[PATCH BlueZ 0/3] Receiving monitor data stream over RTT

[PATCH BlueZ 0/3] Receiving monitor data stream over RTT

[Andrzej Kaczmarek]

Hi,

Here's patch series which adds support for receiving monitor data stream over
Segger RTT channel. This allows to stream data from embedded device without
need to spare a UART for monitor data and is also much faster. It is now
supported by Apache Mynewt (NimBLE stack), but I believe it can be also added
to other RTOS-es like Zephyr Project.

RTT is handled natively by talking to J-Link via libjlinkarm.so. Since there
is no public documentation for this library, interface was done mostly by
trial and error so it may be lacking something - I tried it with few Cortex-M
devices and it works smoothly.

Both J-Link and RTT needs few configuration parameters to work so I combined
them into two command line options:
  -J --jlink <device>,<interface>,<speed>,<serialno>
  -R --rtt <address>,<area>,<buffer>

<device> - one of devices supported by J-Link (no default)
<interface> - only 'swd' supported for now (default: swd)
<speed> - interface speed (default: 1000)
<serialno> - emu serial number or 0 if not used (detault: 0)
<address> - RTT control block address (default: 0)
<area> - RTT control block search area length (default: 0)
<buffer> - RTT buffer name with monitor data stream (default: monitor)


Andrzej Kaczmarek (3):
  monitor: Extract TTY data processing to separate function
  monitor: Add interface for J-Link library
  monitor: Add support for reading over J-Link RTT

 Makefile.tools    |   3 +-
 monitor/control.c |  87 +++++++++++++----
 monitor/control.h |   1 +
 monitor/jlink.c   | 282 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 monitor/jlink.h   |  27 ++++++
 monitor/main.c    |  30 +++++-
 6 files changed, 409 insertions(+), 21 deletions(-)
 create mode 100644 monitor/jlink.c
 create mode 100644 monitor/jlink.h

-- 
2.16.2

[PATCH BlueZ 1/3] monitor: Extract TTY data processing to separate function

[Andrzej Kaczmarek]

---
 monitor/control.c | 37 +++++++++++++++++++++----------------
 1 file changed, 21 insertions(+), 16 deletions(-)

diff --git a/monitor/control.c b/monitor/control.c
index 1cd79ca5d..98f414be9 100644
--- a/monitor/control.c
+++ b/monitor/control.c
@@ -1262,23 +1262,8 @@ static bool tty_parse_header(uint8_t *hdr, uint8_t len, struct timeval **tv,
 	return true;
 }
 
-static void tty_callback(int fd, uint32_t events, void *user_data)
+static void process_data(struct control_data *data)
 {
-	struct control_data *data = user_data;
-	ssize_t len;
-
-	if (events & (EPOLLERR | EPOLLHUP)) {
-		mainloop_remove_fd(data->fd);
-		return;
-	}
-
-	len = read(data->fd, data->buf + data->offset,
-					sizeof(data->buf) - data->offset);
-	if (len < 0)
-		return;
-
-	data->offset += len;
-
 	while (data->offset >= sizeof(struct tty_hdr)) {
 		struct tty_hdr *hdr = (struct tty_hdr *) data->buf;
 		uint16_t pktlen, opcode, data_len;
@@ -1318,6 +1303,26 @@ static void tty_callback(int fd, uint32_t events, void *user_data)
 	}
 }
 
+static void tty_callback(int fd, uint32_t events, void *user_data)
+{
+	struct control_data *data = user_data;
+	ssize_t len;
+
+	if (events & (EPOLLERR | EPOLLHUP)) {
+		mainloop_remove_fd(data->fd);
+		return;
+	}
+
+	len = read(data->fd, data->buf + data->offset,
+					sizeof(data->buf) - data->offset);
+	if (len < 0)
+		return;
+
+	data->offset += len;
+
+	process_data(data);
+}
+
 int control_tty(const char *path, unsigned int speed)
 {
 	struct control_data *data;
-- 
2.16.2

[PATCH BlueZ 2/3] monitor: Add interface for J-Link library

[Andrzej Kaczmarek]

