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cpu/x86: Move checking for MTRR's as a proxy for proper CPU reset

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Checking for empty MTRR_DEF_TYPE_MSR as a proxy for proper CPU reset
is common across multiple platforms. Therefore place it in a common
location.

Change-Id: I81d82fb9fe27cd9de6085251fe1a5685cdd651fc
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32319
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-by: Furquan Shaikh <furquan@google.com>
This commit is contained in:
Arthur Heymans
2019-04-14 18:38:35 +02:00
committed by Martin Roth
parent 0800194f95
commit c4772b9fd7
3 changed files with 48 additions and 15 deletions
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1
src/soc/intel/common/block/cpu/Makefile.inc
View File

@@ -1,4 +1,5 @@
bootblock-$(CONFIG_SOC_INTEL_COMMON_BLOCK_CAR) += car/cache_as_ram.S
bootblock-$(CONFIG_SOC_INTEL_COMMON_BLOCK_CAR) += ../../../../../cpu/x86/early_reset.S
bootblock-$(CONFIG_FSP_CAR)+= car/cache_as_ram_fsp.S
bootblock-$(CONFIG_SOC_INTEL_COMMON_BLOCK_CPU) += cpulib.c

17
src/soc/intel/common/block/cpu/car/cache_as_ram.S
View File

@@ -28,21 +28,8 @@ bootblock_pre_c_entry:
post_code(0x20)
/*
* Use the MTRR default type MSR as a proxy for detecting INIT#.
* Reset the system if any known bits are set in that MSR. That is
* an indication of the CPU not being properly reset.
*/
check_for_clean_reset:
mov $MTRR_DEF_TYPE_MSR, %ecx
rdmsr
and $(MTRR_DEF_TYPE_EN | MTRR_DEF_TYPE_FIX_EN), %eax
cmp $0, %eax
jz no_reset
/* perform warm reset */
movw $0xcf9, %dx
movb $0x06, %al
outb %al, %dx
movl $no_reset, %esp /* return address */
jmp check_mtrr /* Check if CPU properly reset */
no_reset:
post_code(0x21)