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RE: i386 flopy load problem.


> -----Original Message-----
> From: Jonathan Larmour [mailto:jlarmour@cygnus.co.uk]
> Subject: Re: [ECOS] i386 flopy load problem.
> 
> Fabrice Gautier wrote:
> > 
> > The only way to avoid the problem is to load one sector at 
> a time, and to
> > align _start on 512 bytes. This is slower but who cares?
> 
> How much slower?

Well, I don't really know because anyway images are not very large and it's
difficult to measure anything. At worse it is 18 times slower but track
change is probably the operation that take the most time so i would rather
say it's something like 5 times slower. Anyway the whole boot process is
already long...

> > Attached is a patch against platform.S
> 
> platform.inc :-). Thanks. I have just one query:
 
> _error:		/* halt on error */
> 	cli
> 	hlt
> 	jmp _start
> 
> what is the purpose of jmp _start in the above?

Well, it's just a precaution, in case the hlt return. I would say this could
only happen if a NMI occurs which is not very probable, but who now... 
 
> If you can also give me a ChangeLog entry (not a diff, just the plain
> entry). I'll apply the patch.

Something like:

2000-11-02  Fabrice Gautier <Fabrice_Gautier@sdesigns.com>

        * src/platform.inc (hal_cpu_init): Load image from floppy one
        sector at a time to avoid "DMA access across 64k boundary" error.


Regards,

-- 
Fabrice Gautier
fabrice_gautier@sdesigns.com 

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