runtime: print trace level log messages to UART during startup.

There's no way to retrieve them otherwise if the startup kernel
hangs.
This commit is contained in:
whitequark 2016-11-23 13:49:19 +00:00
parent 0443f83d5e
commit cd7527b701
2 changed files with 19 additions and 4 deletions

View File

@ -1,11 +1,12 @@
use core::{mem, ptr};
use core::cell::RefCell;
use core::cell::{Cell, RefCell};
use log::{self, Log, LogLevel, LogMetadata, LogRecord, LogLevelFilter};
use log_buffer::LogBuffer;
use clock;
pub struct BufferLogger {
buffer: RefCell<LogBuffer<&'static mut [u8]>>
buffer: RefCell<LogBuffer<&'static mut [u8]>>,
trace_to_uart: Cell<bool>
}
unsafe impl Sync for BufferLogger {}
@ -15,7 +16,8 @@ static mut LOGGER: *const BufferLogger = ptr::null();
impl BufferLogger {
pub fn new(buffer: &'static mut [u8]) -> BufferLogger {
BufferLogger {
buffer: RefCell::new(LogBuffer::new(buffer))
buffer: RefCell::new(LogBuffer::new(buffer)),
trace_to_uart: Cell::new(true)
}
}
@ -48,6 +50,14 @@ impl BufferLogger {
pub fn extract<R, F: FnOnce(&str) -> R>(&self, f: F) -> R {
f(self.buffer.borrow_mut().extract())
}
pub fn disable_trace_to_uart(&self) {
if self.trace_to_uart.get() {
trace!("disabling tracing to UART; all further trace messages \
are sent to core log only");
self.trace_to_uart.set(false)
}
}
}
impl Log for BufferLogger {
@ -61,7 +71,10 @@ impl Log for BufferLogger {
writeln!(self.buffer.borrow_mut(),
"[{:12}us] {:>5}({}): {}",
clock::get_us(), record.level(), record.target(), record.args()).unwrap();
if record.level() <= LogLevel::Info {
// Printing to UART is really slow, so avoid doing that when we have an alternative
// route to retrieve the debug messages.
if self.trace_to_uart.get() || record.level() <= LogLevel::Info {
println!("[{:12}us] {:>5}({}): {}",
clock::get_us(), record.level(), record.target(), record.args());
}

View File

@ -583,6 +583,8 @@ pub fn thread(waiter: Waiter, spawner: Spawner) {
}
}
BufferLogger::with_instance(|logger| logger.disable_trace_to_uart());
let addr = SocketAddr::new(IP_ANY, 1381);
let listener = TcpListener::bind(waiter, addr).expect("cannot bind socket");
listener.set_keepalive(true);