4 files changed, 148 insertions, 0 deletions
diff --git a/src/drivers/elog/Kconfig b/src/drivers/elog/Kconfig
index d61dd108575e..867416cc7729 100644
--- a/src/drivers/elog/Kconfig
+++ b/src/drivers/elog/Kconfig
@@ -67,3 +67,20 @@ config ELOG_SHRINK_SIZE
 	  Default is 1K.
 
 endif
+
+config ELOG_BOOT_COUNT
+	depends on ELOG
+	bool "Maintain a monotonic boot number in CMOS"
+	default n
+	help
+	  Store a monotonic boot number in CMOS and provide an interface
+	  to read the current value and increment the counter.  This boot
+	  counter will be logged as part of the System Boot event.
+
+config ELOG_BOOT_COUNT_CMOS_OFFSET
+	depends on ELOG && ELOG_BOOT_COUNT && !USE_OPTION_TABLE
+	int "Offset in CMOS to store the boot count"
+	default 0
+	help
+	  This value must be greater than 16 bytes so as not to interfere
+	  with the standard RTC region.  Requires 8 bytes.
diff --git a/src/drivers/elog/Makefile.inc b/src/drivers/elog/Makefile.inc
index a01841db967d..32509c8ce0c8 100644
--- a/src/drivers/elog/Makefile.inc
+++ b/src/drivers/elog/Makefile.inc
@@ -1 +1,4 @@
 ramstage-$(CONFIG_ELOG) += elog.c
+
+romstage-$(CONFIG_ELOG_BOOT_COUNT) += boot_count.c
+ramstage-$(CONFIG_ELOG_BOOT_COUNT) += boot_count.c
diff --git a/src/drivers/elog/boot_count.c b/src/drivers/elog/boot_count.c
new file mode 100644
index 000000000000..9ea828d04dd8
--- /dev/null
+++ b/src/drivers/elog/boot_count.c
@@ -0,0 +1,122 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2012 The ChromiumOS Authors.  All rights reserved.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA
+ */
+
+#include <console/console.h>
+#include <ip_checksum.h>
+#include <pc80/mc146818rtc.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <elog.h>
+
+/*
+ * We need a region in CMOS to store the boot counter.
+ *
+ * This can either be declared as part of the option
+ * table or statically defined in the board config.
+ */
+#if CONFIG_USE_OPTION_TABLE
+# include "option_table.h"
+# define BOOT_COUNT_CMOS_OFFSET (CMOS_VSTART_boot_count_offset >> 3)
+#else
+# if defined(CONFIG_ELOG_BOOT_COUNT_CMOS_OFFSET)
+#  define BOOT_COUNT_CMOS_OFFSET CONFIG_ELOG_BOOT_COUNT_CMOS_OFFSET
+# else
+#  error "Must define CONFIG_ELOG_BOOT_COUNT_CMOS_OFFSET"
+# endif
+#endif
+
+#define BOOT_COUNT_SIGNATURE 0x4342 /* 'BC' */
+
+struct boot_count {
+	u16 signature;
+	u32 count;
+	u16 checksum;
+} __attribute__ ((packed));
+
+/* Read and validate boot count structure from CMOS */
+static int boot_count_cmos_read(struct boot_count *bc)
+{
+	u8 i, *p;
+	u16 csum;
+
+	for (p = (u8*)bc, i = 0; i < sizeof(*bc); i++, p++)
+		*p = cmos_read(BOOT_COUNT_CMOS_OFFSET + i);
+
+	/* Verify signature */
+	if (bc->signature != BOOT_COUNT_SIGNATURE) {
+		printk(BIOS_DEBUG, "Boot Count invalid signature\n");
+		return -1;
+	}
+
+	/* Verify checksum over signature and counter only */
+	csum = compute_ip_checksum(bc, offsetof(struct boot_count, checksum));
+
+	if (csum != bc->checksum) {
+		printk(BIOS_DEBUG, "Boot Count checksum mismatch\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+/* Write boot count structure to CMOS */
+static void boot_count_cmos_write(struct boot_count *bc)
+{
+	u8 i, *p;
+
+	/* Checksum over signature and counter only */
+	bc->checksum = compute_ip_checksum(
+		bc, offsetof(struct boot_count, checksum));
+
+	for (p = (u8*)bc, i = 0; i < sizeof(*bc); i++, p++)
+		cmos_write(*p, BOOT_COUNT_CMOS_OFFSET + i);
+}
+
+/* Increment boot count and return the new value */
+u32 boot_count_increment(void)
+{
+	struct boot_count bc;
+
+	/* Read and increment boot count */
+	if (boot_count_cmos_read(&bc) < 0) {
+		/* Structure invalid, re-initialize */
+		bc.signature = BOOT_COUNT_SIGNATURE;
+		bc.count = 0;
+	}
+
+	/* Increment boot counter */
+	bc.count++;
+
+	/* Write the new count to CMOS */
+	boot_count_cmos_write(&bc);
+
+	printk(BIOS_DEBUG, "Boot Count incremented to %u\n", bc.count);
+	return bc.count;
+}
+
+/* Return the current boot count */
+u32 boot_count_read(void)
+{
+	struct boot_count bc;
+
+	if (boot_count_cmos_read(&bc) < 0)
+		return 0;
+
+	return bc.count;
+}
diff --git a/src/drivers/elog/elog.c b/src/drivers/elog/elog.c
index 9c0fa930ad39..12198839070f 100644
--- a/src/drivers/elog/elog.c
+++ b/src/drivers/elog/elog.c
@@ -780,6 +780,12 @@ int elog_init(void)
 		elog_add_event_word(ELOG_TYPE_LOG_CLEAR,
 				    elog_get_flash()->total_size);
 
+#if CONFIG_ELOG_BOOT_COUNT && !defined(__SMM__)
+	/* Log boot count event except in S3 resume */
+	if (acpi_slp_type != 3)
+		elog_add_event_dword(ELOG_TYPE_BOOT, boot_count_read());
+#endif
+
 	return 0;
 }