Problem on ADS board

[Rudolf Ladyzhenskii]

Hi, all

I am running Linux 2.4.6 on Motorola 8260ADS board.

I can start kernel (I use ppcboot) and get it booting and run simple
applications.  If I try to run a complex application, board crashes without
any warning and it also writes to the FLASH memory, corrupting it and
setting lock bits on one of the 4 chips on Flash SIMM.

Flash is not mapped into Linux memory space at all as far as I can see, so I
do not quite understand how it can write there. Also to write to the flash,
it has to execute a sequence of specific commands and there is no code to do
so. At least I did not put in any and I could not see any.

Some additional information that may be useful:
I downloaded a program called memtester. This program tries to allocate as
much memory as it can, then mlock it and run some tests on it. Allocation
succeds, but somewhere in the locking part, system crashes. This program
executes in the user space, so it should not crash the kernel, but it does.
Also, I tried to see with BDI2000 what is going on. Results I am getting are
somewhat strange:
Most of the times, when board crashes, BDI2000 prompt says "Target reset
detected" and it tries to re-initialize the board.
In some cases, BDI2000 was saying that board is still running. Halting it
reveals that it tries to execute something out of addresses in the beginnig
of SDRAM (SDRAM starts at 0x0000_0000). Address translation is turned on, so
I would really expect to see addresses offset of 0xC000_0000, because Linux
was executing on board. If I let board run (with BDI2000 "go" command) and
then halt it again, I may see that it halted in the kernel (addresses are
offset). Starting and stopping the program in this manner shows me that
current execution address jumps between offsetted and non-offsetetd
addresses.

I would appreciate any ideas on the subject.

BTW, same version of kernel is running on 750 CPU runnign same memtester and
there are no problems at all.

Thank you,

/************************/
Rudolf Ladyzhenskii
Senior DSP Engineer
Advanced Communication Technologies
ph.  +61 3 8080 8215
fax. +61 3 9672 8800
Level 9, 190 Queen Street,
Melbourne, 3000
Australia
/***********************/


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/