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U-boot's stack space on a Sequoia board

U-Boot Corey Ashford 2 participants 4 messages Sep 15, 2012 – Sep 17, 2012 1 message not in the archive

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#1 lore raw

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

#2 lore raw

Dear Corey Ashford,

Quoted 3 lines · In message <[email protected]> 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.

Quoted 1 line

So I have a couple of questions:

Please update, then try again.

Best regards,

Wolfgang Denk

Signature · 4 lines
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
#3 lore raw
Quoted 11 lines · Wolfgang Denk

Dear Corey Ashford,

Quoted 3 lines · In message <[email protected]> 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.

Quoted 8 lines
Quoted 1 line

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

#4 lore raw

Dear Corey Ashford,

Quoted 5 lines · In message <[email protected]> you wrote:
Quoted 2 lines

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

Signature · 5 lines
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_