Add microsecond boot time measurement

This defines the basics of a new boot time measurement feature. This allows
logging of very accurate time measurements as the boot proceeds, by using
an available microsecond counter.

To enable the feature, define CONFIG_BOOTSTAGE in your board config file.
Also available is CONFIG_BOOTSTAGE_REPORT which will cause a report to be
printed just before handing off to the OS.

BUG=chromium-os:13875
TEST=build and boot, check that progress is reported before running Linux:

Timer summary in microseconds:
       Mark    Elapsed  Stage
          0          0  awake
  2,181,078  2,181,078  usb_start
 11,861,817  9,680,739  bootp_start
 11,884,610     22,793  bootp_stop
 11,884,689         79  tftp start
 15,271,536  3,386,847  tftp done
 15,271,568         32  bootm_start
 15,406,551    134,983  start_kernel

Change-Id: I71b89c8402dc5dec75e68333bd24a6bab7500a1b
Reviewed-on: http://gerrit.chromium.org/gerrit/197
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>

1 files changed, 98 insertions, 0 deletions

diff --git a/common/bootstage.c b/common/bootstage.c
new file mode 100644
index 0000000000..6fd0083a68
--- /dev/null
+++ b/common/bootstage.c
@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2011, Google Inc. All rights reserved.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * 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; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+
+/*
+ * This module records the progress of boot and arbitrary commands, and
+ * permits accurate timestamping of each. The records can optionally be
+ * passed to kernel in the ATAGs
+ */
+
+#include <common.h>
+
+
+struct bootstage_record {
+	uint32_t time_us;
+	const char *name;
+};
+
+static struct bootstage_record record[BOOTSTAGE_COUNT];
+
+uint32_t bootstage_mark(enum bootstage_id id, const char *name)
+{
+	struct bootstage_record *rec = &record[id];
+
+	/* Only record the first event for each */
+	if (!rec->name) {
+		rec->time_us = (uint32_t)timer_get_us();
+		rec->name = name;
+	}
+	return rec->time_us;
+}
+
+static void print_time(unsigned long us_time)
+{
+	char str[12], *s;
+	int grab = 3;
+
+	/* We don't seem to have %'d in U-Boot */
+	sprintf(str, "%9ld", us_time);
+	for (s = str; *s; s += grab) {
+		if (s != str)
+			putc(s[-1] != ' ' ? ',' : ' ');
+		printf("%.*s", grab, s);
+		grab = 3;
+	}
+}
+
+static uint32_t print_time_record(enum bootstage_id id,
+			struct bootstage_record *rec, uint32_t prev)
+{
+	print_time(rec->time_us);
+	print_time(rec->time_us - prev);
+	if (rec->name)
+		printf("  %s\n", rec->name);
+	else
+		printf("  id=%d\n", id);
+	return rec->time_us;
+}
+
+void bootstage_report(void)
+{
+	int id;
+	uint32_t prev;
+
+	puts("Timer summary in microseconds:\n");
+	printf("%11s%11s  %s\n", "Mark", "Elapsed", "Stage");
+
+	/* Fake the first record - we could get it from early boot */
+	prev = 0;
+	record[BOOTSTAGE_AWAKE].name = "awake";
+
+	for (id = 0; id < BOOTSTAGE_COUNT; id++) {
+		struct bootstage_record *rec = &record[id];
+
+		if (id == BOOTSTAGE_AWAKE || rec->time_us != 0)
+			prev = print_time_record(id, rec, prev);
+	}
+}
+