Andre Schwarz andre.schwarz@matrix-vision.de wrote on 2010/10/26 14:34:57:
All,
Having a look at include/asm/global_data.h gives some 40 ulongs for my MPC8377 system. Current CONFIG_SYS_GBL_DATA_SIZE= 0x100 which should be enough.
Indeed. I was asking because I just discovered that most of the PowerPC boards are actually broken in this respect - 89 % of them, 170 out of 191 :-(
The system is still dead after removing the 4 nops after _start.
actually I'm facing another issue and don't now whether this might be related to this thread or not.
Just before relocation in arch/powerpc/lib/board.c the CPU gets a "check stop" followed by reset during "memset()" in line 493.
[snip] DRAM: 256 MiB Top of RAM usable for U-Boot at: 10000000 Reserving 341k for U-Boot at: 0ffaa000 Reserving 512k for malloc() at: 0ff29f80
- reset -
U-Boot 2010.09-00488-g5edbadb-dirty (Oct 26 2010 - 14:16:00) MPC83XX
Reset Status: Check Stop, External/Internal Soft, External/Internal Hard
I know that DDR might not be 100% stable but it is basically set up properly. Removing the memset yields the next debug messages before resetting again while setting up SP.
Is the DDR required to work 100% for a simple write operation or might there be another problem ?
Yes, DDR must be correct. You might get a bit further by turning off the data cache.