Introduce message logging support

This adds a buffer for log messages and a 'dmesg' command to
print the messages. The log buffer is implemented as log objects
rather than a string buffer. This makes it easy to implement
limiting the messages, cleaning the buffer and timestamping
the messages.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 100 insertions, 0 deletions

diff --git a/commands/dmesg.c b/commands/dmesg.c
new file mode 100644
index 0000000000..b2bb334e24
--- /dev/null
+++ b/commands/dmesg.c
@@ -0,0 +1,100 @@
+/*
+ * dmesg.c - barebox logbuffer handling
+ *
+ * Copyright (c) 2014 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
+ *
+ * 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 version 2
+ * as published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ */
+#include <common.h>
+#include <malloc.h>
+#include <command.h>
+#include <globalvar.h>
+#include <environment.h>
+#include <getopt.h>
+#include <clock.h>
+
+static int do_dmesg(int argc, char *argv[])
+{
+	int opt, i;
+	int delete_buf = 0, emit = 0;
+	unsigned flags = 0;
+
+	while ((opt = getopt(argc, argv, "ctde")) > 0) {
+		switch (opt) {
+		case 'c':
+			delete_buf = 1;
+			break;
+		case 't':
+			flags |= BAREBOX_LOG_PRINT_TIME;
+			break;
+		case 'd':
+			flags |= BAREBOX_LOG_DIFF_TIME;
+			break;
+		case 'e':
+			emit = 1;
+			break;
+		default:
+			return COMMAND_ERROR_USAGE;
+		}
+	}
+
+	if (emit) {
+		char *buf;
+		int len = 0;
+
+		for (i = optind; i < argc; i++)
+			len += strlen(argv[i]) + 1;
+
+		buf = malloc(len + 2);
+		if (!buf)
+			return -ENOMEM;
+
+		len = 0;
+
+		for (i = optind; i < argc; i++)
+			len += sprintf(buf + len, "%s ", argv[i]);
+
+		*(buf + len) = '\n';
+		*(buf + len + 1) = 0;
+
+		pr_info(buf);
+
+		free(buf);
+
+		return 0;
+	}
+
+	log_print(flags);
+
+	if (delete_buf)
+		log_clean(10);
+
+	return 0;
+}
+
+BAREBOX_CMD_HELP_START(dmesg)
+BAREBOX_CMD_HELP_TEXT("Options:")
+BAREBOX_CMD_HELP_OPT ("-c",		"Delete messages after printing them")
+BAREBOX_CMD_HELP_OPT ("-d",		"Show a time delta to the last message")
+BAREBOX_CMD_HELP_OPT ("-e <msg>",	"Emit a log message")
+BAREBOX_CMD_HELP_OPT ("-t",		"Show timestamp informations")
+BAREBOX_CMD_HELP_END
+
+BAREBOX_CMD_START(dmesg)
+	.cmd	= do_dmesg,
+	BAREBOX_CMD_DESC("Print or control log messages")
+	BAREBOX_CMD_OPTS("[-cdet]")
+	BAREBOX_CMD_GROUP(CMD_GRP_INFO)
+	BAREBOX_CMD_HELP(cmd_dmesg_help)
+BAREBOX_CMD_END