This adds simple interface to libjlinkarm.so which will be used to read
data from RTT buffer. It was mostly made by trial and error since there
is no public documentation for this library so it may lack something,
but seems to work fine with few Cortex-M devices I tried.
---
 monitor/jlink.c | 282 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 monitor/jlink.h |  27 ++++++
 2 files changed, 309 insertions(+)
 create mode 100644 monitor/jlink.c
 create mode 100644 monitor/jlink.h

diff --git a/monitor/jlink.c b/monitor/jlink.c
new file mode 100644
index 000000000..5470c2db8
--- /dev/null
+++ b/monitor/jlink.c
@@ -0,0 +1,282 @@
+/*
+ *
+ *  BlueZ - Bluetooth protocol stack for Linux
+ *
+ *  Copyright (C) 2018  Codecoup
+ *
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library 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
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <dlfcn.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "jlink.h"
+
+#define RTT_CONTROL_START		0
+#define RTT_CONTROL_STOP		1
+#define RTT_CONTROL_GET_DESC		2
+#define RTT_CONTROL_GET_NUM_BUF		3
+#define RTT_CONTROL_GET_STAT		4
+
+#define RTT_DIRECTION_UP		0
+#define RTT_DIRECTION_DOWN		1
+
+static const char * const jlink_so_name[] = {
+	"/usr/lib/libjlinkarm.so",
+	"/usr/lib/libjlinkarm.so.6",
+	"/opt/SEGGER/JLink/libjlinkarm.so",
+	"/opt/SEGGER/JLink/libjlinkarm.so.6",
+};
+
+struct rtt_desc {
+	uint32_t index;
+	uint32_t dummy;
+	char name[32];
+	uint32_t size;
+	uint32_t flags;
+};
+
+static struct rtt_desc rtt_desc;
+
+typedef int (*jlink_emu_selectbyusbsn_func) (unsigned int sn);
+typedef int (*jlink_open_func) (void);
+typedef int (*jlink_execcommand_func) (char *in, char *out, int size);
+typedef int (*jlink_tif_select_func) (int);
+typedef void (*jlink_setspeed_func) (long int speed);
+typedef int (*jlink_connect_func) (void);
+typedef unsigned int (*jlink_getsn_func) (void);
+typedef void (*jlink_emu_getproductname_func) (char *out, int size);
+typedef int (*jlink_rtterminal_control_func) (int cmd, void *data);
+typedef int (*jlink_rtterminal_read_func) (int cmd, char *buf, int size);
+
+struct jlink {
+	jlink_emu_selectbyusbsn_func emu_selectbyusbsn;
+	jlink_open_func open;
+	jlink_execcommand_func execcommand;
+	jlink_tif_select_func tif_select;
+	jlink_setspeed_func setspeed;
+	jlink_connect_func connect;
+	jlink_getsn_func getsn;
+	jlink_emu_getproductname_func emu_getproductname;
+	jlink_rtterminal_control_func rtterminal_control;
+	jlink_rtterminal_read_func rtterminal_read;
+};
+
+static struct jlink jlink;
+
+#ifndef NELEM
+#define NELEM(x) (sizeof(x) / sizeof((x)[0]))
+#endif
+
+int jlink_init(void)
+{
+	void *so;
+	unsigned int i;
+
+	for (i = 0; i < NELEM(jlink_so_name); i++) {
+		so = dlopen(jlink_so_name[i], RTLD_LAZY);
+		if (so)
+			break;
+	}
+
+	if (!so)
+		return -EIO;
+
+	jlink.emu_selectbyusbsn = dlsym(so, "JLINK_EMU_SelectByUSBSN");
+	jlink.open = dlsym(so, "JLINK_Open");
+	jlink.execcommand = dlsym(so, "JLINK_ExecCommand");
+	jlink.tif_select = dlsym(so, "JLINK_TIF_Select");
+	jlink.setspeed = dlsym(so, "JLINK_SetSpeed");
+	jlink.connect = dlsym(so, "JLINK_Connect");
+	jlink.getsn = dlsym(so, "JLINK_GetSN");
+	jlink.emu_getproductname = dlsym(so, "JLINK_EMU_GetProductName");
+	jlink.rtterminal_control = dlsym(so, "JLINK_RTTERMINAL_Control");
+	jlink.rtterminal_read = dlsym(so, "JLINK_RTTERMINAL_Read");
+
+	if (!jlink.emu_selectbyusbsn || !jlink.open || !jlink.execcommand ||
+			!jlink.tif_select || !jlink.setspeed ||
+			!jlink.connect || !jlink.getsn ||
+			!jlink.emu_getproductname ||
+			!jlink.rtterminal_control || !jlink.rtterminal_read)
+		return -EIO;
+
+	return 0;
+}
+
