From 94bc8353f7de07dd9e676346bf865424fb40f953 Mon Sep 17 00:00:00 2001
From: equation314 <equation618@gmail.com>
Date: Thu, 29 Nov 2018 00:39:44 +0800
Subject: [PATCH 1/6] user: create SFS image in Makefile

---
 crate/riscv            |  1 -
 kernel/Makefile        | 27 +++++++++++++++-----
 user/Makefile          | 58 +++++++++++++++++++++++++++++++++++++++---
 user/x86_64-ucore.json |  3 ++-
 4 files changed, 76 insertions(+), 13 deletions(-)
 delete mode 160000 crate/riscv

diff --git a/crate/riscv b/crate/riscv
deleted file mode 160000
index a37a65f..0000000
--- a/crate/riscv
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit a37a65fa13a00c5aa0068c3f2b5d55af6a37dd93
diff --git a/kernel/Makefile b/kernel/Makefile
index 0e1a2e8..ef57cea 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -27,16 +27,20 @@ kernel := target/$(target)/$(mode)/ucore
 bin := target/$(target)/$(mode)/kernel.bin
 bootimage := target/$(target)/bootimage.bin
 
-user_bin_path := ../user/target/$(arch)-ucore/debug
+user_dir := ../user
+user_bin_path := $(user_dir)/target/$(arch)-ucore/debug
 user_bins := $(patsubst $(user_bin_path)/%.d, $(user_bin_path)/%, $(wildcard $(user_bin_path)/*.d))
 user_obj := build/$(arch)/user.o
-SFSIMG := ../user/ucore32.img
+sfsimg := $(user_dir)/build/user-$(arch).img
+
+export ARCH = $(arch)
+export SFSIMG = $(sfsimg)
 
 ### qemu options ###
 ifeq ($(arch), x86_64)
 qemu_opts := \
 	-drive format=raw,file=$(bootimage) \
-	-drive format=raw,file=$(SFSIMG),media=disk,cache=writeback \
+	-drive format=raw,file=$(sfsimg),media=disk,cache=writeback \
 	-smp cores=$(smp) \
 	-serial mon:stdio \
 	-device isa-debug-exit \
@@ -99,7 +103,7 @@ cc := $(prefix)gcc
 as := $(prefix)as
 gdb := $(prefix)gdb
 
-.PHONY: all clean run build asm doc justrun kernel
+.PHONY: all clean run build asm doc justrun debug kernel install
 
 all: kernel
 
@@ -112,10 +116,10 @@ doc:
 
 run: build justrun
 
-justrun:
+justrun: $(sfsimg)
 	@qemu-system-$(arch) $(qemu_opts) || [ $$? -eq 11 ] # run qemu and assert it exit 11
 
-debug: $(kernel) $(bin)
+debug: $(kernel) $(bin) $(sfsimg)
 	@qemu-system-$(arch) $(qemu_opts) -s -S &
 	@sleep 1
 	@$(gdb) $(kernel) -x ../tools/gdbinit
@@ -156,16 +160,25 @@ else ifeq ($(arch), aarch64)
 	@$(objcopy) $(kernel) --strip-all -O binary $@
 endif
 
-kernel:
 ifeq ($(arch), x86_64)
+kernel:
 	@bootimage build $(build_args)
 else
+kernel: $(sfsimg)
+ifeq ($(arch), riscv32)
 	@-patch -p0 -N -b \
 		$(shell rustc --print sysroot)/lib/rustlib/src/rust/src/libcore/sync/atomic.rs \
 		src/arch/riscv32/atomic.patch
+endif
 	@CC=$(cc) cargo xbuild $(build_args)
 endif
 
+
+
+### user programs ###
+$(sfsimg):
+	@cd $(user_dir) && make sfsimg
+
 # make user.o from binary files
 $(user_obj): $(user_bins)
 	@cd $(user_bin_path) && \
diff --git a/user/Makefile b/user/Makefile
index 185ca0f..9b0648b 100644
--- a/user/Makefile
+++ b/user/Makefile
@@ -1,5 +1,55 @@
-# arch = {riscv32, x86_64}
-arch := riscv32
+# arch = {riscv32, x86_64, aarch64}
+# mode = {debug, release}
+arch ?= riscv32
+mode ?= debug
 
