Add a qemu-bios executable to start the BIOS disk image in QEMU

Cargo.toml

@@ -2,6 +2,7 @@
 name = "blog_os"
 version = "0.1.0"
 edition = "2021"
+default-run = "blog_os"
 
 [workspace]
 members = ["kernel"]

src/bin/qemu-bios.rs

@@ -0,0 +1,12 @@
+use std::{
+    env,
+    process::{self, Command},
+};
+
+fn main() {
+    let mut qemu = Command::new("qemu-system-x86_64");
+    qemu.arg("-drive");
+    qemu.arg(format!("format=raw,file={}", env!("BIOS_IMAGE")));
+    let exit_status = qemu.status().unwrap();
+    process::exit(exit_status.code().unwrap_or(-1));
+}