+int jlink_connect(char *cfg)
+{
+	const char *device = NULL;
+	int tif = 1;
+	unsigned int speed = 1000;
+	unsigned int serial_no = 0;
+	char *tok;
+	char buf[64];
+
+	tok = strtok(cfg, ",");
+	device = tok;
+
+	tok = strtok(NULL, ",");
+	if (!tok)
+		goto connect;
+	if (strlen(tok)) {
+		if (!strcasecmp("swd", tok))
+			tif = 1;
+		else
+			return -EINVAL;
+	}
+
+	tok = strtok(NULL, ",");
+	if (!tok)
+		goto connect;
+	if (strlen(tok))
+		speed = atoi(tok);
+
+	tok = strtok(NULL, ",");
+	if (!tok)
+		goto connect;
+	if (strlen(tok))
+		serial_no = atoi(tok);
+
+connect:
+	if (serial_no)
+		if (jlink.emu_selectbyusbsn(serial_no) < 0) {
+			fprintf(stderr, "Failed to select emu by SN\n");
+			return -ENODEV;
+		}
+
+	if (jlink.open() < 0) {
+		fprintf(stderr, "Failed to open J-Link\n");
+		return -ENODEV;
+	}
+
+	snprintf(buf, sizeof(buf), "device=%s", device);
+	if (jlink.execcommand(buf, NULL, 0) < 0) {
+		fprintf(stderr, "Failed to select target device\n");
+		return -ENODEV;
+	}
+
+	if (jlink.tif_select(tif) < 0) {
+		fprintf(stderr, "Failed to select target interface\n");
+		return -ENODEV;
+	}
+
+	jlink.setspeed(speed);
+
+	if (jlink.connect() < 0) {
+		fprintf(stderr, "Failed to open target\n");
+		return -EIO;
+	}
+
+	serial_no = jlink.getsn();
+	jlink.emu_getproductname(buf, sizeof(buf));
+
+	printf("Connected to %s (S/N: %u)\n", buf, serial_no);
+
+	return 0;
+}
+
+int jlink_start_rtt(char *cfg)
+{
+	unsigned int address = 0;
+	unsigned int area_size = 0;
+	const char *buffer = "monitor";
+	char *tok;
+	char cmd[64];
+	int rtt_dir;
+	int count;
+	int i;
+
+	if (!cfg)
+		goto find_rttcb;
+
+	tok = strtok(cfg, ",");
+	if (strlen(tok)) {
+		address = strtol(tok, NULL, 0);
+		area_size = 0x1000;
+	}
+
+	tok = strtok(NULL, ",");
+	if (!tok)
+		goto find_rttcb;
+	if (strlen(tok))
+		area_size = strtol(tok, NULL, 0);
+
+	tok = strtok(NULL, ",");
+	if (!tok)
+		goto find_rttcb;
+	if (strlen(tok))
+		buffer = tok;
+
+find_rttcb:
+	if (address || area_size) {
+		if (!area_size)
+			snprintf(cmd, sizeof(cmd), "SetRTTAddr 0x%x", address);
+		else
+			snprintf(cmd, sizeof(cmd),
+						"SetRTTSearchRanges 0x%x 0x%x",
+						address, area_size);
+
+		if (jlink.execcommand(cmd, NULL, 0) < 0)
+			return -EIO;
+	}
+
+	if (jlink.rtterminal_control(RTT_CONTROL_START, NULL) < 0) {
+		fprintf(stderr, "Failed to initialize RTT\n");
+		return -1;
+	}
+
+	/* RTT may need some time to find control block so we need to wait */
+	do {
+		usleep(100);
+		rtt_dir = RTT_DIRECTION_UP;
+		count = jlink.rtterminal_control(RTT_CONTROL_GET_NUM_BUF,
+								&rtt_dir);
+	} while (count < 0);
+
+	for (i = 0; i < count; i++) {
+		memset(&rtt_desc, 0, sizeof(rtt_desc));
+		rtt_desc.index = i;
+
+		if (jlink.rtterminal_control(RTT_CONTROL_GET_DESC,
+								&rtt_desc) < 0)
+			continue;
+
+		if (rtt_desc.size > 0 && !strcmp(buffer, rtt_desc.name))
+			break;
+	}
+
+	if (i == count)
+		return -ENODEV;
+
+	printf("Using RTT up buffer #%d (size: %d)\n", i, rtt_desc.size);
+
+	return 0;
+}
+
+int jlink_rtt_read(void *buf, size_t size)
+{
+	return jlink.rtterminal_read(rtt_desc.index, buf, size);
+}
diff --git a/monitor/jlink.h b/monitor/jlink.h
new file mode 100644
index 000000000..d7c76704c
--- /dev/null
+++ b/monitor/jlink.h
@@ -0,0 +1,27 @@
+/*
+ *
+ *  BlueZ - Bluetooth protocol stack for Linux
+ *
+ *  Copyright (C) 2018  Codecoup
+ *
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library 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
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+int jlink_init(void);
+int jlink_connect(char *cfg);
+int jlink_start_rtt(char *cfg);
+int jlink_rtt_read(void *buf, size_t size);
-- 
2.16.2

