I just sent in this patch to bring ACPI to p3b-f, after way too long:
https://review.coreboot.org/c/coreboot/+/41098
I've run into two problems with this work and hoping for insights.
First, Linux kernel is throwing a warning. Full dmesg (from kernel start to prompt) attached, but it's these lines in particular:
[ 5.977786] ACPI Warning: SystemIO range 0x0000000000000F00-0x0000000000000F07 conflicts with OpRegion 0x0000000000000F00-0x0000000000000F06 (\SM00) (20150930/utaddress-254) [ 5.978202] ACPI: If an ACPI driver is available for this device, you should use it instead of the native driver
It is probably related to some SMBus manipulation I imported from OEM firmware that is going to be needed for S3 suspend - It actually has code to talk to an onboard proprietary ASIC over SMBus to blink the power LED and turn off the fan among other things. I later dumped the coreboot SSDT and found that it wrote a device claiming the PIIX4 PM/SMBus ports, so I revised my other patch to completely drop mine, but the conflict remains. Now I can't pinpoint where the conflict comes from.
Second, the command I needed to run to enable flashrom no longer works. i2cset simply said "Write failed". I have to completely disable ACPI to be able to flash. The two problems may be related, but I can't tell for sure.
One thing I could do for the second problem is to do the sequence in mainboard ramstage init, but it depends on the southbridge GPO setting to put that chip into the right state. How are these device enable hooks ordered? Does all southbridge hooks get run first before mainboard hooks?
Thanks for your help Keith