-all:
-	cargo xbuild --target $(arch)-ucore.json
\ No newline at end of file
+rust_src_dir := src/bin
+rust_bin_path := target/$(arch)-ucore/$(mode)
+user_rust_bins := $(patsubst $(rust_src_dir)/%.rs, $(rust_bin_path)/%, $(wildcard $(rust_src_dir)/*.rs))
+c_src_dir :=
+c_bin_path :=
+user_c_bins :=
+user_bins := $(user_rust_bins) $(user_c_bins)
+
+build_path := build
+sfsroot := $(build_path)/sfsroot-$(arch)
+sfsimg := $(build_path)/user-$(arch).img
+
+mksfs := mksfs
+
+build_args := --target $(arch)-ucore.json
+ifeq ($(mode), release)
+build_args := $(build_args) --release
+endif
+
+.PHONY: all clean build-rust build-c build mksfs sfsimg
+
+all: $(sfsimg)
+
+build-rust:
+	@echo Building user rust programs
+	@cargo xbuild $(build_args)
+
+build-c:
+	@echo Building user C programs
+
+build: build-rust build-c
+
+mksfs:
+ifeq ($(shell which $(mksfs)),)
+	@cargo install --git https://github.com/wangrunji0408/SimpleFileSystem-Rust --features="std"
+endif
+
+$(sfsroot): build
+	@mkdir -p $(sfsroot)/
+	@cp $(user_bins) $(sfsroot)/
+
+$(sfsimg): mksfs $(sfsroot)
+	@echo Creating SFS image at $@
+	@$(mksfs) zip $(sfsroot) $@
+
+sfsimg: $(sfsimg)
+
+clean:
+	@cargo clean
+	@rm -rf $(build_path)
diff --git a/user/x86_64-ucore.json b/user/x86_64-ucore.json
index c587146..6510efa 100644
--- a/user/x86_64-ucore.json
+++ b/user/x86_64-ucore.json
@@ -7,8 +7,9 @@
   "target-c-int-width": "32",
   "os": "none",
   "executables": true,
+  "linker": "rust-lld",
   "linker-flavor": "ld.lld",
   "panic-strategy": "abort",
   "disable-redzone": true,
   "features": "-mmx,-sse,+soft-float"
-}
\ No newline at end of file
+}

From f882a085d68bab9bbd287b7cc01e7f69bba61866 Mon Sep 17 00:00:00 2001
From: equation314 <equation618@gmail.com>
Date: Thu, 29 Nov 2018 01:22:44 +0800
Subject: [PATCH 2/6] user: link created SFS image in kernel

---
 .gitignore             |  9 +++--
 crate/atags/Cargo.lock | 14 --------
 kernel/Makefile        |  6 ++--
 kernel/build.rs        | 75 +++++++++++++++++++++++++++++++++---------
 kernel/src/fs.rs       | 17 ++--------
 kernel/src/shell.rs    | 11 ++++---
 6 files changed, 76 insertions(+), 56 deletions(-)
 delete mode 100644 crate/atags/Cargo.lock

diff --git a/.gitignore b/.gitignore
index fe8b1fd..975d0c4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,11 +1,10 @@
 build
 target
 /kernel/src/arch/x86_64/interrupt/vector.asm
-/crate/bit-allocator/Cargo.lock
-/crate/memory/Cargo.lock
-/crate/bbl/Cargo.lock
-/crate/sync/Cargo.lock
-/crate/process/Cargo.lock
+
+Cargo.lock
+!kernel/Cargo.lock
+!user/Cargo.lock
 
 .DS_Store
 
diff --git a/crate/atags/Cargo.lock b/crate/atags/Cargo.lock
deleted file mode 100644
index 42d11eb..0000000
--- a/crate/atags/Cargo.lock
+++ /dev/null
@@ -1,14 +0,0 @@
-[[package]]
-name = "atags"
-version = "0.1.0"
-dependencies = [
- "volatile 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "volatile"
-version = "0.2.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[metadata]
-"checksum volatile 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)" = "d9ca391c55768e479d5c2f8beb40c136df09257292a809ea514e82cfdfc15d00"
diff --git a/kernel/Makefile b/kernel/Makefile
index ef57cea..3f4f76b 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -12,6 +12,7 @@
 #   d    = int | in_asm | ...	QEMU debug info
 #   mode = debug | release
 #   LOG  = off | error | warn | info | debug | trace
+#   SFSIMG = SFS image path of user programs
 #   smp                         SMP core number
 #   board = fpga				Only available on riscv32, build without bbl, run on board
 #         | raspi3				Only available on aarch64, run on Raspberry Pi 3 Model B/B+
@@ -31,6 +32,7 @@ user_dir := ../user
 user_bin_path := $(user_dir)/target/$(arch)-ucore/debug
 user_bins := $(patsubst $(user_bin_path)/%.d, $(user_bin_path)/%, $(wildcard $(user_bin_path)/*.d))
 user_obj := build/$(arch)/user.o
+sfsroot := $(user_dir)/build/sfsroot-$(arch)
 sfsimg := $(user_dir)/build/user-$(arch).img
 
 export ARCH = $(arch)
@@ -40,7 +42,7 @@ export SFSIMG = $(sfsimg)
 ifeq ($(arch), x86_64)
 qemu_opts := \
 	-drive format=raw,file=$(bootimage) \
-	-drive format=raw,file=$(sfsimg),media=disk,cache=writeback \
+	-drive format=raw,file=$(SFSIMG),media=disk,cache=writeback \
 	-smp cores=$(smp) \
 	-serial mon:stdio \
 	-device isa-debug-exit \
@@ -176,7 +178,7 @@ endif
 
