blob: 0026cbc83acd4813bb5026faa76427376f5858d2 [file] [log] [blame]
//! Trivial capsule to provide minimal debug printing support for userspace.
//!
//! The default TockOS Console class does heavier-weight stuff with UART
//! multiplexing and asynchronous sending and such, which is usually _not_ what
//! is wanted in a debug serial port. This capsule implements only one command,
//! which dumps data from an allow'ed buffer directly to a memory-mapped UART
//! peripheral.
//!
//! Usage - send buffer directly to UART:
//! let driver_num = capsules::debug_uart::DRIVER_NUM;
//! let allow = syscalls::allow(driver_num, 0, &mut buffer);
//! let result = syscalls::command(driver_num, 0, buffer.len(), 0);
//! drop(allow);
use kernel::{AppId, AppSlice, Callback, Driver, Grant, ReturnCode, Shared};
#[derive(Default)]
pub struct AppData {
pub buffer: Option<AppSlice<Shared, u8>>,
}
pub struct DprintfCapsule {
pub app_data_grant: Grant<AppData>,
}
impl Driver for DprintfCapsule {
fn subscribe(&self, _: usize, _: Option<Callback>, _: AppId) -> ReturnCode {
ReturnCode::EINVAL
}
fn command(&self, minor_num: usize, r2: usize, _: usize, app_id: AppId) -> ReturnCode {
if minor_num != 0 {
return ReturnCode::EINVAL;
}
let _ = self.app_data_grant.enter(app_id, |app_data, _| {
if let Some(buf) = &app_data.buffer {
matcha_hal::dprintf_hal::send_sync(buf.as_ref(), r2);
}
});
return ReturnCode::SUCCESS;
}
fn allow(&self, app_id: AppId, _: usize, slice: Option<AppSlice<Shared, u8>>) -> ReturnCode {
let _ = self.app_data_grant.enter(app_id, |app_data, _| {
app_data.buffer = slice;
});
return ReturnCode::SUCCESS;
}
}