From 00ac4d8bf1218cb9f99d6d109e1c70d04a57f7ea Mon Sep 17 00:00:00 2001
From: zhanghx0905 <731931282@qq.com>
Date: Fri, 19 Nov 2021 21:35:57 +0800
Subject: [PATCH] update user module to 2021autumn version

---
 .gitignore                      |  13 +-
 os/Makefile                     |   4 +-
 os/build.rs                     |  33 ++++--
 os/src/config.rs                |   2 +-
 os/src/syscall/mod.rs           |   2 +-
 os/src/syscall/process.rs       |  20 +++-
 os/src/timer.rs                 |   6 +-
 user/Cargo.toml                 |   5 +-
 user/Makefile                   |  29 ++++-
 user/src/bin/cat.rs             |  34 ++++++
 user/src/bin/exit.rs            |   7 +-
 user/src/bin/fantastic_text.rs  |   2 +-
 user/src/bin/filetest_simple.rs |  38 ++++++
 user/src/bin/forktest.rs        |   4 +-
 user/src/bin/forktest2.rs       |   7 +-
 user/src/bin/forktest_simple.rs |   2 +-
 user/src/bin/forktree.rs        |   2 +-
 user/src/bin/hello_world.rs     |   2 +-
 user/src/bin/huge_write.rs      |  36 ++++++
 user/src/bin/initproc.rs        |  12 +-
 user/src/bin/matrix.rs          |   5 +-
 user/src/bin/pipe_large_test.rs |  18 +--
 user/src/bin/pipetest.rs        |   4 +-
 user/src/bin/run_pipe_test.rs   |   4 +-
 user/src/bin/sleep.rs           |   4 +-
 user/src/bin/sleep_simple.rs    |   8 +-
 user/src/bin/stack_overflow.rs  |   4 +-
 user/src/bin/test_exit0.rs      |  17 +++
 user/src/bin/test_exit1.rs      |  17 +++
 user/src/bin/test_file0.rs      |  31 +++++
 user/src/bin/test_file1.rs      |  26 ++++
 user/src/bin/test_file2.rs      |  46 ++++++++
 user/src/bin/test_getpid.rs     |  18 +++
 user/src/bin/test_mail0.rs      |  27 +++++
 user/src/bin/test_mail1.rs      |  28 +++++
 user/src/bin/test_mail2.rs      |  60 ++++++++++
 user/src/bin/test_mail3.rs      |  34 ++++++
 user/src/bin/test_mmap0.rs      |  33 ++++++
 user/src/bin/test_mmap1.rs      |  25 ++++
 user/src/bin/test_mmap2.rs      |  26 ++++
 user/src/bin/test_mmap3.rs      |  25 ++++
 user/src/bin/test_sleep.rs      |  24 ++++
 user/src/bin/test_sleep1.rs     |  22 ++++
 user/src/bin/test_spawn0.rs     |  29 +++++
 user/src/bin/test_spawn1.rs     |  35 ++++++
 user/src/bin/test_unmap.rs      |  36 ++++++
 user/src/bin/test_unmap2.rs     |  23 ++++
 user/src/bin/test_usertest.rs   |  48 ++++++++
 user/src/bin/test_write1.rs     |  31 +++++
 user/src/bin/user_shell.rs      |  12 +-
 user/src/bin/usertests.rs       |  17 ++-
 user/src/bin/yield.rs           |   2 +-
 user/src/console.rs             |  51 +++++++-
 user/src/lang_items.rs          |   9 +-
 user/src/lib.rs                 | 202 ++++++++++++++++++++++++++++----
 user/src/syscall.rs             | 154 ++++++++++++++++++++----
 56 files changed, 1278 insertions(+), 137 deletions(-)
 create mode 100644 user/src/bin/cat.rs
 create mode 100644 user/src/bin/filetest_simple.rs
 create mode 100644 user/src/bin/huge_write.rs
 create mode 100644 user/src/bin/test_exit0.rs
 create mode 100644 user/src/bin/test_exit1.rs
 create mode 100644 user/src/bin/test_file0.rs
 create mode 100644 user/src/bin/test_file1.rs
 create mode 100644 user/src/bin/test_file2.rs
 create mode 100644 user/src/bin/test_getpid.rs
 create mode 100644 user/src/bin/test_mail0.rs
 create mode 100644 user/src/bin/test_mail1.rs
 create mode 100644 user/src/bin/test_mail2.rs
 create mode 100644 user/src/bin/test_mail3.rs
 create mode 100644 user/src/bin/test_mmap0.rs
 create mode 100644 user/src/bin/test_mmap1.rs
 create mode 100644 user/src/bin/test_mmap2.rs
 create mode 100644 user/src/bin/test_mmap3.rs
 create mode 100644 user/src/bin/test_sleep.rs
 create mode 100644 user/src/bin/test_sleep1.rs
 create mode 100644 user/src/bin/test_spawn0.rs
 create mode 100644 user/src/bin/test_spawn1.rs
 create mode 100644 user/src/bin/test_unmap.rs
 create mode 100644 user/src/bin/test_unmap2.rs
 create mode 100644 user/src/bin/test_usertest.rs
 create mode 100644 user/src/bin/test_write1.rs

diff --git a/.gitignore b/.gitignore
index c44aa4fa..850a4907 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,10 +1,7 @@
-.idea/*
-os/target/*
-os/.idea/*
+.idea
+Cargo.lock
+target
 os/src/link_app.S
 os/last-*
-os/Cargo.lock
-user/target/*
-user/.idea/*
-user/Cargo.lock
-tools/
+user/build
+tools
diff --git a/os/Makefile b/os/Makefile
index 35049e01..a9ed0b73 100644
--- a/os/Makefile
+++ b/os/Makefile
@@ -29,6 +29,8 @@ OBJCOPY := rust-objcopy --binary-architecture=riscv64
 # Disassembly
 DISASM ?= -x
 
+TEST ?= 0
+
 build: env switch-check $(KERNEL_BIN)
 
 switch-check:
@@ -48,7 +50,7 @@ $(KERNEL_BIN): kernel
 	@$(OBJCOPY) $(KERNEL_ELF) --strip-all -O binary $@
 
 kernel:
-	@cd ../user && make build
+	@cd ../user && make build TEST=$(TEST)
 	@echo Platform: $(BOARD)
 	@cp src/linker-$(BOARD).ld src/linker.ld
 	@cargo build --release --features "board_$(BOARD)"
diff --git a/os/build.rs b/os/build.rs
index e32fa7ab..3f9d84d1 100644
--- a/os/build.rs
+++ b/os/build.rs
@@ -1,5 +1,5 @@
+use std::fs::{read_dir, File};
 use std::io::{Result, Write};
-use std::fs::{File, read_dir};
 
 fn main() {
     println!("cargo:rerun-if-changed=../user/src/");
@@ -7,11 +7,11 @@ fn main() {
     insert_app_data().unwrap();
 }
 
-static TARGET_PATH: &str = "../user/target/riscv64gc-unknown-none-elf/release/";
+static TARGET_PATH: &str = "../user/build/elf/";
 
 fn insert_app_data() -> Result<()> {
     let mut f = File::create("src/link_app.S").unwrap();
-    let mut apps: Vec<_> = read_dir("../user/src/bin")
+    let mut apps: Vec<_> = read_dir("../user/build/elf/")
         .unwrap()
         .into_iter()
         .map(|dir_entry| {
@@ -22,35 +22,46 @@ fn insert_app_data() -> Result<()> {
         .collect();
     apps.sort();
 
-    writeln!(f, r#"
+    writeln!(
+        f,
+        r#"
     .align 3
     .section .data
     .global _num_app
 _num_app:
-    .quad {}"#, apps.len())?;
+    .quad {}"#,
+        apps.len()
+    )?;
 
     for i in 0..apps.len() {
         writeln!(f, r#"    .quad app_{}_start"#, i)?;
     }
     writeln!(f, r#"    .quad app_{}_end"#, apps.len() - 1)?;
 
-    writeln!(f, r#"
+    writeln!(
+        f,
+        r#"
     .global _app_names
-_app_names:"#)?;
+_app_names:"#
+    )?;
     for app in apps.iter() {
         writeln!(f, r#"    .string "{}""#, app)?;
     }
 
     for (idx, app) in apps.iter().enumerate() {
         println!("app_{}: {}", idx, app);
-        writeln!(f, r#"
+        writeln!(
+            f,
+            r#"
     .section .data
     .global app_{0}_start
     .global app_{0}_end
     .align 3
 app_{0}_start:
-    .incbin "{2}{1}"
-app_{0}_end:"#, idx, app, TARGET_PATH)?;
+    .incbin "{2}{1}.elf"
+app_{0}_end:"#,
+            idx, app, TARGET_PATH
+        )?;
     }
     Ok(())
-}
\ No newline at end of file
+}
diff --git a/os/src/config.rs b/os/src/config.rs
index 852800be..1b2cf21c 100644
--- a/os/src/config.rs
+++ b/os/src/config.rs
@@ -6,7 +6,7 @@ pub const KERNEL_HEAP_SIZE: usize = 0x20_0000;
 pub const MEMORY_END: usize = 0x80600000;
 
