From 51ce41c0e661fd9cb9207463bcbd920e55b44a62 Mon Sep 17 00:00:00 2001 From: Bill XIE Date: Sun, 29 Mar 2020 21:40:04 +0800 Subject: [PATCH] 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 Reviewed-on: https://review.coreboot.org/c/coreboot/+/39906 Reviewed-by: Angel Pons Tested-by: build bot (Jenkins) --- src/drivers/pc80/rtc/option.c | 36 +++++++++++++++++------------------ 1 file changed, 18 insertions(+), 18 deletions(-) diff --git a/src/drivers/pc80/rtc/option.c b/src/drivers/pc80/rtc/option.c index bb697dfba1..dc78dbbf30 100644 --- a/src/drivers/pc80/rtc/option.c +++ b/src/drivers/pc80/rtc/option.c @@ -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); + } }