User:Imate900/32-bit assembler bare bones: Difference between revisions
Jump to navigation
Jump to search
Content deleted Content added
Restored page from RSS feed. DO NOT DELETE MEANINGFUL CONTENT WITHOUT DISCUSSION |
Fixed markup going amiss |
||
| Line 5: | Line 5: | ||
== GRUB == |
== GRUB == |
||
All we need is something like this (GNU as): |
All we need is something like this (GNU as): |
||
<pre> |
|||
.global loader # making entry point visible to linker |
.global loader # making entry point visible to linker |
||
| Line 22: | Line 23: | ||
# Write the kernel here |
# Write the kernel here |
||
jmp _start |
jmp _start |
||
</pre> |
|||
Link with: |
Link with: |
||
as -o kernel.o kernel.s |
<tt>as -o kernel.o kernel.s</tt> |
||
ld --oformat binary -o kernel.bin kernel.o |
<tt>ld --oformat binary -o kernel.bin kernel.o</tt> |
||
For NASM: |
For NASM: |
||
<pre> |
|||
global loader ; making entry point visible to linker |
global loader ; making entry point visible to linker |
||
| Line 45: | Line 48: | ||
; Write the kernel here |
; Write the kernel here |
||
jmp _start |
jmp _start |
||
</pre> |
|||
Link with: |
Link with: |
||
nasm -f bin kernel.asm |
<tt>nasm -f bin kernel.asm</tt> |
||
Make sure you have a GRUB entry... |
Make sure you have a GRUB entry... |
||
title Assembler Barebones |
title Assembler Barebones |
||
kernel (hd0,0)/boot/kernel.bin |
kernel (hd0,0)/boot/kernel.bin |
||
Now, reboot, and enjoy! |
Now, reboot, and enjoy! |
||
== Raw (No GRUB) == |
|||
Go crazy (you must convert into AT&T syntax if not using NASM)... |
|||
_start: |
|||
cli |
|||
; It might be a Good Idea(tm) to dump your GDT at the end and load it here |
|||
;lgdt [my_gdtr] |
|||
mov eax, cr0 |
|||
or al, 1 |
|||
mov cr0, eax |
|||
; Write your kernel here. |
|||
jmp $ |
|||
[[Category:Bare bones tutorials]] |
[[Category:Bare bones tutorials]] |
||
Revision as of 16:49, 20 April 2009
| Difficulty level |
|---|
 Medium |
| Kernel Designs |
|---|
| Models |
| Other Concepts |
This tutorial will teach you how to make a 32-bit assembler kernel.
GRUB
All we need is something like this (GNU as):
.global loader # making entry point visible to linker # setting up the Multiboot header - see GRUB docs for details .set ALIGN, 1<<0 # align loaded modules on page boundaries .set MEMINFO, 1<<1 # provide memory map .set FLAGS, ALIGN | MEMINFO # this is the Multiboot 'flag' field .set MAGIC, 0x1BADB002 # 'magic number' lets bootloader find the header .set CHECKSUM, -(MAGIC + FLAGS) # checksum required .align 4 .long MAGIC .long FLAGS .long CHECKSUM _start: # Write the kernel here jmp _start
Link with: as -o kernel.o kernel.s ld --oformat binary -o kernel.bin kernel.o
For NASM:
global loader ; making entry point visible to linker ; setting up the Multiboot header - see GRUB docs for details ALIGN equ 1<<0 ; align loaded modules on page boundaries MEMINFO equ 1<<1 ; provide memory map FLAGS equ ALIGN | MEMINFO ; this is the Multiboot 'flag' field MAGIC equ 0x1BADB002 ; 'magic number' lets bootloader find the header CHECKSUM equ -(MAGIC + FLAGS) ; checksum required mboot: dd MAGIC dd FLAGS dd CHECKSUM _start: ; Write the kernel here jmp _start
Link with: nasm -f bin kernel.asm
Make sure you have a GRUB entry...
title Assembler Barebones kernel (hd0,0)/boot/kernel.bin
Now, reboot, and enjoy!