 #[cfg(feature = "board_qemu")]
-pub const MEMORY_END: usize = 0x80800000;
+pub const MEMORY_END: usize = 0x80f00000;
 
 pub const PAGE_SIZE: usize = 0x1000;
 pub const PAGE_SIZE_BITS: usize = 0xc;
diff --git a/os/src/syscall/mod.rs b/os/src/syscall/mod.rs
index 1699e8ca..9e62ee21 100644
--- a/os/src/syscall/mod.rs
+++ b/os/src/syscall/mod.rs
@@ -24,7 +24,7 @@ pub fn syscall(syscall_id: usize, args: [usize; 3]) -> isize {
         SYSCALL_WRITE => sys_write(args[0], args[1] as *const u8, args[2]),
         SYSCALL_EXIT => sys_exit(args[0] as i32),
         SYSCALL_YIELD => sys_yield(),
-        SYSCALL_GET_TIME => sys_get_time(),
+        SYSCALL_GET_TIME => sys_get_time(args[0] as *mut TimeVal, args[1]),
         SYSCALL_GETPID => sys_getpid(),
         SYSCALL_FORK => sys_fork(),
         SYSCALL_EXEC => sys_exec(args[0] as *const u8),
diff --git a/os/src/syscall/process.rs b/os/src/syscall/process.rs
index b425d87d..ead5d0b3 100644
--- a/os/src/syscall/process.rs
+++ b/os/src/syscall/process.rs
@@ -5,7 +5,7 @@ use crate::task::{
     current_user_token,
     add_task,
 };
-use crate::timer::get_time_ms;
+use crate::timer::get_time_us;
 use crate::mm::{
     translated_str,
     translated_refmut,
@@ -13,6 +13,13 @@ use crate::mm::{
 use crate::loader::get_app_data_by_name;
 use alloc::sync::Arc;
 
+#[repr(C)]
+#[derive(Debug)]
+pub struct TimeVal {
+    pub sec: usize,
+    pub usec: usize,
+}
+
 pub fn sys_exit(exit_code: i32) -> ! {
     exit_current_and_run_next(exit_code);
     panic!("Unreachable in sys_exit!");
@@ -23,8 +30,15 @@ pub fn sys_yield() -> isize {
     0
 }
 
-pub fn sys_get_time() -> isize {
-    get_time_ms() as isize
+pub fn sys_get_time(_ts: *mut TimeVal, _tz: usize) -> isize {
+    let _us = get_time_us();
+    // unsafe {
+    //     *ts = TimeVal {
+    //         sec: us / 1_000_000,
+    //         usec: us % 1_000_000,
+    //     };
+    // }
+    0
 }
 
 pub fn sys_getpid() -> isize {
diff --git a/os/src/timer.rs b/os/src/timer.rs
index 92d50e3a..c8b2afe3 100644
--- a/os/src/timer.rs
+++ b/os/src/timer.rs
@@ -3,14 +3,14 @@ use crate::sbi::set_timer;
 use crate::config::CLOCK_FREQ;
 
 const TICKS_PER_SEC: usize = 100;
-const MSEC_PER_SEC: usize = 1000;
+const MICRO_PER_SEC: usize = 1_000_000;
 
 pub fn get_time() -> usize {
     time::read()
 }
 
-pub fn get_time_ms() -> usize {
-    time::read() / (CLOCK_FREQ / MSEC_PER_SEC)
+pub fn get_time_us() -> usize {
+    time::read() / (CLOCK_FREQ / MICRO_PER_SEC)
 }
 
 pub fn set_next_trigger() {
diff --git a/user/Cargo.toml b/user/Cargo.toml
index aa6e20fe..01b75c29 100644
--- a/user/Cargo.toml
+++ b/user/Cargo.toml
@@ -7,4 +7,7 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-buddy_system_allocator = "0.6"
\ No newline at end of file
+buddy_system_allocator = "0.6"
+bitflags = "1.2.1"
+spin = "0.9"
+lazy_static = { version = "1.4.0", features = ["spin_no_std"] }
diff --git a/user/Makefile b/user/Makefile
index 5e0f87c3..1307bab4 100644
--- a/user/Makefile
+++ b/user/Makefile
@@ -2,22 +2,39 @@ TARGET := riscv64gc-unknown-none-elf
 MODE := release
 APP_DIR := src/bin
 TARGET_DIR := target/$(TARGET)/$(MODE)
-APPS := $(wildcard $(APP_DIR)/*.rs)
-ELFS := $(patsubst $(APP_DIR)/%.rs, $(TARGET_DIR)/%, $(APPS))
-BINS := $(patsubst $(APP_DIR)/%.rs, $(TARGET_DIR)/%.bin, $(APPS))
-
+BUILD_DIR := build
 OBJDUMP := rust-objdump --arch-name=riscv64
 OBJCOPY := rust-objcopy --binary-architecture=riscv64
+PY := python3
+
+TEST ?= 0
+ifeq ($(TEST), 0)
+	APPS :=  $(filter-out $(wildcard $(APP_DIR)/test*.rs), $(wildcard $(APP_DIR)/*.rs))
+else
+	APPS :=  $(wildcard $(APP_DIR)/test*.rs) $(APP_DIR)/initproc.rs $(APP_DIR)/user_shell.rs
+endif
+ELFS := $(patsubst $(APP_DIR)/%.rs, $(TARGET_DIR)/%, $(APPS))
 
 elf: $(APPS)
 	@cargo build --release
 
 binary: elf
-	$(foreach elf, $(ELFS), $(OBJCOPY) $(elf) --strip-all -O binary $(patsubst $(TARGET_DIR)/%, $(TARGET_DIR)/%.bin, $(elf));)
+	@$(foreach elf, $(ELFS), \
+		$(OBJCOPY) $(elf) --strip-all -O binary $(patsubst $(TARGET_DIR)/%, $(TARGET_DIR)/%.bin, $(elf)); \
+		cp $(elf) $(patsubst $(TARGET_DIR)/%, $(TARGET_DIR)/%.elf, $(elf));)
 
-build: binary
+pre:
+	@mkdir -p $(BUILD_DIR)/bin/
+	@mkdir -p $(BUILD_DIR)/elf/
+	@mkdir -p $(BUILD_DIR)/app/
+	@$(foreach t, $(APPS), cp $(t) $(BUILD_DIR)/app/;)
+	
+build: clean pre binary 
+	@$(foreach t, $(ELFS), cp $(t).bin $(BUILD_DIR)/bin/;)
+	@$(foreach t, $(ELFS), cp $(t).elf $(BUILD_DIR)/elf/;)
 
 clean:
 	@cargo clean
+	@rm -rf $(BUILD_DIR)
 
 .PHONY: elf binary build clean
\ No newline at end of file
diff --git a/user/src/bin/cat.rs b/user/src/bin/cat.rs
new file mode 100644
index 00000000..988164d3
--- /dev/null
+++ b/user/src/bin/cat.rs
@@ -0,0 +1,34 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+extern crate alloc;
+
+use user_lib::{
+    open,
+    OpenFlags,
+    close,
+    read,
+};
+use alloc::string::String;
+
+#[no_mangle]
+pub fn main(argc: usize, argv: &[&str]) -> i32 {
+    assert!(argc == 2);
+    let fd = open(argv[1], OpenFlags::RDONLY);
+    if fd == -1 {
+        panic!("Error occured when opening file");
+    }
+    let fd = fd as usize;
+    let mut buf = [0u8; 16];
+    let mut s = String::new();
+    loop {
+        let size = read(fd, &mut buf) as usize;
+        if size == 0 { break; }
+        s.push_str(core::str::from_utf8(&buf[..size]).unwrap());
+    }
+    println!("{}", s);
+    close(fd);
+    0
+}
\ No newline at end of file
diff --git a/user/src/bin/exit.rs b/user/src/bin/exit.rs
index 5bde550b..60510c90 100644
--- a/user/src/bin/exit.rs
+++ b/user/src/bin/exit.rs
@@ -3,7 +3,7 @@
 
 #[macro_use]
 extern crate user_lib;
-use user_lib::{fork, yield_, waitpid, exit, wait};
+use user_lib::{exit, fork, wait, waitpid, yield_};
 
 const MAGIC: i32 = -0x10384;
 
@@ -13,7 +13,9 @@ pub fn main() -> i32 {
     let pid = fork();
     if pid == 0 {
         println!("I am the child.");
-        for _ in 0..7 { yield_(); }
+        for _ in 0..7 {
+            yield_();
+        }
         exit(MAGIC);
     } else {
         println!("I am parent, fork a child pid {}", pid);
@@ -26,4 +28,3 @@ pub fn main() -> i32 {
     println!("exit pass.");
     0
 }
-
diff --git a/user/src/bin/fantastic_text.rs b/user/src/bin/fantastic_text.rs
index bb51db30..a3402ff6 100644
--- a/user/src/bin/fantastic_text.rs
+++ b/user/src/bin/fantastic_text.rs
@@ -41,4 +41,4 @@ pub fn main() -> i32 {
         println!("{}", color_text!(text, i));
     }
     0
-}
\ No newline at end of file
+}
diff --git a/user/src/bin/filetest_simple.rs b/user/src/bin/filetest_simple.rs
new file mode 100644
index 00000000..60fda6aa
--- /dev/null
+++ b/user/src/bin/filetest_simple.rs
@@ -0,0 +1,38 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::{
+    open,
+    close,
+    read,
+    write,
+    OpenFlags,
+};
+
+#[no_mangle]
+pub fn main() -> i32 {
+    let test_str = "Hello, world!";
+    let filea = "filea\0";
+    let fd = open(filea, OpenFlags::CREATE | OpenFlags::WRONLY);
+    assert!(fd > 0);
+    let fd = fd as usize;
+    write(fd, test_str.as_bytes());
+    close(fd);
+
+    let fd = open(filea, OpenFlags::RDONLY);
+    assert!(fd > 0);
+    let fd = fd as usize;
+    let mut buffer = [0u8; 100];
+    let read_len = read(fd, &mut buffer) as usize;
+    close(fd);
+
+    assert_eq!(
+        test_str,
+        core::str::from_utf8(&buffer[..read_len]).unwrap(),
+    );
+    println!("file_test passed!");
+    0
+}
\ No newline at end of file
diff --git a/user/src/bin/forktest.rs b/user/src/bin/forktest.rs
index fea6967c..22b53a94 100644
--- a/user/src/bin/forktest.rs
+++ b/user/src/bin/forktest.rs
@@ -4,7 +4,7 @@
 #[macro_use]
 extern crate user_lib;
 
