[coreboot-gerrit] Change in coreboot[master]: lib/fmap: Add optional pre-RAM cache

[Julius Werner (Code Review)]

Julius Werner has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/36657 )

Change subject: lib/fmap: Add optional pre-RAM cache
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Patch Set 9:

(1 comment)

Sorry for the issues and thanks to Arthur for taking care of them (CB:36908)!

https://review.coreboot.org/c/coreboot/+/36657/9/src/lib/fmap.c 
File src/lib/fmap.c:

https://review.coreboot.org/c/coreboot/+/36657/9/src/lib/fmap.c@119 
PS9, Line 119: 	if (!region_device_sz(&cache->rdev))
> Suppose car_get_var_ptr returns 0 (e.g. […]

Hmm... yeah, no, I assumed that the result of car_get_var_ptr() was always valid. It seems that FSP 1.0 has some more weird quirks.

If I understand it correctly there might be a way to solve with with the car_get_ptr()/car_set_ptr() stuff, but it would be complicated because the relative pointer into another CAR region is inside the struct mem_region_device, so we'd have to take the whole use of region_device in here apart and open code it instead. I don't think that's worth it, so how about just disabling pre-RAM caching on those platforms? CB:36937