This is the mail archive of the ecos-discuss@sources.redhat.com mailing list for the eCos project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

RE: Loading linux image through redboot.


Hi Ian,

       Thanks for ur help. I am using redboot to download linux image. After
 downloading the linux image through load command at location 0x100000. Now
for 
 executing this image which redboot command (go or exec) is needed.  As I
have read somewhere that 
 exec is not supported on i386 system.

Regards,
Shailesh Dixit

-----Original Message-----
From: Ian Campbell [mailto:icampbell@arcomcontrols.com]
Sent: Friday, October 11, 2002 4:52 PM
To: ecos-discuss@sources.redhat.com
Subject: Re: [ECOS] Loading linux image through redboot.


>         Is it possible to load linux image for x86 system through
redboot.If
> it is possible then at which location the setup code and system code must
be
> loaded and whether it     
>         requires change in source code ?

I solved this problem by stripping the setup code from the start of the
linux image and booting that directly in protected mode. It's a bit of a
hack, but I was able to make it work.

1) Create raw image without the realmode header. This corresponds to
arch/i386/boot/compressed/bvmlinux.out

	dd if=bzImage of=kernel bs=1024 skip=3

2) Load the file 'kernel' onto the board at 0x100000 using whatever
method you choose.

3) Build the attached .c and .S into RedBoot. Note that these have been
stripped down to the basics removing some device specific stuff. They
are completely untested (not even built), although the non-stripped down
version works for my application. You may need to tweak them. If so you
should read the kernel docs carefully. Especially
Documentation/i386/boot.txt. Also read the the source for the real mode
part, in particular arch/i386/boot/setup.S.

The .c file attempts to setup the same environment as the real mode
header in linux does. The .S part then resets the GDT to match linux and
begins executing the code.

Perhaps someone would like to massage into something suitable for the
generic i386 arch directory, unfortunately I don't have time right at
the minute.

Cheers,
Ian.
-- 
Ian Campbell
Design Engineer

Arcom Control Systems Ltd,
Clifton Road,
Cambridge CB1 7EA
United Kingdom

Tel: +44 (0)1223 403465
E-Mail: icampbell@arcomcontrols.com
Web: http://www.arcomcontrols.com


________________________________________________________________________
This email has been scanned for all viruses by the MessageLabs SkyScan
service. For more information on a proactive anti-virus service working
around the clock, around the globe, visit http://www.messagelabs.com
________________________________________________________________________

-- 
Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
and search the list archive: http://sources.redhat.com/ml/ecos-discuss


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]