Re: 2.6.x partition breakage and dual booting

Andries Brouwer
2004-06-03T10:39:30Z

On Thu, Jun 03, 2004 at 08:51:35AM +0200, Frediano Ziglio wrote:

> Actually I'm writing two patch:
> - extending EDD code to provide DPTE informations and signature for all
> drives
> - modify IDE code to match BIOS disks.

That second part is undesirable.
The Linux IDE code is not interested in getting a conjecture about
how other operating systems would name or number the disks.

> How to match BIOS with Linux?

It is impossible. But you can easily do a 95% job.

> I think it's important to know BIOS point of view. Linux provide these
> information so we have two choices to solve the problem:
> - correct the informations we return
> - do not return anything and let user space programs do the job!

Yes, leave it to user space. That is what we do today.

> - EDD 2.0. I don't understand why Linux code int 41h/46h and ignore
> these informations.

Long ago, long before EDD, disks actually had a geometry, and it was
necessary to find it in order to do I/O to e.g. MFM disks.
Today disk geometry is not related to the disk, but to the BIOS.
The kernel has no need to know it.

Andries