-use user_lib::{fork, wait, exit};
+use user_lib::{exit, fork, wait};
 
 const MAX_CHILD: usize = 40;
 
@@ -31,4 +31,4 @@ pub fn main() -> i32 {
     }
     println!("forktest pass.");
     0
-}
\ No newline at end of file
+}
diff --git a/user/src/bin/forktest2.rs b/user/src/bin/forktest2.rs
index d08a4120..c91ce152 100644
--- a/user/src/bin/forktest2.rs
+++ b/user/src/bin/forktest2.rs
@@ -4,7 +4,7 @@
 #[macro_use]
 extern crate user_lib;
 
-use user_lib::{fork, wait, getpid, exit, sleep, get_time};
+use user_lib::{exit, fork, get_time, getpid, sleep, wait};
 
 static NUM: usize = 30;
 
@@ -14,7 +14,8 @@ pub fn main() -> i32 {
         let pid = fork();
         if pid == 0 {
             let current_time = get_time();
-            let sleep_length = (current_time as i32 as isize) * (current_time as i32 as isize) % 1000 + 1000;
+            let sleep_length =
+                (current_time as i32 as isize) * (current_time as i32 as isize) % 1000 + 1000;
             println!("pid {} sleep for {} ms", getpid(), sleep_length);
             sleep(sleep_length as usize);
             println!("pid {} OK!", getpid());
@@ -30,4 +31,4 @@ pub fn main() -> i32 {
     assert!(wait(&mut exit_code) < 0);
     println!("forktest2 test passed!");
     0
-}
\ No newline at end of file
+}
diff --git a/user/src/bin/forktest_simple.rs b/user/src/bin/forktest_simple.rs
index 821fba64..29a624b4 100644
--- a/user/src/bin/forktest_simple.rs
+++ b/user/src/bin/forktest_simple.rs
@@ -25,4 +25,4 @@ pub fn main() -> i32 {
         println!("child process pid = {}, exit code = {}", pid, exit_code);
         0
     }
-}
\ No newline at end of file
+}
diff --git a/user/src/bin/forktree.rs b/user/src/bin/forktree.rs
index 2debf6c5..bfcfc4ca 100644
--- a/user/src/bin/forktree.rs
+++ b/user/src/bin/forktree.rs
@@ -4,7 +4,7 @@
 #[macro_use]
 extern crate user_lib;
 
-use user_lib::{sleep, getpid, fork, exit, yield_};
+use user_lib::{exit, fork, getpid, sleep, yield_};
 
 const DEPTH: usize = 4;
 
diff --git a/user/src/bin/hello_world.rs b/user/src/bin/hello_world.rs
index de4a6a92..10d3f26c 100644
--- a/user/src/bin/hello_world.rs
+++ b/user/src/bin/hello_world.rs
@@ -8,4 +8,4 @@ extern crate user_lib;
 pub fn main() -> i32 {
     println!("Hello world from user mode program!");
     0
-}
\ No newline at end of file
+}
diff --git a/user/src/bin/huge_write.rs b/user/src/bin/huge_write.rs
new file mode 100644
index 00000000..dd502231
--- /dev/null
+++ b/user/src/bin/huge_write.rs
@@ -0,0 +1,36 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::{
+    OpenFlags,
+    open,
+    close,
+    write,
+    get_time,
+};
+
+#[no_mangle]
+pub fn main() -> i32 {
+    let mut buffer = [0u8; 1024]; // 1KiB
+    for i in 0..buffer.len() {
+        buffer[i] = i as u8;
+    }
+    let f = open("testf", OpenFlags::CREATE | OpenFlags::WRONLY);
+    if f < 0 {
+        panic!("Open test file failed!");
+    }
+    let f = f as usize;
+    let start = get_time();
+    let size_mb = 1usize;
+    for _ in 0..1024*size_mb {
+        write(f, &buffer);
+    }
+    close(f);
+    let time_ms = (get_time() - start) as usize;
+    let speed_kbs = size_mb * 1000000 / time_ms;
+    println!("time cost = {}ms, write speed = {}KiB/s", time_ms, speed_kbs);
+    0
+}
\ No newline at end of file
diff --git a/user/src/bin/initproc.rs b/user/src/bin/initproc.rs
index 6d30fdb6..71bed27e 100644
--- a/user/src/bin/initproc.rs
+++ b/user/src/bin/initproc.rs
@@ -4,12 +4,7 @@
 #[macro_use]
 extern crate user_lib;
 
-use user_lib::{
-    fork,
-    wait,
-    exec,
-    yield_,
-};
+use user_lib::{exec, fork, wait, yield_};
 
 #[no_mangle]
 fn main() -> i32 {
@@ -25,10 +20,9 @@ fn main() -> i32 {
             }
             println!(
                 "[initproc] Released a zombie process, pid={}, exit_code={}",
-                pid,
-                exit_code,
+                pid, exit_code,
             );
         }
     }
     0
-}
\ No newline at end of file
+}
diff --git a/user/src/bin/matrix.rs b/user/src/bin/matrix.rs
index 8ef2c044..3dfff386 100644
--- a/user/src/bin/matrix.rs
+++ b/user/src/bin/matrix.rs
@@ -4,7 +4,7 @@
 #[macro_use]
 extern crate user_lib;
 
-use user_lib::{fork, wait, yield_, exit, getpid, get_time};
+use user_lib::{exit, fork, get_time, getpid, wait, yield_};
 
 static NUM: usize = 35;
 const N: usize = 10;
@@ -27,6 +27,7 @@ fn work(times: isize) {
         for i in 0..N {
             for j in 0..N {
                 c[i][j] = 0;
+                #[allow(clippy::needless_range_loop)]
                 for k in 0..N {
                     c[i][j] = (c[i][j] + a[i][k] * b[k][j]) % P;
                 }
@@ -65,4 +66,4 @@ pub fn main() -> i32 {
     assert!(wait(&mut exit_code) < 0);
     println!("matrix passed.");
     0
-}
\ No newline at end of file
+}
diff --git a/user/src/bin/pipe_large_test.rs b/user/src/bin/pipe_large_test.rs
index 121987be..eeac1044 100644
--- a/user/src/bin/pipe_large_test.rs
+++ b/user/src/bin/pipe_large_test.rs
@@ -6,8 +6,8 @@ extern crate user_lib;
 
 extern crate alloc;
 
-use user_lib::{fork, close, pipe, read, write, wait, get_time};
 use alloc::format;
+use user_lib::{close, fork, get_time, pipe, read, wait, write};
 
 const LENGTH: usize = 3000;
 #[no_mangle]
@@ -40,11 +40,14 @@ pub fn main() -> i32 {
         // close write end of up pipe
         close(up_pipe_fd[1]);
         // generate a long random string
-        for i in 0..LENGTH {
-            random_str[i] = get_time() as u8;
+        for ch in random_str.iter_mut().take(LENGTH) {
+            *ch = get_time() as u8;
         }
         // send it
-        assert_eq!(write(down_pipe_fd[1], &random_str) as usize, random_str.len());
+        assert_eq!(
+            write(down_pipe_fd[1], &random_str) as usize,
+            random_str.len()
+        );
         // close write end of down pipe
         close(down_pipe_fd[1]);
         // calculate sum(parent)
@@ -57,13 +60,12 @@ pub fn main() -> i32 {
         // check
         assert_eq!(
             sum,
-            str::parse::<usize>(
-                core::str::from_utf8(&child_result[..result_len]).unwrap()
-            ).unwrap()
+            str::parse::<usize>(core::str::from_utf8(&child_result[..result_len]).unwrap())
+                .unwrap()
         );
         let mut _unused: i32 = 0;
         wait(&mut _unused);
         println!("pipe_large_test passed!");
         0
     }
-}
\ No newline at end of file
+}
diff --git a/user/src/bin/pipetest.rs b/user/src/bin/pipetest.rs
index c151fbdd..5436c63f 100644
--- a/user/src/bin/pipetest.rs
+++ b/user/src/bin/pipetest.rs
@@ -4,7 +4,7 @@
 #[macro_use]
 extern crate user_lib;
 
-use user_lib::{fork, close, pipe, read, write, wait};
+use user_lib::{close, fork, pipe, read, wait, write};
 
 static STR: &str = "Hello, world!";
 
@@ -41,4 +41,4 @@ pub fn main() -> i32 {
         println!("pipetest passed!");
         0
     }
-}
\ No newline at end of file
+}
diff --git a/user/src/bin/run_pipe_test.rs b/user/src/bin/run_pipe_test.rs
index ca2afd15..447eeea9 100644
--- a/user/src/bin/run_pipe_test.rs
+++ b/user/src/bin/run_pipe_test.rs
@@ -4,7 +4,7 @@
 #[macro_use]
 extern crate user_lib;
 
-use user_lib::{fork, exec, wait};
+use user_lib::{exec, fork, wait};
 
