Stdio for UEFI

- Uses Simple Text Output Protocol and Simple Text Input Protocol
- Reading is done one character at a time
- Writing is done with max 4096 characters

Signed-off-by: Ayush Singh <ayushdevel1325@gmail.com>
This commit is contained in:
Ayush Singh 2023-09-28 00:33:24 +05:30
parent b0a72173bb
commit 3f4a289016
No known key found for this signature in database
GPG Key ID: 05CEF5C789E55A74
3 changed files with 163 additions and 2 deletions

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@ -259,7 +259,7 @@
all(target_vendor = "fortanix", target_env = "sgx"),
feature(slice_index_methods, coerce_unsized, sgx_platform)
)]
#![cfg_attr(windows, feature(round_char_boundary))]
#![cfg_attr(any(windows, target_os = "uefi"), feature(round_char_boundary))]
#![cfg_attr(target_os = "xous", feature(slice_ptr_len))]
//
// Language features:

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@ -36,7 +36,6 @@ pub mod path;
pub mod pipe;
#[path = "../unsupported/process.rs"]
pub mod process;
#[path = "../unsupported/stdio.rs"]
pub mod stdio;
#[path = "../unsupported/thread.rs"]
pub mod thread;

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@ -0,0 +1,162 @@
use crate::io;
use crate::iter::Iterator;
use crate::mem::MaybeUninit;
use crate::os::uefi;
use crate::ptr::NonNull;
const MAX_BUFFER_SIZE: usize = 8192;
pub struct Stdin;
pub struct Stdout;
pub struct Stderr;
impl Stdin {
pub const fn new() -> Stdin {
Stdin
}
}
impl io::Read for Stdin {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
let st: NonNull<r_efi::efi::SystemTable> = uefi::env::system_table().cast();
let stdin = unsafe { (*st.as_ptr()).con_in };
// Try reading any pending data
let inp = match read_key_stroke(stdin) {
Ok(x) => x,
Err(e) if e == r_efi::efi::Status::NOT_READY => {
// Wait for keypress for new data
wait_stdin(stdin)?;
read_key_stroke(stdin).map_err(|x| io::Error::from_raw_os_error(x.as_usize()))?
}
Err(e) => {
return Err(io::Error::from_raw_os_error(e.as_usize()));
}
};
// Check if the key is printiable character
if inp.scan_code != 0x00 {
return Err(io::const_io_error!(io::ErrorKind::Interrupted, "Special Key Press"));
}
// SAFETY: Iterator will have only 1 character since we are reading only 1 Key
// SAFETY: This character will always be UCS-2 and thus no surrogates.
let ch: char = char::decode_utf16([inp.unicode_char]).next().unwrap().unwrap();
if ch.len_utf8() > buf.len() {
return Ok(0);
}
ch.encode_utf8(buf);
Ok(ch.len_utf8())
}
}
impl Stdout {
pub const fn new() -> Stdout {
Stdout
}
}
impl io::Write for Stdout {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
let st: NonNull<r_efi::efi::SystemTable> = uefi::env::system_table().cast();
let stdout = unsafe { (*st.as_ptr()).con_out };
write(stdout, buf)
}
fn flush(&mut self) -> io::Result<()> {
Ok(())
}
}
impl Stderr {
pub const fn new() -> Stderr {
Stderr
}
}
impl io::Write for Stderr {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
let st: NonNull<r_efi::efi::SystemTable> = uefi::env::system_table().cast();
let stderr = unsafe { (*st.as_ptr()).std_err };
write(stderr, buf)
}
fn flush(&mut self) -> io::Result<()> {
Ok(())
}
}
// UCS-2 character should occupy 3 bytes at most in UTF-8
pub const STDIN_BUF_SIZE: usize = 3;
pub fn is_ebadf(_err: &io::Error) -> bool {
true
}
pub fn panic_output() -> Option<impl io::Write> {
uefi::env::try_system_table().map(|_| Stderr::new())
}
fn write(
protocol: *mut r_efi::protocols::simple_text_output::Protocol,
buf: &[u8],
) -> io::Result<usize> {
let mut utf16 = [0; MAX_BUFFER_SIZE / 2];
// Get valid UTF-8 buffer
let utf8 = match crate::str::from_utf8(buf) {
Ok(x) => x,
Err(e) => unsafe { crate::str::from_utf8_unchecked(&buf[..e.valid_up_to()]) },
};
// Clip UTF-8 buffer to max UTF-16 buffer we support
let utf8 = &utf8[..utf8.floor_char_boundary(utf16.len() - 1)];
for (i, ch) in utf8.encode_utf16().enumerate() {
utf16[i] = ch;
}
unsafe { simple_text_output(protocol, &mut utf16) }?;
Ok(utf8.len())
}
unsafe fn simple_text_output(
protocol: *mut r_efi::protocols::simple_text_output::Protocol,
buf: &mut [u16],
) -> io::Result<()> {
let res = unsafe { ((*protocol).output_string)(protocol, buf.as_mut_ptr()) };
if res.is_error() { Err(io::Error::from_raw_os_error(res.as_usize())) } else { Ok(()) }
}
fn wait_stdin(stdin: *mut r_efi::protocols::simple_text_input::Protocol) -> io::Result<()> {
let boot_services: NonNull<r_efi::efi::BootServices> =
uefi::env::boot_services().unwrap().cast();
let wait_for_event = unsafe { (*boot_services.as_ptr()).wait_for_event };
let wait_for_key_event = unsafe { (*stdin).wait_for_key };
let r = {
let mut x: usize = 0;
(wait_for_event)(1, [wait_for_key_event].as_mut_ptr(), &mut x)
};
if r.is_error() { Err(io::Error::from_raw_os_error(r.as_usize())) } else { Ok(()) }
}
fn read_key_stroke(
stdin: *mut r_efi::protocols::simple_text_input::Protocol,
) -> Result<r_efi::protocols::simple_text_input::InputKey, r_efi::efi::Status> {
let mut input_key: MaybeUninit<r_efi::protocols::simple_text_input::InputKey> =
MaybeUninit::uninit();
let r = unsafe { ((*stdin).read_key_stroke)(stdin, input_key.as_mut_ptr()) };
if r.is_error() {
Err(r)
} else {
let input_key = unsafe { input_key.assume_init() };
Ok(input_key)
}
}