coreboot-kgpe-d16/src/cpu/x86/early_reset.S
Arthur Heymans c4772b9fd7 cpu/x86: Move checking for MTRR's as a proxy for proper CPU reset
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>
2019-04-21 23:29:29 +00:00

45 lines
1.2 KiB
ArmAsm

/*
* This file is part of the coreboot project.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
/*
* input %esp: return address (not pointer to return address!)
* clobber the content of eax, ecx, edx
*/
#include <cpu/x86/mtrr.h>
.section .text
.global check_mtrr
check_mtrr:
/* 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:
movl $MTRR_DEF_TYPE_MSR, %ecx
rdmsr
andl $(MTRR_DEF_TYPE_EN | MTRR_DEF_TYPE_FIX_EN), %eax
cmp $0, %eax
jnz warm_reset
jmp *%esp
/* perform warm reset */
warm_reset:
movw $0xcf9, %dx
movb $0x06, %al
outb %al, %dx
/* Should not reach this*/
.Lhlt:
hlt
jmp .Lhlt