (0xffffffff),"0" (cs),"g" (ct)
+	);
+return __res-cs;
+}
+
+extern inline char * strpbrk(const char * cs,const char * ct)
+{
+register char * __res __asm__("si");
+__asm__("cld\n\t"
+	"movl %4,%%edi\n\t"
+	"repne\n\t"
+	"scasb\n\t"
+	"notl %%ecx\n\t"
+	"decl %%ecx\n\t"
+	"movl %%ecx,%%edx\n"
+	"1:\tlodsb\n\t"
+	"testb %%al,%%al\n\t"
+	"je 2f\n\t"
+	"movl %4,%%edi\n\t"
+	"movl %%edx,%%ecx\n\t"
+	"repne\n\t"
+	"scasb\n\t"
+	"jne 1b\n\t"
+	"decl %0\n\t"
+	"jmp 3f\n"
+	"2:\txorl %0,%0\n"
+	"3:"
+	:"=S" (__res):"a" (0),"c" (0xffffffff),"0" (cs),"g" (ct)
+	);
+return __res;
+}
+
+extern inline char * strstr(const char * cs,const char * ct)
+{
+register char * __res __asm__("ax");
+__asm__("cld\n\t" \
+	"movl %4,%%edi\n\t"
+	"repne\n\t"
+	"scasb\n\t"
+	"notl %%ecx\n\t"
+	"decl %%ecx\n\t"	/* NOTE! This also sets Z if searchstring='' */
+	"movl %%ecx,%%edx\n"
+	"1:\tmovl %4,%%edi\n\t"
+	"movl %%esi,%%eax\n\t"
+	"movl %%edx,%%ecx\n\t"
+	"repe\n\t"
+	"cmpsb\n\t"
+	"je 2f\n\t"		/* also works for empty string, see above */
+	"xchgl %%eax,%%esi\n\t"
+	"incl %%esi\n\t"
+	"cmpb $0,-1(%%eax)\n\t"
+	"jne 1b\n\t"
+	"xorl %%eax,%%eax\n\t"
+	"2:"
+	:"=a" (__res):"0" (0),"c" (0xffffffff),"S" (cs),"g" (ct)
+	);
+return __res;
+}
+
+extern inline int strlen(const char * s)
+{
+register int __res ;
+__asm__("cld\n\t"
+	"repne\n\t"
+	"scasb\n\t"
+	"notl %0\n\t"
+	"decl %0"
+	:"=c" (__res):"D" (s),"a" (0),"0" (0xffffffff));
+return __res;
+}
+
+extern char * ___strtok;
+
+extern inline char * strtok(char * s,const char * ct)
+{
+register char * __res __asm__("si");
+__asm__("testl %1,%1\n\t"
+	"jne 1f\n\t"
+	"testl %0,%0\n\t"
+	"je 8f\n\t"
+	"movl %0,%1\n"
+	"1:\txorl %0,%0\n\t"
+	"movl $-1,%%ecx\n\t"
+	"xorl %%eax,%%eax\n\t"
+	"cld\n\t"
+	"movl %4,%%edi\n\t"
+	"repne\n\t"
+	"scasb\n\t"
+	"notl %%ecx\n\t"
+	"decl %%ecx\n\t"
+	"je 7f\n\t"			/* empty delimeter-string */
+	"movl %%ecx,%%edx\n"
+	"2:\tlodsb\n\t"
+	"testb %%al,%%al\n\t"
+	"je 7f\n\t"
+	"movl %4,%%edi\n\t"
+	"movl %%edx,%%ecx\n\t"
+	"repne\n\t"
+	"scasb\n\t"
+	"je 2b\n\t"
+	"decl %1\n\t"
+	"cmpb $0,(%1)\n\t"
+	"je 7f\n\t"
+	"movl %1,%0\n"
+	"3:\tlodsb\n\t"
+	"testb %%al,%%al\n\t"
+	"je 5f\n\t"
+	"movl %4,%%edi\n\t"
+	"movl %%edx,%%ecx\n\t"
+	"repne\n\t"
+	"scasb\n\t"
+	"jne 3b\n\t"
+	"decl %1\n\t"
+	"cmpb $0,(%1)\n\t"
+	"je 5f\n\t"
+	"movb $0,(%1)\n\t"
+	"incl %1\n\t"
+	"jmp 6f\n"
+	"5:\txorl %1,%1\n"
+	"6:\tcmpb $0,(%0)\n\t"
+	"jne 7f\n\t"
+	"xorl %0,%0\n"
+	"7:\ttestl %0,%0\n\t"
+	"jne 8f\n\t"
+	"movl %0,%1\n"
+	"8:"
+	:"=b" (__res),"=S" (___strtok)
+	:"0" (___strtok),"1" (s),"g" (ct)
+	);
+return __res;
+}
+
+extern inline void * memcpy(void * dest,const void * src, int n)
+{
+__asm__("cld\n\t"
+	"rep\n\t"
+	"movsb"
+	::"c" (n),"S" (src),"D" (dest)
+	);
+return dest;
+}
+
+extern inline void * memmove(void * dest,const void * src, int n)
+{
+if (dest<src)
+__asm__("cld\n\t"
+	"rep\n\t"
+	"movsb"
+	::"c" (n),"S" (src),"D" (dest)
+	);
+else
+__asm__("std\n\t"
+	"rep\n\t"
+	"movsb"
+	::"c" (n),"S" (src+n-1),"D" (dest+n-1)
+	);
+return dest;
+}
+
+extern inline int memcmp(const void * cs,const void * ct,int count)
+{
+register int __res __asm__("ax");
+__asm__("cld\n\t"
+	"repe\n\t"
+	"cmpsb\n\t"
+	"je 1f\n\t"
+	"movl $1,%%eax\n\t"
+	"jl 1f\n\t"
+	"negl %%eax\n"
+	"1:"
+	:"=a" (__res):"0" (0),"D" (cs),"S" (ct),"c" (count)
+	);
+return __res;
+}
+
+extern inline void * memchr(const void * cs,char c,int count)
+{
+register void * __res __asm__("di");
+if (!count)
+	return NULL;
+__asm__("cld\n\t"
+	"repne\n\t"
+	"scasb\n\t"
+	"je 1f\n\t"
+	"movl $1,%0\n"
+	"1:\tdecl %0"
+	:"=D" (__res):"a" (c),"D" (cs),"c" (count)
+	);
+return __res;
+}
+
+extern inline void * memset(void * s,char c,int count)
+{
+__asm__("cld\n\t"
+	"rep\n\t"
+	"stosb"
+	::"a" (c),"D" (s),"c" (count)
+	);
+return s;
+}
+
+#endif

os/os/linux/include/sys/stat.h

@@ -0,0 +1,60 @@
+#ifndef _SYS_STAT_H
+#define _SYS_STAT_H
+
+#include <sys/types.h>
+
+struct stat {
+	dev_t	st_dev;
+	ino_t	st_ino;
+	umode_t	st_mode;
+	nlink_t	st_nlink;
+	uid_t	st_uid;
+	gid_t	st_gid;
+	dev_t	st_rdev;
+	off_t	st_size;
+	time_t	st_atime;
+	time_t	st_mtime;
+	time_t	st_ctime;
+};
+
+#define S_IFMT  00170000
+#define S_IFLNK	 0120000
+#define S_IFREG  0100000
+#define S_IFBLK  0060000
+#define S_IFDIR  0040000
+#define S_IFCHR  0020000
+#define S_IFIFO  0010000
+#define S_ISUID  0004000
+#define S_ISGID  0002000
+#define S_ISVTX  0001000
+
+#define S_ISLNK(m)	(((m) & S_IFMT) == S_IFLNK)
+#define S_ISREG(m)	(((m) & S_IFMT) == S_IFREG)
+#define S_ISDIR(m)	(((m) & S_IFMT) == S_IFDIR)
+#define S_ISCHR(m)	(((m) & S_IFMT) == S_IFCHR)
+#define S_ISBLK(m)	(((m) & S_IFMT) == S_IFBLK)
+#define S_ISFIFO(m)	(((m) & S_IFMT) == S_IFIFO)
+
+#define S_IRWXU 00700
+#define S_IRUSR 00400
+#define S_IWUSR 00200
+#define S_IXUSR 00100
+
+#define S_IRWXG 00070
+#define S_IRGRP 00040
+#define S_IWGRP 00020
+#define S_IXGRP 00010
+
+#define S_IRWXO 00007
+#define S_IROTH 00004
+#define S_IWOTH 00002
+#define S_IXOTH 00001
+
+extern int chmod(const char *_path, mode_t mode);
+extern int fstat(int fildes, struct stat *stat_buf);
+extern int mkdir(const char *_path, mode_t mode);
+extern int mkfifo(const char *_path, mode_t mode);
+extern int stat(const char *filename, struct stat *stat_buf);
+extern mode_t umask(mode_t mask);
+
+#endif

os/os/linux/include/sys/times.h

@@ -0,0 +1,15 @@
+#ifndef _TIMES_H
+#define _TIMES_H
+
+#include <sys/types.h>
+
+struct tms {
+	time_t tms_utime;
+	time_t tms_stime;
+	time_t tms_cutime;
+	time_t tms_cstime;
+};
+
+extern time_t times(struct tms * tp);
+
+#endif

os/os/linux/include/sys/types.h

@@ -0,0 +1,46 @@
+#ifndef _SYS_TYPES_H
+#define _SYS_TYPES_H
+
+#ifndef _SIZE_T
+#define _SIZE_T
+typedef unsigned int size_t;
+#endif
+
+#ifndef _TIME_T
+#define _TIME_T
+typedef long time_t;
+#endif
+
+#ifndef _PTRDIFF_T
+#define _PTRDIFF_T
+typedef long ptrdiff_t;
+#endif
+
+#ifndef NULL
+#define NULL ((void *) 0)
+#endif
+
+typedef int pid_t;
+typedef unsigned short uid_t;
+typedef unsigned char gid_t;
+typedef unsigned short dev_t;
+typedef unsigned short ino_t;
+typedef unsigned short mode_t;
+typedef unsigned short umode_t;
+typedef unsigned char nlink_t;
+typedef int daddr_t;
+typedef long off_t;
+typedef unsigned char u_char;
+typedef unsigned short ushort;
+
+typedef struct { int quot,rem; } div_t;
+typedef struct { long quot,rem; } ldiv_t;
+
+struct ustat {
+	daddr_t f_tfree;
+	ino_t f_tinode;
+	char f_fname[6];
+	char f_fpack[6];
+};
+
+#endif

os/os/linux/include/sys/utsname.h

@@ -0,0 +1,16 @@
+#ifndef _SYS_UTSNAME_H
+#define _SYS_UTSNAME_H
+
+#include <sys/types.h>
+
+struct utsname {
+	char sysname[9];
+	char nodename[9];
+	char release[9];
+	char version[9];
+	char machine[9];
+};
+
+extern int uname(struct utsname * utsbuf);
+
+#endif

