stm32mon: add logging capability

When debugging STM32 programming over UART it is very helpful to be
able to analyze the log of exchanges between the programmer and the
chip.

This patch adds a command line option which allows to specify the name
of the file to save the log in.

BRANCH=none
BUG=none
TEST=verified that when -L option is given the appropriate log file is
     created:
  head ../../../chroot/tmp/flash.log
  w:  7f
  r:  79
  w:  02 fd
  r:  79
  r:  01 04 42
  r:  79
  w:  00 ff
  r:  79
  r:  0b 31 00 01 02 11 21 31 44 63 73 82 92
  r:  79

Change-Id: I78f566ce1a70d3e1a2f7df7ea4d049001a7d0b1d
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1168159
Reviewed-by: Mary Ruthven <mruthven@chromium.org>

1 files changed, 84 insertions, 11 deletions

diff --git a/util/stm32mon.c b/util/stm32mon.c
index 3c4e313df2..d52bcf81d5 100644
--- a/util/stm32mon.c
+++ b/util/stm32mon.c
@@ -152,6 +152,57 @@ static void discard_input(int);
 
 #define MIN(a, b) ((a) < (b) ? (a) : (b))
 
+/* On user request save all data exchange with the target in this log file. */
+static FILE *log_file;
+
+/*
+ * Print data into the log file, in hex, 16 bytes per line, prefix the first
+ * line with the value supplied by the caller (usually 'r' or 'w' for
+ * read/write).
+ */
+static void dump_log(const char *prefix, const void *data, size_t count)
+{
+	size_t i;
+
+	fprintf(log_file, "%s: ", prefix);
+	for (i = 0; i < count; i++) {
+		if (i && !(i  % 16))
+			fprintf(log_file, "\n   ");
+		fprintf(log_file, " %02x", ((uint8_t *)data)[i]);
+	}
+
+	if (count % 16)
+		fprintf(log_file, "\n");
+
+	/* Make sure all data is there even in case of aborts/crashes. */
+	fflush(log_file);
+}
+
+/*
+ * Wrappers for standard library read() and write() functions. Add transferred
+ * data to the log if log file is opened.
+ */
+static ssize_t read_wrapper(int fd, void *buf, size_t count)
+{
+	ssize_t rv = read(fd, buf, count);
+
+	if (log_file && (rv > 0))
+		dump_log("r", buf, rv);
+
+	return rv;
+}
+
+static ssize_t write_wrapper(int fd, const void *buf, size_t count)
+{
+	ssize_t rv;
+
+	rv = write(fd, buf, count);
+
+	if (log_file && (rv > 0))
+		dump_log("w", buf, rv);
+
+	return rv;
+}
 int open_serial(const char *port)
 {
 	int fd, res;
@@ -278,7 +329,7 @@ static void discard_input(int fd)
 	/* eat trailing garbage */
 	count_of_zeros = 0;
 	do {
-		res = read(fd, buffer, sizeof(buffer));
+		res = read_wrapper(fd, buffer, sizeof(buffer));
 		if (res > 0) {
 
 			/* Discard zeros in the beginning of the buffer. */
@@ -317,7 +368,7 @@ int wait_for_ack(int fd)
 	uint8_t ack = RESP_ACK;
 
 	while (time(NULL) < deadline) {
-		res = read(fd, &resp, 1);
+		res = read_wrapper(fd, &resp, 1);
 		if ((res < 0) && (errno != EAGAIN)) {
 			perror("Failed to read answer");
 			return -EIO;
@@ -325,13 +376,13 @@ int wait_for_ack(int fd)
 		if (res == 1) {
 			if (resp == RESP_ACK) {
 				if (mode == MODE_SPI) /* Ack the ACK */
-					if (write(fd, &ack, 1) != 1)
+					if (write_wrapper(fd, &ack, 1) != 1)
 						return -EIO;
 				return 0;
 			} else if (resp == RESP_NACK) {
 				fprintf(stderr, "NACK\n");
 				if (mode == MODE_SPI) /* Ack the NACK */
-					if (write(fd, &ack, 1) != 1)
+					if (write_wrapper(fd, &ack, 1) != 1)
 						return -EIO;
 				discard_input(fd);
 				return -EINVAL;
@@ -360,7 +411,8 @@ int send_command(int fd, uint8_t cmd, payload_t *loads, int cnt,
 	int cmd_off = mode == MODE_SPI ? 0 : 1;
 
