ELOG: Add support for generating SMBIOS type15 table

This standared SMBIOS 0able describes the location and format
of the event log to the OS and applications.  In this case the
pointer is a 32bit physical address pointer to the log in
memory mapped flash.

Look for SMBIOS type15 entry with 'dmidecode -t 15'

Handle 0x0004, DMI type 15, 23 bytes
System Event Log
        Area Length: 4095 bytes
        Header Start Offset: 0x0000
        Header Length: 8 bytes
        Data Start Offset: 0x0008
        Access Method: Memory-mapped physical 32-bit address
        Access Address: 0xFFB6F000
        Status: Valid, Not Full
        Change Token: 0x00000000
        Header Format: OEM-specific
        Supported Log Type Descriptors: 0

Change-Id: I1e7729e604000f197e26e69991a2867e869197a6
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: http://review.coreboot.org/1314
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

2 files changed, 44 insertions, 0 deletions

diff --git a/src/drivers/elog/elog.c b/src/drivers/elog/elog.c
index 8e56b85242..9c0fa930ad 100644
--- a/src/drivers/elog/elog.c
+++ b/src/drivers/elog/elog.c
@@ -20,6 +20,7 @@
 #include <arch/acpi.h>
 #include <console/console.h>
 #include <pc80/mc146818rtc.h>
+#include <smbios.h>
 #include <spi.h>
 #include <spi_flash.h>
 #include <stdint.h>
@@ -677,6 +678,34 @@ static int elog_spi_init(void)
 }
 
 /*
+ * Fill out SMBIOS Type 15 table entry so the
+ * event log can be discovered at runtime.
+ */
+int elog_smbios_write_type15(unsigned long *current, int handle)
+{
+	struct smbios_type15 *t = (struct smbios_type15 *)*current;
+	int len = sizeof(struct smbios_type15);
+
+	memset(t, 0, len);
+	t->type = SMBIOS_EVENT_LOG;
+	t->length = len - 2;
+	t->handle = handle;
+	t->area_length = elog_get_flash()->total_size - 1;
+	t->header_offset = 0;
+	t->data_offset = sizeof(struct elog_header);
+	t->access_method = SMBIOS_EVENTLOG_ACCESS_METHOD_MMIO32;
+	t->log_status = SMBIOS_EVENTLOG_STATUS_VALID;
+	t->change_token = 0;
+	t->address = (u32)elog_get_flash()->backing_store;
+	t->header_format = ELOG_HEADER_TYPE_OEM;
+	t->log_type_descriptors = 0;
+	t->log_type_descriptor_length = 2;
+
+	*current += len;
+	return len;
+}
+
+/*
  * Clear the entire event log
  */
 int elog_clear(void)
diff --git a/src/drivers/elog/elog_internal.h b/src/drivers/elog/elog_internal.h
index 2a6a0b7fc4..6d9a0d4bb5 100644
--- a/src/drivers/elog/elog_internal.h
+++ b/src/drivers/elog/elog_internal.h
@@ -32,6 +32,21 @@ struct elog_header {
 #define ELOG_SIGNATURE			0x474f4c45  /* 'ELOG' */
 #define ELOG_VERSION			1
 
+/* SMBIOS event log header */
+struct event_header {
+	u8 type;
+	u8 length;
+	u8 year;
+	u8 month;
+	u8 day;
+	u8 hour;
+	u8 minute;
+	u8 second;
+} __attribute__ ((packed));
+
+/* SMBIOS Type 15 related constants */
+#define ELOG_HEADER_TYPE_OEM		0x88
+
 typedef enum elog_descriptor_type {
 	ELOG_DESCRIPTOR_UNKNOWN,
 	ELOG_DESCRIPTOR_MEMORY,