 
 ### user programs ###
-$(sfsimg):
+$(sfsimg): $(sfsroot)
 	@cd $(user_dir) && make sfsimg
 
 # make user.o from binary files
diff --git a/kernel/build.rs b/kernel/build.rs
index ec94d4e..e85f6f3 100644
--- a/kernel/build.rs
+++ b/kernel/build.rs
@@ -1,23 +1,42 @@
 extern crate cc;
 
 use std::fs::File;
-use std::io::{Write, Result};
+use std::path::Path;
+use std::io::{Result, Write};
 
 fn main() {
-	if std::env::var("TARGET").unwrap().find("x86_64").is_some() {
-//		cc::Build::new()
-//			.file("src/arch/x86_64/driver/apic/lapic.c")
-//			.file("src/arch/x86_64/driver/keyboard/keyboard.c")
-//			.flag("-mcmodel=large")
-//			.compile("cobj");
-		gen_vector_asm().unwrap();
-	}
-	if std::env::var("TARGET").unwrap().find("riscv32").is_some() {
-		cc::Build::new()
-			.file("src/arch/riscv32/compiler_rt.c")
-			.flag("-march=rv32ia")
-			.flag("-mabi=ilp32")
-			.compile("atomic_rt");
+	println!("cargo:rerun-if-env-changed=LOG");
+
+	let arch: String = std::env::var("ARCH").unwrap();
+	match arch.as_str() {
+		"x86_64" => {
+			// cc::Build::new()
+			// 	.file("src/arch/x86_64/driver/apic/lapic.c")
+			// 	.file("src/arch/x86_64/driver/keyboard/keyboard.c")
+			// 	.flag("-mcmodel=large")
+			// 	.compile("cobj");
+			gen_vector_asm().unwrap();
+		}
+		"riscv32" => {
+			cc::Build::new()
+				.file("src/arch/riscv32/compiler_rt.c")
+				.flag("-march=rv32ia")
+				.flag("-mabi=ilp32")
+				.compile("atomic_rt");
+			if let Ok(file_path) = gen_sfsimg_asm() {
+				cc::Build::new()
+					.file(&file_path)
+					.flag("-march=rv32ia")
+					.flag("-mabi=ilp32")
+					.compile("sfsimg");
+			}
+		}
+		"aarch64" => {
+			if let Ok(file_path) = gen_sfsimg_asm() {
+				cc::Build::new().file(&file_path).compile("cobj");
+			}
+		}
+		_ => panic!("Unknown arch {}", arch),
 	}
 }
 
@@ -43,4 +62,28 @@ fn gen_vector_asm() -> Result<()> {
 		writeln!(f, "\t.quad vector{}", i)?;
 	}
 	Ok(())
-}
\ No newline at end of file
+}
+
+fn gen_sfsimg_asm() -> Result<std::path::PathBuf> {
+	let out_dir = std::env::var("OUT_DIR").unwrap();
+	let sfsimg = std::env::var("SFSIMG").unwrap();
+
+	let file_path = Path::new(&out_dir).join("sfsimg.S");
+	let mut f = File::create(&file_path).unwrap();
+
+	write!(f, "# generated by build.rs - do not edit")?;
+	write!(f, r#"
+	.section .rodata
+	.align 12
+	.global _user_img_start
+	.global _user_img_end
+_user_img_start:
+    .incbin "{}"
+_user_img_end:
+"#, sfsimg)?;
+
+	println!("cargo:rerun-if-changed={}", sfsimg);
+	println!("cargo:rerun-if-env-changed=SFSIMG");
+
+	Ok(file_path)
+}
diff --git a/kernel/src/fs.rs b/kernel/src/fs.rs
index 9fea7d7..a1a52f2 100644
--- a/kernel/src/fs.rs
+++ b/kernel/src/fs.rs
@@ -10,32 +10,19 @@ use crate::arch::driver::ide;
 use crate::sync::Condvar;
 use crate::sync::SpinNoIrqLock as Mutex;
 