os/os/linux/include/sys/wait.h

@@ -0,0 +1,23 @@
+#ifndef _SYS_WAIT_H
+#define _SYS_WAIT_H
+
+#include <sys/types.h>
+
+#define _LOW(v)		( (v) & 0377)
+#define _HIGH(v)	( ((v) >> 8) & 0377)
+
+/* options for waitpid, WUNTRACED not supported */
+#define WNOHANG		1
+#define WUNTRACED	2
+
+#define WIFEXITED(s)	(!((s)&0xFF)
+#define WIFSTOPPED(s)	(((s)&0xFF)==0x7F)
+#define WEXITSTATUS(s)	(((s)>>8)&0xFF)
+#define WTERMSIG(s)	((s)&0x7F)
+#define WSTOPSIG(s)	(((s)>>8)&0xFF)
+#define WIFSIGNALED(s)	(((unsigned int)(s)-1 & 0xFFFF) < 0xFF)
+
+pid_t wait(int *stat_loc);
+pid_t waitpid(pid_t pid, int *stat_loc, int options);
+
+#endif

os/os/linux/include/termios.h

@@ -0,0 +1,228 @@
+#ifndef _TERMIOS_H
+#define _TERMIOS_H
+
+#define TTY_BUF_SIZE 1024
+
+/* 0x54 is just a magic number to make these relatively uniqe ('T') */
+
+#define TCGETS		0x5401
+#define TCSETS		0x5402
+#define TCSETSW		0x5403
+#define TCSETSF		0x5404
+#define TCGETA		0x5405
+#define TCSETA		0x5406
+#define TCSETAW		0x5407
+#define TCSETAF		0x5408
+#define TCSBRK		0x5409
+#define TCXONC		0x540A
+#define TCFLSH		0x540B
+#define TIOCEXCL	0x540C
+#define TIOCNXCL	0x540D
+#define TIOCSCTTY	0x540E
+#define TIOCGPGRP	0x540F
+#define TIOCSPGRP	0x5410
+#define TIOCOUTQ	0x5411
+#define TIOCSTI		0x5412
+#define TIOCGWINSZ	0x5413
+#define TIOCSWINSZ	0x5414
+#define TIOCMGET	0x5415
+#define TIOCMBIS	0x5416
+#define TIOCMBIC	0x5417
+#define TIOCMSET	0x5418
+#define TIOCGSOFTCAR	0x5419
+#define TIOCSSOFTCAR	0x541A
+#define TIOCINQ		0x541B
+
+struct winsize {
+	unsigned short ws_row;
+	unsigned short ws_col;
+	unsigned short ws_xpixel;
+	unsigned short ws_ypixel;
+};
+
+#define NCC 8
+struct termio {
+	unsigned short c_iflag;		/* input mode flags */
+	unsigned short c_oflag;		/* output mode flags */
+	unsigned short c_cflag;		/* control mode flags */
+	unsigned short c_lflag;		/* local mode flags */
+	unsigned char c_line;		/* line discipline */
+	unsigned char c_cc[NCC];	/* control characters */
+};
+
+#define NCCS 17
+struct termios {
+	unsigned long c_iflag;		/* input mode flags */
+	unsigned long c_oflag;		/* output mode flags */
+	unsigned long c_cflag;		/* control mode flags */
+	unsigned long c_lflag;		/* local mode flags */
+	unsigned char c_line;		/* line discipline */
+	unsigned char c_cc[NCCS];	/* control characters */
+};
+
+/* c_cc characters */
+#define VINTR 0
+#define VQUIT 1
+#define VERASE 2
+#define VKILL 3
+#define VEOF 4
+#define VTIME 5
+#define VMIN 6
+#define VSWTC 7
+#define VSTART 8
+#define VSTOP 9
+#define VSUSP 10
+#define VEOL 11
+#define VREPRINT 12
+#define VDISCARD 13
+#define VWERASE 14
+#define VLNEXT 15
+#define VEOL2 16
+
+/* c_iflag bits */
+#define IGNBRK	0000001
+#define BRKINT	0000002
+#define IGNPAR	0000004
+#define PARMRK	0000010
+#define INPCK	0000020
+#define ISTRIP	0000040
+#define INLCR	0000100
+#define IGNCR	0000200
+#define ICRNL	0000400
+#define IUCLC	0001000
+#define IXON	0002000
+#define IXANY	0004000
+#define IXOFF	0010000
+#define IMAXBEL	0020000
+
+/* c_oflag bits */
+#define OPOST	0000001
+#define OLCUC	0000002
+#define ONLCR	0000004
+#define OCRNL	0000010
+#define ONOCR	0000020
+#define ONLRET	0000040
+#define OFILL	0000100
+#define OFDEL	0000200
+#define NLDLY	0000400
+#define   NL0	0000000
+#define   NL1	0000400
+#define CRDLY	0003000
+#define   CR0	0000000
+#define   CR1	0001000
+#define   CR2	0002000
+#define   CR3	0003000
+#define TABDLY	0014000
+#define   TAB0	0000000
+#define   TAB1	0004000
+#define   TAB2	0010000
+#define   TAB3	0014000
+#define   XTABS	0014000
+#define BSDLY	0020000
+#define   BS0	0000000
+#define   BS1	0020000
+#define VTDLY	0040000
+#define   VT0	0000000
+#define   VT1	0040000
+#define FFDLY	0040000
+#define   FF0	0000000
+#define   FF1	0040000
+
+/* c_cflag bit meaning */
+#define CBAUD	0000017
+#define  B0	0000000		/* hang up */
+#define  B50	0000001
+#define  B75	0000002
+#define  B110	0000003
+#define  B134	0000004
+#define  B150	0000005
+#define  B200	0000006
+#define  B300	0000007
+#define  B600	0000010
+#define  B1200	0000011
+#define  B1800	0000012
+#define  B2400	0000013
+#define  B4800	0000014
+#define  B9600	0000015
+#define  B19200	0000016
+#define  B38400	0000017
+#define EXTA B19200
+#define EXTB B38400
+#define CSIZE	0000060
+#define   CS5	0000000
+#define   CS6	0000020
+#define   CS7	0000040
+#define   CS8	0000060
+#define CSTOPB	0000100
+#define CREAD	0000200
+#define CPARENB	0000400
+#define CPARODD	0001000
+#define HUPCL	0002000
+#define CLOCAL	0004000
+#define CIBAUD	03600000		/* input baud rate (not used) */
+#define CRTSCTS	020000000000		/* flow control */
+
+#define PARENB CPARENB
+#define PARODD CPARODD
+
+/* c_lflag bits */
+#define ISIG	0000001
+#define ICANON	0000002
+#define XCASE	0000004
+#define ECHO	0000010
+#define ECHOE	0000020
+#define ECHOK	0000040
+#define ECHONL	0000100
+#define NOFLSH	0000200
+#define TOSTOP	0000400
+#define ECHOCTL	0001000
+#define ECHOPRT	0002000
+#define ECHOKE	0004000
+#define FLUSHO	0010000
+#define PENDIN	0040000
+#define IEXTEN	0100000
+
+/* modem lines */
+#define TIOCM_LE	0x001
+#define TIOCM_DTR	0x002
+#define TIOCM_RTS	0x004
+#define TIOCM_ST	0x008
+#define TIOCM_SR	0x010
+#define TIOCM_CTS	0x020
+#define TIOCM_CAR	0x040
+#define TIOCM_RNG	0x080
+#define TIOCM_DSR	0x100
+#define TIOCM_CD	TIOCM_CAR
+#define TIOCM_RI	TIOCM_RNG
+
+/* tcflow() and TCXONC use these */
+#define	TCOOFF		0
+#define	TCOON		1
+#define	TCIOFF		2
+#define	TCION		3
+
+/* tcflush() and TCFLSH use these */
+#define	TCIFLUSH	0
+#define	TCOFLUSH	1
+#define	TCIOFLUSH	2
+
+/* tcsetattr uses these */
+#define	TCSANOW		0
+#define	TCSADRAIN	1
+#define	TCSAFLUSH	2
+
+typedef int speed_t;
+
+extern speed_t cfgetispeed(struct termios *termios_p);
+extern speed_t cfgetospeed(struct termios *termios_p);
+extern int cfsetispeed(struct termios *termios_p, speed_t speed);
+extern int cfsetospeed(struct termios *termios_p, speed_t speed);
+extern int tcdrain(int fildes);
+extern int tcflow(int fildes, int action);
+extern int tcflush(int fildes, int queue_selector);
+extern int tcgetattr(int fildes, struct termios *termios_p);
+extern int tcsendbreak(int fildes, int duration);
+extern int tcsetattr(int fildes, int optional_actions,
+	struct termios *termios_p);
+
+#endif

os/os/linux/include/time.h

@@ -0,0 +1,42 @@
+#ifndef _TIME_H
+#define _TIME_H
+
+#ifndef _TIME_T
+#define _TIME_T
+typedef long time_t;
+#endif
+
+#ifndef _SIZE_T
+#define _SIZE_T
+typedef unsigned int size_t;
+#endif
+
+#define CLOCKS_PER_SEC 100
+
+typedef long clock_t;
+
+struct tm {
+	int tm_sec;
+	int tm_min;
+	int tm_hour;
+	int tm_mday;
+	int tm_mon;
+	int tm_year;
+	int tm_wday;
+	int tm_yday;
+	int tm_isdst;
+};
+
+clock_t clock(void);
+time_t time(time_t * tp);
+double difftime(time_t time2, time_t time1);
+time_t mktime(struct tm * tp);
+
+char * asctime(const struct tm * tp);
+char * ctime(const time_t * tp);
+struct tm * gmtime(const time_t *tp);
+struct tm *localtime(const time_t * tp);
+size_t strftime(char * s, size_t smax, const char * fmt, const struct tm * tp);
+void tzset(void);
+
+#endif

