Add more comment in kernel but not finished

kernel/src/arch/riscv32/context.rs

@@ -11,6 +11,7 @@ pub struct TrapFrame {
 }
 
 /// 用于在内核栈中构造新线程的中断帧
+/// The trapframe for building new process in kernel
 impl TrapFrame {
     fn new_kernel_thread(entry: extern fn(usize) -> !, arg: usize, sp: usize) -> Self {
         use core::mem::zeroed;

kernel/src/fs.rs

@@ -15,6 +15,7 @@ _binary_user_riscv_img_end:
 "#);
 
 pub fn shell() {
+    // load riscv32/x86_64 user program
     #[cfg(target_arch = "riscv32")]
     let device = {
         extern {
@@ -36,6 +37,7 @@ pub fn shell() {
     const BUF_SIZE: usize = 0x40000;
     let layout = Layout::from_size_align(BUF_SIZE, 0x1000).unwrap();
     let buf = unsafe{ slice::from_raw_parts_mut(alloc(layout), BUF_SIZE) };
+    // start interaction
     loop {
         print!(">> ");
         use console::get_line;

kernel/src/lib.rs

@@ -61,16 +61,20 @@ pub mod arch;
 pub mod arch;
 
 pub fn kmain() -> ! {
+    // Init the first kernel process(idle proc)
     process::init();
+    // enable the interrupt
     unsafe { arch::interrupt::enable(); }
 
-    fs::shell();
+    // the test is not supported in riscv32(maybe)
+    //thread::test::local_key();
+    //thread::test::unpack();
+    //sync::test::philosopher_using_mutex();
+    //sync::test::philosopher_using_monitor();
+    //sync::mpsc::test::test_all();
 
-//    thread::test::local_key();
-//    thread::test::unpack();
-//    sync::test::philosopher_using_mutex();
-//    sync::test::philosopher_using_monitor();
-//    sync::mpsc::test::test_all();
+    // come into shell
+    fs::shell();
 
     loop {}
 }

kernel/src/process/mod.rs

@@ -9,6 +9,10 @@ mod context;
 
 type Processor = Processor_<Context, StrideScheduler>;
 
+/*
+* @brief:
+*   initialize a new kernel process (idleproc)
+*/
 pub fn init() {
     PROCESSOR.call_once(||
         SpinNoIrqLock::new({