add bootimage

.cargo/config.toml

@@ -5,3 +5,6 @@ build-std-features = ["compiler-builtins-mem"]
 
 [build]
 target = "x86_64-rust_kernel.json"
+
+[target.'cfg(target_os = "none")']
+runner = "bootimage runner"

Cargo.lock

@@ -2,6 +2,15 @@
 # It is not intended for manual editing.
 version = 4
 
+[[package]]
+name = "bootloader"
+version = "0.9.34"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "13f6a8a495d2f93fe3d6eb3a224f9aa749a63cfd746ed03eb5ddcbd00ade7d8f"
+
 [[package]]
 name = "rust-kernel"
 version = "0.1.0"
+dependencies = [
+ "bootloader",
+]

Cargo.toml

@@ -17,3 +17,4 @@ test = false
 bench = false
 
 [dependencies]
+bootloader = "0.9"

src/main.rs

@@ -1,9 +1,19 @@
 #![no_std]
 #![no_main]
 
+static HELLLO: &[u8] = b"Hello World!";
 
-#![unsafe(no_mangle)]
+#[unsafe(no_mangle)]
 pub extern "C" fn _start() -> ! {
+    let vga_buffer = 0xb8000 as *mut u8;
+    
+    for (i, &byte) in HELLLO.iter().enumerate() {
+        unsafe {
+            *vga_buffer.offset(i as isize * 2) = byte;
+            *vga_buffer.offset(i as isize * 2 +1) = 0xb;
+        }
+    }
+    
     loop {
         
     }