.set ALIGN, 1<<0 .set MEMINFO, 1<<1 .set FLAGS, ALIGN | MEMINFO .set MAGIC, 0x1BADB002 .set CHECKSUM, -(MAGIC + FLAGS) .section .multiboot .align 4 .long MAGIC .long FLAGS .long CHECKSUM # C stack startup .section .bss .align 16 stack_bottom: .skip 16384 stack_top: # GDT segment register setup .global _gdt_flush .extern _gp _gdt_flush: lgdt (_gp) #load the GDT with the special pointer mov %ax, 0x10 #offset from GDT to data segment mov %ds, ax mov %es, ax mov %fs, ax mov %gs, ax mov %ss, ax jmp 0x08:flush2 #long jump flush2: ret #return to c code # start function - calls kernel_main .section .text .global _start .type _start, @function _start: movl $stack_top, %esp call _init call kernel_main cli 1: hlt jmp 1b .size _start, . - _start