Pass address of multiboot info structure to rust_main

src/arch/x86_64/boot.asm

@@ -5,6 +5,7 @@ section .text
 bits 32
 start:
     mov esp, stack_top
+    mov edi, ebx       ; move Multiboot info pointer to edi
 
     call check_multiboot
     call check_cpuid

src/lib.rs

@@ -12,7 +12,7 @@ extern crate spin;
 mod vga_buffer;
 
 #[no_mangle]
-pub extern fn rust_main() {
+pub extern fn rust_main(multiboot_information_address: usize) {
     vga_buffer::clear_screen();
     println!("Hello World{}", "!");