 #[no_mangle]
 pub fn main() -> i32 {
@@ -18,4 +18,4 @@ pub fn main() -> i32 {
         }
     }
     0
-}
\ No newline at end of file
+}
diff --git a/user/src/bin/sleep.rs b/user/src/bin/sleep.rs
index beba78c6..641a4f9d 100644
--- a/user/src/bin/sleep.rs
+++ b/user/src/bin/sleep.rs
@@ -4,7 +4,7 @@
 #[macro_use]
 extern crate user_lib;
 
-use user_lib::{sleep, exit, get_time, fork, waitpid};
+use user_lib::{exit, fork, get_time, sleep, waitpid};
 
 fn sleepy() {
     let time: usize = 100;
@@ -27,4 +27,4 @@ pub fn main() -> i32 {
     println!("use {} msecs.", get_time() - current_time);
     println!("sleep pass.");
     0
-}
\ No newline at end of file
+}
diff --git a/user/src/bin/sleep_simple.rs b/user/src/bin/sleep_simple.rs
index 4c058f87..7015a3d4 100644
--- a/user/src/bin/sleep_simple.rs
+++ b/user/src/bin/sleep_simple.rs
@@ -13,7 +13,11 @@ pub fn main() -> i32 {
     println!("current time_msec = {}", start);
     sleep(100);
     let end = get_time();
-    println!("time_msec = {} after sleeping 100 ticks, delta = {}ms!", end, end - start);
+    println!(
+        "time_msec = {} after sleeping 100 ticks, delta = {}ms!",
+        end,
+        end - start
+    );
     println!("r_sleep passed!");
     0
-}
\ No newline at end of file
+}
diff --git a/user/src/bin/stack_overflow.rs b/user/src/bin/stack_overflow.rs
index e0ea471d..5d365f5d 100644
--- a/user/src/bin/stack_overflow.rs
+++ b/user/src/bin/stack_overflow.rs
@@ -5,7 +5,7 @@
 extern crate user_lib;
 
 fn f(d: usize) {
-    println!("d = {}",d);
+    println!("d = {}", d);
     f(d + 1);
 }
 
