gistfile1.txt

org 7c00h
jmp 0:start

start:
   xor ax, ax
   mov ds, ax
   mov eax, 80000000h
   cpuid
   cmp eax, 80000000h
   jb no32

   mov eax, 80000001h
   cpuid
   bt edx, 29
   jnc no64

   mov bx, success_str
   call puts

   in al, 092h
   or al, 2
   out 092h, al

   xor ax, ax
   mov es, ax
   mov bx, kernel_init

   mov ah, 02h
   mov al, 01h
   mov ch, 0
   mov cl, 2
   mov dh, 0
   mov dl, 0
   int 13h
   jc fail

   jmp 0:kernel_init

puts:
   mov si, 0
   mov ah, 0eh

   puts_loop:
   mov al, [bx + si]
   cmp al, 0
   je puts_end
   int 10h

   inc si
   jmp puts_loop

   puts_end:
   ret


no32:
   mov bx, no32_str
   call puts
   jmp $

no64:
   mov bx, no64_str
   call puts
   jmp $

fail:
   mov bx, fail_str
   call puts
   jmp $


no32_str: db "No 32-bit! :(", 0ah, 0dh, 00h
no64_str: db "No 64-bit! :(", 0ah, 0dh, 00h
success_str: db "Yay! :D", 0ah, 0dh, 00h
fail_str: db "Failed to load :(", 0ah, 0dh, 00h

# Pad
times 510 - ($-$$) db 0
   db 55h
   db 0aah


# Sector 2
kernel_init:
   mov bx, kernel_init_str
   call puts
   jmp $


kernel_init_str: db "Kernel init!", 0ah, 0dh, 00h

times 1024 - ($-$$) db 0