os/os/linux/include/unistd.h

@@ -0,0 +1,276 @@
+#ifndef _UNISTD_H
+#define _UNISTD_H
+
+/* ok, this may be a joke, but I'm working on it */
+#define _POSIX_VERSION 198808L
+
+#define _POSIX_CHOWN_RESTRICTED	/* only root can do a chown (I think..) */
+#define _POSIX_NO_TRUNC		/* no pathname truncation (but see in kernel) */
+#define _POSIX_VDISABLE '\0'	/* character to disable things like ^C */
+/*#define _POSIX_SAVED_IDS */	/* we'll get to this yet */
+/*#define _POSIX_JOB_CONTROL */	/* we aren't there quite yet. Soon hopefully */
+
+#define STDIN_FILENO	0
+#define STDOUT_FILENO	1
+#define STDERR_FILENO	2
+
+#ifndef NULL
+#define NULL    ((void *)0)
+#endif
+
+/* access */
+#define F_OK	0
+#define X_OK	1
+#define W_OK	2
+#define R_OK	4
+
+/* lseek */
+#define SEEK_SET	0
+#define SEEK_CUR	1
+#define SEEK_END	2
+
+/* _SC stands for System Configuration. We don't use them much */
+#define _SC_ARG_MAX		1
+#define _SC_CHILD_MAX		2
+#define _SC_CLOCKS_PER_SEC	3
+#define _SC_NGROUPS_MAX		4
+#define _SC_OPEN_MAX		5
+#define _SC_JOB_CONTROL		6
+#define _SC_SAVED_IDS		7
+#define _SC_VERSION		8
+
+/* more (possibly) configurable things - now pathnames */
+#define _PC_LINK_MAX		1
+#define _PC_MAX_CANON		2
+#define _PC_MAX_INPUT		3
+#define _PC_NAME_MAX		4
+#define _PC_PATH_MAX		5
+#define _PC_PIPE_BUF		6
+#define _PC_NO_TRUNC		7
+#define _PC_VDISABLE		8
+#define _PC_CHOWN_RESTRICTED	9
+
+#include <sys/stat.h>
+#include <sys/times.h>
+#include <sys/utsname.h>
+#include <utime.h>
+
+#ifdef __LIBRARY__
+
+#define __NR_setup	0	/* used only by init, to get system going */
+#define __NR_exit	1
+#define __NR_fork	2
+#define __NR_read	3
+#define __NR_write	4
+#define __NR_open	5
+#define __NR_close	6
+#define __NR_waitpid	7
+#define __NR_creat	8
+#define __NR_link	9
+#define __NR_unlink	10
+#define __NR_execve	11
+#define __NR_chdir	12
+#define __NR_time	13
+#define __NR_mknod	14
+#define __NR_chmod	15
+#define __NR_chown	16
+#define __NR_break	17
+#define __NR_stat	18
+#define __NR_lseek	19
+#define __NR_getpid	20
+#define __NR_mount	21
+#define __NR_umount	22
+#define __NR_setuid	23
+#define __NR_getuid	24
+#define __NR_stime	25
+#define __NR_ptrace	26
+#define __NR_alarm	27
+#define __NR_fstat	28
+#define __NR_pause	29
+#define __NR_utime	30
+#define __NR_stty	31
+#define __NR_gtty	32
+#define __NR_access	33
+#define __NR_nice	34
+#define __NR_ftime	35
+#define __NR_sync	36
+#define __NR_kill	37
+#define __NR_rename	38
+#define __NR_mkdir	39
+#define __NR_rmdir	40
+#define __NR_dup	41
+#define __NR_pipe	42
+#define __NR_times	43
+#define __NR_prof	44
+#define __NR_brk	45
+#define __NR_setgid	46
+#define __NR_getgid	47
+#define __NR_signal	48
+#define __NR_geteuid	49
+#define __NR_getegid	50
+#define __NR_acct	51
+#define __NR_phys	52
+#define __NR_lock	53
+#define __NR_ioctl	54
+#define __NR_fcntl	55
+#define __NR_mpx	56
+#define __NR_setpgid	57
+#define __NR_ulimit	58
+#define __NR_uname	59
+#define __NR_umask	60
+#define __NR_chroot	61
+#define __NR_ustat	62
+#define __NR_dup2	63
+#define __NR_getppid	64
+#define __NR_getpgrp	65
+#define __NR_setsid	66
+#define __NR_sigaction	67
+#define __NR_sgetmask	68
+#define __NR_ssetmask	69
+#define __NR_setreuid	70
+#define __NR_setregid	71
+#define __NR_sigsuspend	72
+#define __NR_sigpending	73
+#define __NR_sethostname 74
+#define __NR_setrlimit	75
+#define __NR_getrlimit	76
+#define __NR_getrusage	77
+#define __NR_gettimeofday	78
+#define __NR_settimeofday	79
+#define __NR_getgroups	80
+#define __NR_setgroups  81
+#define __NR_select	82
+#define __NR_symlink	83
+#define __NR_lstat	84
+#define __NR_readlink	85
+#define __NR_uselib	86
+#define __NR_execve2	87
+#define __NR_getdents	88
+#define __NR_pipe2	89
+#define __NR_sleep	90
+#define __NR_getcwd	91
+#define _syscall0(type,name) \
+type name(void) \
+{ \
+long __res; \
+__asm__ volatile ("int $0x80" \
+	: "=a" (__res) \
+	: "0" (__NR_##name)); \
+if (__res >= 0) \
+	return (type) __res; \
+errno = -__res; \
+return -1; \
+}
+
+#define _syscall1(type,name,atype,a) \
+type name(atype a) \
+{ \
+long __res; \
+__asm__ volatile ("int $0x80" \
+	: "=a" (__res) \
+	: "0" (__NR_##name),"b" ((long)(a))); \
+if (__res >= 0) \
+	return (type) __res; \
+errno = -__res; \
+return -1; \
+}
+
+#define _syscall2(type,name,atype,a,btype,b) \
+type name(atype a,btype b) \
+{ \
+long __res; \
+__asm__ volatile ("int $0x80" \
+	: "=a" (__res) \
+	: "0" (__NR_##name),"b" ((long)(a)),"c" ((long)(b))); \
+if (__res >= 0) \
+	return (type) __res; \
+errno = -__res; \
+return -1; \
+}
+
+#define _syscall3(type,name,atype,a,btype,b,ctype,c) \
+type name(atype a,btype b,ctype c) \
+{ \
+long __res; \
+__asm__ volatile ("int $0x80" \
+	: "=a" (__res) \
+	: "0" (__NR_##name),"b" ((long)(a)),"c" ((long)(b)),"d" ((long)(c))); \
+if (__res>=0) \
+	return (type) __res; \
+errno=-__res; \
+return -1; \
+}
+
+#endif /* __LIBRARY__ */
+
+extern int errno;
+
+int access(const char * filename, mode_t mode);
+int acct(const char * filename);
+int alarm(int sec);
+int brk(void * end_data_segment);
+void * sbrk(ptrdiff_t increment);
+int chdir(const char * filename);
+int chmod(const char * filename, mode_t mode);
+int chown(const char * filename, uid_t owner, gid_t group);
+int chroot(const char * filename);
+int close(int fildes);
+int creat(const char * filename, mode_t mode);
+int dup(int fildes);
+int execve(const char * filename, char ** argv, char ** envp);
+int execv(const char * pathname, char ** argv);
+int execvp(const char * file, char ** argv);
+int execl(const char * pathname, char * arg0, ...);
+int execlp(const char * file, char * arg0, ...);
+int execle(const char * pathname, char * arg0, ...);
+volatile void exit(int status);
+volatile void _exit(int status);
+int fcntl(int fildes, int cmd, ...);
+int fork(void);
+int getpid(void);
+int getuid(void);
+int geteuid(void);
+int getgid(void);
+int getegid(void);
+int ioctl(int fildes, int cmd, ...);
+int kill(pid_t pid, int signal);
+int link(const char * filename1, const char * filename2);
+int lseek(int fildes, off_t offset, int origin);
+int mknod(const char * filename, mode_t mode, dev_t dev);
+int mount(const char * specialfile, const char * dir, int rwflag);
+int nice(int val);
+int open(const char * filename, int flag, ...);
+int pause(void);
+int pipe(int * fildes);
+int read(int fildes, char * buf, off_t count);
+int setpgrp(void);
+int setpgid(pid_t pid,pid_t pgid);
+int setuid(uid_t uid);
+int setgid(gid_t gid);
+void (*signal(int sig, void (*fn)(int)))(int);
+int stat(const char * filename, struct stat * stat_buf);
+int fstat(int fildes, struct stat * stat_buf);
+int stime(time_t * tptr);
+int sync(void);
+time_t time(time_t * tloc);
+time_t times(struct tms * tbuf);
+int ulimit(int cmd, long limit);
+mode_t umask(mode_t mask);
+int umount(const char * specialfile);
+int uname(struct utsname * name);
+int unlink(const char * filename);
+int ustat(dev_t dev, struct ustat * ubuf);
+int utime(const char * filename, struct utimbuf * times);
+pid_t waitpid(pid_t pid,int * wait_stat,int options);
+pid_t wait(int * wait_stat);
+int write(int fildes, const char * buf, off_t count);
+int dup2(int oldfd, int newfd);
+int getppid(void);
+pid_t getpgrp(void);
+pid_t setsid(void);
+int sys_getdents(unsigned int fd, struct linux_dirent *d, unsigned int count);
+int sys_pipe2(unsigned long * fildes,int flag);
+int sys_sleep(unsigned int seconds);
+#define __always_inline inline __attribute__((always_inline))
+
+#endif

os/os/linux/include/utime.h

@@ -0,0 +1,13 @@
+#ifndef _UTIME_H
+#define _UTIME_H
+
+#include <sys/types.h>	/* I know - shouldn't do this, but .. */
+
+struct utimbuf {
+	time_t actime;
+	time_t modtime;
+};
+
+extern int utime(const char *filename, struct utimbuf *times);
+
+#endif