@@ -14,4 +14,4 @@ pub fn main() -> i32 {
     println!("It should trigger segmentation fault!");
     f(0);
     0
-}
\ No newline at end of file
+}
diff --git a/user/src/bin/test_exit0.rs b/user/src/bin/test_exit0.rs
new file mode 100644
index 00000000..3bae851f
--- /dev/null
+++ b/user/src/bin/test_exit0.rs
@@ -0,0 +1,17 @@
+#![no_std]
+#![no_main]
+
+extern crate user_lib;
+use user_lib::exit;
+
+/*
+辅助测例，正常退出，不输出 FAIL 即可。
+*/
+
+#[allow(unreachable_code)]
+#[no_mangle]
+pub fn main() -> i32 {
+    exit(66778);
+    panic!("FAIL: T.T\n");
+    0
+}
diff --git a/user/src/bin/test_exit1.rs b/user/src/bin/test_exit1.rs
new file mode 100644
index 00000000..47c09cb5
--- /dev/null
+++ b/user/src/bin/test_exit1.rs
@@ -0,0 +1,17 @@
+#![no_std]
+#![no_main]
+
+extern crate user_lib;
+use user_lib::exit;
+
+/*
+辅助测例，正常退出，不输出 FAIL 即可。
+*/
+
+#[allow(unreachable_code)]
+#[no_mangle]
+pub fn main() -> i32 {
+    exit(-233);
+    panic!("FAIL: T.T\n");
+    0
+}
diff --git a/user/src/bin/test_file0.rs b/user/src/bin/test_file0.rs
new file mode 100644
index 00000000..0b61fc92
--- /dev/null
+++ b/user/src/bin/test_file0.rs
@@ -0,0 +1,31 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::{close, open, read, write, OpenFlags};
+
+/// 测试文件基本读写，输出　Test file0 OK! 就算正确。
+
+#[no_mangle]
+pub fn main() -> i32 {
+    let test_str = "Hello, world!";
+    let fname = "fname\0";
+    let fd = open(fname, OpenFlags::CREATE | OpenFlags::WRONLY);
+    assert!(fd > 0);
+    let fd = fd as usize;
+    write(fd, test_str.as_bytes());
+    close(fd);
+
+    let fd = open(fname, OpenFlags::RDONLY);
+    assert!(fd > 0);
+    let fd = fd as usize;
+    let mut buffer = [0u8; 100];
+    let read_len = read(fd, &mut buffer) as usize;
+    close(fd);
+
+    assert_eq!(test_str, core::str::from_utf8(&buffer[..read_len]).unwrap(),);
+    println!("Test file0 OK!");
+    0
+}
diff --git a/user/src/bin/test_file1.rs b/user/src/bin/test_file1.rs
new file mode 100644
index 00000000..6565121a
--- /dev/null
+++ b/user/src/bin/test_file1.rs
@@ -0,0 +1,26 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+use user_lib::{close, fstat, open, OpenFlags, Stat, StatMode};
+
+/// 测试 fstat，输出　Test fstat OK! 就算正确。
+
+#[no_mangle]
+pub fn main() -> i32 {
+    let fname = "fname1\0";
+    let fd = open(fname, OpenFlags::CREATE | OpenFlags::WRONLY);
+    assert!(fd > 0);
+    let fd = fd as usize;
+    let stat: Stat = Stat::new();
+    let ret = fstat(fd, &stat);
+    assert_eq!(ret, 0);
+    assert_eq!(stat.mode, StatMode::FILE);
+    assert_eq!(stat.nlink, 1);
+    close(fd);
+    // unlink(fname);
+    // It's recommended to rebuild the disk image. This program will not clean the file "fname1".
+    println!("Test fstat OK!");
+    0
+}
diff --git a/user/src/bin/test_file2.rs b/user/src/bin/test_file2.rs
new file mode 100644
index 00000000..c6463141
--- /dev/null
+++ b/user/src/bin/test_file2.rs
@@ -0,0 +1,46 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+use user_lib::{close, fstat, link, open, read, unlink, write, OpenFlags, Stat};
+
+/// 测试 link/unlink，输出　Test link OK! 就算正确。
+
+#[no_mangle]
+pub fn main() -> i32 {
+    let test_str = "Hello, world!";
+    let fname = "fname2\0";
+    let (lname0, lname1, lname2) = ("linkname0\0", "linkname1\0", "linkname2\0");
+    let fd = open(fname, OpenFlags::CREATE | OpenFlags::WRONLY) as usize;
+    link(fname, lname0);
+    let stat = Stat::new();
+    fstat(fd, &stat);
+    assert_eq!(stat.nlink, 2);
+    link(fname, lname1);
+    link(fname, lname2);
+    fstat(fd, &stat);
+    assert_eq!(stat.nlink, 4);
+    write(fd, test_str.as_bytes());
+    close(fd);
+
+    unlink(fname);
+    let fd = open(lname0, OpenFlags::RDONLY) as usize;
+    let stat2 = Stat::new();
+    let mut buf = [0u8; 100];
+    let read_len = read(fd, &mut buf) as usize;
+    assert_eq!(test_str, core::str::from_utf8(&buf[..read_len]).unwrap(),);
+    fstat(fd, &stat2);
+    assert_eq!(stat2.dev, stat.dev);
+    assert_eq!(stat2.ino, stat.ino);
+    assert_eq!(stat2.nlink, 3);
+    unlink(lname1);
+    unlink(lname2);
+    fstat(fd, &stat2);
+    assert_eq!(stat2.nlink, 1);
+    close(fd);
+    unlink(lname0);
+    // It's Ok if you don't delete the inode and data blocks.
+    println!("Test link OK!");
+    0
+}
diff --git a/user/src/bin/test_getpid.rs b/user/src/bin/test_getpid.rs
new file mode 100644
index 00000000..66ee7323
--- /dev/null
+++ b/user/src/bin/test_getpid.rs
@@ -0,0 +1,18 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::getpid;
+
+/*
+辅助测例 打印子进程 pid
+*/
+
+#[no_mangle]
+pub fn main() -> i32 {
+    let pid = getpid();
+    println!("Test getpid OK! pid = {}", pid);
+    0
+}
diff --git a/user/src/bin/test_mail0.rs b/user/src/bin/test_mail0.rs
new file mode 100644
index 00000000..420f285b
--- /dev/null
+++ b/user/src/bin/test_mail0.rs
@@ -0,0 +1,27 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::{getpid, mail_read, mail_write};
+
+const BUF_LEN: usize = 256;
+
+/// 测试邮箱基本功能，输出　mail0 test OK! 就算正确。
+
+#[no_mangle]
+fn main() -> i32 {
+    let pid = getpid();
+    let buffer0 = ['a' as u8; 27];
+    assert_eq!(mail_write(pid as usize, &buffer0), 27);
+    let buffer1 = ['b' as u8; BUF_LEN + 1];
+    assert_eq!(mail_write(pid as usize, &buffer1), BUF_LEN as isize);
+    let mut buf = [0u8; BUF_LEN];
+    assert_eq!(mail_read(&mut buf), 27);
+    assert_eq!(buf[..27], buffer0);
+    assert_eq!(mail_read(&mut buf[..27]), 27);
+    assert_eq!(buf[..27], buffer1[..27]);
+    println!("mail0 test OK!");
+    0
+}
diff --git a/user/src/bin/test_mail1.rs b/user/src/bin/test_mail1.rs
new file mode 100644
index 00000000..3e02ba92
--- /dev/null
+++ b/user/src/bin/test_mail1.rs
@@ -0,0 +1,28 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::{getpid, mail_read, mail_write};
+
+const BUF_LEN: usize = 256;
+const MAIL_MAX: usize = 16;
+
+/// 测试邮箱容量，输出 mail1 test OK! 就算正确。
+
+#[no_mangle]
+fn main() -> i32 {
+    let pid = getpid();
+    let buffer0 = ['a' as u8; BUF_LEN];
+    for _ in 0..MAIL_MAX {
+        assert_eq!(mail_write(pid as usize, &buffer0), BUF_LEN as isize);
+    }
+    assert_eq!(mail_write(pid as usize, &buffer0), -1);
+    let mut buf = [0u8; BUF_LEN];
+    assert_eq!(mail_read(&mut buf), BUF_LEN as isize);
+    assert_eq!(mail_write(pid as usize, &buffer0), BUF_LEN as isize);
+    assert_eq!(mail_write(pid as usize, &buffer0), -1);
+    println!("mail1 test OK!");
+    0
+}
diff --git a/user/src/bin/test_mail2.rs b/user/src/bin/test_mail2.rs
new file mode 100644
index 00000000..4a51193a
--- /dev/null
+++ b/user/src/bin/test_mail2.rs
@@ -0,0 +1,60 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::{exit, fork, mail_read, mail_write, sleep, wait};
+
+const BUF_LEN: usize = 256;
+
+// 双进程邮箱测试，最终输出 mail2 test OK! 就算正确。
+
+#[no_mangle]
+fn main() -> i32 {
+    let pid = fork();
+    if pid == 0 {
+        println!("I am child");
+        let mut buffer = [0u8; BUF_LEN];
+        assert_eq!(mail_read(&mut buffer), -1);
+        println!("child read 1 mail fail");
+        println!("child sleep 2s");
+        sleep(2000 as usize);
+        for i in 0..16 {
+            let mut buffer = [0u8; BUF_LEN];
+            assert_eq!(mail_read(&mut buffer), BUF_LEN as isize);
+            assert_eq!(buffer, [i as u8; BUF_LEN]);
+        }
+        println!("child read 16 mails succeed");
+        assert_eq!(mail_read(&mut buffer), -1);
+        println!("child read 1 mail fail");
+        println!("child sleep 1s");
+        sleep(1000 as usize);
+        assert_eq!(mail_read(&mut buffer), BUF_LEN as isize);
+        assert_eq!(buffer, [16 as u8; BUF_LEN]);
+        println!("child read 1 mail succeed");
+        println!("child exit");
+        exit(0);
+    }
+    println!("I am father");
+    println!("father sleep 1s");
+    sleep(1000 as usize);
+    for i in 0..16 {
+        let buffer = [i as u8; BUF_LEN];
+        assert_eq!(mail_write(pid as usize, &buffer), BUF_LEN as isize);
+    }
+    println!("father wirte 16 mails succeed");
+    let buffer = [16 as u8; BUF_LEN];
+    assert_eq!(mail_write(pid as usize, &buffer), -1);
+    println!("father wirte 1 mail fail");
+    println!("father sleep 1.5s");
+    sleep(1500 as usize);
+    assert_eq!(mail_write(pid as usize, &buffer), BUF_LEN as isize);
+    println!("father wirte 1 mail succeed");
+
+    let mut xstate: i32 = -100;
+    assert!(wait(&mut xstate) > 0);
+    assert_eq!(xstate, 0);
+    println!("mail2 test OK!");
+    0
+}
diff --git a/user/src/bin/test_mail3.rs b/user/src/bin/test_mail3.rs
new file mode 100644
index 00000000..b8a7979e
--- /dev/null
+++ b/user/src/bin/test_mail3.rs
@@ -0,0 +1,34 @@
+#![no_std]
+#![no_main]
+
+extern crate core;
+#[macro_use]
+extern crate user_lib;
+
+use core::slice;
+use user_lib::{getpid, mail_read, mail_write};
+
+const BUF_LEN: usize = 256;
+const MAIL_MAX: usize = 16;
+const BAD_ADDRESS: usize = 0x90000000;
+
+/// 邮箱错误参数测试，输出 mail3 test OK! 就算正确。
+
+#[no_mangle]
+fn main() -> i32 {
+    let pid = getpid();
+    let null = unsafe { slice::from_raw_parts(BAD_ADDRESS as *const _, 10) };
+    assert_eq!(mail_write(pid as usize, &null), -1);
+    let mut empty = ['a' as u8; 0];
+    assert_eq!(mail_write(pid as usize, &empty), 0);
+    assert_eq!(mail_read(&mut empty), -1);
+    let buffer0 = ['a' as u8; BUF_LEN];
+    for _ in 0..MAIL_MAX {
+        assert_eq!(mail_write(pid as usize, &buffer0), BUF_LEN as isize);
+    }
+    assert_eq!(mail_write(pid as usize, &empty), -1);
+    assert_eq!(mail_read(&mut empty), 0);
+    assert_eq!(mail_write(pid as usize, &empty), -1);
+    println!("mail3 test OK!");
+    0
+}
diff --git a/user/src/bin/test_mmap0.rs b/user/src/bin/test_mmap0.rs
new file mode 100644
index 00000000..5247eec2
--- /dev/null
+++ b/user/src/bin/test_mmap0.rs
@@ -0,0 +1,33 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::mmap;
+
+/*
+理想结果：输出 Test 04_1 OK!
+*/
+
+#[no_mangle]
+fn main() -> i32 {
+    let start: usize = 0x10000000;
+    let len: usize = 4096;
+    let prot: usize = 3;
+    assert_eq!(0, mmap(start, len, prot));
+    for i in start..(start + len) {
+        let addr: *mut u8 = i as *mut u8;
+        unsafe {
+            *addr = i as u8;
+        }
+    }
+    for i in start..(start + len) {
+        let addr: *mut u8 = i as *mut u8;
+        unsafe {
+            assert_eq!(*addr, i as u8);
+        }
+    }
+    println!("Test 04_1 OK!");
+    0
+}
diff --git a/user/src/bin/test_mmap1.rs b/user/src/bin/test_mmap1.rs
new file mode 100644
index 00000000..63d6411d
--- /dev/null
+++ b/user/src/bin/test_mmap1.rs
@@ -0,0 +1,25 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::mmap;
+
+/*
+理想结果：程序触发访存异常，被杀死。不输出 error 就算过。
+*/
+
+#[no_mangle]
+fn main() -> i32 {
+    let start: usize = 0x10000000;
+    let len: usize = 4096;
+    let prot: usize = 1;
+    assert_eq!(0, mmap(start, len, prot));
+    let addr: *mut u8 = start as *mut u8;
+    unsafe {
+        *addr = start as u8;
+    }
+    println!("Should cause error, Test 04_2 fail!");
+    0
+}
diff --git a/user/src/bin/test_mmap2.rs b/user/src/bin/test_mmap2.rs
new file mode 100644
index 00000000..2489fa64
--- /dev/null
+++ b/user/src/bin/test_mmap2.rs
@@ -0,0 +1,26 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::mmap;
+
+/*
+理想结果：程序触发访存异常，被杀死。不输出 error 就算过。
+*/
+
+#[no_mangle]
+fn main() -> i32 {
+    let start: usize = 0x10000000;
+    let len: usize = 4096;
+    let prot: usize = 2;
+    assert_eq!(0, mmap(start, len, prot));
+    let addr: *mut u8 = start as *mut u8;
+    unsafe {
+        // *addr = start as u8; // can't write, R == 0 && W == 1 is illegal in riscv
+        assert!(*addr != 0);
+    }
+    println!("Should cause error, Test 04_2 fail!");
+    0
+}
diff --git a/user/src/bin/test_mmap3.rs b/user/src/bin/test_mmap3.rs
new file mode 100644
index 00000000..d9d04b61
--- /dev/null
+++ b/user/src/bin/test_mmap3.rs
@@ -0,0 +1,25 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::mmap;
+
+/*
+理想结果：对于错误的 mmap 返回 -1，最终输出 Test 04_4 test OK!
+*/
+
+#[no_mangle]
+fn main() -> i32 {
+    let start: usize = 0x10000000;
+    let len: usize = 4096;
+    let prot: usize = 3;
+    assert_eq!(0, mmap(start, len, prot));
+    assert_eq!(mmap(start - len, len + 1, prot), -1);
+    assert_eq!(mmap(start + len + 1, len, prot), -1);
+    assert_eq!(mmap(start + len, len, 0), -1);
+    assert_eq!(mmap(start + len, len, prot | 8), -1);
+    println!("Test 04_4 test OK!");
+    0
+}
diff --git a/user/src/bin/test_sleep.rs b/user/src/bin/test_sleep.rs
new file mode 100644
index 00000000..1312f6c3
--- /dev/null
+++ b/user/src/bin/test_sleep.rs
@@ -0,0 +1,24 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::{get_time, yield_};
+
+/// 正确输出：（无报错信息）
+/// get_time OK! {...}
+/// Test sleep OK!
+
+#[no_mangle]
+fn main() -> i32 {
+    let current_time = get_time();
+    assert!(current_time > 0);
+    println!("get_time OK! {}", current_time);
+    let wait_for = current_time + 3000;
+    while get_time() < wait_for {
+        yield_();
+    }
+    println!("Test sleep OK!");
+    0
+}
diff --git a/user/src/bin/test_sleep1.rs b/user/src/bin/test_sleep1.rs
new file mode 100644
index 00000000..da0cae32
--- /dev/null
+++ b/user/src/bin/test_sleep1.rs
@@ -0,0 +1,22 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::{get_time, sleep};
+
+#[no_mangle]
+pub fn main() -> i32 {
+    let start = get_time();
+    println!("current time_msec = {}", start);
+    sleep(100);
+    let end = get_time();
+    println!(
+        "time_msec = {} after sleeping 100 ticks, delta = {}ms!",
+        end,
+        end - start
+    );
+    println!("Test sleep1 passed!");
+    0
+}
diff --git a/user/src/bin/test_spawn0.rs b/user/src/bin/test_spawn0.rs
new file mode 100644
index 00000000..2d09fc0d
--- /dev/null
+++ b/user/src/bin/test_spawn0.rs
@@ -0,0 +1,29 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::{spawn, wait};
+const MAX_CHILD: usize = 40;
+
+/*
+理想结果：生成 MAX_CHILD 个 getpid 的子进程，全部结束后，输出 Test spawn0 OK!
+*/
+
+#[no_mangle]
+pub fn main() -> i32 {
+    for _ in 0..MAX_CHILD {
+        let cpid = spawn("test_getpid\0");
+        assert!(cpid >= 0, "child pid invalid");
+        println!("new child {}", cpid);
+    }
+    let mut exit_code: i32 = 0;
+    for _ in 0..MAX_CHILD {
+        assert!(wait(&mut exit_code) > 0, "wait stopped early");
+        assert_eq!(exit_code, 0, "error exit ocde {}", exit_code);
+    }
+    assert!(wait(&mut exit_code) <= 0, "wait got too many");
+    println!("Test spawn0 OK!");
+    0
+}
diff --git a/user/src/bin/test_spawn1.rs b/user/src/bin/test_spawn1.rs
new file mode 100644
index 00000000..99352cba
--- /dev/null
+++ b/user/src/bin/test_spawn1.rs
@@ -0,0 +1,35 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::{spawn, wait, waitpid};
+
+/// 程序行为：先后产生 3 个有特定返回值的程序，检查 waitpid 能够获取正确返回值。
+
+/// 理想输出：
+/// new child i
+/// Test wait OK!
+/// Test waitpid OK!
+
+#[no_mangle]
+pub fn main() -> i32 {
+    let cpid = spawn("test_exit0\0");
+    assert!(cpid >= 0, "child pid invalid");
+    println!("new child {}", cpid);
+    let mut exit_code: i32 = 0;
+    let exit_pid = wait(&mut exit_code);
+    assert_eq!(exit_pid, cpid, "error exit pid");
+    assert_eq!(exit_code, 66778, "error exit code");
+    println!("Test wait OK!");
+    let (cpid0, cpid1) = (spawn("test_exit0\0"), spawn("test_exit1\0"));
+    let exit_pid = waitpid(cpid1 as usize, &mut exit_code);
+    assert_eq!(exit_pid, cpid1, "error exit pid");
+    assert_eq!(exit_code, -233, "error exit code");
+    let exit_pid = wait(&mut exit_code);
+    assert_eq!(exit_pid, cpid0, "error exit pid");
+    assert_eq!(exit_code, 66778, "error exit code");
+    println!("Test waitpid OK!");
+    0
+}
diff --git a/user/src/bin/test_unmap.rs b/user/src/bin/test_unmap.rs
new file mode 100644
index 00000000..b64f862f
--- /dev/null
+++ b/user/src/bin/test_unmap.rs
@@ -0,0 +1,36 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::{mmap, munmap};
+
+/*
+理想结果：输出 Test 04_5 ummap OK!
+*/
+
+#[no_mangle]
+fn main() -> i32 {
+    let start: usize = 0x10000000;
+    let len: usize = 4096;
+    let prot: usize = 3;
+    assert_eq!(0, mmap(start, len, prot));
+    assert_eq!(mmap(start + len, len * 2, prot), 0);
+    assert_eq!(munmap(start, len), 0);
+    assert_eq!(mmap(start - len, len + 1, prot), 0);
+    for i in (start - len)..(start + len * 3) {
+        let addr: *mut u8 = i as *mut u8;
+        unsafe {
+            *addr = i as u8;
+        }
+    }
+    for i in (start - len)..(start + len * 3) {
+        let addr: *mut u8 = i as *mut u8;
+        unsafe {
+            assert_eq!(*addr, i as u8);
+        }
+    }
+    println!("Test 04_5 ummap OK!");
+    0
+}
diff --git a/user/src/bin/test_unmap2.rs b/user/src/bin/test_unmap2.rs
new file mode 100644
index 00000000..85ddb750
--- /dev/null
+++ b/user/src/bin/test_unmap2.rs
@@ -0,0 +1,23 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::{mmap, munmap};
+
+/*
+理想结果：输出 Test 04_6 ummap2 OK!
+*/
+
+#[no_mangle]
+fn main() -> i32 {
+    let start: usize = 0x10000000;
+    let len: usize = 4096;
+    let prot: usize = 3;
+    assert_eq!(0, mmap(start, len, prot));
+    assert_eq!(munmap(start, len + 1), -1);
+    assert_eq!(munmap(start + 1, len - 1), -1);
+    println!("Test 04_6 ummap2 OK!");
+    0
+}
diff --git a/user/src/bin/test_usertest.rs b/user/src/bin/test_usertest.rs
new file mode 100644
index 00000000..335169d8
--- /dev/null
+++ b/user/src/bin/test_usertest.rs
@@ -0,0 +1,48 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+static TESTS: &[&str] = &[
+    "test_sleep\0",
+    "test_sleep1\0",
+    "test_mmap0\0",
+    "test_mmap1\0",
+    "test_mmap2\0",
+    "test_mmap3\0",
+    "test_unmap\0",
+    "test_unmap2\0",
+    "test_spawn0\0",
+    "test_spawn1\0",
+    "test_mail0\0",
+    "test_mail1\0",
+    "test_mail2\0",
+    "test_mail3\0",
+];
+
+use user_lib::{exec, fork, waitpid};
+
+/// 辅助测例，运行所有其他测例。
+
+#[no_mangle]
+pub fn main() -> i32 {
+    for test in TESTS {
+        println!("Usertests: Running {}", test);
+        let pid = fork();
+        if pid == 0 {
+            exec(*test);
+            panic!("unreachable!");
+        } else {
+            let mut exit_code: i32 = Default::default();
+            let wait_pid = waitpid(pid as usize, &mut exit_code);
+            assert_eq!(pid, wait_pid);
+            println!(
+                "\x1b[32mUsertests: Test {} in Process {} exited with code {}\x1b[0m",
+                test, pid, exit_code
+            );
+        }
+    }
+    println!("ch6 Usertests passed!");
+    0
+}
diff --git a/user/src/bin/test_write1.rs b/user/src/bin/test_write1.rs
new file mode 100644
index 00000000..276ad9c8
--- /dev/null
+++ b/user/src/bin/test_write1.rs
@@ -0,0 +1,31 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+use user_lib::{write, STDOUT};
+const DATA_STRING: &str = "string from data section\n";
+
+/// 正确输出：
+/// string from data section
+/// strinstring from stack section
+/// strin
+/// Test write1 OK!
+
+#[no_mangle]
+pub fn main() -> i32 {
+    assert_eq!(write(1234, DATA_STRING.as_bytes()), -1);
+    assert_eq!(
+        write(STDOUT, DATA_STRING.as_bytes()),
+        DATA_STRING.len() as isize
+    );
+    assert_eq!(write(STDOUT, &DATA_STRING.as_bytes()[..5]), 5);
+    let stack_string = "string from stack section\n";
+    assert_eq!(
+        write(STDOUT, stack_string.as_bytes()),
+        stack_string.len() as isize
+    );
+    assert_eq!(write(STDOUT, &stack_string.as_bytes()[..5]), 5);
+    println!("\nTest write1 OK!");
+    0
+}
diff --git a/user/src/bin/user_shell.rs b/user/src/bin/user_shell.rs
index 796bddb5..184655ac 100644
--- a/user/src/bin/user_shell.rs
+++ b/user/src/bin/user_shell.rs
@@ -12,19 +12,22 @@ const DL: u8 = 0x7fu8;
 const BS: u8 = 0x08u8;
 
