cr50/ec: add a console command to display event logs.

'dlog' console command is introduced, which displays event logs on
console. To activate this command, CONFIG_CMD_DLOG should be defined
in board.h.

'dlog clear' clears all event logs.

BUG=b:63760920
BRANCH=cr50
TEST=manually

> help dlog
Usage: dlog [clear]
Display/clear TPM event logs

> tpm_log 1 0xABCD
> tpm_log 2 0x1234
> dlog
 TIMESTAMP | TYPE |  DATA | SIZE | PAYLOAD
       749      1  0xABCD      0
      8325      2  0x1234      0
> dlog clear
> dlog
 TIMESTAMP | TYPE |  DATA | SIZE | PAYLOAD
>

Change-Id: I313beeb2e5ec04c108296cd4c017d938aab24b0d
Signed-off-by: Namyoon Woo <namyoon@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1454136
Reviewed-by: Mary Ruthven <mruthven@chromium.org>

2 files changed, 69 insertions, 10 deletions

diff --git a/common/event_log.c b/common/event_log.c
index 8da9c31ceb..994967664c 100644
--- a/common/event_log.c
+++ b/common/event_log.c
@@ -4,6 +4,7 @@
  */
 
 #include "common.h"
+#include "console.h"
 #include "event_log.h"
 #include "hooks.h"
 #include "task.h"
@@ -12,9 +13,10 @@
 
 /* Event log FIFO */
 #define UNIT_SIZE sizeof(struct event_log_entry)
-#define LOG_SIZE (CONFIG_EVENT_LOG_SIZE/UNIT_SIZE)
-static struct event_log_entry __bss_slow log_events[LOG_SIZE];
-BUILD_ASSERT(POWER_OF_TWO(LOG_SIZE));
+#define UNIT_COUNT (CONFIG_EVENT_LOG_SIZE/UNIT_SIZE)
+#define UNIT_COUNT_MASK		(UNIT_COUNT - 1)
+static struct event_log_entry __bss_slow log_events[UNIT_COUNT];
+BUILD_ASSERT(POWER_OF_TWO(UNIT_COUNT));
 
 /*
  * The FIFO pointers are defined as following :
@@ -58,25 +60,25 @@ void log_add_event(uint8_t type, uint8_t size, uint16_t data,
 	/* --- end of critical section --- */
 
 	/* Out of space : discard the oldest entry */
-	while ((LOG_SIZE - (current_tail - log_head)) < total_size) {
+	while ((UNIT_COUNT - (current_tail - log_head)) < total_size) {
 		struct event_log_entry *oldest;
 		/* --- critical section : atomically free-up space --- */
 		interrupt_disable();
-		oldest = log_events + (log_head & (LOG_SIZE - 1));
+		oldest = log_events + (log_head & UNIT_COUNT_MASK);
 		log_head += ENTRY_SIZE(EVENT_LOG_SIZE(oldest->size));
 		interrupt_enable();
 		/* --- end of critical section --- */
 	}
 
-	r = log_events + (current_tail & (LOG_SIZE - 1));
+	r = log_events + (current_tail & UNIT_COUNT_MASK);
 
 	r->timestamp = timestamp;
 	r->type = type;
 	r->size = size;
 	r->data = data;
 	/* copy the payload into the FIFO */
-	first = MIN(total_size - 1, (LOG_SIZE -
-		    (current_tail & (LOG_SIZE - 1))) - 1);
+	first = MIN(total_size - 1, (UNIT_COUNT -
+		    (current_tail & UNIT_COUNT_MASK)) - 1);
 	if (first)
 		memcpy(r->payload, payload, first * UNIT_SIZE);
 	if (first < total_size - 1)
@@ -103,9 +105,9 @@ retry:
 		return UNIT_SIZE;
 	}
 
-	entry = log_events + (current_head & (LOG_SIZE - 1));
+	entry = log_events + (current_head & UNIT_COUNT_MASK);
 	total_size = ENTRY_SIZE(EVENT_LOG_SIZE(entry->size));
-	first = MIN(total_size, LOG_SIZE - (current_head & (LOG_SIZE - 1)));
+	first = MIN(total_size, UNIT_COUNT - (current_head & UNIT_COUNT_MASK));
 	memcpy(r, entry, first * UNIT_SIZE);
 	if (first < total_size)
 		memcpy(r + first, log_events, (total_size-first) * UNIT_SIZE);
@@ -125,3 +127,58 @@ retry:
 
 	return total_size * UNIT_SIZE;
 }
+
+#ifdef CONFIG_CMD_DLOG
+/*
+ * Display TPM event logs.
+ */
+static int command_dlog(int argc, char **argv)
+{
+	size_t log_cur;
+	const uint8_t * const log_events_end =
+		(uint8_t *)&log_events[UNIT_COUNT];
+
+	if (argc > 1) {
+		if (!strcasecmp(argv[1], "clear")) {
+			interrupt_disable();
+			log_head = log_tail = log_tail_next = 0;
+			interrupt_enable();
+
+			return EC_SUCCESS;
+		}
+		/* Too many parameters */
+		return EC_ERROR_PARAM1;
+	}
+
+	ccprintf(" TIMESTAMP | TYPE |  DATA | SIZE | PAYLOAD\n");
+	log_cur = log_head;
+	while (log_cur != log_tail) {
+		struct event_log_entry *r;
+		uint8_t *payload;
+		uint32_t payload_bytes;
+
+		r = &log_events[log_cur & UNIT_COUNT_MASK];
+		payload_bytes = EVENT_LOG_SIZE(r->size);
+		log_cur += ENTRY_SIZE(payload_bytes);
+
+		ccprintf("%10d   %4d  0x%04X   %4d   ", r->timestamp, r->type,
+			r->data, payload_bytes);
+
+		/* display payload if exists */
+		payload = r->payload;
+		while (payload_bytes--) {
+			if (payload >= log_events_end)
+				payload = (uint8_t *)&log_events[0];
+
+			ccprintf("%02X", *payload);
+			payload++;
+		}
+		ccprintf("\n");
+	}
+	return EC_SUCCESS;
+}
+DECLARE_CONSOLE_COMMAND(dlog,
+			command_dlog,
+			"[clear]",
+			"Display/clear TPM event logs");
+#endif
diff --git a/common/tpm_registers.c b/common/tpm_registers.c
index 74fff76082..397d067742 100644
--- a/common/tpm_registers.c
+++ b/common/tpm_registers.c
@@ -764,9 +764,11 @@ int tpm_reset_request(int wait_until_done, int wipe_nvmem_first)
 		return EC_ERROR_BUSY;
 	}
 
+#ifdef CONFIG_TPM_LOGGING
 	/* Record input parameters as two bits in the data field. */
 	tpm_log_event(TPM_EVENT_INIT,
 		      (!!wait_until_done << 1) | !!wipe_nvmem_first);
+#endif
 
 	reset_in_progress = 1;
 	wipe_result = EC_SUCCESS;