os/fs/
stdio.rs

1use super::File;
2use crate::mm::UserBuffer;
3use crate::sbi::console_getchar;
4use crate::task::suspend_current_and_run_next;
5
6pub struct Stdin;
7
8pub struct Stdout;
9
10impl File for Stdin {
11    fn readable(&self) -> bool {
12        true
13    }
14    fn writable(&self) -> bool {
15        false
16    }
17    fn read(&self, mut user_buf: UserBuffer) -> usize {
18        assert_eq!(user_buf.len(), 1);
19        // busy loop
20        let mut c: usize;
21        loop {
22            c = console_getchar();
23            if c == 0 {
24                suspend_current_and_run_next();
25                continue;
26            } else {
27                break;
28            }
29        }
30        let ch = c as u8;
31        unsafe {
32            user_buf.buffers[0].as_mut_ptr().write_volatile(ch);
33        }
34        1
35    }
36    fn write(&self, _user_buf: UserBuffer) -> usize {
37        panic!("Cannot write to stdin!");
38    }
39}
40
41impl File for Stdout {
42    fn readable(&self) -> bool {
43        false
44    }
45    fn writable(&self) -> bool {
46        true
47    }
48    fn read(&self, _user_buf: UserBuffer) -> usize {
49        panic!("Cannot read from stdout!");
50    }
51    fn write(&self, user_buf: UserBuffer) -> usize {
52        for buffer in user_buf.buffers.iter() {
53            print!("{}", core::str::from_utf8(*buffer).unwrap());
54        }
55        user_buf.len()
56    }
57}
os/fs/stdio.rs

os/fs/
stdio.rs
