Attention is currently required from: Nico Huber, Subrata Banik, Patrick Rudolph. Sridhar Siricilla has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/61380 )
Change subject: soc/inte/common: Add support to control coreboot and Intel SoC features ......................................................................
Patch Set 2:
(1 comment)
File src/soc/intel/common/block/cse/cse_lite.c:
https://review.coreboot.org/c/coreboot/+/61380/comment/3ab67c19_4976edf7 PS2, Line 666: is_cse_fw_update_enabled
is there any restriction that on after FSI, we can't read the softstrap ?
There is no point enabling the SOC_INTEL_COMMON_BLOCK_DEBUG_FEATURE since we don't want override native coreboot/SoC functionality/features (for example CSE FW update get triggered through debug flag) post FSI and Descriptor Region is Read-only. The intention of SOC_INTEL_COMMON_BLOCK_DEBUG_FEATURE for debug purposes. BTW,SOC_INTEL_COMMON_BLOCK_DEBUG_FEATURE doesn't use soft strap area. It uses unused area (OEM section) as scratch pad.
Are you thinking if this region is locked and what value we will read, will that be always `1` (meaning CSE FW update is enable? in that case, you should opt for cse_fw_update_enable instead `disable`, so if softstrap is locked on production system, it will still read as `enable`/1)
By default, OEM SECTION contains all 0XFF, empty area. If nothing is written to OEM section, when coreboot reads, it gets 0xFF. But, our override logic looks for 1 to control the specific CB/SoC feature.
Hence, guard is required.
Why? to protect it from reading ?
No need to read as we want to withdraw the logic during FSI.
Also, please note SOC_INTEL_COMMON_BLOCK_DEBUG_FEATURE will be used to control >>other SOC/coreboot features as well going forward.
Any pointer about those *other SOC/coreboot features*, unless we have some >visibility it just a vision that you have and we are missing that might be.
I will try to share the feature set we want to control through SOC_INTEL_COMMON_BLOCK_DEBUG_FEATURE flag by next week.