 use alloc::string::String;
-use user_lib::{fork, exec, waitpid};
 use user_lib::console::getchar;
+use user_lib::{exec, flush, fork, waitpid};
+
+// 利用 pipe 机制为 Shell 实现管道运算符 '|'
 
 #[no_mangle]
 pub fn main() -> i32 {
     println!("Rust user shell");
     let mut line: String = String::new();
     print!(">> ");
+    flush();
     loop {
         let c = getchar();
         match c {
             LF | CR => {
-                println!("");
+                println!();
                 if !line.is_empty() {
                     line.push('\0');
                     let pid = fork();
@@ -44,19 +47,22 @@ pub fn main() -> i32 {
                     line.clear();
                 }
                 print!(">> ");
+                flush();
             }
             BS | DL => {
                 if !line.is_empty() {
                     print!("{}", BS as char);
                     print!(" ");
                     print!("{}", BS as char);
+                    flush();
                     line.pop();
                 }
             }
             _ => {
                 print!("{}", c as char);
+                flush();
                 line.push(c as char);
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/user/src/bin/usertests.rs b/user/src/bin/usertests.rs
index 7a4a6d7b..8f69534f 100644
--- a/user/src/bin/usertests.rs
+++ b/user/src/bin/usertests.rs
@@ -8,14 +8,18 @@ static TESTS: &[&str] = &[
     "exit\0",
     "fantastic_text\0",
     "forktest\0",
-    "forktest2\0",
     "forktest_simple\0",
     "hello_world\0",
     "matrix\0",
-    "sleep\0",
-    "sleep_simple\0",
     "stack_overflow\0",
     "yield\0",
+    "pipetest\0",
+    // 正确实现 sys_get_time 后这些程序才能运行
+    // "pipe_large_test\0",
+    // "forktest2\0",
+    // "sleep\0",
+    // "sleep_simple\0",
+    // "forktree\0",
 ];
 
