OSDev.org

Hi all,

First I have to say i did not learn the assembly language... so the question i guess is more
easily asked than be answered.
I have my own website :http://212.114.109.207/boot/boot.html where you can
enter in the first textarea some 'bootloader code' if you press the make iso button there
will be a .iso output wich you can burn on a dvd-rw. The bootloader works.
Its made with the command(php):

$op=system("genisoimage -b prog".$getal.".img -no-emul-boot -boot-load-size 4 -o discprog".$getal.".iso /var/www/boot/ >> ".$getal."3.txt 2>&1 ",$back);

In the second textarea(second[random].img) you can add more code(at least that is the idea)...
but how to jump to that file(second[random].img).

I burned an .iso file on my own dvd-rw(TDK) and it contains a lot of files...
The second[random].img file is what i am looking for... i opened the burned .iso
file with: 'iso-buster' and if i am right it said : LBA 37.
I burned it on a other dvd-rw(HEMA) and it said : LBA 36.

So how do i jump to that file...?

Thx,

Frederik

Every loader system, whether it be first stage, second, third, twenty third, whatever, must be at one stage or another file system aware. The CD/DVD you are using, most likely has a file system on it. Your loader *must* parse this file system to find the file and its location. Even if you simply use blocks of data, your loader will eventually have to parse some kind of list to retrieve the correct block.

My opinion is not to start OS Development using a CD or DVD (.ISO image) as your starting media device. I would use a hard drive image which means that you can, with minor changes, make it work on a floppy, USB thumb drive, hard drive, etc., even a bootable CD once you get the idea of how they work.

As another note, you really need to give more information. Did you create your own boot loader for this ISO image? If you did, you should understand the file system the CD/DVD media uses.

Anyway, my opinion is to start with an easier form of media.

Hope this helps,
Ben
http://www.fysnet.net/osdesign_book_series.htm

Thank you for your comment/reaction .
I did 'this' once on a floppy (happy with it ), but from understanding
it totally it never came.
I have more the hope to program a simple os ,without
learning assembly (doing it with functions)... but i will fail

Thx again ,

Frederik

If you don't understand assembler (which begs the question of how you wrote this code in the first place) then you probably shouldn't attempt a bootloader. Copy-pasting code that you don't understand is a recipe for failure.

There are a number of good bootloaders; use one of them and concentrate on the programming that interests you, and is within your capabilities.