[coreboot] Supermicro H8QME-2+ mct_d fatal exit.

Knut Kujat knuku at gap.upv.es
Wed Mar 10 17:26:47 CET 2010


I finally know that my issue must be related with the smbus registers
because on a vendor bios running machine and using i2cdetect and i2cdump
I get several values for different i2c devices detected, I get the same
values when I successfully start with coreboot. But when I start with
coreboot and fail with mcr_d fatal exit those registers are blank, I
know that because I found a nice piece of code dumping smbus registers
on the h8dme board :D thx to the autor!!

I also know that reading these registers out may cause them to get lost!
I'm not sure why?!

Now my question is how do I initialize these registers with the values
known from the vendor BIOS? smb_write_byte doesn't seems to work or
maybe I'm using it wrong.

Knut Kujat.

Knut Kujat escribió:
> Hello,
> thx all of you for your comments. Here a little update :)
> I now know why the boards worked just fine up here in my lab. To know if
> the board would work after being unplugged I always "only" unplugged the
> electrical cable but never the monitor attached to the board I figured
> out that the monitor is providing enough juice to maintain whatever
> alive in the board so after plugging the electrical cable on again
> coreboot started fine. Another thing I figured out is that it seems that
> the front leds of the board a managed by GPIO as well, is this right? If
> so it seems that something is wrong with GPIO because the power on led
> never works with coreboot.
> thx,
> Knut Kujat.
> ron minnich escribió:
>> Just FYI:
>> on our first system with Arima boards in 2002, everything worked well
>> until we started booting 64-bit kernels. I'm not kidding. We did not
>> find the SMBUS MUX on the boards until we had unreliable coreboot
>> boots of 64-bit kernels. For quite some time the boards worked fine.
>> Ollie found the SMBUS MUX by examining schematics.
>> So the SMBUS mux can appear in strange ways, at strange times. This
>> sounds like one of those times. SMBUS muxes are more common than you
>> might think and the default power-on state is not always very well
>> determined.
>> ron

More information about the coreboot mailing list