os/os/linux/init/main.c

@@ -0,0 +1,216 @@
+/*
+ *  linux/init/main.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+#define __LIBRARY__
+#include <unistd.h>
+#include <time.h>
+
+/*
+ * we need this inline - forking from kernel space will result
+ * in NO COPY ON WRITE (!!!), until an execve is executed. This
+ * is no problem, but for the stack. This is handled by not letting
+ * main() use the stack at all after fork(). Thus, no function
+ * calls - which means inline code for fork too, as otherwise we
+ * would use the stack upon exit from 'fork()'.
+ *
+ * Actually only pause and fork are needed inline, so that there
+ * won't be any messing with the stack from main(), but we define
+ * some others too.
+ */
+ 
+__always_inline _syscall0(int,fork)
+__always_inline _syscall0(int,pause)
+__always_inline _syscall1(int,setup,void *,BIOS)
+__always_inline _syscall0(int,sync)
+
+#include <linux/tty.h>
+#include <linux/sched.h>
+#include <linux/head.h>
+#include <asm/system.h>
+#include <asm/io.h>
+
+#include <stddef.h>
+#include <stdarg.h>
+#include <fcntl.h>
+#include <sys/types.h>
+
+#include <linux/fs.h>
+
+static char printbuf[1024];
+
+extern int vsprintf();
+extern void init(void);
+extern void blk_dev_init(void);
+extern void chr_dev_init(void);
+extern void hd_init(void);
+extern void floppy_init(void);
+extern void mem_init(long start, long end);
+extern long rd_init(long mem_start, int length);
+extern long kernel_mktime(struct tm * tm);
+extern long startup_time;
+
+/*
+ * This is set up by the setup-routine at boot-time
+ */
+#define EXT_MEM_K (*(unsigned short *)0x90002)
+#define DRIVE_INFO (*(struct drive_info *)0x90080)
+#define ORIG_ROOT_DEV (*(unsigned short *)0x901FC)
+
+/*
+ * Yeah, yeah, it's ugly, but I cannot find how to do this correctly
+ * and this seems to work. I anybody has more info on the real-time
+ * clock I'd be interested. Most of this was trial and error, and some
+ * bios-listing reading. Urghh.
+ */
+
+#define CMOS_READ(addr) ({ \
+outb_p(0x80|addr,0x70); \
+inb_p(0x71); \
+})
+
+#define BCD_TO_BIN(val) ((val)=((val)&15) + ((val)>>4)*10)
+
+static void time_init(void)
+{
+	struct tm time;
+
+	do {
+		time.tm_sec = CMOS_READ(0);
+		time.tm_min = CMOS_READ(2);
+		time.tm_hour = CMOS_READ(4);
+		time.tm_mday = CMOS_READ(7);
+		time.tm_mon = CMOS_READ(8);
+		time.tm_year = CMOS_READ(9);
+	} while (time.tm_sec != CMOS_READ(0));
+	BCD_TO_BIN(time.tm_sec);
+	BCD_TO_BIN(time.tm_min);
+	BCD_TO_BIN(time.tm_hour);
+	BCD_TO_BIN(time.tm_mday);
+	BCD_TO_BIN(time.tm_mon);
+	BCD_TO_BIN(time.tm_year);
+	time.tm_mon--;
+	startup_time = kernel_mktime(&time);
+}
+
+static long memory_end = 0;
+static long buffer_memory_end = 0;
+static long main_memory_start = 0;
+
+struct drive_info { char dummy[32]; } drive_info;
+
+void main(void)		/* This really IS void, no error here. */
+{			/* The startup routine assumes (well, ...) this */
+/*
+ * Interrupts are still disabled. Do necessary setups, then
+ * enable them
+ */
+ 	ROOT_DEV = ORIG_ROOT_DEV;
+	__asm__ volatile ("cld");   /* by wyj */ 	
+ 	drive_info = DRIVE_INFO;
+	memory_end = (1<<20) + (EXT_MEM_K<<10);
+	memory_end &= 0xfffff000;
+	if (memory_end > 16*1024*1024)
+		memory_end = 16*1024*1024;
+	if (memory_end > 12*1024*1024) 
+		buffer_memory_end = 4*1024*1024;
+	else if (memory_end > 6*1024*1024)
+		buffer_memory_end = 2*1024*1024;
+	else
+		buffer_memory_end = 1*1024*1024;
+	main_memory_start = buffer_memory_end;
+#ifdef RAMDISK
+	main_memory_start += rd_init(main_memory_start, RAMDISK*1024);
+#endif
+	mem_init(main_memory_start,memory_end);
+	trap_init();
+	blk_dev_init();
+	chr_dev_init();
+	tty_init();
+	time_init();
+	sched_init();
+	buffer_init(buffer_memory_end);
+	hd_init();
+	floppy_init();
+	sti();
+	move_to_user_mode();
+	if (!fork()) {		/* we count on this going ok */
+		init();
+	}
+/*
+ *   NOTE!!   For any other task 'pause()' would mean we have to get a
+ * signal to awaken, but task0 is the sole exception (see 'schedule()')
+ * as task 0 gets activated at every idle moment (when no other tasks
+ * can run). For task0 'pause()' just means we go check if some other
+ * task can run, and if not we return here.
+ */
+	for(;;) pause();
+}
+
+static int printf(const char *fmt, ...)
+{
+	va_list args;
+	int i;
+
+	va_start(args, fmt);
+	write(1,printbuf,i=vsprintf(printbuf, fmt, args));
+	va_end(args);
+	return i;
+}
+
+static char * argv_rc[] = { "/bin/sh", NULL };
+static char * envp_rc[] = { "HOME=/", NULL, NULL };
+
+static char * argv[] = { "-/bin/sh",NULL };
+static char * envp[] = { "HOME=/usr/root", NULL, NULL };
+
+void init(void)
+{
+	int pid,i;
+
+	setup((void *) &drive_info);
+	(void) open("/dev/tty0",O_RDWR,0);
+	(void) dup(0);
+	(void) dup(0);
+	printf("%d buffers = %d bytes buffer space\n\r",NR_BUFFERS,
+		NR_BUFFERS*BLOCK_SIZE);
+	printf("Free mem: %d bytes\n\r",memory_end-main_memory_start);
+	if (!(pid=fork())) {
+		close(0);
+		if (open("/etc/rc",O_RDONLY,0))
+			_exit(1);
+		execve("/bin/sh",argv_rc,envp_rc);
+		_exit(2);
+	}
+	if (pid>0)
+		while (pid != wait(&i))
+			/* nothing */;
+	while (1) {
+		if ((pid=fork())<0) {
+			printf("Fork failed in init\r\n");
+			continue;
+		}
+		if (!pid) {
+			close(0);close(1);close(2);
+			setsid();
+			(void) open("/dev/tty0",O_RDWR,0);
+			(void) dup(0);
+			(void) dup(0);
+			_exit(execve("/bin/sh",argv,envp));
+		}
+		while (1)
+			if (pid == wait(&i))
+				break;
+		printf("\n\rchild %d died with code %04x\n\r",pid,i);
+		sync();
+	}
+	_exit(0);	/* NOTE! _exit, not exit() */
+}
+
+void print_nr(int sid)
+{
+	if (sid > 86)
+		printk(" --syscall: sid=%d, pid=%d\n", sid, current->pid);
+}

os/os/linux/kernel/Makefile

@@ -0,0 +1,83 @@
+#
+# Makefile for the FREAX-kernel.
+#
+# Note! Dependencies are done automagically by 'make dep', which also
+# removes any old dependencies. DON'T put your own dependencies here
+# unless it's something special (ie not a .c file).
+#
+
+AR	=ar
+AS	=as
+LD	=ld
+LDFLAGS	=-m elf_i386 -Ttext 0 -e startup_32
+CC	=gcc -march=i386
+CFLAGS	=-w -g -fomit-frame-pointer -finline-functions \
+	-nostdinc -fno-stack-protector -mcld -I../include
+CPP	=gcc -E -nostdinc -I../include
+
+.c.s:
+	$(CC) $(CFLAGS) \
+	-S -o $*.s $<
+.s.o:
+	$(AS) -o $*.o $<
+.c.o:
+	$(CC) $(CFLAGS) \
+	-c -o $*.o $<
+
+OBJS  = sched.o system_call.o traps.o asm.o fork.o \
+	panic.o pipe2.o printk.o vsprintf.o sys.o execve2.o exit.o \
+	signal.o mktime.o getdents.o
+
+kernel.o: $(OBJS)
+	$(LD) -r -o kernel.o $(OBJS)
+	sync
+
+clean:
+	rm -f core *.o *.a tmp_make keyboard.s
+	for i in *.c;do rm -f `basename $$i .c`.s;done
+	(cd chr_drv; make clean)
+	(cd blk_drv; make clean)
+	(cd math; make clean)
+
+dep:
+	sed '/\#\#\# Dependencies/q' < Makefile > tmp_make
+	(for i in *.c;do echo -n `echo $$i | sed 's,\.c,\.s,'`" "; \
+		$(CPP) -M $$i;done) >> tmp_make
+	cp tmp_make Makefile
+	(cd chr_drv; make dep)
+	(cd blk_drv; make dep)
+
+### Dependencies:
+exit.s exit.o : exit.c ../include/errno.h ../include/signal.h \
+  ../include/sys/types.h ../include/sys/wait.h ../include/linux/sched.h \
+  ../include/linux/head.h ../include/linux/fs.h ../include/linux/mm.h \
+  ../include/linux/kernel.h ../include/linux/tty.h ../include/termios.h \
+  ../include/asm/segment.h 
+fork.s fork.o : fork.c ../include/errno.h ../include/linux/sched.h \
+  ../include/linux/head.h ../include/linux/fs.h ../include/sys/types.h \
+  ../include/linux/mm.h ../include/signal.h ../include/linux/kernel.h \
+  ../include/asm/segment.h ../include/asm/system.h 
+mktime.s mktime.o : mktime.c ../include/time.h 
+panic.s panic.o : panic.c ../include/linux/kernel.h ../include/linux/sched.h \
+  ../include/linux/head.h ../include/linux/fs.h ../include/sys/types.h \
+  ../include/linux/mm.h ../include/signal.h 
+printk.s printk.o : printk.c ../include/stdarg.h ../include/stddef.h \
+  ../include/linux/kernel.h 
+sched.s sched.o : sched.c ../include/linux/sched.h ../include/linux/head.h \
+  ../include/linux/fs.h ../include/sys/types.h ../include/linux/mm.h \
+  ../include/signal.h ../include/linux/kernel.h ../include/linux/sys.h \
+  ../include/linux/fdreg.h ../include/asm/system.h ../include/asm/io.h \
+  ../include/asm/segment.h 
+signal.s signal.o : signal.c ../include/linux/sched.h ../include/linux/head.h \
+  ../include/linux/fs.h ../include/sys/types.h ../include/linux/mm.h \
+  ../include/signal.h ../include/linux/kernel.h ../include/asm/segment.h 
+sys.s sys.o : sys.c ../include/errno.h ../include/linux/sched.h \
+  ../include/linux/head.h ../include/linux/fs.h ../include/sys/types.h \
+  ../include/linux/mm.h ../include/signal.h ../include/linux/tty.h \
+  ../include/termios.h ../include/linux/kernel.h ../include/asm/segment.h \
+  ../include/sys/times.h ../include/sys/utsname.h 
+traps.s traps.o : traps.c ../include/string.h ../include/linux/head.h \
+  ../include/linux/sched.h ../include/linux/fs.h ../include/sys/types.h \
+  ../include/linux/mm.h ../include/signal.h ../include/linux/kernel.h \
+  ../include/asm/system.h ../include/asm/segment.h ../include/asm/io.h 
+vsprintf.s vsprintf.o : vsprintf.c ../include/stdarg.h ../include/string.h 

