[U-Boot] U-boot's stack space on a Sequoia board

[U-Boot] U-boot's stack space on a Sequoia board

[Corey Ashford]

Hello,

I recently spent quite a lot of time finding a problem where U-boot was
overwriting part of its stack onto my kernel that I had downloaded via
tftpboot.

The board I am using is a Sequoia, powerpc 440EPx board running U-boot
1.2.0-gc0c292b2 (Jun 5 2007 - 07:16:12).

I found that when I booted my Linux kernel, part of its text space was
corrupted upon entry.  I traced this back to U-boot writing a command
line and board info record into its own stack space (- 2048 bytes).
This happens in common/cmd_bootm.c

What surprised me was that this board (fairly old now) has 256M of
memory, but U-boot's stack pointer was around the 8MB point (the pointer
to the board info record passed into my kernel is address 0x007ffe70 --
just under 8M).

So I have a couple of questions:

1) Any idea why the stack pointer would be so low in memory?
2) Is there any way to tell, once the board is up and running U-boot,
where its stack space is so that I can be sure to avoid running into it?

The U-boot that is running on this board wasn't compiled with DEBUG enabled.

Thanks for your consideration,

- Corey

[U-Boot] U-boot's stack space on a Sequoia board

[Wolfgang Denk]

Dear Corey Ashford,

In message <5053CCB5.3070606@linux.vnet.ibm.com> you wrote:
> 
> The board I am using is a Sequoia, powerpc 440EPx board running U-boot
> 1.2.0-gc0c292b2 (Jun 5 2007 - 07:16:12).

Frankly: we don't really care any longer about 5 years old code.  The
Sequoia board is well supported in mainline U-Boot, so please update
and use current code instead.

> So I have a couple of questions:

Please update, then try again.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
"Pull the wool over your own eyes!"                - J.R. "Bob" Dobbs

[U-Boot] U-boot's stack space on a Sequoia board

[Corey Ashford]

On 09/15/2012 01:27 AM, Wolfgang Denk wrote:
> Dear Corey Ashford,
>
> In message <5053CCB5.3070606@linux.vnet.ibm.com> you wrote:
>>
>> The board I am using is a Sequoia, powerpc 440EPx board running U-boot
>> 1.2.0-gc0c292b2 (Jun 5 2007 - 07:16:12).
>
> Frankly: we don't really care any longer about 5 years old code.  The
> Sequoia board is well supported in mainline U-Boot, so please update
> and use current code instead.
>
>> So I have a couple of questions:
>
> Please update, then try again.
>
> Best regards,
>
> Wolfgang Denk
>

Dear Wolfgang Denk,

OK, and thank you for your quick reply.  I don't have physical access to 
this board, but I'll ask around to find if this is something we can do.

Regards,

- Corey

[U-Boot] U-boot's stack space on a Sequoia board

[Wolfgang Denk]

Dear Corey Ashford,

In message <50575CB3.20305@linux.vnet.ibm.com> you wrote:
>
> > Please update, then try again.

> OK, and thank you for your quick reply.  I don't have physical access to 
> this board, but I'll ask around to find if this is something we can do.

No physical access is needed for such an update (unless you botch it
and need to access the BDI3000, or to switch the jumpers to boot the
backup version from NAND - if you were clever enough to install one
there first).

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Be careful what you wish for. You never know who will be listening.
                                      - Terry Pratchett, _Soul Music_