G'Day U-boot users,
I'm trying to get U-boot going on a custom built board based on the PXA255. Unfortunately, I'm having a few problems, and got to the if(clueless){ send email to mailing list } part of the porting to a new board sequence. :-).
I'm stepping through the code using a Multi-ICE, and am able to reliably read the flash, downloading the entire program, etc, so I'm fairly certain that the flash is hooked up and working ok. I can also disassemble this using arm-linux-objdump, and get some sane-looking output (1st 1000 lines clagged below).
Now, what's odd is that when I'm stepping through the code, it seems to work pretty well up until the point (at address 0x550) where it loads a particular register's address into R3 (e.g. ldr r3,0x00000744). It seems to load the top 16 bits without any worries, but the bottom 16 bits are FFFF (rather than the bottom half of the address of the OS counter register).
I had a quick look back at what it does when its setting up the GPIO registers, and it seems that it happens sporadically while its doing any ldr instruction. It doesn't seem to be correlated with the address, and looking at the disassembly, the correct values are being read by the processor.
Is there anything different that the ldr instruction would do (as opposed to when I'm reading it out with multi-ice?) that might cause this effect?
Before I noticed this problem, I was getting prefetch faults, and unknown instruction exceptions on a mov instruction (hence the addition of the nops at 0x56c to see whether it was dependent on the address - the addition of the nops caused the code above it to break in the way I described above.
There exists the possibility that the processor has been killed by ESD or something, but I thought I'd email you guys in a last ditch effort before I go about the rather arduous task of pulling off the BGA and place another one.
Any ideas? Any further information that I can provide that might shed some light on the situation? I've attached the memsetup.S file that all this is generated from (from address 0x444 onward).
Many thanks in advance,
Dave.
- David Snowdon PhD Student National ICT Australia (NICTA) Phone: 9385 7355 Email: daves@cse.unsw.edu.au
- David Snowdon PhD Student National ICT Australia (NICTA) Phone: 9385 7355 Email: daves@cse.unsw.edu.au