kern
annotate src/mboot.S @ 0:662ff2170531
starting the kernel
| author | John Tsiombikas <nuclear@member.fsf.org> |
|---|---|
| date | Wed, 01 Dec 2010 22:02:42 +0200 |
| parents | |
| children | ebe5e0e44a9d |
| rev | line source |
|---|---|
| nuclear@0 | 1 #define MAGIC 0x1badb002 |
| nuclear@0 | 2 #define FLAGS 0 |
| nuclear@0 | 3 #define STACK_SIZE 0x4000 |
| nuclear@0 | 4 |
| nuclear@0 | 5 .text |
| nuclear@0 | 6 .globl _start |
| nuclear@0 | 7 _start: |
| nuclear@0 | 8 /* jump over the multiboot header onto the startup code */ |
| nuclear@0 | 9 jmp kentry |
| nuclear@0 | 10 |
| nuclear@0 | 11 .align 4 |
| nuclear@0 | 12 /* multiboot header */ |
| nuclear@0 | 13 mboot_hdr: |
| nuclear@0 | 14 .long MAGIC |
| nuclear@0 | 15 .long FLAGS |
| nuclear@0 | 16 .long -(MAGIC + FLAGS) /* checksum */ |
| nuclear@0 | 17 .fill 5, 4 /* fill out the rest with zeroes */ |
| nuclear@0 | 18 |
| nuclear@0 | 19 kentry: |
| nuclear@0 | 20 /* setup a temporary kernel stack */ |
| nuclear@0 | 21 movl $(stack + STACK_SIZE), %esp |
| nuclear@0 | 22 /* reset eflags register */ |
| nuclear@0 | 23 pushl $0 |
| nuclear@0 | 24 popf |
| nuclear@0 | 25 /* call the kernel main function */ |
| nuclear@0 | 26 call kmain |
| nuclear@0 | 27 /* we dropped out of main, halt the CPU */ |
| nuclear@0 | 28 cli |
| nuclear@0 | 29 hlt |
| nuclear@0 | 30 |
| nuclear@0 | 31 /* space for the temporary kernel stack */ |
| nuclear@0 | 32 .comm stack, STACK_SIZE |