use user shell by default. fix kernel shell removing user thread.

crate/process/src/thread.rs

@@ -32,9 +32,7 @@ fn new_kernel_context(entry: extern fn(usize) -> !, arg: usize) -> Box<Context>
 
 /// Gets a handle to the thread that invokes it.
 pub fn current() -> Thread {
-    Thread {
-        pid: processor().pid(),
-    }
+    Thread { pid: processor().pid() }
 }
 
 /// Puts the current thread to sleep for the specified amount of time.
@@ -162,6 +160,13 @@ impl<T> JoinHandle<T> {
             processor().yield_now();
         }
     }
+    /// Force construct a JoinHandle struct
+    pub unsafe fn _of(pid: Pid) -> JoinHandle<T> {
+        JoinHandle {
+            thread: Thread { pid },
+            mark: PhantomData,
+        }
+    }
 }
 
 //pub struct LocalKey<T: 'static> {

kernel/src/arch/riscv32/mod.rs

@@ -27,7 +27,7 @@ pub extern fn rust_main(hartid: usize, dtb: usize, hart_mask: usize) -> ! {
     timer::init();
 
     ::process::init();
-    ::thread::spawn(::shell::shell);
+    ::thread::spawn(::shell::run_user_shell);
 
     unsafe { cpu::start_others(hart_mask); }
     ::kmain();

kernel/src/arch/x86_64/mod.rs

@@ -48,7 +48,7 @@ pub extern "C" fn _start(boot_info: &'static BootInfo) -> ! {
     driver::init();
 
     ::process::init();
-    ::thread::spawn(::shell::shell);
+    ::thread::spawn(::shell::run_user_shell);
 
     AP_CAN_INIT.store(true, Ordering::Relaxed);
 

kernel/src/fs.rs

@@ -1,5 +1,5 @@
 use simple_filesystem::*;
-use alloc::{boxed::Box, sync::Arc, string::String, collections::VecDeque};
+use alloc::{boxed::Box, sync::Arc, string::String, collections::VecDeque, vec::Vec};
 #[cfg(target_arch = "x86_64")]
 use arch::driver::ide;
 use sync::Condvar;
@@ -139,4 +139,18 @@ impl INode for Stdout {
         Ok(buf.len())
     }
     impl_inode!();
+}
+
+pub trait INodeExt {
+    fn read_as_vec(&self) -> Result<Vec<u8>>;
+}
+
+impl INodeExt for INode {
+    fn read_as_vec(&self) -> Result<Vec<u8>> {
+        let size = self.info()?.size;
+        let mut buf = Vec::with_capacity(size);
+        unsafe { buf.set_len(size); }
+        self.read_at(0, buf.as_mut_slice())?;
+        Ok(buf)
+    }
 }

kernel/src/shell.rs

@@ -2,17 +2,19 @@
 
 use alloc::string::String;
 use alloc::vec::Vec;
-use fs::ROOT_INODE;
+use fs::{ROOT_INODE, INodeExt};
 use 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(' ')));
+}
 
 pub fn shell() {
     let files = ROOT_INODE.list().unwrap();
     println!("Available programs: {:?}", files);
 
-    const BUF_SIZE: usize = 0x40000;
-    let mut buf = Vec::with_capacity(BUF_SIZE);
-    unsafe { buf.set_len(BUF_SIZE); }
     loop {
         print!(">> ");
         let cmd = get_line();
@@ -21,10 +23,9 @@ pub fn shell() {
         }
         let name = cmd.split(' ').next().unwrap();
         if let Ok(file) = ROOT_INODE.lookup(name) {
-            let len = file.read_at(0, &mut *buf).unwrap();
-            let pid = processor().manager().add(ContextImpl::new_user(&buf[..len], cmd.split(' ')));
-            processor().manager().wait(thread::current().id(), pid);
-            processor().yield_now();
+            let data = file.read_as_vec().unwrap();
+            let pid = processor().manager().add(ContextImpl::new_user(data.as_slice(), cmd.split(' ')));
+            unsafe { thread::JoinHandle::<()>::_of(pid) }.join().unwrap();
         } else {
             println!("Program not exist");
         }