From 6713e550733565616209656acb361a52b9512c14 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Mon, 17 Aug 2015 15:16:38 +0200
Subject: [PATCH] Pass Multiboot structure pointer as argument

---
 src/arch/x86_64/boot.asm           | 1 +
 src/arch/x86_64/long_mode_init.asm | 2 +-
 src/lib.rs                         | 2 +-
 3 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/arch/x86_64/boot.asm b/src/arch/x86_64/boot.asm
index 5759fa69..41074cbb 100644
--- a/src/arch/x86_64/boot.asm
+++ b/src/arch/x86_64/boot.asm
@@ -19,6 +19,7 @@ section .text
 bits 32
 start:
     mov esp, stack_top
+    mov edi, ebx
 
     call check_multiboot
     call check_cpuid
diff --git a/src/arch/x86_64/long_mode_init.asm b/src/arch/x86_64/long_mode_init.asm
index 1dfb0186..47927d58 100644
--- a/src/arch/x86_64/long_mode_init.asm
+++ b/src/arch/x86_64/long_mode_init.asm
@@ -20,7 +20,7 @@ bits 64
 long_mode_start:
     call setup_SSE
 
-    ; call rust main
+    ; call rust main (with multiboot pointer in rdi)
     call rust_main
 .os_returned:
     ; rust main returned, print `OS returned!`
diff --git a/src/lib.rs b/src/lib.rs
index 32b00cca..bc30a4e5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -24,7 +24,7 @@ use core::fmt::Write;
 mod vga_buffer;
 
 #[no_mangle]
-pub extern fn rust_main() {
+pub extern fn rust_main(multiboot_address: usize) {
     // ATTENTION: we have a very small stack and no guard page
     use vga_buffer::{Writer, Color};