[coreboot] New patch to review for coreboot: 63c1148 rtc: erase CMOS memory after power failure

[Stefan Reinauer]

Stefan Reinauer ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/1697

-gerrit

commit 63c1148e53397d73c7c61bc5784349b6a4650d91
Author: Vincent Palatin 
Date:   Tue Aug 7 17:03:40 2012 -0700

rtc: erase CMOS memory after power failure

When a power failure happens on the RTC rail, the CMOS memory (including
    the RTC registers) is filled with garbage.
    So, we erase the full first bank (112 bytes) and we reset the RTC date
    to the build date.

To test, disconnect the CMOS battery to produce an RTC power
    failure, then boot the machine and observe the RTC date is the build
    date using "cat /sys/class/rtc/rtc0/date"

Change-Id: I684bb3ad5079f96825555d4ed84dc0f7914e9884
    Signed-off-by: Vincent Palatin 
---
 Makefile.inc                   |  4 ++++
 src/drivers/pc80/mc146818rtc.c | 34 ++++++++++++++++++++--------------
 2 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/Makefile.inc b/Makefile.inc
index 3f079cd..7d32a96 100644
--- a/Makefile.inc
+++ b/Makefile.inc
@@ -179,6 +179,10 @@ $(obj)/build.h: .xcompile
    printf "#define COREBOOT_VERSION "$(KERNELVERSION)"\n" >> $(obj)/build.ht
    printf "#define COREBOOT_EXTRA_VERSION "$(COREBOOT_EXTRA_VERSION)"\n" >> $(obj)/build.ht
    printf "#define COREBOOT_BUILD "`LANG= date`"\n" >> $(obj)/build.ht
+	printf "#define COREBOOT_BUILD_YEAR `LANG= date +"%-y"`\n" >> $(obj)/build.ht
+	printf "#define COREBOOT_BUILD_MONTH `LANG= date +"%-m"` \n" >> $(obj)/build.ht
+	printf "#define COREBOOT_BUILD_DAY `LANG= date +"%-d"`\n" >> $(obj)/build.ht
+	printf "#define COREBOOT_BUILD_WEEKDAY `LANG= date +"%-u"`\n" >> $(obj)/build.ht
    printf "#define COREBOOT_DMI_DATE "`LANG= date +"%m/%d/%Y"`"\n" >> $(obj)/build.ht
    printf "\n" >> $(obj)/build.ht
    printf "#define COREBOOT_COMPILER "$(shell LANG= $(CC) --version | head -n1)"\n" >> $(obj)/build.ht
diff --git a/src/drivers/pc80/mc146818rtc.c b/src/drivers/pc80/mc146818rtc.c
index efeb378..d832544 100644
--- a/src/drivers/pc80/mc146818rtc.c
+++ b/src/drivers/pc80/mc146818rtc.c
@@ -1,4 +1,5 @@
 #include <stdint.h>
+#include <build.h>
 #include <console/console.h>
 #include <pc80/mc146818rtc.h>
 #include <boot/coreboot_tables.h>
@@ -79,15 +80,14 @@

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? */
+	/* Now setup a default date equals to the build date */
    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);
+	cmos_write(COREBOOT_BUILD_WEEKDAY, RTC_CLK_DAYOFWEEK);
+	cmos_write(COREBOOT_BUILD_DAY, RTC_CLK_DAYOFMONTH);
+	cmos_write(COREBOOT_BUILD_MONTH, RTC_CLK_MINUTE);
+	cmos_write(COREBOOT_BUILD_YEAR, RTC_CLK_YEAR);
    if (has_century) cmos_write(0x20, RTC_CLK_ALTCENTURY);
 }

@@ -129,9 +129,10 @@ static void rtc_set_checksum(int range_start, int range_end, int cks_loc)

void rtc_init(int invalid)
 {
+	int cmos_invalid = 0;
+	int checksum_invalid = 0;
 #if CONFIG_USE_OPTION_TABLE
    unsigned char x;
-	int cmos_invalid, checksum_invalid;
 #endif

printk(BIOS_DEBUG, "RTC Init\n");
@@ -146,17 +147,18 @@ void rtc_init(int invalid)
    		PC_CKS_RANGE_END,PC_CKS_LOC);

#define CLEAR_CMOS 0
+#else
+#define CLEAR_CMOS 1
+#endif
+
    if (invalid || cmos_invalid || checksum_invalid) {
-		printk(BIOS_WARNING, "RTC:%s%s%s%s\n",
-			invalid?" Clear requested":"",
-			cmos_invalid?" Power Problem":"",
-			checksum_invalid?" Checksum invalid":"",
-			CLEAR_CMOS?" zeroing cmos":"");
 #if CLEAR_CMOS
+		int i;
+
    	cmos_write(0, 0x01);
    	cmos_write(0, 0x03);
    	cmos_write(0, 0x05);
-		for(i = 10; i < 48; i++) {
+		for(i = 10; i < 128; i++) {
    		cmos_write(0, i);
    	}

@@ -164,8 +166,12 @@ void rtc_init(int invalid)
    		rtc_update_cmos_date(RTC_HAS_NO_ALTCENTURY);
    	}
 #endif
+		printk(BIOS_WARNING, "RTC:%s%s%s%s\n",
+			invalid?" Clear requested":"",
+			cmos_invalid?" Power Problem":"",
+			checksum_invalid?" Checksum invalid":"",
+			CLEAR_CMOS?" zeroing cmos":"");
    }
-#endif

/* Setup the real time clock */
    cmos_write(RTC_CONTROL_DEFAULT, RTC_CONTROL);