Port cmos.default handling to C environment bootblock

Gather related code in the new file drivers/pc80/rtc/mc146818rtc_boot.c,
call sanitize_cmos() from C environment bootblock.

Change-Id: Ia5c64de208a5986299c0508d0e11eeb8473deef1
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/20768
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/drivers/pc80/rtc/Makefile.inc

@@ -1,5 +1,6 @@
 ifeq ($(CONFIG_ARCH_X86),y)
 
+bootblock-$(CONFIG_DRIVERS_MC146818)	+= mc146818rtc_boot.c
 bootblock-$(CONFIG_DRIVERS_MC146818)	+= mc146818rtc.c
 postcar-$(CONFIG_DRIVERS_MC146818)	+= mc146818rtc.c
 romstage-$(CONFIG_DRIVERS_MC146818)	+= mc146818rtc.c

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

src/drivers/pc80/rtc/mc146818rtc_romcc.c

@@ -1,43 +1,13 @@
 #include <stdint.h>
 #include <pc80/mc146818rtc.h>
 #include <fallback.h>
-#if IS_ENABLED(CONFIG_USE_OPTION_TABLE)
-#include "option_table.h"
-#endif
+
+#include "mc146818rtc_boot.c"
 
 #if  CONFIG_MAX_REBOOT_CNT > 15
 #error "CONFIG_MAX_REBOOT_CNT too high"
 #endif
 
-static 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;
-}
-
-static 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
-}
-
 static inline __attribute__((unused)) int boot_count(uint8_t rtc_byte)
 {
 	return rtc_byte >> 4;