Benamrouche Abdel 
email : draconux _at_ gmail _point_ com
creation date : 2007/01/01
last update : 2008/01/24


Note:
========

How to build linux 0.01 with newer gcc ?
Note : I have not tested it in a real computer, 
because I d'ont have an empty HDD.
I use qemu, and I will explain how to run linux 0.01 in qemu.
If you want to try it in your HDD, then do it at your 
own risk.



Create your virtual HDD :
=========================

create a 40 MB file
> dd if=/dev/zero of=hdb.img bs=1M count=40

setup Cyls, Heads, Sects and create 1 partition
> losetup /dev/loop0 hdb.img
> fdisk -H 4 -S 20 -C 1024 /dev/loop0
with fisk create a primary partition.
Also note where begin the first partition.
it's should be 20 x 512 = 10240
> losetup -d /dev/loop0

create old minix partition
> losetup -o 10240 /dev/loop0 hdb.img
> mkfs.minix -n 14 /dev/loop0

mount your virtual hdd 
> mount /dev/loop0 /mnt/mnt_hdb_img
in your hdd create directory bin and usr
you can write some txt file, if you want to try to read it
Later you you will be able to create copy some userspace program.

before executing qemu don't forget to umount first your hdd


Linux 0.01 kernel :
=====================


In include/linux/config.h and include/linux/hdreg.h:
----------------------------------------------------

change the HDD parameters to match with your virtual HDD

In kernel/hd.c :
----------------

change this line if your HDD is master
> /*0xB0 for slave, 0xA0 for master*/
> outb_p(0xB0|(drive<<4)|head,++port);

I think that's all.
Build your kernel with make.
You should have a file Image, it's your linux 0.01


Keyboard :
----------

Linux 0.01 need a finish keyboard !
You can change it.
TODO : provide us and fr keyboard patch


Simple userland program:
=================

Linux 0.01 don't want to load my a.out binay format builded with newer gcc.
So from linux-0.01-3.x a.out binary format is dropped, instead we use elf loader.

So how to build an elf binary program for our linux 0.01

print_prog.c
-------------------------------------
#include <string.h>
#include <fcntl.h>
#include <unistd.h>

void main(int argc,char* argv[]){
        setsid();
	(void) open("/dev/tty0",O_RDWR,0);
	(void) dup(0);
	(void) dup(0);

	write(1,"bonjour\n",strlen("bonjour\n"));

	_exit(2);
}
--------------------------------------

build it with :
>  gcc -o test.bin main.c -nostdlib -nostdinc -e main -Ttext=100 -static -fno-builtin LINUX_DIR/lib/lib.a -ILINUX_DIR/vgt_test_so/include

where LINUX_DIR is you path to your linux0.01 kernel


Note :
We use here void main() and _exit(0); 
if you want to use int main() and return 0; instead you will need
to add crt0.s
TODO : link to crt0.s


Complex userland program :
==========================

Linux 0.01 has a mini-libc ( in lib/ folder )
If you want to port a comlex program ( for example emacs ) you will probably
need a lot of function wich are not implemented.

If you don't want to implement it, just use something like  dietlibc or uclibc.
Note : I have ported dietlibc, and it's work fine.
Maybe uclibc is better ... I don't know.

So to create a program using dietlibc :
TODO : write command here


Execute your kernel:
=====================

qemu -fda Image -hdb hdb.img -boot a -m 8


voila, that's all.
happy hacking
Abdel