diff options
Diffstat (limited to 'src/drivers/pc80/rtc/mc146818rtc_boot.c')
-rw-r--r-- | src/drivers/pc80/rtc/mc146818rtc_boot.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/src/drivers/pc80/rtc/mc146818rtc_boot.c b/src/drivers/pc80/rtc/mc146818rtc_boot.c new file mode 100644 index 0000000000..c5cd86ce85 --- /dev/null +++ b/src/drivers/pc80/rtc/mc146818rtc_boot.c @@ -0,0 +1,78 @@ +/* + * 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; version 2 of the License. + * + * 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. + */ + +#include <stdint.h> +#ifdef __ROMCC__ +#include <arch/cbfs.h> +#else +#include <cbfs.h> +#endif +#include <pc80/mc146818rtc.h> +#if IS_ENABLED(CONFIG_USE_OPTION_TABLE) +#include <option_table.h> +#endif + +int cmos_error(void); +int cmos_error(void) +{ + unsigned char reg_d; + /* See if the cmos error condition has been flagged */ + reg_d = cmos_read(RTC_REG_D); + return (reg_d & RTC_VRT) == 0; +} + +int cmos_chksum_valid(void); +int cmos_chksum_valid(void) +{ +#if IS_ENABLED(CONFIG_USE_OPTION_TABLE) + unsigned char addr; + u16 sum, old_sum; + + sum = 0; + /* Compute the cmos checksum */ + for (addr = LB_CKS_RANGE_START; addr <= LB_CKS_RANGE_END; addr++) + sum += cmos_read(addr); + + /* Read the stored checksum */ + old_sum = cmos_read(LB_CKS_LOC) << 8; + old_sum |= cmos_read(LB_CKS_LOC + 1); + + return sum == old_sum; +#else + return 0; +#endif +} + +#if IS_ENABLED(CONFIG_USE_OPTION_TABLE) +void sanitize_cmos(void) +{ + if (cmos_error() || !cmos_chksum_valid() || + IS_ENABLED(CONFIG_STATIC_OPTION_TABLE)) { + size_t length = 128; + const unsigned char *cmos_default = +#ifdef __ROMCC__ + walkcbfs("cmos.default"); +#else + cbfs_boot_map_with_leak("cmos.default", + CBFS_COMPONENT_CMOS_DEFAULT, &length); +#endif + if (cmos_default) { + int i; + cmos_disable_rtc(); + for (i = 14; i < MIN(128, length); i++) + cmos_write_inner(cmos_default[i], i); + cmos_enable_rtc(); + } + } +} +#endif |