diff options
| author | Arthur Heymans <arthur@aheymans.xyz> | 2019-04-14 18:38:35 +0200 |
|---|---|---|
| committer | Martin Roth <martinroth@google.com> | 2019-04-21 23:29:29 +0000 |
| commit | c4772b9fd7fcc29d09d7617dc8cff922118814d7 (patch) | |
| tree | 93087aecbff5988ab88888df0eec86d5fd1d92ed /src/cpu/x86/early_reset.S | |
| parent | 0800194f95933d6337ba2e7900a1f02671aed3ba (diff) | |
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>
Diffstat (limited to 'src/cpu/x86/early_reset.S')
| -rw-r--r-- | src/cpu/x86/early_reset.S | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/src/cpu/x86/early_reset.S b/src/cpu/x86/early_reset.S new file mode 100644 index 0000000000..ec015abe22 --- /dev/null +++ b/src/cpu/x86/early_reset.S @@ -0,0 +1,45 @@ +/* + * 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 |