-// Hard link user program
-#[cfg(target_arch = "riscv32")]
-global_asm!(r#"
-    .section .rodata
-    .align 12
-    .global _user_img_start
-    .global _user_img_end
-_user_img_start:
-    .incbin "../user/user-riscv.img"
-_user_img_end:
-"#);
-
 lazy_static! {
     pub static ref ROOT_INODE: Arc<INode> = {
-        #[cfg(target_arch = "riscv32")]
+        #[cfg(any(target_arch = "riscv32", target_arch = "aarch64"))]
         let device = {
             extern {
                 fn _user_img_start();
                 fn _user_img_end();
             }
+            // Hard link user program
             Box::new(unsafe { MemBuf::new(_user_img_start, _user_img_end) })
         };
         #[cfg(target_arch = "x86_64")]
         let device = Box::new(ide::IDE::new(1));
-        #[cfg(target_arch = "aarch64")]
-        let device = unimplemented!();
 
         let sfs = SimpleFileSystem::open(device).expect("failed to open SFS");
         sfs.root_inode()
diff --git a/kernel/src/shell.rs b/kernel/src/shell.rs
index 1dcd521..b8443f3 100644
--- a/kernel/src/shell.rs
+++ b/kernel/src/shell.rs
@@ -6,12 +6,15 @@ use crate::fs::{ROOT_INODE, INodeExt};
 use crate::process::*;
 
 pub fn run_user_shell() {
-    let inode = ROOT_INODE.lookup("sh").unwrap();
-    let data = inode.read_as_vec().unwrap();
-    processor().manager().add(ContextImpl::new_user(data.as_slice(), "sh".split(' ')), 0);
+    if let Ok(inode) = ROOT_INODE.lookup("sh") {
+        let data = inode.read_as_vec().unwrap();
+        processor().manager().add(ContextImpl::new_user(data.as_slice(), "sh".split(' ')), 0);
+    } else {
+        processor().manager().add(ContextImpl::new_kernel(shell, 0), 0);
+    }
 }
 
-pub fn shell() {
+pub extern fn shell(_arg: usize) -> ! {
     let files = ROOT_INODE.list().unwrap();
     println!("Available programs: {:?}", files);
 

From e86229cb71cffe92f007e6e279b2c8ac448425b8 Mon Sep 17 00:00:00 2001
From: equation314 <equation618@gmail.com>
Date: Sun, 2 Dec 2018 19:44:05 +0800
Subject: [PATCH 3/6] user: user rust programs are runnable

---
 kernel/build.rs                          |  2 +-
 kernel/src/process/context.rs            |  4 +++
 kernel/src/syscall.rs                    |  1 +
 user/aarch64-ucore.json                  |  5 +++
 user/riscv32-ucore.json                  |  7 +++-
 user/src/arch/aarch64/user.ld            | 46 ++++++++++++++++++++++++
 user/src/arch/riscv32/user.ld            | 46 ++++++++++++++++++++++++
 user/src/arch/x86_64/user.ld             | 46 ++++++++++++++++++++++++
 user/src/bin/{hello.rs => hello_rust.rs} |  4 ++-
 user/ucore-ulib/src/lang_items.rs        | 42 +++++++++++++++++++---
 user/ucore-ulib/src/syscall.rs           | 37 +++++++++++++++++--
 user/x86_64-ucore.json                   |  5 +++
 12 files changed, 234 insertions(+), 11 deletions(-)
 create mode 100644 user/src/arch/aarch64/user.ld
 create mode 100644 user/src/arch/riscv32/user.ld
 create mode 100644 user/src/arch/x86_64/user.ld
 rename user/src/bin/{hello.rs => hello_rust.rs} (50%)

diff --git a/kernel/build.rs b/kernel/build.rs
index e85f6f3..73117d7 100644
--- a/kernel/build.rs
+++ b/kernel/build.rs
@@ -33,7 +33,7 @@ fn main() {
 		}
 		"aarch64" => {
 			if let Ok(file_path) = gen_sfsimg_asm() {
-				cc::Build::new().file(&file_path).compile("cobj");
+				cc::Build::new().file(&file_path).compile("sfsimg");
 			}
 		}
 		_ => panic!("Unknown arch {}", arch),
diff --git a/kernel/src/process/context.rs b/kernel/src/process/context.rs
index 14b78b7..e5b5829 100644
--- a/kernel/src/process/context.rs
+++ b/kernel/src/process/context.rs
@@ -110,6 +110,10 @@ impl ContextImpl {
         unsafe {
             memory_set.with(|| {
                 for ph in elf.program_iter() {
+                    if ph.get_type() != Ok(Type::Load) {
+                        continue;
+                    }
+
                     let virt_addr = ph.virtual_addr() as usize;
                     let offset = ph.offset() as usize;
                     let file_size = ph.file_size() as usize;
diff --git a/kernel/src/syscall.rs b/kernel/src/syscall.rs
index 98a0f9e..4935c29 100644
--- a/kernel/src/syscall.rs
+++ b/kernel/src/syscall.rs
@@ -284,6 +284,7 @@ fn get_file(fd: usize) -> Result<&'static Arc<Mutex<File>>, SysError> {
 pub type SysResult = Result<i32, SysError>;
 
