Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/38512 )
Change subject: soc/intel/skylake: Only reserve TPM area for !CONFIG_TPM_CR50 device ......................................................................
Patch Set 3:
(1 comment)
https://review.coreboot.org/c/coreboot/+/38512/3/src/soc/intel/skylake/acpi/... File src/soc/intel/skylake/acpi/systemagent.asl:
https://review.coreboot.org/c/coreboot/+/38512/3/src/soc/intel/skylake/acpi/... PS3, Line 185: #if !CONFIG(TPM_CR50)
'#if CONFIG(LPC_TPM)' is not necessarily correct either. I believe we need a semantic that specifically indicates memory mapped TPM that conforms to the PC client TPM spec (didn't want to locate the exact one).
Yes, if we wanted to advertise memory-mapped TPM support. But isn't it that we advertise here what is decoded (no matter if there is a device behind it)?
For instance, if the PCH does positively decode it, the OS would have to avoid that range for resource allocation. It can only do that if we tell it to.
I couldn't find any clue in the EDS, if the decoding is conditional. Should we risk anything just to make some log look nicer?