Add IO and Serial

moon/Cargo.lock

@@ -5,3 +5,12 @@ version = 3
 [[package]]
 name = "moon"
 version = "0.1.0"
+dependencies = [
+ "spin",
+]
+
+[[package]]
+name = "spin"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e63cff320ae2c57904679ba7cb63280a3dc4613885beafb148ee7bf9aa9042d"

moon/Cargo.toml

@@ -16,3 +16,4 @@ strip = "debuginfo"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+spin = "0.5.2"

moon/src/arch/io.rs

@@ -0,0 +1,34 @@
+#[cfg(target_arch = "x86_64")]
+pub use super::x86_64::io::*;
+
+pub mod serial {
+    #[cfg(target_arch = "x86_64")]
+    pub use super::super::x86_64::io::*;
+
+    pub fn write(s: &str) -> () {
+        for byte in s.bytes() {
+            match byte {
+                0x20..=0x7e | b'\n' => serial::putchar(byte),
+                _ => serial::putchar(0xfe),
+            }
+        }
+    }
+}
+
+use core::fmt;
+
+pub struct Serial
+{
+
+}
+
+impl fmt::Write for Serial {
+    fn write_str(&mut self, s: &str) -> fmt::Result {
+        serial::write(s);
+        Ok(())
+    }
+}
+
+use spin::Mutex;
+
+pub static SERIAL: Mutex<Serial> = Mutex::new(Serial {});

moon/src/arch/mod.rs

@@ -1,4 +1,5 @@
 pub mod cpu;
+pub mod io;
 
 #[cfg(target_arch = "x86_64")]
 mod x86_64;

moon/src/arch/x86_64/io.rs

@@ -0,0 +1,35 @@
+#![cfg(target_arch = "x86_64")]
+#![allow(dead_code)]
+
+pub const COM1: u16 = 0x3f8;
+
+use core::arch::asm;
+
+pub unsafe fn outportb(port: u16, value: u8) -> () {
+    asm!("out dx, al", in("al") value, in("dx") port);
+}
+
+pub unsafe fn inportb(port: u16) -> u8 {
+    let value: u8;
+    asm!("in al, dx", out("al") value, in("dx") port);
+    return value;
+}
+
+pub unsafe fn io_delay() -> () {
+    outportb(0x80,0);
+}
+
+pub mod serial {
+    use super::*;
+
+    unsafe fn wait() -> () {
+        while (inportb(COM1 + 5) & 0x20) == 0 {
+            asm!("pause");
+        }
+    }
+    
+    pub fn putchar(c: u8) -> () {
+        unsafe { wait(); }
+        unsafe { outportb(COM1, c); }
+    }
+}

moon/src/arch/x86_64/mod.rs

@@ -1 +1,3 @@
-pub mod cpu;
+#![cfg(target_arch = "x86_64")]
+pub mod cpu;
+pub mod io;

moon/src/log.rs

@@ -0,0 +1,19 @@
+use crate::arch::io::SERIAL;
+use core::fmt;
+
+#[macro_export]
+macro_rules! print {
+    ($($arg:tt)*) => ($crate::log::_print(format_args!($($arg)*)));
+}
+
+#[macro_export]
+macro_rules! println {
+    () => ($crate::print!("\n"));
+    ($($arg:tt)*) => ($crate::print!("{}\n", format_args!($($arg)*)));
+}
+
+#[doc(hidden)]
+pub fn _print(args: fmt::Arguments) {
+    use core::fmt::Write;
+    SERIAL.lock().write_fmt(args).unwrap();
+}

moon/src/main.rs

@@ -9,6 +9,7 @@ mod panic;
 mod util;
 mod init;
 mod arch;
+mod log;
 
 use arch::cpu;
 
@@ -21,6 +22,8 @@ pub extern "C" fn _start() -> ! {
     init::check_magic();
 
     video::clear(Color::White);
+
+    println!("Hello, world!");
     
     cpu::halt();
 

moon/src/panic.rs

@@ -1,6 +1,9 @@
 use core::panic::PanicInfo;
 
+use crate::println;
+
 #[panic_handler]
-fn panic(_info: &PanicInfo) -> ! {
+fn panic(info: &PanicInfo) -> ! {
+    println!("Kernel {}", info);
     loop {}
 }