 #[repr(i32)]
+#[derive(Debug)]
 pub enum SysError {
     VfsError,
     InvalidFile,
diff --git a/user/aarch64-ucore.json b/user/aarch64-ucore.json
index 357c2e3..7d9e167 100644
--- a/user/aarch64-ucore.json
+++ b/user/aarch64-ucore.json
@@ -13,6 +13,11 @@
   "linker": "rust-lld",
   "linker-flavor": "ld.lld",
   "linker-is-gnu": true,
+  "pre-link-args": {
+    "ld.lld": [
+      "-Tsrc/arch/aarch64/user.ld"
+    ]
+  },
   "llvm-target": "aarch64-unknown-none",
   "no-compiler-rt": true,
   "features": "+a53,+strict-align,-neon",
diff --git a/user/riscv32-ucore.json b/user/riscv32-ucore.json
index 37dac6f..354279e 100644
--- a/user/riscv32-ucore.json
+++ b/user/riscv32-ucore.json
@@ -11,6 +11,11 @@
   "max-atomic-width": "32",
   "linker": "rust-lld",
   "linker-flavor": "ld.lld",
+  "pre-link-args": {
+    "ld.lld": [
+      "-Tsrc/arch/riscv32/user.ld"
+    ]
+  },
   "executables": true,
   "panic-strategy": "abort",
   "relocation-model": "static",
@@ -27,4 +32,4 @@
     "msp430-interrupt",
     "x86-interrupt"
   ]
-}
\ No newline at end of file
+}
diff --git a/user/src/arch/aarch64/user.ld b/user/src/arch/aarch64/user.ld
new file mode 100644
index 0000000..b989922
--- /dev/null
+++ b/user/src/arch/aarch64/user.ld
@@ -0,0 +1,46 @@
+/* Simple linker script for ucore user-level programs.
+   See the GNU ld 'info' manual ("info ld") to learn the syntax. */
+
+OUTPUT_ARCH(aarch64)
+ENTRY(_start)
+
+SECTIONS {
+    /* Load programs at this address: "." means the current address */
+    . = 0xffff000000000000;
+
+    .text : {
+        *(.text .stub .text.* .gnu.linkonce.t.*)
+    }
+
+    PROVIDE(etext = .); /* Define the 'etext' symbol to this value */
+
+    .rodata : {
+        *(.rodata .rodata.* .gnu.linkonce.r.*)
+    }
+
+    /* Adjust the address for the data segment to the next page */
+    . = ALIGN(0x1000);
+
+    /* The data segment */
+    .data : {
+        *(.data)
+        *(.data.*)
+    }
+
+    .sdata : {
+        *(.sdata)
+        *(.sdata.*)
+    }
+
+    PROVIDE(edata = .);
+
+    .bss : {
+        *(.bss)
+    }
+
+    PROVIDE(end = .);
+
+    /DISCARD/ : {
+        *(.eh_frame .note.GNU-stack .comment)
+    }
+}
diff --git a/user/src/arch/riscv32/user.ld b/user/src/arch/riscv32/user.ld
new file mode 100644
index 0000000..80ac4e5
--- /dev/null
+++ b/user/src/arch/riscv32/user.ld
@@ -0,0 +1,46 @@
+/* Simple linker script for ucore user-level programs.
+   See the GNU ld 'info' manual ("info ld") to learn the syntax. */
+
+OUTPUT_ARCH(riscv)
+ENTRY(_start)
+
+SECTIONS {
+    /* Load programs at this address: "." means the current address */
+    . = 0x800020;
+
+    .text : {
+        *(.text .stub .text.* .gnu.linkonce.t.*)
+    }
+
+    PROVIDE(etext = .); /* Define the 'etext' symbol to this value */
+
+    .rodata : {
+        *(.rodata .rodata.* .gnu.linkonce.r.*)
+    }
+
+    /* Adjust the address for the data segment to the next page */
+    . = ALIGN(0x1000);
+
+    /* The data segment */
+    .data : {
+        *(.data)
+        *(.data.*)
+    }
+
+    .sdata : {
+        *(.sdata)
+        *(.sdata.*)
+    }
+
+    PROVIDE(edata = .);
+
+    .bss : {
+        *(.bss)
+    }
+
+    PROVIDE(end = .);
+
+    /DISCARD/ : {
+        *(.eh_frame .note.GNU-stack .comment)
+    }
+}
diff --git a/user/src/arch/x86_64/user.ld b/user/src/arch/x86_64/user.ld
new file mode 100644
index 0000000..b135c9f
--- /dev/null
+++ b/user/src/arch/x86_64/user.ld
@@ -0,0 +1,46 @@
+/* Simple linker script for ucore user-level programs.
+   See the GNU ld 'info' manual ("info ld") to learn the syntax. */
+
+OUTPUT_ARCH(x86_64)
+ENTRY(_start)
+
+SECTIONS {
+    /* Load programs at this address: "." means the current address */
+    . = 0x800020;
+
+    .text : {
+        *(.text .stub .text.* .gnu.linkonce.t.*)
+    }
+
+    PROVIDE(etext = .); /* Define the 'etext' symbol to this value */
+
+    .rodata : {
+        *(.rodata .rodata.* .gnu.linkonce.r.*)
+    }
+
+    /* Adjust the address for the data segment to the next page */
+    . = ALIGN(0x1000);
+
+    /* The data segment */
+    .data : {
+        *(.data)
+        *(.data.*)
+    }
+
+    .sdata : {
+        *(.sdata)
+        *(.sdata.*)
+    }
+
+    PROVIDE(edata = .);
+
+    .bss : {
+        *(.bss)
+    }
+
+    PROVIDE(end = .);
+
+    /DISCARD/ : {
+        *(.eh_frame .note.GNU-stack .comment)
+    }
+}
diff --git a/user/src/bin/hello.rs b/user/src/bin/hello_rust.rs
similarity index 50%
rename from user/src/bin/hello.rs
rename to user/src/bin/hello_rust.rs
index 5a29680..72e3040 100644
--- a/user/src/bin/hello.rs
+++ b/user/src/bin/hello_rust.rs
@@ -7,5 +7,7 @@ extern crate ucore_ulib;
 // IMPORTANT: Must define main() like this
 #[no_mangle]
 pub fn main() {
-    println!("Hello uCore!");
+    println!("Hello Rust uCore!");
+    println!("I am process {}.", ucore_ulib::syscall::sys_getpid());
+    println!("hello pass.");
 }
diff --git a/user/ucore-ulib/src/lang_items.rs b/user/ucore-ulib/src/lang_items.rs
index 89e5334..29aff8c 100644
--- a/user/ucore-ulib/src/lang_items.rs
+++ b/user/ucore-ulib/src/lang_items.rs
@@ -1,15 +1,47 @@
-use syscall::sys_exit;
+use syscall::{sys_close, sys_dup, sys_exit, sys_open};
+use syscall::{O_RDONLY, O_WRONLY};
 use core::alloc::Layout;
 use core::panic::PanicInfo;
 
