Link a user program from xv6-x86_64 in. Add elf crate.

Cargo.toml

@@ -10,6 +10,7 @@ crate-type = ["staticlib"]
 use_apic = []
 test = []
 qemu_auto_exit = []
+link_user_program = []
 
 [dependencies]
 bit_field = "0.7.0"
@@ -22,6 +23,7 @@ x86_64 = "0.1.2"
 once = "0.3.3"
 linked_list_allocator = "0.5.0"
 redox_syscall = "0.1.37"
+xmas-elf = "0.6"
 
 [build-dependencies]
 cc = "1.0"

Makefile

@@ -10,9 +10,17 @@ grub_cfg := $(boot_src)/grub.cfg
 assembly_source_files := $(wildcard $(boot_src)/*.asm)
 assembly_object_files := $(patsubst $(boot_src)/%.asm, \
 	build/arch/$(arch)/boot/%.o, $(assembly_source_files))
+user_object_files := $(wildcard user/*.o)
 qemu_opts := -cdrom $(iso) -smp 4 -serial mon:stdio
 features := use_apic
 
+link_user = 1
+
+ifdef link_user
+features := $(features) link_user_program
+assembly_object_files := $(assembly_object_files) $(user_object_files)
+endif
+
 ifdef travis
 test := 1
 features := $(features) qemu_auto_exit

src/arch/x86_64/boot/linker.ld

@@ -6,6 +6,8 @@ KERNEL_OFFSET = 0xffffff0000000000;
 
 SECTIONS {
 
+  /* bootloader for first processor */
+
   . = BOOT_OFFSET;
 
   .rodata.32 :
@@ -39,8 +41,16 @@ SECTIONS {
   entryother_end = . - OTHER_OFFSET + entryother_start;
   . = entryother_end;           /* recover va */
 
+  /* kernel */
+
   . += KERNEL_OFFSET;
 
+  .user ALIGN(4K): AT(ADDR(.user) - KERNEL_OFFSET)
+  {
+    KEEP(user/*.o (.data))
+    . = ALIGN(4K);
+  }
+
   .rodata : AT(ADDR(.rodata) - KERNEL_OFFSET)
   {
     *(.rodata .rodata.*)

src/lib.rs

@@ -32,6 +32,7 @@ extern crate linked_list_allocator;
 extern crate lazy_static;
 extern crate bit_field;
 extern crate syscall;
+extern crate xmas_elf;
 
 #[macro_use]    // print!
 mod io;

src/process/mod.rs

@@ -14,11 +14,36 @@ mod processor;
 /// * Debug: 用于Debug输出
 use arch::interrupt::TrapFrame;
 
+// TODO: 使用宏来更优雅地导入符号，现在会有编译错误
+//
+//    #![feature(concat_idents)]
+//
+//    macro_rules! binary_symbol {
+//        ($name: ident) => {
+//            extern {
+//                fn concat_idents!(_binary_user_, $name, _start)();
+//                fn concat_idents!(_binary_user_, $name, _end)();
+//            }
+//        };
+//    }
+//
+//    binary_symbol!(forktest);
+
+#[cfg(feature = "link_user_program")]
+extern {
+    fn _binary_user_forktest_start();
+    fn _binary_user_forktest_end();
+}
+
+
 pub fn init(mc: &mut MemoryController) {
     PROCESSOR.call_once(|| {Mutex::new({
         let mut processor = Processor::new(mc);
         let initproc = Process::new_init(mc);
         let idleproc = Process::new("idle", idle_thread, mc);
+        #[cfg(feature = "link_user_program")]
+        let forktest = Process::new_user(_binary_user_forktest_start as usize,
+                                         _binary_user_forktest_end as usize);
         processor.add(initproc);
         processor.add(idleproc);
         processor

src/process/process.rs

@@ -1,5 +1,7 @@
 use super::*;
 use memory::Stack;
+use xmas_elf::ElfFile;
+use core::slice;
 
 #[derive(Debug)]
 pub struct Process {
@@ -47,4 +49,16 @@ impl Process {
             rsp: 0, // will be set at first schedule
         }
     }
+
+    pub fn new_user(begin: usize, end: usize) -> Self {
+        let slice = unsafe{ slice::from_raw_parts(begin as *const u8, end - begin) };
+        let elf = ElfFile::new(slice).expect("failed to read elf");
+        for program_header in elf.program_iter() {
+            println!("{:?}", program_header);
+        }
+//        for section in elf.section_iter() {
+//            println!("{:?}", section);
+//        }
+        unimplemented!();
+    }
 }