test/boot.s

   1         movw $0x0, %ax
   2         movw %ax, %ds
   3
   4         movw $str, %si
   5         call print_str
   6         jmp hang
   7
   8 #
   9 # Print the string in SI register
  10 #
  11 # INPUT: SI = The string to print
  12 #
  13 print_str:
  14         movb $0x0e, %ah
  15         movb $0x0f, %bh
  16         movb $0x00, %bl
  17 .next_char:
  18         lodsb
  19         or %al, %al
  20         jz .ret
  21         int $0x10
  22         jmp .next_char
  23 .ret:
  24         ret
  25
  26 hang:
  27         jmp hang
  28
  29 str:
  30         .string "Hello World\n"
  31
  32 .org 0x1fe, 0x90
  33 .word 0xaa55            # bootsector flag