+// used for panic
+macro_rules! print {
+    ($($arg:tt)*) => ({
+        $crate::syscall::print_putc(format_args!($($arg)*));
+    });
+}
+
 #[linkage = "weak"]
 #[no_mangle]
 fn main() {
     panic!("No main() linked");
 }
 
+fn initfd(fd2: usize, path: &str, open_flags: usize) -> i32 {
+    let fd1 = sys_open(path, open_flags);
+    if fd1 < 0 {
+        return fd1;
+    }
+    let mut ret = fd1;
+    let fd1 = fd1 as usize;
+    if fd1 != fd2 {
+        sys_close(fd2);
+        ret = sys_dup(fd1, fd2);
+        sys_close(fd1);
+    }
+    return ret;
+}
+
 #[no_mangle]
-pub extern fn _start(_argc: isize, _argv: *const *const u8) -> ! {
+pub extern "C" fn _start(_argc: isize, _argv: *const *const u8) -> ! {
+    let fd = initfd(0, "stdin:", O_RDONLY);
+    if fd < 0 {
+        panic!("open <stdin> failed: {}.", fd);
+    }
+    let fd = initfd(1, "stdout:", O_WRONLY);
+    if fd < 0 {
+        panic!("open <stdout> failed: {}.", fd);
+    }
+
     main();
     sys_exit(0)
 }
@@ -31,12 +63,12 @@ fn oom(_: Layout) -> ! {
 }
 
 #[no_mangle]
-pub extern fn abort() -> ! {
+pub extern "C" fn abort() -> ! {
     sys_exit(2)
 }
 
 #[no_mangle]
-pub extern fn __mulsi3(mut a: u32, mut b: u32) -> u32 {
+pub extern "C" fn __mulsi3(mut a: u32, mut b: u32) -> u32 {
     let mut r: u32 = 0;
 
     while a > 0 {
@@ -48,4 +80,4 @@ pub extern fn __mulsi3(mut a: u32, mut b: u32) -> u32 {
     }
 
     r
-}
\ No newline at end of file
+}
diff --git a/user/ucore-ulib/src/syscall.rs b/user/ucore-ulib/src/syscall.rs
index f707142..1a75785 100644
--- a/user/ucore-ulib/src/syscall.rs
+++ b/user/ucore-ulib/src/syscall.rs
@@ -17,14 +17,29 @@ pub fn print(args: fmt::Arguments) {
     StdOut.write_fmt(args).unwrap();
 }
 
