This repository has been archived on 2024-06-25. You can view files and clone it, but cannot push or open issues or pull requests.
rockOS/kernel/arch/i386/boot.S
2022-07-18 09:59:04 +03:00

35 lines
906 B
ArmAsm

# Declare constants for multiboot header
.set ALIGN, 1<<0 # align loaded modules on page boundaries
.set MEMINFO, 1<<1 # provide memory map
.set FLAGS, ALIGN | MEMINFO # multiboot flag field
.set MAGIC, 0x1BADB002 # magic number for bootloader to find header
.set CHECKSUM, -(MAGIC + FLAGS) # checksum of above
# Declare header in multiboot standard
.section .multiboot
.align 4
.long MAGIC
.long FLAGS
.long CHECKSUM
# Reserve a stack for initial thread
.section .bss
.align 16
stack_bottom:
.skip 16384 # 16 KiB
stack_top:
# kernel entry point
.section .text
.global _start
.type _start, @function
_start:
movl $stack_top, %esp
call _init # call global constructors
call kernel_main # transfer control to main kernel
# Hang if kernel_main unexpectedly returns
cli
1: hlt
jmp 1b
.size _start, . - _start