Introduction to Creating Your Own OS with Ubuntu
This article is tips for creating HariboteOS.
System Setup
- OS: Ubuntu 18.04
Tools Used
Binary editor
- hexedit
sudo apt install hexedit
- ghex
sudo apt install ghex
Assembler
- nasm
sudo apt install nasm
nasm input.asm -o output (-l output.lst)
C Compiler
- gcc
gcc -march=i486 -m32 -fno-pie -nostdlib -T [linkerfile] -g *.c *.o -o bootpack.bin
Make OS Image
You can merge asmhead.bin and bootpack.bin by using cat to connect them as text.
cat asmhead.bin bootpack.bin > os.sys
Use mtools to export the OS image.
mformat -f 1440 -C -B ipl.bin -i os.img ::
mcopy -i os.img os.sys ::
The meaning of the options in mtools is as follows.
| Options | Descriptions |
|---|---|
| -f | Filesize |
| -C | Create MS-MOS file system |
| -B | Boot sector |
Emulator
I used QEMU and VirtualBox as emulators. Since there was a problem that QEMU did not work well, I used VirtualBox after I faced the problem.
When using QEMU, you can boot OS with the following command. -fda means image uses floppy disk format.
qemu-system-i386 -fda os.img