 use user_lib::{exec, fork, waitpid};
@@ -32,9 +36,12 @@ pub fn main() -> i32 {
             let mut exit_code: i32 = Default::default();
             let wait_pid = waitpid(pid as usize, &mut exit_code);
             assert_eq!(pid, wait_pid);
-            println!("\x1b[32mUsertests: Test {} in Process {} exited with code {}\x1b[0m", test, pid, exit_code);
+            println!(
+                "\x1b[32mUsertests: Test {} in Process {} exited with code {}\x1b[0m",
+                test, pid, exit_code
+            );
         }
     }
     println!("Usertests passed!");
     0
-}
\ No newline at end of file
+}
diff --git a/user/src/bin/yield.rs b/user/src/bin/yield.rs
index 55032e40..78b1468c 100644
--- a/user/src/bin/yield.rs
+++ b/user/src/bin/yield.rs
@@ -14,4 +14,4 @@ pub fn main() -> i32 {
     }
     println!("yield pass.");
     0
-}
\ No newline at end of file
+}
diff --git a/user/src/console.rs b/user/src/console.rs
index 810ebba1..d47c8264 100644
--- a/user/src/console.rs
+++ b/user/src/console.rs
@@ -1,21 +1,52 @@
+use alloc::collections::vec_deque::VecDeque;
+use alloc::sync::Arc;
 use core::fmt::{self, Write};
+use spin::mutex::Mutex;
 
-const STDIN: usize = 0;
-const STDOUT: usize = 1;
+pub const STDIN: usize = 0;
+pub const STDOUT: usize = 1;
+
+const CONSOLE_BUFFER_SIZE: usize = 256 * 10;
 
 use super::{read, write};
+use lazy_static::*;
+
+struct ConsoleBuffer(VecDeque<u8>);
+
+lazy_static! {
+    static ref CONSOLE_BUFFER: Arc<Mutex<ConsoleBuffer>> = {
+        let buffer = VecDeque::<u8>::with_capacity(CONSOLE_BUFFER_SIZE);
+        Arc::new(Mutex::new(ConsoleBuffer(buffer)))
+    };
+}
 
-struct Stdout;
+impl ConsoleBuffer {
+    fn flush(&mut self) -> isize {
+        let s: &[u8] = self.0.make_contiguous();
+        let ret = write(STDOUT, s);
+        self.0.clear();
+        ret
+    }
+}
 
-impl Write for Stdout {
+impl Write for ConsoleBuffer {
     fn write_str(&mut self, s: &str) -> fmt::Result {
-        write(STDOUT, s.as_bytes());
+        for c in s.as_bytes().iter() {
+            self.0.push_back(*c);
+            if (*c == b'\n' || self.0.len() == CONSOLE_BUFFER_SIZE) && -1 == self.flush() {
+                return Err(fmt::Error);
+            }
+        }
         Ok(())
     }
 }
 
+#[allow(unused)]
 pub fn print(args: fmt::Arguments) {
-    Stdout.write_fmt(args).unwrap();
+    let mut buf = CONSOLE_BUFFER.lock();
+    // buf.write_fmt(args).unwrap();
+    // BUG FIX: 关闭 stdout 后，本函数不能触发 panic，否则会造成死锁
+    buf.write_fmt(args);
 }
 
 #[macro_export]
@@ -27,6 +58,9 @@ macro_rules! print {
 
 #[macro_export]
 macro_rules! println {
+    () => {
+        $crate::console::print(format_args!("\n"));
+    };
     ($fmt: literal $(, $($arg: tt)+)?) => {
         $crate::console::print(format_args!(concat!($fmt, "\n") $(, $($arg)+)?));
     }
@@ -37,3 +71,8 @@ pub fn getchar() -> u8 {
     read(STDIN, &mut c);
     c[0]
 }
+
+pub fn flush() {
+    let mut buf = CONSOLE_BUFFER.lock();
+    buf.flush();
+}
diff --git a/user/src/lang_items.rs b/user/src/lang_items.rs
index b5b98e08..c65aa421 100644
--- a/user/src/lang_items.rs
+++ b/user/src/lang_items.rs
@@ -4,9 +4,14 @@ use super::exit;
 fn panic_handler(panic_info: &core::panic::PanicInfo) -> ! {
     let err = panic_info.message().unwrap();
     if let Some(location) = panic_info.location() {
-        println!("Panicked at {}:{}, {}", location.file(), location.line(), err);
+        println!(
+            "Panicked at {}:{}, {}",
+            location.file(),
+            location.line(),
+            err
+        );
     } else {
         println!("Panicked: {}", err);
     }
     exit(-1);
-}
\ No newline at end of file
+}
diff --git a/user/src/lib.rs b/user/src/lib.rs
index 0dfe73c3..d97fbf33 100644
--- a/user/src/lib.rs
+++ b/user/src/lib.rs
@@ -6,13 +6,17 @@
 
 #[macro_use]
 pub mod console;
-mod syscall;
 mod lang_items;
+mod syscall;
 
 extern crate alloc;
+extern crate core;
+#[macro_use]
+extern crate bitflags;
 
-use syscall::*;
 use buddy_system_allocator::LockedHeap;
+pub use console::{flush, STDIN, STDOUT};
+pub use syscall::*;
 
 const USER_HEAP_SIZE: usize = 16384;
 
