Zheng Bao (zheng.bao@amd.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/1389
-gerrit
commit 31b06e2259ccfd84e8fe1f5f0bc1b2bcb58c6a28 Author: zbao fishbaozi@gmail.com Date: Thu Aug 2 19:02:26 2012 +0800
RTC: Add a routine to check if the CMOS date is valid
If the CMOS is cleared or someone writes some random date/time on purpose, the CMOS date register has a invalid date. This will hurts some OS, like Windows 7, which hangs at MS logo forever. When we detect that, we need to write a reasonable date in CMOS.
Alexandru Gagniuc: Hmm, it would be interesting to use the date the coreboot image was built and set that as the default date. At least until time travel is invented.
Change-Id: Ic1c7a2d60e711265686441c77bdf7891a7efb42e Signed-off-by: Zheng Bao zheng.bao@amd.com Signed-off-by: zbao fishbaozi@gmail.com --- src/drivers/pc80/mc146818rtc.c | 43 ++++++++++++++++++++++++++++++++------- src/include/pc80/mc146818rtc.h | 5 ++++ 2 files changed, 40 insertions(+), 8 deletions(-)
diff --git a/src/drivers/pc80/mc146818rtc.c b/src/drivers/pc80/mc146818rtc.c index 99d670d..cc14a41 100644 --- a/src/drivers/pc80/mc146818rtc.c +++ b/src/drivers/pc80/mc146818rtc.c @@ -77,6 +77,20 @@ # define RTC_VRT 0x80 /* valid RAM and time */ /**********************************************************************/
+static void rtc_update_cmos_date(u8 has_century) +{ + /* Now setup a default date of Sat 1 January 2000 */ + /* TODO: Set the time as building time? Is it reasonable? */ + cmos_write(0, RTC_CLK_SECOND); + cmos_write(0, RTC_CLK_MINUTE); + cmos_write(1, RTC_CLK_HOUR); + cmos_write(7, RTC_CLK_DAYOFWEEK); + cmos_write(1, RTC_CLK_DAYOFMONTH); + cmos_write(1, RTC_CLK_MINUTE); + cmos_write(0, RTC_CLK_YEAR); + if (has_century) cmos_write(0x20, RTC_CLK_ALTCENTURY); +} + #if CONFIG_USE_OPTION_TABLE static int rtc_checksum_valid(int range_start, int range_end, int cks_loc) { @@ -147,14 +161,7 @@ void rtc_init(int invalid) }
if (cmos_invalid) { - /* Now setup a default date of Sat 1 January 2000 */ - cmos_write(0, 0x00); /* seconds */ - cmos_write(0, 0x02); /* minutes */ - cmos_write(1, 0x04); /* hours */ - cmos_write(7, 0x06); /* day of week */ - cmos_write(1, 0x07); /* day of month */ - cmos_write(1, 0x08); /* month */ - cmos_write(0, 0x09); /* year */ + rtc_update_cmos_date(RTC_HAS_NO_ALTCENTURY); } #endif } @@ -338,3 +345,23 @@ int set_option(const char *name, void *value) return 0; } #endif /* CONFIG_USE_OPTION_TABLE */ + +/* + * If the CMOS is cleared, the rtc_reg has the invalid date. That + * hurts some OSes. Even if we don't set USE_OPTION_TABLE, we need + * to make sure the date is valid. + */ +void rtc_check_update_cmos_date(u8 has_century) +{ + u8 year, century; + + /* Note: We need to check if the hardware supports RTC_CLK_ALTCENTURY. */ + century = has_century ? cmos_read(RTC_CLK_ALTCENTURY) : 0; + year = cmos_read(RTC_CLK_YEAR); + + /* TODO: If century is 0xFF, 100% that the cmos is cleared. + * Other than that, so far rtc_year is the only entry to check if the date is valid. */ + if (century > 0x99 || year > 0x99) { /* Invalid date */ + rtc_update_cmos_date(has_century); + } +} diff --git a/src/include/pc80/mc146818rtc.h b/src/include/pc80/mc146818rtc.h index 9f18ba4..a916761 100644 --- a/src/include/pc80/mc146818rtc.h +++ b/src/include/pc80/mc146818rtc.h @@ -87,6 +87,10 @@ #define RTC_CLK_DAYOFMONTH 7 #define RTC_CLK_MONTH 8 #define RTC_CLK_YEAR 9 +#define RTC_CLK_ALTCENTURY 0x32 + +#define RTC_HAS_ALTCENTURY 1 +#define RTC_HAS_NO_ALTCENTURY 0
/* On PCs, the checksum is built only over bytes 16..45 */ #define PC_CKS_RANGE_START 16 @@ -136,6 +140,7 @@ static inline void cmos_write32(u8 offset, u32 value)
#if !defined(__ROMCC__) void rtc_init(int invalid); +void rtc_check_update_cmos_date(u8 has_century); #if CONFIG_USE_OPTION_TABLE int set_option(const char *name, void *val); int get_option(void *dest, const char *name);