Re: boot.S - source question

[Martin Baute]

Am Dienstag, 2. August 2005 23:40 schrieben Sie:

> On Tuesday 02 August 2005 05:51, Martin Baute wrote:
> > The thing is, unless I'm missing something, at this
> > point %si is pointing to the zero byte at the end
> > of notification_message... so where is %si set to
> > a reasonable value, which I have missed?
>
> Look at the code before that. It calls a BIOS function which sets %si when
> successful. You can get more info from Ralf Brown's Interrupt List.

I know the RBIL... and it doesn't say anything about %si
being set by INT 13h, AH=0x41, BX=0x55AAh, which is
the reason I'm confused...

> > I just want to understand how the stage1 works...
>
> Why?

I'm one of the moderators of the OS-FAQ at mega-tokyo.com,
and would like to improve our tutorial material on bootsectors.
As such, I'm trying to write a bootsector of my own, and was
looking at "known good" implementations to get some inspiration
(i.e., learning about the INT's involved instead of taking the
RBIL and guessing).

No fear, I'm not copying source, and anyway my bootsector
will be a rather primitive chainloader only. But that piece of
GRUB code worried me.

Regards,
--
Martin Baute
address@hidden