[coreboot] Help getting a P2B board running with coreboot

Mark Marshall mark.marshall at csr.com
Wed Oct 21 19:27:06 CEST 2009


I've been lurking here for some time, and am slowly trying to get a ASUS 
P2B board to run with coreboot.  This is mainly so that I can get to 
grips with how coreboot works - the P2B seemed to be an easy starting 
point (well documented and cheap, they're on e-bay for < £10).

I've built a ROM image from earlier today and loaded it into a flash, 
and I do get some serial output.  I can see coreboot attempts to 
initialize the memory and then hangs when it tries to copy the CBFS 
image to RAM.

I uncommented one of the lines in the auto.c file so that I do a memory 
test just before the copy from cbfs.  The hang occurs when writing to 
the RAM.  I looked at the assembler, and it was using the MOVNTI 
instruction, which I don't think is supported by the CPU I'm using.

After changing the HAVE_MOVNTI build define I tried again, this time I 
get a reset when writing to the RAM.

The RAM that I'm using isn't a 64MB one, and the raminit code implies 
that it may only work with this size of chip.  Is this something easy 
that I can change (if this is the only problem then there's a good 
chance that I can work out the correct values from the data sheet)?

Are there other reasons why a P2B board won't just run out of the box? 
What else can be causing a write to RAM to go wrong?  What other tests 
can I make?

Is there a know-good revision from SVN that I can sync to knowing that 
that version will(should) work?

If I use serialice (or something else) what do we expect to happen if I 
write to (or read from RAM) before it has been initialized?  What about 
if it has been wrongly initialized?  (I surprised that it seems to cause 
  a reboot.)

I know that these are basic questions, but any help would be greatly 


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