+pub fn print_putc(args: fmt::Arguments) {
+    SysPutc.write_fmt(args).unwrap();
+}
+
 struct StdOut;
+struct SysPutc;
 
 impl fmt::Write for StdOut {
     fn write_str(&mut self, s: &str) -> fmt::Result {
-        match sys_write(0, s.as_ptr(), s.len()) {
-            0 => Ok(()),
-            _ => Err(fmt::Error::default()),
+        if sys_write(1, s.as_ptr(), s.len()) >= 0 {
+            Ok(())
+        } else {
+            Err(fmt::Error::default())
+        }
+    }
+}
+
+impl fmt::Write for SysPutc {
+    fn write_str(&mut self, s: &str) -> fmt::Result {
+        for c in s.bytes() {
+            sys_putc(c as char);
         }
+        Ok(())
     }
 }
 
@@ -77,6 +92,10 @@ pub fn sys_close(fd: usize) -> i32 {
     sys_call(SYS_CLOSE, fd, 0, 0, 0, 0, 0)
 }
 
+pub fn sys_dup(fd1: usize, fd2: usize) -> i32 {
+    sys_call(SYS_DUP, fd1, fd2, 0, 0, 0, 0)
+}
+
 /// Fork the current process. Return the child's PID.
 pub fn sys_fork() -> i32 {
     sys_call(SYS_FORK, 0, 0, 0, 0, 0, 0)
@@ -144,3 +163,15 @@ const SYS_GETCWD: usize = 121;
 const SYS_GETDIRENTRY: usize = 128;
 const SYS_DUP: usize = 130;
 const SYS_LAB6_SET_PRIORITY: usize = 255;
+
+/* VFS flags */
+// TODO: use bitflags
+// flags for open: choose one of these
+pub const O_RDONLY: usize = 0; // open for reading only
+pub const O_WRONLY: usize = 1; // open for writing only
+pub const O_RDWR: usize = 2; // open for reading and writing
+// then or in any of these:
+pub const O_CREAT: usize = 0x00000004; // create file if it does not exist
+pub const O_EXCL: usize = 0x00000008; // error if O_CREAT and the file exists
+pub const O_TRUNC: usize = 0x00000010; // truncate file upon open
+pub const O_APPEND: usize = 0x00000020; // append on each write
diff --git a/user/x86_64-ucore.json b/user/x86_64-ucore.json
index 6510efa..a8ace2c 100644
--- a/user/x86_64-ucore.json
+++ b/user/x86_64-ucore.json
@@ -9,6 +9,11 @@
   "executables": true,
   "linker": "rust-lld",
   "linker-flavor": "ld.lld",
+  "pre-link-args": {
+    "ld.lld": [
+      "-Tsrc/arch/x86_64/user.ld"
+    ]
+  },
   "panic-strategy": "abort",
   "disable-redzone": true,
   "features": "-mmx,-sse,+soft-float"

From 710b6d1a28f518fde70315be949be1ee239454ab Mon Sep 17 00:00:00 2001
From: equation314 <equation618@gmail.com>
Date: Sun, 2 Dec 2018 19:51:52 +0800
Subject: [PATCH 4/6] user: update Makefiles

---
 kernel/Makefile | 16 +++++++---------
 user/Makefile   | 12 ++++++++----
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/kernel/Makefile b/kernel/Makefile
index 3f4f76b..7771d54 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -32,11 +32,9 @@ user_dir := ../user
 user_bin_path := $(user_dir)/target/$(arch)-ucore/debug
 user_bins := $(patsubst $(user_bin_path)/%.d, $(user_bin_path)/%, $(wildcard $(user_bin_path)/*.d))
 user_obj := build/$(arch)/user.o
-sfsroot := $(user_dir)/build/sfsroot-$(arch)
-sfsimg := $(user_dir)/build/user-$(arch).img
 
 export ARCH = $(arch)
-export SFSIMG = $(sfsimg)
+export SFSIMG = $(user_dir)/build/user-$(arch).img
 
 ### qemu options ###
 ifeq ($(arch), x86_64)
@@ -105,7 +103,7 @@ cc := $(prefix)gcc
 as := $(prefix)as
 gdb := $(prefix)gdb
 
-.PHONY: all clean run build asm doc justrun debug kernel install
+.PHONY: all clean run build asm doc justrun debug kernel sfsimg install
 
 all: kernel
 
@@ -116,12 +114,12 @@ clean:
 doc:
 	@cargo rustdoc -- --document-private-items
 
-run: build justrun
+run: build sfsimg justrun
 
-justrun: $(sfsimg)
+justrun:
 	@qemu-system-$(arch) $(qemu_opts) || [ $$? -eq 11 ] # run qemu and assert it exit 11
 
