[coreboot] coreboot halts at "doing early_mtrr"

austinro at msu.edu austinro at msu.edu
Fri Jul 30 23:20:32 CEST 2010

Quoting Patrick Georgi <patrick at georgi-clan.de>:

> Am 30.07.2010 19:35, schrieb austinro at msu.edu:
>> I have a Jetway 7F4K1G5S-LF board I'm trying to get working.
> Just to make things clear - that's a Via C7 board, yes?


>> Any ideas?
> We moved the C7 boards over to CAR (cache as RAM), but couldn't test all
> of them (due to availability etc). Disabling cache before RAM is
> available (and all data structures, esp. the stack are moved to RAM)
> makes the system hang.
> From looking at the board's romstage.c, it seems that early_mtrr_init is
> ran before RAM init, but after CAR enable.
> Do you get further after disabling early_mtrr_init (which disables
> caching to activate the new MTRR config) completely?

Commenting out the call to early_mtrr_init() lets coreboot run to completion.

That's odd.  I assumed the call to "write_cr0(cr0)" in cache.h was  
responsible somehow, since that was where it stopped when  
"early_mtrr_init" called "disable_cache", but I left the print  
statements in disable_cache, and they were all printed repeatedly this  
time, so "write_cr0" only causes a problem when called early (during  


Tried it again and with memtest as the payload and it doesn't see any  
memory.  Memtest pops up on the screen :
L1 cache: 64K
L2 cache: 128K
L3 cache: none
Memory :    0K
(That last one is a zero K).


(Thanks Patrick!)

More information about the coreboot mailing list