elog: move functionality to commonlib/bsd

This commit moves some drivers/elog/ functionality to commonlib/bsd
since they will be called from util/cbfstool/.

In particular:
 * elog_fill_timestamp(), elog_update_checksum(), elog_checksum_event()
   were moved to commonlib/bsd/elog
 * elog_fill_timestamp() receives the time parameters and updates the
   event based on the "time" arguments.

The original elog_*() functions were written by Duncan Laurie
(see CB:1311) and he gave permission to re-license the code to BSD.

BUG=b:172210863

Change-Id: I67d5ad6e7c4d486b3d4ebb25be77998173cee5a9
Signed-off-by: Ricardo Quesada <ricardoq@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56985
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

2 files changed, 50 insertions, 2 deletions

diff --git a/src/commonlib/bsd/elog.c b/src/commonlib/bsd/elog.c
index 6c927aaf22..a5e644c4af 100644
--- a/src/commonlib/bsd/elog.c
+++ b/src/commonlib/bsd/elog.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: BSD-3-Clause */
 
+#include <commonlib/bsd/bcd.h>
 #include <commonlib/bsd/elog.h>
 #include <stddef.h>
 
@@ -40,7 +41,48 @@ const struct event_header *elog_get_next_event(const struct event_header *event)
 /* return the data associated to the event_header. */
 const void *event_get_data(const struct event_header *event)
 {
-	// Pointing to the next event returns the data, since data is the first field
-	// right after the header.
+	/*
+	 * Pointing to the next event returns the data, since data is the first
+	 * field right after the header.
+	 */
 	return (const void *)(&event[1]);
 }
+
+/* Populate timestamp in event header with given time. */
+void elog_fill_timestamp(struct event_header *event, uint8_t sec, uint8_t min,
+			 uint8_t hour, uint8_t mday, uint8_t mon, uint8_t year)
+{
+	event->second = bin2bcd(sec);
+	event->minute = bin2bcd(min);
+	event->hour = bin2bcd(hour);
+	event->day = bin2bcd(mday);
+	event->month = bin2bcd(mon);
+	event->year = bin2bcd(year % 100);
+
+	/* Basic check of expected ranges. */
+	if (event->month > 0x12 || event->day > 0x31 || event->hour > 0x23 ||
+	    event->minute > 0x59 || event->second > 0x59) {
+		event->year   = 0;
+		event->month  = 0;
+		event->day    = 0;
+		event->hour   = 0;
+		event->minute = 0;
+		event->second = 0;
+	}
+}
+
+void elog_update_checksum(struct event_header *event, uint8_t checksum)
+{
+	uint8_t *event_data = (uint8_t *)event;
+	event_data[event->length - 1] = checksum;
+}
+
+uint8_t elog_checksum_event(const struct event_header *event)
+{
+	uint8_t index, checksum = 0;
+	const uint8_t *data = (const uint8_t *)event;
+
+	for (index = 0; index < event->length; index++)
+		checksum += data[index];
+	return checksum;
+}
diff --git a/src/commonlib/bsd/include/commonlib/bsd/elog.h b/src/commonlib/bsd/include/commonlib/bsd/elog.h
index 0d41157758..2ac15f0a4f 100644
--- a/src/commonlib/bsd/include/commonlib/bsd/elog.h
+++ b/src/commonlib/bsd/include/commonlib/bsd/elog.h
@@ -313,5 +313,11 @@ struct elog_event_extended_event {
 enum cb_err elog_verify_header(const struct elog_header *header);
 const struct event_header *elog_get_next_event(const struct event_header *event);
 const void *event_get_data(const struct event_header *event);
+void elog_fill_timestamp(struct event_header *event, uint8_t sec, uint8_t min,
+			 uint8_t hour, uint8_t mday, uint8_t mon, uint8_t year);
+/* Update the checksum at the last byte. */
+void elog_update_checksum(struct event_header *event, uint8_t checksum);
+/* Simple byte checksum for events. */
+uint8_t elog_checksum_event(const struct event_header *event);
 
 #endif  /* _COMMONLIB_BSD_ELOG_H_ */