Hello world works!

Makefile

@@ -1,4 +1,5 @@
-boot.efi : 
+.phony: all
+all : 
 	rustc -O -c --lib boot.rs
 	x86_64-efi-pe-ld -g --oformat pei-x86-64 --dll --subsystem 10:1.0 --major-os-version 0 --heap 0,0 -nostdlib --stack 0x1000,0 -pie -Bsymbolic -nocombreloc -e efi_main boot.o -o boot.efi
 

boot.rs

@@ -12,15 +12,72 @@ struct EFI_TABLE_HEADER {
 
 struct EFI_SYSTEM_TABLE {
     Hdr : EFI_TABLE_HEADER,
+    FirmwareVendor : *u16,
+    FirmwareRevision : u32,
+    ConsoleInHandle : EFI_HANDLE,
+    ConIn : *EFI_SIMPLE_TEXT_INPUT_PROTOCOL,
+    ConsoleOutHandle : EFI_HANDLE,
+    ConOut : *EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL,
+    // ... other stuff that we're ignoring for now.
 }
 
-#[no_mangle]
-pub fn efi_main(_ImageHandle : EFI_HANDLE, _SystemTable : EFI_SYSTEM_TABLE) -> int {
-    loop {}
+struct EFI_SIMPLE_TEXT_INPUT_PROTOCOL;
+
+struct EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL {
+    Reset : EFI_TEXT_RESET,
+    OutputString : EFI_TEXT_STRING,
+    // ... and more stuff that we're ignoring.
 }
 
+type EFI_TEXT_RESET = *();
+
+type EFI_TEXT_STRING = extern "win64" fn(*EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL,
+                                            *u16);
+
 #[no_mangle]
-pub fn __morestack() {
-    // Terrible things will happen if this is ever called.
-    loop {}
-}
+#[no_split_stack]
+pub extern "win64" fn efi_main(_ImageHandle : EFI_HANDLE, SystemTable : *EFI_SYSTEM_TABLE) -> int {
+    unsafe {
+        let SystemTable = *SystemTable;
+        let vendor = SystemTable.FirmwareVendor;
+        let conout = SystemTable.ConOut;
+        let output = (*conout).OutputString;
+
+        let hello = ['H' as u16,
+                     'e' as u16,
+                     'l' as u16,
+                     'l' as u16,
+                     'o' as u16,
+                     ',' as u16,
+                     ' ' as u16,
+                     'W' as u16,
+                     'o' as u16,
+                     'r' as u16,
+                     'l' as u16,
+                     'd' as u16,
+                     '\r' as u16,
+                     '\n' as u16,
+                     0u16];
+        let (hello_ptr, _) = buf_ptr(hello);
+
+        output(conout, hello_ptr);
+
+        loop {
+        }
+    }
+}
+
+fn buf_ptr<T>(buf: &[T]) -> (*T, uint) {
+    unsafe { transmute(buf) }
+}
+
+//#[no_mangle]
+//#[no_split_stack]
+//pub fn __morestack() {
+//    // If this is called, something horrible probably happened...
+//}
+
+extern "rust-intrinsic" {
+    pub fn transmute<T,U>(val: T) -> U;
+//    pub fn size_of<T>() -> uint;
+}