[coreboot-gerrit] Change in coreboot[master]: arch/x86: Add postcar_frame_add_ramcache() API

[Subrata Banik (Code Review)]

Subrata Banik has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/34805 )

Change subject: arch/x86: Add postcar_frame_add_ramcache() API
......................................................................

Patch Set 1:

(1 comment)

https://review.coreboot.org/c/coreboot/+/34805/1/src/arch/x86/postcar_loader... 
File src/arch/x86/postcar_loader.c:

https://review.coreboot.org/c/coreboot/+/34805/1/src/arch/x86/postcar_loader... 
PS1, Line 135: MTRR_TYPE_WRPROT
> anything >12MB size is causing

again back into same understanding that marking top_of_ram 16MB as WB is causing hang while jumping into postcar entry.

As per my understanding cache lines are getting invalided as it might be full by this time.

< 12MB is helping because my postcar is loading somewhere >12MB size in top_of_ram hence accessing those memory might not reflect into caching. if the moment i have marked the area where postcar supposed to get loaded (>12MB), i'm seeing hang.

Aaron, any idea what we should do here?