Hi HTH,
Thanks for the information. My problem is that "md 0xFFFFE000" and any other read command up to this address works fine. Its just when I try to read @ 0xFFFF F000 I see this problem.
I didn't see any obvious problem with the global and static initialization.
Nikhil
Hi Nikhil,
If I understand you correctly, this sounds like improperly initialized variables in your build. This is very likely a (build | link | initialization | relocation) issue (pick any combination).
The "md 0xFFFFF000" command is using the default value for the number of objects, which comes from a static variable dp_last_length that is initialized to 0x40 (see common/cmd_mem.c): uint dp_last_length = 0x40;
If dp_last_length is not initialized properly to 0x40 on start up, unexpected things are going to happen. I don't see an obvious path to an illegal access to location 0x00000000, but it could be.
In addition, if you hit <enter> with no command the first time your board boots, the command parser tries to run the last command you executed. Of course, there *is no* "last command", which ties into my theory of uninitialized static/global variables.
I would suspect your link control isn't linking the static variable initialization in the right section or your (compiler's) initialization of the static variables isn't working as expected.
HTH, gvb
On Feb 15, 2008 10:15 AM, Jerry Van Baren gerald.vanbaren@ge.com wrote:
Nikhil Gautam wrote:
Hi Everyone,
I am try to use the u-boot to program the NOR flash on my proprietary board based on AMCC sequoia board. I can boot from 1Gb NAND flash ok but everytime I try access the last 4K of NOR flash, U-boot gives me following error and reboots:-
{{{ U-Boot$ md 0xFFFFF000 fffff000:Bus Fault @ 0x00000000, fixup 0x00000000 Machine check in kernel mode. Caused by (from msr): regs 0fe8fca8 Unknown values in msr NIP: 00000000 XER: 20000000 LR: 0FF6412C REGS: 0fe8fca8 TRAP: 0200 DAR: 041F0000 MSR: 00000000 EE: 0 PR: 0 FP: 0 ME: 0 IR/DR: 00
GPR00: 0FF6412C 0FE8FD98 7FFFFFFF EF600300 00000000 00000001 00000001 C838AE89 GPR08: 0FF5145C 00000000 01FCA055 03F940AB 0FE8FB50 041F0000 0FFACD00 0EED0000 GPR16: 00000000 00000000 00000000 00000000 0FE8FDA0 00000040 0FE8FDA0 0FE8FDA0 GPR24: 00000000 00000100 00000010 00000004 FFFFF000 0FE8FF40 0FFADB58 0FE8FDA0 Call backtrace: machine check }}}
I get the same error if I press "ENTER" after u-boot gives me the prompt. If I type some command its ok and then its fine thereafter.
I know the NOR flash is ok because I used BDI to program it and also I can access this address when I boot from NOR flash.
Any Clue?
Thanks In Advance!
Nikhil Gautam