-debug: $(kernel) $(bin) $(sfsimg)
+debug: $(kernel) $(bin)
 	@qemu-system-$(arch) $(qemu_opts) -s -S &
 	@sleep 1
 	@$(gdb) $(kernel) -x ../tools/gdbinit
@@ -166,7 +164,7 @@ ifeq ($(arch), x86_64)
 kernel:
 	@bootimage build $(build_args)
 else
-kernel: $(sfsimg)
+kernel: sfsimg
 ifeq ($(arch), riscv32)
 	@-patch -p0 -N -b \
 		$(shell rustc --print sysroot)/lib/rustlib/src/rust/src/libcore/sync/atomic.rs \
@@ -178,7 +176,7 @@ endif
 
 
 ### user programs ###
-$(sfsimg): $(sfsroot)
+sfsimg:
 	@cd $(user_dir) && make sfsimg
 
 # make user.o from binary files
diff --git a/user/Makefile b/user/Makefile
index 9b0648b..6c5f860 100644
--- a/user/Makefile
+++ b/user/Makefile
@@ -35,16 +35,20 @@ build-c:
 
 build: build-rust build-c
 
+$(user_rust_bins): build-rust
+
+$(user_c_bins): build-c
+
 mksfs:
 ifeq ($(shell which $(mksfs)),)
 	@cargo install --git https://github.com/wangrunji0408/SimpleFileSystem-Rust --features="std"
 endif
 
-$(sfsroot): build
-	@mkdir -p $(sfsroot)/
-	@cp $(user_bins) $(sfsroot)/
+$(sfsroot): $(user_bins)
+	@mkdir -p $@
+	@cp $^ $@/
 
-$(sfsimg): mksfs $(sfsroot)
+$(sfsimg): $(user_bins) $(sfsroot) | mksfs
 	@echo Creating SFS image at $@
 	@$(mksfs) zip $(sfsroot) $@
 

From 66ac30d4014604bee395b37f94d12ae1335b1834 Mon Sep 17 00:00:00 2001
From: equation314 <equation618@gmail.com>
Date: Sun, 2 Dec 2018 19:56:29 +0800
Subject: [PATCH 5/6] user: update make clean in kernel/

---
 kernel/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/Makefile b/kernel/Makefile
index 7771d54..d8ed131 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -109,6 +109,7 @@ all: kernel
 
 clean:
 	@cargo clean
+	@cd $(user_dir) && make clean
 	@rm -rf ../riscv-pk/build
 
 doc:

From d5a6eb2020658b3dd1c4825032397053f89295ea Mon Sep 17 00:00:00 2001
From: equation314 <equation618@gmail.com>
Date: Mon, 3 Dec 2018 12:30:03 +0800
Subject: [PATCH 6/6] user: fix build error

---
 kernel/Cargo.toml                 | 1 +
 kernel/Makefile                   | 2 +-
 user/ucore-ulib/src/lang_items.rs | 4 ++--
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/kernel/Cargo.toml b/kernel/Cargo.toml
index e8ba981..aa429ce 100644
--- a/kernel/Cargo.toml
+++ b/kernel/Cargo.toml
@@ -63,6 +63,7 @@ minimum-image-size = 0      # The minimum output file size (in MiB)
 # (the "{}" will be replaced with the path to the bootable disk image)
 run-command = ["qemu-system-x86_64",
     "-drive", "format=raw,file={}",
+    # TODO: use SFSIMG environment variable
     "-drive", "format=raw,file=../user/img/ucore-i386-pic.img,media=disk,cache=writeback",
     "-serial", "mon:stdio",
     "-device", "isa-debug-exit",
diff --git a/kernel/Makefile b/kernel/Makefile
index beaee8a..87668a4 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -48,7 +48,7 @@ qemu_opts := \
 ifeq ($(arch), x86_64)
 qemu_opts += \
 	-drive format=raw,file=$(bootimage) \
-	-drive format=raw,file="../user/img/ucore-i386-pic.img",media=disk,cache=writeback \
+	-drive format=raw,file=$(SFSIMG),media=disk,cache=writeback \
 	-serial mon:stdio \
 	-device isa-debug-exit
 
diff --git a/user/ucore-ulib/src/lang_items.rs b/user/ucore-ulib/src/lang_items.rs
index 4fd3ed2..e1e58d8 100644
--- a/user/ucore-ulib/src/lang_items.rs
+++ b/user/ucore-ulib/src/lang_items.rs
@@ -1,5 +1,5 @@
-use syscall::{sys_close, sys_dup, sys_exit, sys_open};
-use syscall::{O_RDONLY, O_WRONLY};
+use crate::syscall::{sys_close, sys_dup, sys_exit, sys_open};
+use crate::syscall::{O_RDONLY, O_WRONLY};
 use core::alloc::Layout;
 use core::panic::PanicInfo;