From a86f59b32eb86a1ccb94bf1e627c1115c3b6b217 Mon Sep 17 00:00:00 2001
From: Tianhao Wang <shrik3@mailbox.org>
Date: Thu, 6 Jun 2024 00:02:53 +0200
Subject: io: add serial output through port 0x3f8 (qemu)

not yet wrapped with fmt macros because I want some thing stateless.
(i.e. I don't want to pass `&mut self` to write_str...).
---
 src/machine/device_io.rs |  2 +-
 src/machine/mod.rs       |  1 +
 src/machine/serial.rs    | 16 ++++++++++++++++
 3 files changed, 18 insertions(+), 1 deletion(-)
 create mode 100644 src/machine/serial.rs

(limited to 'src/machine')

diff --git a/src/machine/device_io.rs b/src/machine/device_io.rs
index 2a0c907..9a530f1 100644
--- a/src/machine/device_io.rs
+++ b/src/machine/device_io.rs
@@ -4,7 +4,7 @@ pub use crate::arch::x86_64::io_port::*;
 // either use the io functions directly, or via a IOPort instance.
 pub struct IOPort(u16);
 impl IOPort {
-	pub fn new(port: u16) -> Self {
+	pub const fn new(port: u16) -> Self {
 		Self(port)
 	}
 	pub fn inw(&self) -> u16 {
diff --git a/src/machine/mod.rs b/src/machine/mod.rs
index a2cf730..b2b026f 100644
--- a/src/machine/mod.rs
+++ b/src/machine/mod.rs
@@ -5,5 +5,6 @@ pub mod key;
 pub mod keyctrl;
 pub mod mem;
 pub mod multiboot;
+pub mod serial;
 
 // TODO: this module *should* be arch independent.
diff --git a/src/machine/serial.rs b/src/machine/serial.rs
new file mode 100644
index 0000000..edb18c0
--- /dev/null
+++ b/src/machine/serial.rs
@@ -0,0 +1,16 @@
+use crate::machine::device_io::IOPort;
+use core::{fmt, str};
+/// serial output through port 3f8 (qemu), stateless, not thread safe.
+pub struct Serial {}
+impl Serial {
+	const PORT: IOPort = IOPort::new(0x3f8);
+	pub fn putchar(ch: char) {
+		Self::PORT.outb(ch as u8);
+	}
+
+	pub fn print(s: &str) {
+		for c in s.bytes() {
+			Self::putchar(c as char);
+		}
+	}
+}
-- 
cgit v1.2.3-70-g09d2