Rudolf Marek escribió: > >> 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?! >> >> > > There is a multiplexer on SMBus, this confirms my theory. Please check > the GPIO. > > Imagine the multiplexer acts as some kind of rail switch. The > transactions on smbus never reach thhe memory chips (the SPD eeprom). > You need to find a pin to control the multiplexer. > > Rudolf Thanks, because of your hints I was able to figure out that I needed to set up the spd_rom in romstage.c I also added the GPIOs settings as read from vendor BIOS and now the power on led works :).
thx, Knut Kujat. > > > >> 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. >> >> THX, >> 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 >>>> >>>> >>> >> >> > > > -- coreboot mailing list: [email protected] http://www.coreboot.org/mailman/listinfo/coreboot
