[coreboot] More v3 questions/issues

Myles Watson mylesgw at gmail.com
Thu Dec 18 15:22:21 CET 2008

On Wed, Dec 17, 2008 at 11:38 PM, Corey Osgood <corey.osgood at gmail.com>wrote:

> On Wed, Dec 17, 2008 at 11:04 PM, Corey Osgood <corey.osgood at gmail.com>wrote:
>> On Wed, Dec 17, 2008 at 8:55 PM, Peter Stuge <peter at stuge.se> wrote:
>>> Corey Osgood wrote:
>>> > would there be any problem with calling functions to enable mtrrs
>>> > and the cache (if it's not already) from the end of disable_car()?
>>> None whatsoever. Commit at will.
>> It didn't help, disable_car() already does essentially the same thing;
>> disable cache, enable mtrrs, re-enable cache. I'm comparing memtest between
>> the stock bios and coreboot right now, the throughput for the stock bios is
>> 6122MB/s for L1 cache and 574MB/s for memory. With v2, it's 3265 and 191,
>> respectively (using ROMCC), with v3 it's 15 and 18. So something's not right
>> somewhere. The other thing is that in v2 and v3, the CPU is only running at
>> 800MHz in memtest, but with the stock BIOS it runs at 1.5GHz, that's
>> probably the reason for the differing cache throughputs. Anyways, I'm diving
>> into both v2 and v3 and trying to track down why this is running so slowly.
> <insert happy dance here>
> From the currently-running memtest86 on coreboot-v3:
> L1 Cache:  128K   3265 MB/s
> Memory  :  480M    240 MB/s


> That's right, faster then v2 :) I've managed to coerce the northbridge into
> running the memory at 200MHz (DDR400) without locking up the system like it
> does in v2, and also to use 1GB of ram, which the fuctory BIOS only sees as
> 512MB, and v2 for some reason trips over. However, it's a mixed blessing,
> even though memtest86 now runs at an acceptable speed, coreboot is still
> running fairly slowly. I'm attaching a patch that brings over mtrr.c from v2
> and hacks it to work with v3, but no sign-off because IMO it's not ready to
> be committed. I'll try booting a FILO payload and a kernel tomorrow, but
> right now it's time for some sleep.

I know it takes a while to try new things, but have you tried a different
debug level.  Switching Serengeti from BIOS_SPEW to BIOS_INFO cuts boot time
by about 10x.  I'm interested if that's true for you too.

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