tree ee33bd6e144c36ad598765673f2602c2acf03f8f
parent e3a079cff89b8101d0b0a3a77938bd1c6ddaf752
author Arthur Heymans <arthur@aheymans.xyz> 1620631411 +0200
committer Werner Zeh <werner.zeh@siemens.com> 1622193186 +0000

cpu/x86/entry16.S: Make Intel CBnT TOCTOU safe

Intel CBnT (and Boot Guard) makes the chain of trust TOCTOU safe by
setting up NEM (non eviction mode) in the ACM. The CBnT IBB (Initial
BootBlock) therefore should not disable caching.

Sidenote: the MSR macros are taken from the slimbootloader project.

TESTED: ocp/Deltalake boot with and without CBnT and also a broken
CBnT setup.

Change-Id: Id2031e4e406655e14198e45f137ba152f8b6f567
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/54010
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Christian Walter <christian.walter@9elements.com>