将TTY与stdio进行连接,实现基本的stdio功能 (#217)

* 将stdio与tty接上

kernel/src/process/process.c

@@ -48,6 +48,7 @@ extern void process_exit_signal(struct process_control_block *pcb);
 extern void initial_proc_init_signal(struct process_control_block *pcb);
 extern void rs_process_exit_fpstate(struct process_control_block *pcb);
 extern int process_init_files();
+extern int rs_init_stdio();
 
 // 设置初始进程的PCB
 #define INITIAL_PROC(proc)                                                                                             \
@@ -452,10 +453,6 @@ ul do_execve(struct pt_regs *regs, char *path, char *argv[], char *envp[])
     current_pcb->mm->brk_end = brk_start_addr;
     current_pcb->mm->stack_start = stack_start_addr;
 
-    // 关闭之前的文件描述符
-    process_exit_files(current_pcb);
-    process_init_files();
-
     // 清除进程的vfork标志位
     current_pcb->flags &= ~PF_VFORK;
 
@@ -540,9 +537,10 @@ struct process_control_block *process_init_rt_pcb(struct process_control_block *
 ul initial_kernel_thread(ul arg)
 {
     kinfo("initial proc running...\targ:%#018lx, vruntime=%d", arg, current_pcb->virtual_runtime);
-
-    scm_enable_double_buffer();
-
+    int val = 0;
+    val = scm_enable_double_buffer();
+    
+    rs_init_stdio();
     // block_io_scheduler_init();
     ahci_init();
     mount_root_fs();

kernel/src/process/process.rs

@@ -7,7 +7,7 @@ use alloc::boxed::Box;
 
 use crate::{
     arch::{asm::current::current_pcb, fpu::FpState},
-    filesystem::vfs::file::{File, FileDescriptorVec},
+    filesystem::vfs::{file::{File, FileDescriptorVec, FileMode}, ROOT_INODE},
     include::bindings::bindings::{
         process_control_block, CLONE_FS, PROC_INTERRUPTIBLE,
         PROC_RUNNING, PROC_STOPPED, PROC_UNINTERRUPTIBLE,
@@ -350,4 +350,37 @@ pub extern "C" fn rs_process_exit_fpstate(pcb: &'static mut process_control_bloc
     }
 }
 
+#[no_mangle]
+pub extern "C" fn rs_init_stdio() -> i32 {
+    let r = init_stdio();
+    if r.is_ok() {
+        return 0;
+    } else {
+        return r.unwrap_err().to_posix_errno();
+    }
+}
 // =========== 以上为导出到C的函数，在将来，进程管理模块被完全重构之后，需要删掉他们 END ============
+
+/// @brief 初始化pid=1的进程的stdio
+pub fn init_stdio() -> Result<(), SystemError> {
+    if current_pcb().pid != 1 {
+        return Err(SystemError::EPERM);
+    }
+    let tty_inode = ROOT_INODE()
+        .lookup("/dev/tty0")
+        .expect("Init stdio: can't find tty0");
+    let stdin =
+        File::new(tty_inode.clone(), FileMode::O_RDONLY).expect("Init stdio: can't create stdin");
+    let stdout =
+        File::new(tty_inode.clone(), FileMode::O_WRONLY).expect("Init stdio: can't create stdout");
+    let stderr = File::new(tty_inode.clone(), FileMode::O_WRONLY | FileMode::O_SYNC)
+        .expect("Init stdio: can't create stderr");
+
+    /*
+        按照规定，进程的文件描述符数组的前三个位置，分别是stdin, stdout, stderr
+     */
+    assert_eq!(current_pcb().alloc_fd(stdin).unwrap(), 0);
+    assert_eq!(current_pcb().alloc_fd(stdout).unwrap(), 1);
+    assert_eq!(current_pcb().alloc_fd(stderr).unwrap(), 2);
+    return Ok(());
+}