[U-Boot-Users] BSS initialization wrong on ARM??

[Andrea Scian]

Hi all,

----- Original Message -----
From: "Wolfgang Denk" <wd at denx.de>
To: "Markus Pietrek" <maillist at fsforth.de>
Cc: <u-boot-users at lists.sourceforge.net>; "Andrea Scian"
<andrea.scian at wawnet.biz>
Sent: Wednesday, June 09, 2004 1:45 AM
Subject: Re: [U-Boot-Users] BSS initialization wrong on ARM??


> Dear Markus,
>
> in message <200405041112.56047.maillist at fsforth.de> you wrote:
> >
> > on the smdk2410 I found out that the BSS segment is initialized at
offset 0x4
> > and not with offset 0x0, leaving the first entry undefined (in my case
> > timer_load_val), at least with gcc-3.3. Cause of pain is
> > arm920t/start.S:clear_bss
>
> I think you are right. Thanks for pointing out.
>
> > clear_bss:
> > ldr r0, _bss_start /* find start of bss segment        */
> > add r0, r0, #4 /* start at first byte of bss       */
> > ldr r1, _bss_end /* stop here                        */
> >
> > I think the add has to be removed. This also seems to be the case on
arm720t
> > and arm926ejs.
>
> Actually _all_ ARM  systems  are  affected  -  except  s3c44b0  which
> doesn't clear BSS at all?
>
>
> Andrea, am I missing something, or is the clear_bss code  missing  in
> your port for the s3c44b0 processor?
>

You're right Wolfgang: the clear_bss code is missing in my port for the
s3c44b0 port. This because I've used as reference another "ARM family" code
for my port and, in fact, it was miss there too (at that time I've port
u-boot version 1.0.2).
Fortunately (or should I say "unfortunately"!?) I've no problem with bss (at
least until now), I suppose because my global variable are initialized at
runtime too.
I will soon fix this problem, probably when we will port the newer version
of u-boot to our platform.

Thanks to you and to Markus for pointing it out!

Regards,

Andrea Scian

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> Best regards,
>
> Wolfgang Denk
>
> --
> Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
> Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
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>