 	/* Send the command index */
-	res = write(fd, cmd_frame + cmd_off, sizeof(cmd_frame) - cmd_off);
+	res = write_wrapper(fd, cmd_frame + cmd_off,
+			    sizeof(cmd_frame) - cmd_off);
 	if (res <= 0) {
 		perror("Failed to write command frame");
 		return -1;
@@ -392,7 +444,7 @@ int send_command(int fd, uint8_t cmd, payload_t *loads, int cnt,
 		size++;
 		data_ptr = data;
 		while (size) {
-			res = write(fd, data_ptr, size);
+			res = write_wrapper(fd, data_ptr, size);
 			if (res < 0) {
 				perror("Failed to write command payload");
 				free(data);
@@ -418,9 +470,10 @@ int send_command(int fd, uint8_t cmd, payload_t *loads, int cnt,
 	/* Read the answer payload */
 	if (resp) {
 		if (mode == MODE_SPI) /* ignore dummy byte */
-			if (read(fd, resp, 1) < 0)
+			if (read_wrapper(fd, resp, 1) < 0)
 				return -1;
-		while ((resp_size > 0) && (res = read(fd, resp, resp_size))) {
+		while ((resp_size > 0) &&
+		       (res = read_wrapper(fd, resp, resp_size))) {
 			if (res < 0) {
 				perror("Failed to read payload");
 				return -1;
@@ -484,7 +537,7 @@ int init_monitor(int fd)
 
 	while (1) {
 		/* Send the command index */
-		res = write(fd, &init, 1);
+		res = write_wrapper(fd, &init, 1);
 		if (res <= 0) {
 			perror("Failed to write command");
 			return -1;
@@ -931,6 +984,7 @@ static const struct option longopts[] = {
 	{"adapter", 1, 0, 'a'},
 	{"spi", 1, 0, 's'},
 	{"length", 1, 0, 'n'},
+	{"logfile", 1, 0, 'L'},
 	{"offset", 1, 0, 'o'},
 	{"progressbar", 0, 0, 'p'},
 	{NULL, 0, 0, 0}
@@ -941,7 +995,8 @@ void display_usage(char *program)
 	fprintf(stderr,
 		"Usage: %s [-a <i2c_adapter> [-l address ]] | [-s]"
 		" [-d <tty>] [-b <baudrate>]] [-u] [-e] [-U]"
-		" [-r <file>] [-w <file>] [-o offset] [-l length] [-g] [-p]\n",
+		" [-r <file>] [-w <file>] [-o offset] [-n length] [-g] [-p]"
+		" [-L <log_file>]\n",
 		program);
 	fprintf(stderr, "Can access the controller via serial port or i2c\n");
 	fprintf(stderr, "Serial port mode:\n");
@@ -965,6 +1020,8 @@ void display_usage(char *program)
 	fprintf(stderr, "--g[o] : jump to execute flash entrypoint\n");
 	fprintf(stderr, "--p[rogressbar] : use a progress bar instead of "
 			"the spinner\n");
+	fprintf(stderr, "-L[ogfile] <file> : save all communications exchange "
+		"in a log file\n");
 
 	exit(2);
 }
@@ -995,8 +1052,9 @@ int parse_parameters(int argc, char **argv)
 {
 	int opt, idx;
 	int flags = 0;
+	const char *log_file_name = NULL;
 
-	while ((opt = getopt_long(argc, argv, "a:l:b:d:eghn:o:pr:s:w:uU?",
+	while ((opt = getopt_long(argc, argv, "a:l:b:d:eghL:n:o:pr:s:w:uU?",
 				  longopts, &idx)) != -1) {
 		switch (opt) {
 		case 'a':
@@ -1023,6 +1081,9 @@ int parse_parameters(int argc, char **argv)
 		case '?':
 			display_usage(argv[0]);
 			break;
+		case 'L':
+			log_file_name = optarg;
+			break;
 		case 'n':
 			length = strtol(optarg, NULL, 0);
 			break;
@@ -1050,6 +1111,15 @@ int parse_parameters(int argc, char **argv)
 			break;
 		}
 	}
+
+	if (log_file_name) {
+		log_file = fopen(log_file_name, "w");
+		if (!log_file) {
+			fprintf(stderr, "failed to open %s for writing\n",
+				log_file_name);
+			exit(2);
+		}
+	}
 	return flags;
 }
 
@@ -1130,6 +1200,9 @@ int main(int argc, char **argv)
 	/* Normal exit */
 	ret = 0;
 terminate:
+	if (log_file)
+		fclose(log_file);
+
 	/* Close serial port */
 	close(ser);
 	return ret;