[U-Boot] Incorrect memtest range on MPC8536DS

[Felix Radensky]

Hi, Wolfgang

Wolfgang Denk wrote:
> Dear Felix Radensky,
>
> In message <4A843B9B.2000203 at embedded-sol.com> you wrote:
>   
>> Hi,
>>
>> If run without arguments, mtest hangs on MPC8536DS.
>> I guess this is because of the following definitions:
>>
>> #define CONFIG_SYS_MEMTEST_START    0x00000000
>> #define CONFIG_SYS_MEMTEST_END        0x7fffffff
>>
>> I was able to successfully run mtest on 0x00100000 - 0x10000000.
>>
>> What is the largest safe range for this platform ?
>>     
>
> It depends on RAM size and stack usage. Usually 1 or 2 MB below stack
> base is safe enough.
>   

Thanks for clarifying. This platform has 512MB of RAM.
The stack pointer is at 0x1fe2df48. Test works fine with upper
limit set to 0x1fd2df48.

For some reason I cannot set lower limit to 0x00000000.
The lowest working address is 0x00000a98. At 0x00000a97
the test hangs, and at 0x00000a96 I get the following crash:

IP: 1FF30000 XER: 20000000 LR: 1FF30000 REGS: 1fe2dbd0 TRAP: 0700 DAR: 
00000000
MSR: 00001000 EE: 0 PR: 0 FP: 0 ME: 1 IR/DR: 00

GPR00: 1FF30000 1FE2DCC0 1FE2DF64 1FE2DCD0 00000001 0000000C FFFFFFFF 
00000000
GPR08: 1FF99715 0000398C FFFFFFFF 1FFB0120 48022084 5E36E3C4 1FFA9F00 
00000000
GPR16: 1FF54880 1FF96508 00000000 1FF996F8 00001000 1FE2DCC0 00000000 
1FF30000
GPR24: 1FF33AE8 00000A96 00000001 1FD2DF48 00000000 1FE35648 1FFAABE0 
00000003
** Illegal Instruction **
Call backtrace:
1FF30000 1FF4A524 1FF56924 1FF5600C 1FF5618C 1FF58CEC 1FF33748
1FF315FC
Program Check Exception
### ERROR ### Please RESET the board ###

The faulting address (0x1FF30000) seems to be the relocation address, as the
following debug messages indicate:

Top of RAM usable for U-Boot at: 20000000
Reserving 805k for U-Boot at: 1ff30000
Reserving 1032k for malloc() at: 1fe2e000
Reserving 80 Bytes for Board Info at: 1fe2dfb0
Reserving 76 Bytes for Global Data at: 1fe2df64
Stack Pointer at: 1fe2df48
New Stack Pointer is: 1fe2df48
Now running in RAM - U-Boot at: 1ff30000

Can you (or Kumar) please explain what's going on here ?

Thanks a lot.

Felix.