soc/intel/apollolake: Set default memory type to uncacheable

Set the default memory type in MTRRCap register to 0. This ensures
that even if the MTRR Enable bit is set in MTRRCap register, the
default memory type is still uncacheable.

Change-Id: I63e7993f8b65dabbab60e7c1bb8d6d89ef4da9ee
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/14428
Tested-by: build bot (Jenkins)
Reviewed-by: Andrey Petrov <andrey.petrov@intel.com>
This commit is contained in:
Furquan Shaikh 2016-04-19 15:49:23 -07:00
parent defbdcf3e5
commit 581c42807d
1 changed files with 3 additions and 1 deletions

View File

@ -63,7 +63,9 @@ clear_var_mtrr:
/* Configure default memory type to uncacheable (UC) */
mov $MTRR_DEF_TYPE_MSR, %ecx
rdmsr
and $MTRR_DEF_TYPE_MASK, %eax
/* Clear enable bits and set default type to UC. */
and $~(MTRR_DEF_TYPE_MASK | MTRR_DEF_TYPE_EN | \
MTRR_DEF_TYPE_FIX_EN), %eax
wrmsr
post_code(0x24)