引导加载程序上的魔术数字0x1BADB002和0xAA55有什么区别

Question

.code16                   ;generate 16-bit code
.text                     ;executable code location
     .globl _start;
_start:                   
     . = _start + 510     
     .byte 0x55           ;append boot signature
     .byte 0xaa           ;append boot signature

;nasm directive - 32 bit
bits 32
section .text
        ;multiboot spec
        align 4
        dd 0x1BADB002                   ;magic
        dd 0x00                         flags
        dd -(0x1BADB002 + 0x00)

0x1BADB002和0x550xaa，引导加载程序有什么区别？