GNUBoot
/
coreboot-kgpe-d16
2
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

drivers/pc80/rtc: Always load cmos.default if measured boot is enabled 

cmos.default used to be loaded only when cmos is needed to be reset,
but conditional loading of CBFS files may change the calculated PCRs
if measurement is hooked on each loading.

In order to resolve this, loadings should be made less conditional,
(if a file might be used, it should be loaded and measured) but the
use of loaded data remains conditional.

Change-Id: If6ea0d1cbaa7d96f7dea7e77b7548ca2b30efe9e
Signed-off-by: Bill XIE <persmule@hardenedlinux.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39906
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
This commit is contained in:
Bill XIE 2020-03-29 21:40:04 +08:00 committed by Patrick Georgi
parent 5117c27cc1
commit 51ce41c0e6
1 changed files with 18 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
src/drivers/pc80/rtc/option.c
View File

@ -239,25 +239,25 @@ int cmos_lb_cks_valid(void)
return cmos_checksum_valid(LB_CKS_RANGE_START, LB_CKS_RANGE_END, LB_CKS_LOC);
}
static void cmos_load_defaults(void)
{
size_t length = 128;
size_t i;
const unsigned char *cmos_default =
cbfs_boot_map_with_leak("cmos.default",
CBFS_COMPONENT_CMOS_DEFAULT, &length);
if (!cmos_default)
return;
u8 control_state = cmos_disable_rtc();
for (i = 14; i < MIN(128, length); i++)
cmos_write_inner(cmos_default[i], i);
cmos_restore_rtc(control_state);
}
void sanitize_cmos(void)
{
if (cmos_error() || !cmos_lb_cks_valid() || CONFIG(STATIC_OPTION_TABLE))
cmos_load_defaults();
const unsigned char *cmos_default;
const bool cmos_need_reset =
CONFIG(STATIC_OPTION_TABLE) || cmos_error() || !cmos_lb_cks_valid();
size_t length = 128;
size_t i;
if (CONFIG(TPM_MEASURED_BOOT) || cmos_need_reset) {
cmos_default = cbfs_boot_map_with_leak("cmos.default",
CBFS_COMPONENT_CMOS_DEFAULT, &length);
if (!cmos_default || !cmos_need_reset)
return;
u8 control_state = cmos_disable_rtc();
for (i = 14; i < MIN(128, length); i++)
cmos_write_inner(cmos_default[i], i);
cmos_restore_rtc(control_state);
}
}