@@ -42,22 +46,155 @@ fn main() -> i32 {
     panic!("Cannot find main!");
 }
 
-pub fn close(fd: usize) -> isize { sys_close(fd) }
-pub fn pipe(pipe_fd: &mut [usize]) -> isize { sys_pipe(pipe_fd) }
-pub fn read(fd: usize, buf: &mut [u8]) -> isize { sys_read(fd, buf) }
-pub fn write(fd: usize, buf: &[u8]) -> isize { sys_write(fd, buf) }
-pub fn exit(exit_code: i32) -> ! { sys_exit(exit_code); }
-pub fn yield_() -> isize { sys_yield() }
-pub fn get_time() -> isize { sys_get_time() }
-pub fn getpid() -> isize { sys_getpid() }
-pub fn fork() -> isize { sys_fork() }
-pub fn exec(path: &str) -> isize { sys_exec(path) }
+bitflags! {
+    pub struct OpenFlags: u32 {
+        const RDONLY = 0;
+        const WRONLY = 1 << 0;
+        const RDWR = 1 << 1;
+        const CREATE = 1 << 9;
+        const TRUNC = 1 << 10;
+    }
+}
+
+#[repr(C)]
+#[derive(Debug, Default)]
+pub struct TimeVal {
+    pub sec: usize,
+    pub usec: usize,
+}
+
+impl TimeVal {
+    pub fn new() -> Self {
+        Self::default()
+    }
+}
+
+#[repr(C)]
+#[derive(Debug)]
+pub struct Stat {
+    /// ID of device containing file
+    pub dev: u64,
+    /// inode number
+    pub ino: u64,
+    /// file type and mode
+    pub mode: StatMode,
+    /// number of hard links
+    pub nlink: u32,
+    /// unused pad
+    pad: [u64; 7],
+}
+
+impl Stat {
+    pub fn new() -> Self {
+        Stat {
+            dev: 0,
+            ino: 0,
+            mode: StatMode::NULL,
+            nlink: 0,
+            pad: [0; 7],
+        }
+    }
+}
+
+impl Default for Stat {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+bitflags! {
+    pub struct StatMode: u32 {
+        const NULL  = 0;
+        /// directory
+        const DIR   = 0o040000;
+        /// ordinary regular file
+        const FILE  = 0o100000;
+    }
+}
+
+const AT_FDCWD: isize = -100;
+
+pub fn open(path: &str, flags: OpenFlags) -> isize {
+    sys_openat(AT_FDCWD as usize, path, flags.bits, OpenFlags::RDWR.bits)
+}
+
+pub fn close(fd: usize) -> isize {
+    if fd == STDOUT {
+        console::flush();
+    }
+    sys_close(fd)
+}
+
+pub fn read(fd: usize, buf: &mut [u8]) -> isize {
+    sys_read(fd, buf)
+}
+
+pub fn write(fd: usize, buf: &[u8]) -> isize {
+    sys_write(fd, buf)
+}
+
+pub fn link(old_path: &str, new_path: &str) -> isize {
+    sys_linkat(AT_FDCWD as usize, old_path, AT_FDCWD as usize, new_path, 0)
+}
+
+pub fn unlink(path: &str) -> isize {
+    sys_unlinkat(AT_FDCWD as usize, path, 0)
+}
+
+pub fn fstat(fd: usize, st: &Stat) -> isize {
+    sys_fstat(fd, st)
+}
+
+pub fn mail_read(buf: &mut [u8]) -> isize {
+    sys_mail_read(buf)
+}
+
+pub fn mail_write(pid: usize, buf: &[u8]) -> isize {
+    sys_mail_write(pid, buf)
+}
+
+pub fn exit(exit_code: i32) -> ! {
+    console::flush();
+    sys_exit(exit_code);
+}
+
+pub fn yield_() -> isize {
+    sys_yield()
+}
+
+pub fn get_time() -> isize {
+    let time = TimeVal::new();
+    match sys_get_time(&time, 0) {
+        0 => ((time.sec & 0xffff) * 1000 + time.usec / 1000) as isize,
+        _ => -1,
+    }
+}
+
+pub fn getpid() -> isize {
+    sys_getpid()
+}
+
+pub fn fork() -> isize {
+    sys_fork()
+}
+
+pub fn exec(path: &str) -> isize {
+    sys_exec(path)
+}
+
+pub fn set_priority(prio: isize) -> isize {
+    sys_set_priority(prio)
+}
+
 pub fn wait(exit_code: &mut i32) -> isize {
     loop {
         match sys_waitpid(-1, exit_code as *mut _) {
-            -2 => { yield_(); }
-            // -1 or a real pid
-            exit_pid => return exit_pid,
+            -2 => {
+                sys_yield();
+            }
+            n => {
+                return n;
+            }
         }
     }
 }
@@ -65,15 +202,38 @@ pub fn wait(exit_code: &mut i32) -> isize {
 pub fn waitpid(pid: usize, exit_code: &mut i32) -> isize {
     loop {
         match sys_waitpid(pid as isize, exit_code as *mut _) {
-            -2 => { yield_(); }
-            // -1 or a real pid
-            exit_pid => return exit_pid,
+            -2 => {
+                sys_yield();
+            }
+            n => {
+                return n;
+            }
         }
     }
 }
+
 pub fn sleep(period_ms: usize) {
-    let start = sys_get_time();
-    while sys_get_time() < start + period_ms as isize {
+    let start = get_time();
+    while get_time() < start + period_ms as isize {
         sys_yield();
     }
-}
\ No newline at end of file
+}
+
+pub fn mmap(start: usize, len: usize, prot: usize) -> isize {
+    sys_mmap(start, len, prot)
+}
+
+pub fn munmap(start: usize, len: usize) -> isize {
+    sys_munmap(start, len)
+}
+
+pub fn spawn(path: &str) -> isize {
+    sys_spawn(path)
+}
+
+pub fn dup(fd: usize) -> isize {
+    sys_dup(fd)
+}
+pub fn pipe(pipe_fd: &mut [usize]) -> isize {
+    sys_pipe(pipe_fd)
+}
diff --git a/user/src/syscall.rs b/user/src/syscall.rs
index 2a9f62ea..ebb3eee8 100644
--- a/user/src/syscall.rs
+++ b/user/src/syscall.rs
@@ -1,16 +1,29 @@
-const SYSCALL_CLOSE: usize = 57;
-const SYSCALL_PIPE: usize = 59;
-const SYSCALL_READ: usize = 63;
-const SYSCALL_WRITE: usize = 64;
-const SYSCALL_EXIT: usize = 93;
-const SYSCALL_YIELD: usize = 124;
-const SYSCALL_GET_TIME: usize = 169;
-const SYSCALL_GETPID: usize = 172;
-const SYSCALL_FORK: usize = 220;
-const SYSCALL_EXEC: usize = 221;
-const SYSCALL_WAITPID: usize = 260;
-
-fn syscall(id: usize, args: [usize; 3]) -> isize {
+use super::{Stat, TimeVal};
+
+pub const SYSCALL_OPENAT: usize = 56;
+pub const SYSCALL_CLOSE: usize = 57;
+pub const SYSCALL_READ: usize = 63;
+pub const SYSCALL_WRITE: usize = 64;
+pub const SYSCALL_UNLINKAT: usize = 35;
+pub const SYSCALL_LINKAT: usize = 37;
+pub const SYSCALL_FSTAT: usize = 80;
+pub const SYSCALL_EXIT: usize = 93;
+pub const SYSCALL_YIELD: usize = 124;
+pub const SYSCALL_GETTIMEOFDAY: usize = 169;
+pub const SYSCALL_GETPID: usize = 172;
+pub const SYSCALL_FORK: usize = 220;
+pub const SYSCALL_EXEC: usize = 221;
+pub const SYSCALL_WAITPID: usize = 260;
+pub const SYSCALL_SET_PRIORITY: usize = 140;
+pub const SYSCALL_MUNMAP: usize = 215;
+pub const SYSCALL_MMAP: usize = 222;
+pub const SYSCALL_SPAWN: usize = 400;
+pub const SYSCALL_MAIL_READ: usize = 401;
+pub const SYSCALL_MAIL_WRITE: usize = 402;
+pub const SYSCALL_DUP: usize = 24;
+pub const SYSCALL_PIPE: usize = 59;
+
+pub fn syscall(id: usize, args: [usize; 3]) -> isize {
     let mut ret: isize;
     unsafe {
         asm!(
@@ -24,22 +37,93 @@ fn syscall(id: usize, args: [usize; 3]) -> isize {
     ret
 }
 
-pub fn sys_close(fd: usize) -> isize {
-    syscall(SYSCALL_CLOSE, [fd, 0, 0])
+pub fn syscall6(id: usize, args: [usize; 6]) -> isize {
+    let mut ret: isize;
+    unsafe {
+        asm!("ecall",
+            inlateout("x10") args[0] => ret,
+            in("x11") args[1],
+            in("x12") args[2],
+            in("x13") args[3],
+            in("x14") args[4],
+            in("x15") args[5],
+            in("x17") id
+        );
+    }
+    ret
 }
 
-pub fn sys_pipe(pipe: &mut [usize]) -> isize {
-    syscall(SYSCALL_PIPE, [pipe.as_mut_ptr() as usize, 0, 0])
+pub fn sys_openat(dirfd: usize, path: &str, flags: u32, mode: u32) -> isize {
+    syscall6(
+        SYSCALL_OPENAT,
+        [
+            dirfd,
+            path.as_ptr() as usize,
+            flags as usize,
+            mode as usize,
+            0,
+            0,
+        ],
+    )
+}
+
+pub fn sys_close(fd: usize) -> isize {
+    syscall(SYSCALL_CLOSE, [fd, 0, 0])
 }
 
 pub fn sys_read(fd: usize, buffer: &mut [u8]) -> isize {
-    syscall(SYSCALL_READ, [fd, buffer.as_mut_ptr() as usize, buffer.len()])
+    syscall(
+        SYSCALL_READ,
+        [fd, buffer.as_mut_ptr() as usize, buffer.len()],
+    )
 }
 
 pub fn sys_write(fd: usize, buffer: &[u8]) -> isize {
     syscall(SYSCALL_WRITE, [fd, buffer.as_ptr() as usize, buffer.len()])
 }
 
+pub fn sys_linkat(
+    old_dirfd: usize,
+    old_path: &str,
+    new_dirfd: usize,
+    new_path: &str,
+    flags: usize,
+) -> isize {
+    syscall6(
+        SYSCALL_LINKAT,
+        [
+            old_dirfd,
+            old_path.as_ptr() as usize,
+            new_dirfd,
+            new_path.as_ptr() as usize,
+            flags,
+            0,
+        ],
+    )
+}
+
+pub fn sys_unlinkat(dirfd: usize, path: &str, flags: usize) -> isize {
+    syscall(SYSCALL_UNLINKAT, [dirfd, path.as_ptr() as usize, flags])
+}
+
+pub fn sys_fstat(fd: usize, st: &Stat) -> isize {
+    syscall(SYSCALL_FSTAT, [fd, st as *const _ as usize, 0])
+}
+
+pub fn sys_mail_read(buffer: &mut [u8]) -> isize {
+    syscall(
+        SYSCALL_MAIL_READ,
+        [buffer.as_ptr() as usize, buffer.len(), 0],
+    )
+}
+
+pub fn sys_mail_write(pid: usize, buffer: &[u8]) -> isize {
+    syscall(
+        SYSCALL_MAIL_WRITE,
+        [pid, buffer.as_ptr() as usize, buffer.len()],
+    )
+}
+
 pub fn sys_exit(exit_code: i32) -> ! {
     syscall(SYSCALL_EXIT, [exit_code as usize, 0, 0]);
     panic!("sys_exit never returns!");
@@ -49,8 +133,8 @@ pub fn sys_yield() -> isize {
     syscall(SYSCALL_YIELD, [0, 0, 0])
 }
 
-pub fn sys_get_time() -> isize {
-    syscall(SYSCALL_GET_TIME, [0, 0, 0])
+pub fn sys_get_time(time: &TimeVal, tz: usize) -> isize {
+    syscall(SYSCALL_GETTIMEOFDAY, [time as *const _ as usize, tz, 0])
 }
 
 pub fn sys_getpid() -> isize {
@@ -65,6 +149,30 @@ pub fn sys_exec(path: &str) -> isize {
     syscall(SYSCALL_EXEC, [path.as_ptr() as usize, 0, 0])
 }
 
-pub fn sys_waitpid(pid: isize, exit_code: *mut i32) -> isize {
-    syscall(SYSCALL_WAITPID, [pid as usize, exit_code as usize, 0])
-}
\ No newline at end of file
+pub fn sys_waitpid(pid: isize, xstatus: *mut i32) -> isize {
+    syscall(SYSCALL_WAITPID, [pid as usize, xstatus as usize, 0])
+}
+
+pub fn sys_set_priority(prio: isize) -> isize {
+    syscall(SYSCALL_SET_PRIORITY, [prio as usize, 0, 0])
+}
+
+pub fn sys_mmap(start: usize, len: usize, prot: usize) -> isize {
+    syscall(SYSCALL_MMAP, [start, len, prot])
+}
+
+pub fn sys_munmap(start: usize, len: usize) -> isize {
+    syscall(SYSCALL_MUNMAP, [start, len, 0])
+}
+
+pub fn sys_spawn(path: &str) -> isize {
+    syscall(SYSCALL_SPAWN, [path.as_ptr() as usize, 0, 0])
+}
+
+pub fn sys_dup(fd: usize) -> isize {
+    syscall(SYSCALL_DUP, [fd, 0, 0])
+}
+
+pub fn sys_pipe(pipe: &mut [usize]) -> isize {
+    syscall(SYSCALL_PIPE, [pipe.as_mut_ptr() as usize, 0, 0])
+}