os/os/linux/kernel/asm.s

@@ -0,0 +1,146 @@
+/*
+ *  linux/kernel/asm.s
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+/*
+ * asm.s contains the low-level code for most hardware faults.
+ * page_exception is handled by the mm, so that isn't here. This
+ * file also handles (hopefully) fpu-exceptions due to TS-bit, as
+ * the fpu must be properly saved/resored. This hasn't been tested.
+ */
+
+.globl divide_error,debug,nmi,int3,overflow,bounds,invalid_op
+.globl double_fault,coprocessor_segment_overrun
+.globl invalid_TSS,segment_not_present,stack_segment
+.globl general_protection,coprocessor_error,irq13,reserved
+
+divide_error:
+	pushl $do_divide_error
+no_error_code:
+	xchgl %eax,(%esp)
+	pushl %ebx
+	pushl %ecx
+	pushl %edx
+	pushl %edi
+	pushl %esi
+	pushl %ebp
+	push %ds
+	push %es
+	push %fs
+	pushl $0		# "error code"
+	lea 44(%esp),%edx
+	pushl %edx
+	movl $0x10,%edx
+	mov %dx,%ds
+	mov %dx,%es
+	mov %dx,%fs
+	call *%eax
+	addl $8,%esp
+	pop %fs
+	pop %es
+	pop %ds
+	popl %ebp
+	popl %esi
+	popl %edi
+	popl %edx
+	popl %ecx
+	popl %ebx
+	popl %eax
+	iret
+
+debug:
+	pushl $do_int3		# _do_debug
+	jmp no_error_code
+
+nmi:
+	pushl $do_nmi
+	jmp no_error_code
+
+int3:
+	pushl $do_int3
+	jmp no_error_code
+
+overflow:
+	pushl $do_overflow
+	jmp no_error_code
+
+bounds:
+	pushl $do_bounds
+	jmp no_error_code
+
+invalid_op:
+	pushl $do_invalid_op
+	jmp no_error_code
+
+coprocessor_segment_overrun:
+	pushl $do_coprocessor_segment_overrun
+	jmp no_error_code
+
+reserved:
+	pushl $do_reserved
+	jmp no_error_code
+
+irq13:
+	pushl %eax
+	xorb %al,%al
+	outb %al,$0xF0
+	movb $0x20,%al
+	outb %al,$0x20
+	jmp 1f
+1:	jmp 1f
+1:	outb %al,$0xA0
+	popl %eax
+	jmp coprocessor_error
+
+double_fault:
+	pushl $do_double_fault
+error_code:
+	xchgl %eax,4(%esp)		# error code <-> %eax
+	xchgl %ebx,(%esp)		# &function <-> %ebx
+	pushl %ecx
+	pushl %edx
+	pushl %edi
+	pushl %esi
+	pushl %ebp
+	push %ds
+	push %es
+	push %fs
+	pushl %eax			# error code
+	lea 44(%esp),%eax		# offset
+	pushl %eax
+	movl $0x10,%eax
+	mov %ax,%ds
+	mov %ax,%es
+	mov %ax,%fs
+	call *%ebx
+	addl $8,%esp
+	pop %fs
+	pop %es
+	pop %ds
+	popl %ebp
+	popl %esi
+	popl %edi
+	popl %edx
+	popl %ecx
+	popl %ebx
+	popl %eax
+	iret
+
+invalid_TSS:
+	pushl $do_invalid_TSS
+	jmp error_code
+
+segment_not_present:
+	pushl $do_segment_not_present
+	jmp error_code
+
+stack_segment:
+	pushl $do_stack_segment
+	jmp error_code
+
+general_protection:
+	pushl $do_general_protection
+	jmp error_code
+

os/os/linux/kernel/blk_drv/Makefile

@@ -0,0 +1,58 @@
+#
+# Makefile for the FREAX-kernel block device drivers.
+#
+# Note! Dependencies are done automagically by 'make dep', which also
+# removes any old dependencies. DON'T put your own dependencies here
+# unless it's something special (ie not a .c file).
+#
+
+AR	=ar
+AS	=as
+LD	=ld
+LDFLAGS	=-s -x
+CC	=gcc -march=i386
+CFLAGS	=-w -g -fstrength-reduce -fomit-frame-pointer -mcld \
+	-finline-functions -nostdinc -fno-stack-protector -I../../include
+CPP	=gcc -E -nostdinc -I../../include
+
+.c.s:
+	$(CC) $(CFLAGS) \
+	-S -o $*.s $<
+.s.o:
+	$(AS) -o $*.o $<
+.c.o:
+	$(CC) $(CFLAGS) \
+	-c -o $*.o $<
+
+OBJS  = ll_rw_blk.o floppy.o hd.o ramdisk.o
+
+blk_drv.a: $(OBJS)
+	$(AR) rcs blk_drv.a $(OBJS)
+	sync
+
+clean:
+	rm -f core *.o *.a tmp_make
+	for i in *.c;do rm -f `basename $$i .c`.s;done
+
+dep:
+	sed '/\#\#\# Dependencies/q' < Makefile > tmp_make
+	(for i in *.c;do echo -n `echo $$i | sed 's,\.c,\.s,'`" "; \
+		$(CPP) -M $$i;done) >> tmp_make
+	cp tmp_make Makefile
+
+### Dependencies:
+floppy.s floppy.o : floppy.c ../../include/linux/sched.h ../../include/linux/head.h \
+  ../../include/linux/fs.h ../../include/sys/types.h ../../include/linux/mm.h \
+  ../../include/signal.h ../../include/linux/kernel.h \
+  ../../include/linux/fdreg.h ../../include/asm/system.h \
+  ../../include/asm/io.h ../../include/asm/segment.h blk.h 
+hd.s hd.o : hd.c ../../include/linux/config.h ../../include/linux/sched.h \
+  ../../include/linux/head.h ../../include/linux/fs.h \
+  ../../include/sys/types.h ../../include/linux/mm.h ../../include/signal.h \
+  ../../include/linux/kernel.h ../../include/linux/hdreg.h \
+  ../../include/asm/system.h ../../include/asm/io.h \
+  ../../include/asm/segment.h blk.h 
+ll_rw_blk.s ll_rw_blk.o : ll_rw_blk.c ../../include/errno.h ../../include/linux/sched.h \
+  ../../include/linux/head.h ../../include/linux/fs.h \
+  ../../include/sys/types.h ../../include/linux/mm.h ../../include/signal.h \
+  ../../include/linux/kernel.h ../../include/asm/system.h blk.h 

os/os/linux/kernel/blk_drv/blk.h

@@ -0,0 +1,140 @@
+#ifndef _BLK_H
+#define _BLK_H
+
+#define NR_BLK_DEV	7
+/*
+ * NR_REQUEST is the number of entries in the request-queue.
+ * NOTE that writes may use only the low 2/3 of these: reads
+ * take precedence.
+ *
+ * 32 seems to be a reasonable number: enough to get some benefit
+ * from the elevator-mechanism, but not so much as to lock a lot of
+ * buffers when they are in the queue. 64 seems to be too many (easily
+ * long pauses in reading when heavy writing/syncing is going on)
+ */
+#define NR_REQUEST	32
+
+/*
+ * Ok, this is an expanded form so that we can use the same
+ * request for paging requests when that is implemented. In
+ * paging, 'bh' is NULL, and 'waiting' is used to wait for
+ * read/write completion.
+ */
+struct request {
+	int dev;		/* -1 if no request */
+	int cmd;		/* READ or WRITE */
+	int errors;
+	unsigned long sector;
+	unsigned long nr_sectors;
+	char * buffer;
+	struct task_struct * waiting;
+	struct buffer_head * bh;
+	struct request * next;
+};
+
+/*
+ * This is used in the elevator algorithm: Note that
+ * reads always go before writes. This is natural: reads
+ * are much more time-critical than writes.
+ */
+#define IN_ORDER(s1,s2) \
+((s1)->cmd<(s2)->cmd || (s1)->cmd==(s2)->cmd && \
+((s1)->dev < (s2)->dev || ((s1)->dev == (s2)->dev && \
+(s1)->sector < (s2)->sector)))
+
+struct blk_dev_struct {
+	void (*request_fn)(void);
+	struct request * current_request;
+};
+
+extern struct blk_dev_struct blk_dev[NR_BLK_DEV];
+extern struct request request[NR_REQUEST];
+extern struct task_struct * wait_for_request;
+
+#ifdef MAJOR_NR
+
+/*
+ * Add entries as needed. Currently the only block devices
+ * supported are hard-disks and floppies.
+ */
+
+#if (MAJOR_NR == 1)
+/* ram disk */
+#define DEVICE_NAME "ramdisk"
+#define DEVICE_REQUEST do_rd_request
+#define DEVICE_NR(device) ((device) & 7)
+#define DEVICE_ON(device) 
+#define DEVICE_OFF(device)
+
+#elif (MAJOR_NR == 2)
+/* floppy */
+#define DEVICE_NAME "floppy"
+#define DEVICE_INTR do_floppy
+#define DEVICE_REQUEST do_fd_request
+#define DEVICE_NR(device) ((device) & 3)
+#define DEVICE_ON(device) floppy_on(DEVICE_NR(device))
+#define DEVICE_OFF(device) floppy_off(DEVICE_NR(device))
+
+#elif (MAJOR_NR == 3)
+/* harddisk */
+#define DEVICE_NAME "harddisk"
+#define DEVICE_INTR do_hd
+#define DEVICE_REQUEST do_hd_request
+#define DEVICE_NR(device) (MINOR(device)/5)
+#define DEVICE_ON(device)
+#define DEVICE_OFF(device)
+
+#elif (MAJOR_NR > 3)
+/* unknown blk device */
+#error "unknown blk device"
+
+#endif
+
+#define CURRENT (blk_dev[MAJOR_NR].current_request)
+#define CURRENT_DEV DEVICE_NR(CURRENT->dev)
+
+#ifdef DEVICE_INTR
+void (*DEVICE_INTR)(void) = NULL;
+#endif
+static void (DEVICE_REQUEST)(void);
+
+static inline void unlock_buffer(struct buffer_head * bh)
+{
+	if (!bh->b_lock)
+		printk(DEVICE_NAME ": free buffer being unlocked\n");
+	bh->b_lock=0;
+	wake_up(&bh->b_wait);
+}
+
+static inline void end_request(int uptodate)
+{
+	DEVICE_OFF(CURRENT->dev);
+	if (CURRENT->bh) {
+		CURRENT->bh->b_uptodate = uptodate;
+		unlock_buffer(CURRENT->bh);
+	}
+	if (!uptodate) {
+		printk(DEVICE_NAME " I/O error\n\r");
+		printk("dev %04x, block %d\n\r",CURRENT->dev,
+			CURRENT->bh->b_blocknr);
+	}
+	wake_up(&CURRENT->waiting);
+	wake_up(&wait_for_request);
+	CURRENT->dev = -1;
+	CURRENT = CURRENT->next;
+}
+
+#define INIT_REQUEST \
+repeat: \
+	if (!CURRENT) \
+		return; \
+	if (MAJOR(CURRENT->dev) != MAJOR_NR) \
+		panic(DEVICE_NAME ": request list destroyed"); \
+	if (CURRENT->bh) { \
+		if (!CURRENT->bh->b_lock) \
+			panic(DEVICE_NAME ": block not locked"); \
+	}
+
+#endif
+
+#endif

