[coreboot] Issues with Supermicro H8SCM

[Samir Ibradžić]

Hello Kerry, Thomas, Marc,

I got this board for a personal server project, as well as test platform 
to dive into coreboot. Board is H8SCM-F rev 1.02, one with BMC. Had 
build nice external FT2232 programmer for bailing out of broken flash 
situation, works great. I've experimented with recent coreboot revision, 
ea5c2b6 + Kerry's AGESA patches (thanks a bunch!), and had experienced 
same problem as Thomas, plus some more;

1. Two DIMMs in dual-channel setup wont work, same issue as Thomas, 
2x4GB ECC DIMMs here.

2. After booting via coreboot with same Linux distro, SR5850 NorthBridge 
heatsink instantly gets much more hot than booting via SuperMicro BIOS. 
The temperature is MUCH higher, on idle system, though i can not measure 
this by other method than putting my finger there, and i got instantly 
BURNED when coreboot is being used. I am afraid to fry my board if it 
runs longer this way, it is really that hot.

3. HPET is not being reported at all by coreboot ACPI, OS timer 
precision suffers big deal. Dont know if this is a feature or bug? Dmesg 
clearly shows the difference, all these lines are missing when booting 
via coreboot:

# dmesg | grep -i hpet
[    0.000000] ACPI: HPET 00000000cfeaa5e0 00038 (v01 062911 OEMHPET 
20110629 MSFT 00000097)
[    0.000000] ACPI: HPET id: 0x8300 base: 0xfed00000
[    0.000000] hpet clockevent registered
[    1.132106] hpet0: at MMIO 0xfed00000, IRQs 2, 8, 0, 0
[    1.140072] hpet0: 4 comparators, 32-bit 14.318180 MHz counter
[    1.146104] Switching to clocksource hpet
[    3.499557] rtc0: alarms up to one month, y3k, 114 bytes nvram, hpet irqs

4. CPU (got 4170 HE) frequency scaling only goes as low as 1800MHz in 
coreboot when idle. SuperMicro BIOS easily goes all the way down to 
800MHz. Spotted this in /proc/cpuinfo

5. USB/EHCI - i haven't really tested this, but it seems minor compared 
to 1 & 2.

Now, i know this board is not exactly supported, most probably being an 
AGESA problem, but i would really like to do my best to help to make it 
work better if possible.


@ Kerry,

I was trying to analyze some AGESA code to get to the DIMM problem, but 
most of it is a mystery to me. Could you please point me to the right 
place for "DRAM training" in the code, i am willing to invest some time 
and nerves to test & investigate this, as well as NB overheating 
problem. Any plans to update those AGESA patches for this board?

One strange thing about RAM init is that the coreboot somehow thinks the 
board has 8 slots, but it has only four (there should be no channels 2 & 3);

Socket 0 Channel 0 Dimm 0 found dimm: 00400745
Socket 0 Channel 0 Dimm 1 not found dimm
Socket 0 Channel 1 Dimm 0 found dimm: 00400947
Socket 0 Channel 1 Dimm 1 not found dimm
Socket 0 Channel 2 Dimm 0 not found dimm
Socket 0 Channel 2 Dimm 1 not found dimm
Socket 0 Channel 3 Dimm 0 not found dimm
Socket 0 Channel 3 Dimm 1 not found dimm
  Dct 0 Channel 0
   RegDimmPresent:    1
   SODimmPresent:     0
   ChDimmValid:       1
   DimmPlPresent:     0
   DimmQrPresent:     0
   DimmDrPresent:     0
   DimmSRPresent:     1
   Dimmx4Present:     1
   DimmX8Present:     0
   DimmX16Present:    0
   DimmMirrorPresent: 0
  Dct 1 Channel 0
   RegDimmPresent:    1
   SODimmPresent:     0
   ChDimmValid:       1
   DimmPlPresent:     0
   DimmQrPresent:     0
   DimmDrPresent:     0
   DimmSRPresent:     1
   Dimmx4Present:     1
   DimmX8Present:     0
   DimmX16Present:    0
   DimmMirrorPresent: 0
ASSERTION FAILED: file 
'src/vendorcode/amd/agesa/f10/Proc/Mem/Main/C32/mmflowC32.c',  line 163


Thanks,
Samir