OSDev.org

Hi all, may I have some help, please.

my problem is: my os works very well at VirtualBox, but at real hardware pc, it doesn´t ...

I´m creating a bootable cd with nero, and I´m using grub to start my os.

I cannot read fat at that cd bootable...

anyone could help me, please ?

You're using a FAT filesystem on a CD? That may be part of the problem.
Other than that, nowhere near enough information to tell what the problem is.
Does it even boot on real hardware (does the grub menu show up)?
If it does boot, what happens?

I´m using a bootable cd that I´ve created with nero.

and using grub 0.94 to boot.

it shows grub menu, boot my os, but when is executing like init_fat12(); it waits, waits, waits then I get timeout....

then I just can use a simples functions inside my kernels, none of fat functions, read, write, anything....

Bootable CDs use ISO9660 as their file system instead of FAT12, therefore trying to parse the data on your CD as FAT12-formatted data instead of ISO9660-formatted data won't work.


Regards,
Stephan J.R. van Schaik.

Guys, I think I found why it doesn´t work, I think we´r using a functions that we programing direct the floppy disk controller, right?

so using a bootable cd, we cannot use that functions to read / do anything with file system...

is that right ?



I have to find out another way to read, maybe use a real mode int 0x13? or it doesn´t works ? I´m just confused,

everyone remember windows 98 boot cd ? it start like with msdos using a real mode functions, like msdos does...

so how microsoft do that ? it uses a standart int 0x13? does bios do that emulation and then I can use int 0x13 ? or I have to use

a functions that read from cd controler ?

See EDD functions.

Check this in Nero...
Boot -> Enable expert settings (for advanced users only) -> Expert settings:
Kind of emulation: No Emulation
Boot message:
Load segment of sectors (hex): 7C0
Number of loaded sectors: 4

You can't expect to be able to read sectors from a CD using the floppy disk controller.
Try looking up documentation for whatever CD drive the machine you're trying to run on uses.

Tosi wrote:You can't expect to be able to read sectors from a CD using the floppy disk controller.
Try looking up documentation for whatever CD drive the machine you're trying to run on uses.

Documentation for the drive? no, that is not what is required.