os/os/linux/kernel/blk_drv/floppy.c

@@ -0,0 +1,463 @@
+/*
+ *  linux/kernel/floppy.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+/*
+ * 02.12.91 - Changed to static variables to indicate need for reset
+ * and recalibrate. This makes some things easier (output_byte reset
+ * checking etc), and means less interrupt jumping in case of errors,
+ * so the code is hopefully easier to understand.
+ */
+
+/*
+ * This file is certainly a mess. I've tried my best to get it working,
+ * but I don't like programming floppies, and I have only one anyway.
+ * Urgel. I should check for more errors, and do more graceful error
+ * recovery. Seems there are problems with several drives. I've tried to
+ * correct them. No promises. 
+ */
+
+/*
+ * As with hd.c, all routines within this file can (and will) be called
+ * by interrupts, so extreme caution is needed. A hardware interrupt
+ * handler may not sleep, or a kernel panic will happen. Thus I cannot
+ * call "floppy-on" directly, but have to set a special timer interrupt
+ * etc.
+ *
+ * Also, I'm not certain this works on more than 1 floppy. Bugs may
+ * abund.
+ */
+
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/fdreg.h>
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/segment.h>
+
+#define MAJOR_NR 2
+#include "blk.h"
+
+static int recalibrate = 0;
+static int reset = 0;
+static int seek = 0;
+
+extern unsigned char current_DOR;
+
+#define immoutb_p(val,port) \
+__asm__("outb %0,%1\n\tjmp 1f\n1:\tjmp 1f\n1:"::"a" ((char) (val)),"i" (port))
+
+#define TYPE(x) ((x)>>2)
+#define DRIVE(x) ((x)&0x03)
+/*
+ * Note that MAX_ERRORS=8 doesn't imply that we retry every bad read
+ * max 8 times - some types of errors increase the errorcount by 2,
+ * so we might actually retry only 5-6 times before giving up.
+ */
+#define MAX_ERRORS 8
+
+/*
+ * globals used by 'result()'
+ */
+#define MAX_REPLIES 7
+static unsigned char reply_buffer[MAX_REPLIES];
+#define ST0 (reply_buffer[0])
+#define ST1 (reply_buffer[1])
+#define ST2 (reply_buffer[2])
+#define ST3 (reply_buffer[3])
+
+/*
+ * This struct defines the different floppy types. Unlike minix
+ * linux doesn't have a "search for right type"-type, as the code
+ * for that is convoluted and weird. I've got enough problems with
+ * this driver as it is.
+ *
+ * The 'stretch' tells if the tracks need to be boubled for some
+ * types (ie 360kB diskette in 1.2MB drive etc). Others should
+ * be self-explanatory.
+ */
+static struct floppy_struct {
+	unsigned int size, sect, head, track, stretch;
+	unsigned char gap,rate,spec1;
+} floppy_type[] = {
+	{    0, 0,0, 0,0,0x00,0x00,0x00 },	/* no testing */
+	{  720, 9,2,40,0,0x2A,0x02,0xDF },	/* 360kB PC diskettes */
+	{ 2400,15,2,80,0,0x1B,0x00,0xDF },	/* 1.2 MB AT-diskettes */
+	{  720, 9,2,40,1,0x2A,0x02,0xDF },	/* 360kB in 720kB drive */
+	{ 1440, 9,2,80,0,0x2A,0x02,0xDF },	/* 3.5" 720kB diskette */
+	{  720, 9,2,40,1,0x23,0x01,0xDF },	/* 360kB in 1.2MB drive */
+	{ 1440, 9,2,80,0,0x23,0x01,0xDF },	/* 720kB in 1.2MB drive */
+	{ 2880,18,2,80,0,0x1B,0x00,0xCF },	/* 1.44MB diskette */
+};
+/*
+ * Rate is 0 for 500kb/s, 2 for 300kbps, 1 for 250kbps
+ * Spec1 is 0xSH, where S is stepping rate (F=1ms, E=2ms, D=3ms etc),
+ * H is head unload time (1=16ms, 2=32ms, etc)
+ *
+ * Spec2 is (HLD<<1 | ND), where HLD is head load time (1=2ms, 2=4 ms etc)
+ * and ND is set means no DMA. Hardcoded to 6 (HLD=6ms, use DMA).
+ */
+
+extern void floppy_interrupt(void);
+extern char tmp_floppy_area[1024];
+
+/*
+ * These are global variables, as that's the easiest way to give
+ * information to interrupts. They are the data used for the current
+ * request.
+ */
+static int cur_spec1 = -1;
+static int cur_rate = -1;
+static struct floppy_struct * floppy = floppy_type;
+static unsigned char current_drive = 0;
+static unsigned char sector = 0;
+static unsigned char head = 0;
+static unsigned char track = 0;
+static unsigned char seek_track = 0;
+static unsigned char current_track = 255;
+static unsigned char command = 0;
+unsigned char selected = 0;
+struct task_struct * wait_on_floppy_select = NULL;
+
+void floppy_deselect(unsigned int nr)
+{
+	if (nr != (current_DOR & 3))
+		printk("floppy_deselect: drive not selected\n\r");
+	selected = 0;
+	wake_up(&wait_on_floppy_select);
+}
+
+/*
+ * floppy-change is never called from an interrupt, so we can relax a bit
+ * here, sleep etc. Note that floppy-on tries to set current_DOR to point
+ * to the desired drive, but it will probably not survive the sleep if
+ * several floppies are used at the same time: thus the loop.
+ */
+int floppy_change(unsigned int nr)
+{
+repeat:
+	floppy_on(nr);
+	while ((current_DOR & 3) != nr && selected)
+		interruptible_sleep_on(&wait_on_floppy_select);
+	if ((current_DOR & 3) != nr)
+		goto repeat;
+	if (inb(FD_DIR) & 0x80) {
+		floppy_off(nr);
+		return 1;
+	}
+	floppy_off(nr);
+	return 0;
+}
+
+#define copy_buffer(from,to) \
+__asm__("cld ; rep ; movsl" \
+	::"c" (BLOCK_SIZE/4),"S" ((long)(from)),"D" ((long)(to)) \
+	)
+
+static void setup_DMA(void)
+{
+	long addr = (long) CURRENT->buffer;
+
+	cli();
+	if (addr >= 0x100000) {
+		addr = (long) tmp_floppy_area;
+		if (command == FD_WRITE)
+			copy_buffer(CURRENT->buffer,tmp_floppy_area);
+	}
+/* mask DMA 2 */
+	immoutb_p(4|2,10);
+/* output command byte. I don't know why, but everyone (minix, */
+/* sanches & canton) output this twice, first to 12 then to 11 */
+ 	__asm__("outb %%al,$12\n\tjmp 1f\n1:\tjmp 1f\n1:\t"
+	"outb %%al,$11\n\tjmp 1f\n1:\tjmp 1f\n1:"::
+	"a" ((char) ((command == FD_READ)?DMA_READ:DMA_WRITE)));
+/* 8 low bits of addr */
+	immoutb_p(addr,4);
+	addr >>= 8;
+/* bits 8-15 of addr */
+	immoutb_p(addr,4);
+	addr >>= 8;
+/* bits 16-19 of addr */
+	immoutb_p(addr,0x81);
+/* low 8 bits of count-1 (1024-1=0x3ff) */
+	immoutb_p(0xff,5);
+/* high 8 bits of count-1 */
+	immoutb_p(3,5);
+/* activate DMA 2 */
+	immoutb_p(0|2,10);
+	sti();
+}
+
+static void output_byte(char byte)
+{
+	int counter;
+	unsigned char status;
+
+	if (reset)
+		return;
+	for(counter = 0 ; counter < 10000 ; counter++) {
+		status = inb_p(FD_STATUS) & (STATUS_READY | STATUS_DIR);
+		if (status == STATUS_READY) {
+			outb(byte,FD_DATA);
+			return;
+		}
+	}
+	reset = 1;
+	printk("Unable to send byte to FDC\n\r");
+}
+
+static int result(void)
+{
+	int i = 0, counter, status;
+
+	if (reset)
+		return -1;
+	for (counter = 0 ; counter < 10000 ; counter++) {
+		status = inb_p(FD_STATUS)&(STATUS_DIR|STATUS_READY|STATUS_BUSY);
+		if (status == STATUS_READY)
+			return i;
+		if (status == (STATUS_DIR|STATUS_READY|STATUS_BUSY)) {
+			if (i >= MAX_REPLIES)
+				break;
+			reply_buffer[i++] = inb_p(FD_DATA);
+		}
+	}
+	reset = 1;
+	printk("Getstatus times out\n\r");
+	return -1;
+}
+
+static void bad_flp_intr(void)
+{
+	CURRENT->errors++;
+	if (CURRENT->errors > MAX_ERRORS) {
+		floppy_deselect(current_drive);
+		end_request(0);
+	}
+	if (CURRENT->errors > MAX_ERRORS/2)
+		reset = 1;
+	else
+		recalibrate = 1;
+}	
+
+/*
+ * Ok, this interrupt is called after a DMA read/write has succeeded,
+ * so we check the results, and copy any buffers.
+ */
+static void rw_interrupt(void)
+{
+	if (result() != 7 || (ST0 & 0xf8) || (ST1 & 0xbf) || (ST2 & 0x73)) {
+		if (ST1 & 0x02) {
+			printk("Drive %d is write protected\n\r",current_drive);
+			floppy_deselect(current_drive);
+			end_request(0);
+		} else
+			bad_flp_intr();
+		do_fd_request();
+		return;
+	}
+	if (command == FD_READ && (unsigned long)(CURRENT->buffer) >= 0x100000)
+		copy_buffer(tmp_floppy_area,CURRENT->buffer);
+	floppy_deselect(current_drive);
+	end_request(1);
+	do_fd_request();
+}
+
+inline void setup_rw_floppy(void)
+{
+	setup_DMA();
+	do_floppy = rw_interrupt;
+	output_byte(command);
+	output_byte(head<<2 | current_drive);
+	output_byte(track);
+	output_byte(head);
+	output_byte(sector);
+	output_byte(2);		/* sector size = 512 */
+	output_byte(floppy->sect);
+	output_byte(floppy->gap);
+	output_byte(0xFF);	/* sector size (0xff when n!=0 ?) */
+	if (reset)
+		do_fd_request();
+}
+
+/*
+ * This is the routine called after every seek (or recalibrate) interrupt
+ * from the floppy controller. Note that the "unexpected interrupt" routine
+ * also does a recalibrate, but doesn't come here.
+ */
+static void seek_interrupt(void)
+{
+/* sense drive status */
+	output_byte(FD_SENSEI);
+	if (result() != 2 || (ST0 & 0xF8) != 0x20 || ST1 != seek_track) {
+		bad_flp_intr();
+		do_fd_request();
+		return;
+	}
+	current_track = ST1;
+	setup_rw_floppy();
+}
+
+/*
+ * This routine is called when everything should be correctly set up
+ * for the transfer (ie floppy motor is on and the correct floppy is
+ * selected).
+ */
+static void transfer(void)
+{
+	if (cur_spec1 != floppy->spec1) {
+		cur_spec1 = floppy->spec1;
+		output_byte(FD_SPECIFY);
+		output_byte(cur_spec1);		/* hut etc */
+		output_byte(6);			/* Head load time =6ms, DMA */
+	}
+	if (cur_rate != floppy->rate)
+		outb_p(cur_rate = floppy->rate,FD_DCR);
+	if (reset) {
+		do_fd_request();
+		return;
+	}
+	if (!seek) {
+		setup_rw_floppy();
+		return;
+	}
+	do_floppy = seek_interrupt;
+	if (seek_track) {
+		output_byte(FD_SEEK);
+		output_byte(head<<2 | current_drive);
+		output_byte(seek_track);
+	} else {
+		output_byte(FD_RECALIBRATE);
+		output_byte(head<<2 | current_drive);
+	}
+	if (reset)
+		do_fd_request();
+}
+
+/*
+ * Special case - used after a unexpected interrupt (or reset)
+ */
+static void recal_interrupt(void)
+{
+	output_byte(FD_SENSEI);
+	if (result()!=2 || (ST0 & 0xE0) == 0x60)
+		reset = 1;
+	else
+		recalibrate = 0;
+	do_fd_request();
+}
+
+void unexpected_floppy_interrupt(void)
+{
+	output_byte(FD_SENSEI);
+	if (result()!=2 || (ST0 & 0xE0) == 0x60)
+		reset = 1;
+	else
+		recalibrate = 1;
+}
+
+static void recalibrate_floppy(void)
+{
+	recalibrate = 0;
+	current_track = 0;
+	current_drive = 1;      /* by wyj, ?? */
+	do_floppy = recal_interrupt;
+	output_byte(FD_RECALIBRATE);
+	output_byte(head<<2 | current_drive);
+	if (reset)
+		do_fd_request();
+}
+
+static void reset_interrupt(void)
+{
+	output_byte(FD_SENSEI);
+	(void) result();
+	output_byte(FD_SPECIFY);
+	output_byte(cur_spec1);		/* hut etc */
+	output_byte(6);			/* Head load time =6ms, DMA */
+	do_fd_request();
+}
+
+/*
+ * reset is done by pulling bit 2 of DOR low for a while.
+ */
+static void reset_floppy(void)
+{
+	int i;
+
+	reset = 0;
+	cur_spec1 = -1;
+	cur_rate = -1;
+	recalibrate = 1;
+	printk("Reset-floppy called\n\r");
+	cli();
+	do_floppy = reset_interrupt;
+	outb_p(current_DOR & ~0x04,FD_DOR);
+	for (i=0 ; i<100 ; i++)
+		__asm__("nop");
+	outb(current_DOR,FD_DOR);
+	sti();
+}
+
+static void floppy_on_interrupt(void)
+{
+/* We cannot do a floppy-select, as that might sleep. We just force it */
+	selected = 1;
+	if (current_drive != (current_DOR & 3)) {
+		current_DOR &= 0xFC;
+		current_DOR |= current_drive;
+		outb(current_DOR,FD_DOR);
+		add_timer(2,&transfer);
+	} else
+		transfer();
+}
+
+void do_fd_request(void)
+{
+	unsigned int block;
+
+	seek = 0;
+	if (reset) {
+		reset_floppy();
+		return;
+	}
+	if (recalibrate) {
+		recalibrate_floppy();
+		return;
+	}
+	INIT_REQUEST;
+	floppy = (MINOR(CURRENT->dev)>>2) + floppy_type;
+	if (current_drive != CURRENT_DEV)
+		seek = 1;
+	current_drive = CURRENT_DEV;
+	block = CURRENT->sector;
+	if (block+2 > floppy->size) {
+		end_request(0);
+		goto repeat;
+	}
+	sector = block % floppy->sect;
+	block /= floppy->sect;
+	head = block % floppy->head;
+	track = block / floppy->head;
+	seek_track = track << floppy->stretch;
+	if (seek_track != current_track)
+		seek = 1;
+	sector++;
+	if (CURRENT->cmd == READ)
+		command = FD_READ;
+	else if (CURRENT->cmd == WRITE)
+		command = FD_WRITE;
+	else
+		panic("do_fd_request: unknown command");
+	add_timer(ticks_to_floppy_on(current_drive),&floppy_on_interrupt);
+}
+
+void floppy_init(void)
+{
+	blk_dev[MAJOR_NR].request_fn = DEVICE_REQUEST;
+	set_trap_gate(0x26,&floppy_interrupt);
+	outb(inb_p(0x21)&~0x40,0x21);
+}

