section boot.text progbits alloc exec nowrite align=16 MB_PAGE_ALIGN equ 1<<0 MB_MEM_FIELDS equ 1<<1 %macro multiboot_header 1 align 4 dd 0x1BADB002 dd %1 dd -(0x1BADB002 + (%1)) %endmacro multiboot_header MB_PAGE_ALIGN | MB_MEM_FIELDS