This is the mail archive of the
ecos-discuss@sources.redhat.com
mailing list for the eCos project.
Re: i386 flopy load problem.
- To: Fabrice Gautier <Fabrice_Gautier at sdesigns dot com>
- Subject: Re: [ECOS] i386 flopy load problem.
- From: Jonathan Larmour <jlarmour at cygnus dot co dot uk>
- Date: Thu, 02 Nov 2000 17:20:51 +0000
- CC: "Ecos-List (E-mail)" <ecos-discuss at sourceware dot cygnus dot com>
- Organization: Red Hat UK Ltd.
- References: <5AF611D83988D4118ACF00E0B10400540557FB@mr-intranet.sdesigns.net>
Fabrice Gautier wrote:
>
> The current code for loading from the floppy won't work in many case. It
> will be subject to what i call the "buffer cross 64k boundary problem": The
> bios function can't handle a buffer that cross a 64k boundary (This is also
> refered as "DMA access across 64k boundary" in some docs)
>
> The current code load track by track, and so there is a good chance to cross
> a 64K boundary during a track load, if the image size is big enough.
>
> 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?
> 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?
If you can also give me a ChangeLog entry (not a diff, just the plain
entry). I'll apply the patch.
Jifl
--
Red Hat, 35 Cambridge Place, Cambridge, UK. CB2 1NS Tel: +44 (1223) 728762
"Plan to be spontaneous tomorrow." || These opinions are all my own fault