From 791738aa2691e7fe607f708d3c671c9462b034dc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Kr=C3=B6ning?=
 <martin.kroening@eonerc.rwth-aachen.de>
Date: Mon, 26 Jan 2026 15:30:57 +0100
Subject: [PATCH] build(deps): update uart_16550 to 0.5

---
 Cargo.lock                       | 32 +++++---------------------------
 Cargo.toml                       |  2 +-
 src/arch/x86_64/kernel/serial.rs | 24 +++++++++++++-----------
 3 files changed, 19 insertions(+), 39 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 042dd89d52..10976ab026 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -858,7 +858,7 @@ dependencies = [
  "pci-ids",
  "pci_types",
  "rand_chacha",
- "raw-cpuid 11.6.0",
+ "raw-cpuid",
  "riscv",
  "sbi-rt",
  "semihosting",
@@ -1586,15 +1586,6 @@ version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0c8d0fd677905edcbeedbf2edb6494d676f0e98d54d5cf9bda0b061cb8fb8aba"
 
-[[package]]
-name = "raw-cpuid"
-version = "10.7.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6c297679cb867470fa8c9f67dbba74a78d78e3e98d7cf2b08d6d71540f797332"
-dependencies = [
- "bitflags 1.3.2",
-]
-
 [[package]]
 name = "raw-cpuid"
 version = "11.6.0"
@@ -2015,7 +2006,7 @@ version = "0.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fa1699c0079cb7ff77b57fd429bcfa87b1220898bb303e0e45f75789778a376d"
 dependencies = [
- "raw-cpuid 11.6.0",
+ "raw-cpuid",
  "x86_64",
 ]
 
@@ -2027,13 +2018,11 @@ checksum = "562d481066bde0658276a35467c4af00bdc6ee726305698a55b86e61d7ad82bb"
 
 [[package]]
 name = "uart_16550"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "94d293f51425981fdb1b766beae254dbb711a17e8c4b549dc69b9b7ee0d478d5"
+version = "0.5.0"
+source = "git+https://github.com/rust-osdev/uart_16550.git#c17d30c5b268abe112f37d2b59593a84d49fd780"
 dependencies = [
  "bitflags 2.11.0",
- "rustversion",
- "x86",
+ "embedded-io",
 ]
 
 [[package]]
@@ -2489,17 +2478,6 @@ version = "0.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9edde0db4769d2dc68579893f2306b26c6ecfbe0ef499b013d731b7b9247e0b9"
 
-[[package]]
-name = "x86"
-version = "0.52.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2781db97787217ad2a2845c396a5efe286f87467a5810836db6d74926e94a385"
-dependencies = [
- "bit_field",
- "bitflags 1.3.2",
- "raw-cpuid 10.7.0",
-]
-
 [[package]]
 name = "x86_64"
 version = "0.15.4"
diff --git a/Cargo.toml b/Cargo.toml
index aa5818308c..8a2367934e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -366,7 +366,7 @@ features = [
 [target.'cfg(target_arch = "x86_64")'.dependencies]
 free-list = { version = "0.3", features = ["x86_64"] }
 raw-cpuid = "11"
-uart_16550 = "0.4"
+uart_16550 = { git = "https://github.com/rust-osdev/uart_16550.git", features = ["embedded-io"] }
 x86_64 = "0.15"
 memory_addresses = { version = "0.3", default-features = false, features = [
 	"x86_64",
diff --git a/src/arch/x86_64/kernel/serial.rs b/src/arch/x86_64/kernel/serial.rs
index 7803b9628d..a303910252 100644
--- a/src/arch/x86_64/kernel/serial.rs
+++ b/src/arch/x86_64/kernel/serial.rs
@@ -2,6 +2,8 @@ use alloc::collections::VecDeque;
 
 use embedded_io::{ErrorType, Read, ReadReady, Write};
 use hermit_sync::{InterruptTicketMutex, Lazy};
+use uart_16550::backend::PioBackend;
+use uart_16550::{Config, Uart16550};
 
 #[cfg(feature = "pci")]
 use crate::arch::x86_64::kernel::interrupts;
@@ -16,7 +18,7 @@ static UART_DEVICE: Lazy<InterruptTicketMutex<UartDevice>> =
 	Lazy::new(|| unsafe { InterruptTicketMutex::new(UartDevice::new()) });
 
 struct UartDevice {
-	pub uart: uart_16550::SerialPort,
+	pub uart: Uart16550<PioBackend>,
 	pub buffer: VecDeque<u8>,
 }
 
@@ -27,8 +29,11 @@ impl UartDevice {
 			.serial_port_base
 			.unwrap()
 			.get();
-		let mut uart = unsafe { uart_16550::SerialPort::new(base) };
-		uart.init();
+		let mut uart = unsafe { Uart16550::new_port(base).unwrap() };
+		uart.init(Config::default()).ok();
+		// Once we have a fallback destination for output,
+		// we should log any error above and run
+		// `test_loopback` and `check_connected` here.
 
 		Self {
 			uart,
@@ -64,12 +69,8 @@ impl ReadReady for SerialDevice {
 impl Write for SerialDevice {
 	fn write(&mut self, buf: &[u8]) -> Result<usize, Self::Error> {
 		let mut guard = UART_DEVICE.lock();
-
-		for &data in buf {
-			guard.uart.send(data);
-		}
-
-		Ok(buf.len())
+		let n = guard.uart.write(buf)?;
+		Ok(n)
 	}
 
 	fn flush(&mut self) -> Result<(), Self::Error> {
@@ -81,8 +82,9 @@ impl Write for SerialDevice {
 pub(crate) fn get_serial_handler() -> (InterruptLine, fn()) {
 	fn serial_handler() {
 		let mut guard = UART_DEVICE.lock();
-		if let Ok(c) = guard.uart.try_receive() {
-			guard.buffer.push_back(c);
+
+		while let Ok(byte) = guard.uart.try_receive_byte() {
+			guard.buffer.push_back(byte);
 		}
 
 		drop(guard);