os/os/linux/kernel/blk_drv/hd.c

@@ -0,0 +1,351 @@
+/*
+ *  linux/kernel/hd.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+/*
+ * This is the low-level hd interrupt support. It traverses the
+ * request-list, using interrupts to jump between functions. As
+ * all the functions are called within interrupts, we may not
+ * sleep. Special care is recommended.
+ * 
+ *  modified by Drew Eckhardt to check nr of hd's from the CMOS.
+ */
+
+#include <linux/config.h>
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/hdreg.h>
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/segment.h>
+
+#define MAJOR_NR 3
+#include "blk.h"
+
+#define CMOS_READ(addr) ({ \
+outb_p(0x80|addr,0x70); \
+inb_p(0x71); \
+})
+
+/* Max read/write errors/sector */
+#define MAX_ERRORS	7
+#define MAX_HD		2
+
+static void recal_intr(void);
+
+static int recalibrate = 0; /* 1, wen */
+static int reset = 0;
+
+/*
+ *  This struct defines the HD's and their types.
+ */
+struct hd_i_struct {
+	int head,sect,cyl,wpcom,lzone,ctl;
+	};
+#ifdef HD_TYPE
+struct hd_i_struct hd_info[] = { HD_TYPE };
+#define NR_HD ((sizeof (hd_info))/(sizeof (struct hd_i_struct)))
+#else
+struct hd_i_struct hd_info[] = { {0,0,0,0,0,0},{0,0,0,0,0,0} };
+static int NR_HD = 0;
+#endif
+
+static struct hd_struct {
+	long start_sect;
+	long nr_sects;
+} hd[5*MAX_HD]={{0,0},};
+
+#define port_read(port,buf,nr) \
+__asm__("cld;rep;insw"::"d" (port),"D" (buf),"c" (nr))
+
+#define port_write(port,buf,nr) \
+__asm__("cld;rep;outsw"::"d" (port),"S" (buf),"c" (nr))
+
+extern void hd_interrupt(void);
+extern void rd_load(void);
+
+/* This may be used only once, enforced by 'static int callable' */
+int sys_setup(void * BIOS)
+{
+	static int callable = 1;
+	int i,drive;
+	unsigned char cmos_disks;
+	struct partition *p;
+	struct buffer_head * bh;
+
+	if (!callable)
+		return -1;
+	callable = 0;
+#ifndef HD_TYPE
+	for (drive=0 ; drive<2 ; drive++) {
+		hd_info[drive].cyl = *(unsigned short *) BIOS;
+		hd_info[drive].head = *(unsigned char *) (2+BIOS);
+		hd_info[drive].wpcom = *(unsigned short *) (5+BIOS);
+		hd_info[drive].ctl = *(unsigned char *) (8+BIOS);
+		hd_info[drive].lzone = *(unsigned short *) (12+BIOS);
+		hd_info[drive].sect = *(unsigned char *) (14+BIOS);
+		BIOS += 16;
+	}
+	if (hd_info[1].cyl)
+		NR_HD=2;
+	else
+		NR_HD=1;
+#endif
+	for (i=0 ; i<NR_HD ; i++) {
+		hd[i*5].start_sect = 0;
+		hd[i*5].nr_sects = hd_info[i].head*
+				hd_info[i].sect*hd_info[i].cyl;
+	}
+
+	/*
+		We querry CMOS about hard disks : it could be that 
+		we have a SCSI/ESDI/etc controller that is BIOS
+		compatable with ST-506, and thus showing up in our
+		BIOS table, but not register compatable, and therefore
+		not present in CMOS.
+
+		Furthurmore, we will assume that our ST-506 drives
+		<if any> are the primary drives in the system, and 
+		the ones reflected as drive 1 or 2.
+
+		The first drive is stored in the high nibble of CMOS
+		byte 0x12, the second in the low nibble.  This will be
+		either a 4 bit drive type or 0xf indicating use byte 0x19 
+		for an 8 bit type, drive 1, 0x1a for drive 2 in CMOS.
+
+		Needless to say, a non-zero value means we have 
+		an AT controller hard disk for that drive.
+
+		
+	*/
+
+	if ((cmos_disks = CMOS_READ(0x12)) & 0xf0)
+		if (cmos_disks & 0x0f)
+			NR_HD = 2;
+		else
+			NR_HD = 1;
+	else
+		NR_HD = 0;
+	for (i = NR_HD ; i < 2 ; i++) {
+		hd[i*5].start_sect = 0;
+		hd[i*5].nr_sects = 0;
+	}
+	for (drive=0 ; drive<NR_HD ; drive++) {
+		if (!(bh = bread(0x300 + drive*5,0))) {
+			printk("Unable to read partition table of drive %d\n\r",
+				drive);
+			panic("");
+		}
+		if (bh->b_data[510] != 0x55 || (unsigned char)
+		    bh->b_data[511] != 0xAA) {
+			printk("Bad partition table on drive %d\n\r",drive);
+			panic("");
+		}
+		p = 0x1BE + (void *)bh->b_data;
+		for (i=1;i<5;i++,p++) {
+			hd[i+5*drive].start_sect = p->start_sect;
+			hd[i+5*drive].nr_sects = p->nr_sects;
+		}
+		brelse(bh);
+	}
+	if (NR_HD)
+		printk("Partition table%s ok.\n\r",(NR_HD>1)?"s":"");
+	rd_load();
+	mount_root();
+	return (0);
+}
+
+static int controller_ready(void)
+{
+	/* int retries=10000; */
+	int retries=100000;
+
+	/* while (--retries && (inb_p(HD_STATUS)&0xc0)!=0x40); */
+	while (--retries && (inb_p(HD_STATUS)&0x80));
+	return (retries);
+}
+
+static int win_result(void)
+{
+	int i=inb_p(HD_STATUS);
+
+	if ((i & (BUSY_STAT | READY_STAT | WRERR_STAT | SEEK_STAT | ERR_STAT))
+		== (READY_STAT | SEEK_STAT))
+		return(0); /* ok */
+	if (i&1) i=inb(HD_ERROR);
+	return (1);
+}
+
+static void hd_out(unsigned int drive,unsigned int nsect,unsigned int sect,
+		unsigned int head,unsigned int cyl,unsigned int cmd,
+		void (*intr_addr)(void))
+{
+	register int port asm("dx");
+
+	if (drive>1 || head>15)
+		panic("Trying to write bad sector");
+	if (!controller_ready())
+		panic("HD controller not ready");
+	do_hd = intr_addr;
+	outb_p(hd_info[drive].ctl,HD_CMD);
+	port=HD_DATA;
+	outb_p(hd_info[drive].wpcom>>2,++port);
+	outb_p(nsect,++port);
+	outb_p(sect,++port);
+	outb_p(cyl,++port);
+	outb_p(cyl>>8,++port);
+	outb_p(0xA0|(drive<<4)|head,++port);
+	outb(cmd,++port);
+}
+
+static int drive_busy(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < 10000; i++)
+		if (READY_STAT == (inb_p(HD_STATUS) & (BUSY_STAT|READY_STAT)))
+			break;
+	i = inb(HD_STATUS);
+	i &= BUSY_STAT | READY_STAT | SEEK_STAT;
+	if (i == READY_STAT | SEEK_STAT)
+		return(0);
+	printk("HD controller times out\n\r");
+	return(1);
+}
+
+static void reset_controller(void)
+{
+	int	i;
+
+	outb(4,HD_CMD);
+	for(i = 0; i < 100; i++) nop();
+	outb(hd_info[0].ctl & 0x0f ,HD_CMD);
+	if (drive_busy())
+		printk("HD-controller still busy\n\r");
+	if ((i = inb(HD_ERROR)) != 1)
+		printk("HD-controller reset failed: %02x\n\r",i);
+}
+
+static void reset_hd(int nr)
+{
+	reset_controller();
+	hd_out(nr,hd_info[nr].sect,hd_info[nr].sect,hd_info[nr].head-1,
+		hd_info[nr].cyl,WIN_SPECIFY,&recal_intr);
+}
+
+void unexpected_hd_interrupt(void)
+{
+	printk("Unexpected HD interrupt\n\r");
