62 lines
956 B
ArmAsm
Executable File
62 lines
956 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:
|
|
|
|
# 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
|
|
|
|
|
|
# GDT segment register setup
|
|
.global gdt_flush
|
|
.extern gp
|
|
gdt_flush:
|
|
lgdt (gp) #load the GDT with the special pointer
|
|
mov %eax,0x10 #offset from GDT to data segment
|
|
mov %eax, %ds
|
|
mov %eax, %es
|
|
mov %eax, %fs
|
|
mov %eax, %gs
|
|
mov %eax, %ss
|
|
|
|
pushl 12(%esp)
|
|
push $flush2
|
|
ljmp *(%esp) #long jump
|
|
flush2:
|
|
ret #return to c code
|
|
|
|
.global idt_load
|
|
.extern idtp
|
|
idt_load:
|
|
lidt (idtp)
|
|
ret
|
|
|