Sync/arch/i386/boot.s
2019-04-06 20:00:11 +01:00

52 lines
849 B
ArmAsm
Executable File

.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