add kernel stuff, idt, welcome message

src/lib.rs

@@ -5,12 +5,11 @@ use core::panic::PanicInfo;
 
 #[unsafe(no_mangle)]
 pub extern "C" fn _start() -> ! {
-    // 'k'
-    print("kernel\n");
-    loop {}
+    welcome_serial();
+    halt()
 }
 
-fn print(s: &str) {
+fn print_serial(s: &str) {
     let mut bytes = s.bytes();
     while let Some(b) = bytes.next() {
         unsafe {core::arch::asm!(
@@ -20,8 +19,33 @@ fn print(s: &str) {
     };
 }
 
+fn println_serial(s: &str) {
+    print_serial(s);
+    print_serial("\n");
+}
+
+fn welcome_serial() {
+    print_serial(ANSI_PINK);
+    println_serial("\nWelcome to Bootle OS");
+    println_serial("All code GPL licensed and freely available on git.mtgmonkey.net");
+    print_serial("Enjoy your time! Press "); print_serial(ANSI_RED); print_serial("ctrl+a x"); print_serial(ANSI_PINK); println_serial(" to escape Qemu");
+    print_serial(ANSI_CLEAR);
+}
+
 #[panic_handler]
 fn panic(_: &PanicInfo) -> ! {
-    print("panicked");
-    loop {}
+    print_serial("panicked");
+    halt()
 }
+
+fn halt() -> ! {
+    unsafe {core::arch::asm!(
+        "hlt"
+    )};
+    halt()
+}
+
+const ANSI_CLEAR: &str = "\x1b[0m";
+const ANSI_RED: &str = "\x1b[31m";
+const ANSI_PINK: &str = "\x1b[35m";
+const ANSI_GREEN: &str = "\x1b[32m";