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Re: Re: Patch for x86 bootstrap



On Wed, 25 Apr 2001 12:25:04 -0700
elf@florence.buici.com wrote:

> On Wed, Apr 25, 2001 at 08:54:30PM +0200, Fabrice Gautier wrote:
> > 
> > On Wed, 25 Apr 2001 10:05:30 -0700
> > elf@florence.buici.com wrote:
> > 
> > > If the patch was made a while ago, where is it?
> > 
> > This one has been incorporated in the RedHat CVS back then.
> 
> I am confused.  The code that I can now fetch from anoncvs doesn't
> respect the floppy drive geometry.  Are you saying that a patch for
> this has already been incorporated into RedHat CVS?  And that they
> haven't released it?

Yes and No ! 

This patch has been in CVS for a long time, and is in the version you're
are working on. One comment you're deleting in your patch was introduced
with the very patch i'm talking about.

I just say that Back in November a patch to handle a problem from floppy
loading, the one described by the comment I quoted, was incorporated
into CVS.

Your patch sure add something  else, and is more genreic. But as you were
deleting the comment from the code, I just wanted to be sure that you
had not as the same time reintroduced the problem. 

Well to not confuse you and others more i should explain more precisely:

The problem was that before November, the code would have tried,
with one call to int 13h, to load a full track (18 sectors), across a
64k boundary. The BIOS would not handle that case, some kind of DMA
problem, I think. By loading sector by sector the problem was solved.

I've look at your patch a little more closely, and I don't think it
reintroduce the problem since you are still loading sector by sector. So At
least for loading to an adress aligned on sector size (512b) should be
Okay. 

But, I'm not sure what would happen when your code try to load a sector
across a 64Ko boundary, ie: not a Sector size aligned size, but anyway
the loader has never been designed to handle such a case before.


A+
-- 
Fabrice Gautier <gautier@email.enstfr>


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