+}
+
+static void bad_rw_intr(void)
+{
+	if (++CURRENT->errors >= MAX_ERRORS)
+		end_request(0);
+	if (CURRENT->errors > MAX_ERRORS/2)
+		reset = 1;
+}
+
+static void read_intr(void)
+{
+	if (win_result()) {
+		bad_rw_intr();
+		do_hd_request();
+		return;
+	}
+	port_read(HD_DATA,CURRENT->buffer,256);
+	CURRENT->errors = 0;
+	CURRENT->buffer += 512;
+	CURRENT->sector++;
+	if (--CURRENT->nr_sectors) {
+		do_hd = &read_intr;
+		return;
+	}
+	end_request(1);
+	do_hd_request();
+}
+
+static void write_intr(void)
+{
+	if (win_result()) {
+		bad_rw_intr();
+		do_hd_request();
+		return;
+	}
+	if (--CURRENT->nr_sectors) {
+		CURRENT->sector++;
+		CURRENT->buffer += 512;
+		do_hd = &write_intr;
+		port_write(HD_DATA,CURRENT->buffer,256);
+		return;
+	}
+	end_request(1);
+	do_hd_request();
+}
+
+static void recal_intr(void)
+{
+	if (win_result())
+		bad_rw_intr();
+	do_hd_request();
+}
+
+void do_hd_request(void)
+{
+	int i,r;
+	unsigned int block,dev;
+	unsigned int sec,head,cyl;
+	unsigned int nsect;
+
+	INIT_REQUEST;
+	dev = MINOR(CURRENT->dev);
+	block = CURRENT->sector;
+	if (dev >= 5*NR_HD || block+2 > hd[dev].nr_sects) {
+		end_request(0);
+		goto repeat;
+	}
+	block += hd[dev].start_sect;
+	dev /= 5;
+	__asm__("divl %4":"=a" (block),"=d" (sec):"0" (block),"1" (0),
+		"r" (hd_info[dev].sect));
+	__asm__("divl %4":"=a" (cyl),"=d" (head):"0" (block),"1" (0),
+		"r" (hd_info[dev].head));
+	sec++;
+	nsect = CURRENT->nr_sectors;
+	if (reset) {
+		reset = 0;
+		recalibrate = 1;
+		reset_hd(CURRENT_DEV);
+		return;
+	}
+	if (recalibrate) {
+		recalibrate = 0;
+		hd_out(dev,hd_info[CURRENT_DEV].sect,0,0,0,
+			WIN_RESTORE,&recal_intr);
+		return;
+	}	
+	if (CURRENT->cmd == WRITE) {
+		hd_out(dev,nsect,sec,head,cyl,WIN_WRITE,&write_intr);
+		for(i=0 ; i<3000 && !(r=inb_p(HD_STATUS)&DRQ_STAT) ; i++)
+			/* nothing */ ;
+		if (!r) {
+			bad_rw_intr();
+			goto repeat;
+		}
+		port_write(HD_DATA,CURRENT->buffer,256);
+	} else if (CURRENT->cmd == READ) {
+		hd_out(dev,nsect,sec,head,cyl,WIN_READ,&read_intr);
+	} else
+		panic("unknown hd-command");
+}
+
+void hd_init(void)
+{
+	blk_dev[MAJOR_NR].request_fn = DEVICE_REQUEST;
+	set_intr_gate(0x2E,&hd_interrupt);
+	outb_p(inb_p(0x21)&0xfb,0x21);
+	outb(inb_p(0xA1)&0xbf,0xA1);
+}

os/os/linux/kernel/blk_drv/ll_rw_blk.c

@@ -0,0 +1,165 @@
+/*
+ *  linux/kernel/blk_dev/ll_rw.c
+ *
+ * (C) 1991 Linus Torvalds
+ */
+
+/*
+ * This handles all read/write requests to block devices
+ */
+#include <errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <asm/system.h>
+
+#include "blk.h"
+
+/*
+ * The request-struct contains all necessary data
+ * to load a nr of sectors into memory
+ */
+struct request request[NR_REQUEST];
+
+/*
+ * used to wait on when there are no free requests
+ */
+struct task_struct * wait_for_request = NULL;
+
+/* blk_dev_struct is:
+ *	do_request-address
+ *	next-request
+ */
+struct blk_dev_struct blk_dev[NR_BLK_DEV] = {
+	{ NULL, NULL },		/* no_dev */
+	{ NULL, NULL },		/* dev mem */
+	{ NULL, NULL },		/* dev fd */
+	{ NULL, NULL },		/* dev hd */
+	{ NULL, NULL },		/* dev ttyx */
+	{ NULL, NULL },		/* dev tty */
+	{ NULL, NULL }		/* dev lp */
+};
+
+static inline void lock_buffer(struct buffer_head * bh)
+{
+	cli();
+	while (bh->b_lock)
+		sleep_on(&bh->b_wait);
+	bh->b_lock=1;
+	sti();
+}
+
+static inline void unlock_buffer(struct buffer_head * bh)
+{
+	if (!bh->b_lock)
+		printk("ll_rw_block.c: buffer not locked\n\r");
+	bh->b_lock = 0;
+	wake_up(&bh->b_wait);
+}
+
+/*
+ * add-request adds a request to the linked list.
+ * It disables interrupts so that it can muck with the
+ * request-lists in peace.
+ */
+static void add_request(struct blk_dev_struct * dev, struct request * req)
+{
+	struct request * tmp;
+
+	req->next = NULL;
+	cli();
+	if (req->bh)
+		req->bh->b_dirt = 0;
+	if (!(tmp = dev->current_request)) {
+		dev->current_request = req;
+		sti();
+		(dev->request_fn)();
+		return;
+	}
+	for ( ; tmp->next ; tmp=tmp->next)
+		if ((IN_ORDER(tmp,req) ||
+		    !IN_ORDER(tmp,tmp->next)) &&
+		    IN_ORDER(req,tmp->next))
+			break;
+	req->next=tmp->next;
+	tmp->next=req;
+	sti();
+}
+
+static void make_request(int major,int rw, struct buffer_head * bh)
+{
+	struct request * req;
+	int rw_ahead;
+
+/* WRITEA/READA is special case - it is not really needed, so if the */
+/* buffer is locked, we just forget about it, else it's a normal read */
+	if (rw_ahead = (rw == READA || rw == WRITEA)) {
+		if (bh->b_lock)
+			return;
+		if (rw == READA)
+			rw = READ;
+		else
+			rw = WRITE;
+	}
+	if (rw!=READ && rw!=WRITE)
+		panic("Bad block dev command, must be R/W/RA/WA");
+	lock_buffer(bh);
+	if ((rw == WRITE && !bh->b_dirt) || (rw == READ && bh->b_uptodate)) {
+		unlock_buffer(bh);
+		return;
+	}
+repeat:
+/* we don't allow the write-requests to fill up the queue completely:
+ * we want some room for reads: they take precedence. The last third
+ * of the requests are only for reads.
+ */
+	if (rw == READ)
+		req = request+NR_REQUEST;
+	else
+		req = request+((NR_REQUEST*2)/3);
+/* find an empty request */
+	while (--req >= request)
+		if (req->dev<0)
+			break;
+/* if none found, sleep on new requests: check for rw_ahead */
+	if (req < request) {
+		if (rw_ahead) {
+			unlock_buffer(bh);
+			return;
+		}
+		sleep_on(&wait_for_request);
+		goto repeat;
+	}
+/* fill up the request-info, and add it to the queue */
+	req->dev = bh->b_dev;
+	req->cmd = rw;
+	req->errors=0;
+	req->sector = bh->b_blocknr<<1;
+	req->nr_sectors = 2;
+	req->buffer = bh->b_data;
+	req->waiting = NULL;
+	req->bh = bh;
+	req->next = NULL;
+	add_request(major+blk_dev,req);
+}
+
+void ll_rw_block(int rw, struct buffer_head * bh)
+{
+	unsigned int major;
+
+	if ((major=MAJOR(bh->b_dev)) >= NR_BLK_DEV ||
+	!(blk_dev[major].request_fn)) {
+		printk("Trying to read nonexistent block-device\n\r");
+		return;
+	}
+	make_request(major,rw,bh);
+}
+
+void blk_dev_init(void)
+{
+	int i;
+
+	for (i=0 ; i<NR_REQUEST ; i++) {
+		request[i].dev = -1;
+		request[i].next = NULL;
+	}
+}