[PATCH BlueZ 3/3] monitor: Add support for reading over J-Link RTT

[Andrzej Kaczmarek]

This patch adds support for reading data over J-Link RTT. It can be
used as replacement for TTY when reading from embedded devices since
it's much faster and does block a UART. Data format is the same as
for TTY. At the moment monitor over RTT is only supported by Apache
Mynewt project.

Reading data is done by polling RTT every 1 msec since there is no
blocking API to read something from RTT buffer.

To enable reading from RTT, J-Link and RTT configuration needs to be
passed via command line:
  -J --jlink <device>,<interface>,<speed>,<serialno>
  -R --rtt <address>,<area>,<buffer>

<device> - one of devices supported by J-Link (no default)
<interface> - only 'swd' supported for now (default: swd)
<speed> - interface speed (default: 1000)
<serialno> - emu serial number or 0 if not used (detault: 0)
<address> - RTT control block address (default: 0)
<area> - RTT control block search area length (default: 0)
<buffer> - RTT buffer name with monitor data stream (default: monitor)

Parameters with default values can be omitted.

For example, to read from default nRF52 device and look for RTT buffer
with default name over entire RAM area use:
  btmon -J nrf52 -R 0x20000000,0x10000
---
 Makefile.tools    |  3 ++-
 monitor/control.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 monitor/control.h |  1 +
 monitor/main.c    | 30 ++++++++++++++++++++++++++----
 4 files changed, 79 insertions(+), 5 deletions(-)

diff --git a/Makefile.tools b/Makefile.tools
index 71d083e71..7466633bb 100644
--- a/Makefile.tools
+++ b/Makefile.tools
@@ -59,9 +59,10 @@ monitor_btmon_SOURCES = monitor/main.c monitor/bt.h \
 				monitor/analyze.h monitor/analyze.c \
 				monitor/intel.h monitor/intel.c \
 				monitor/broadcom.h monitor/broadcom.c \
+				monitor/jlink.h monitor/jlink.c \
 				monitor/tty.h
 monitor_btmon_LDADD = lib/libbluetooth-internal.la \
-				src/libshared-mainloop.la @UDEV_LIBS@
+				src/libshared-mainloop.la @UDEV_LIBS@ -ldl
 endif
 
 if TESTING
diff --git a/monitor/control.c b/monitor/control.c
index 98f414be9..73462be42 100644
--- a/monitor/control.c
+++ b/monitor/control.c
@@ -54,6 +54,7 @@
 #include "ellisys.h"
 #include "tty.h"
 #include "control.h"
+#include "jlink.h"
 
 static struct btsnoop *btsnoop_file = NULL;
 static bool hcidump_fallback = false;
@@ -1376,6 +1377,55 @@ int control_tty(const char *path, unsigned int speed)
 	return 0;
 }
 
+static void rtt_callback(int id, void *user_data)
+{
+	struct control_data *data = user_data;
+	ssize_t len;
+
+	do {
+		len = jlink_rtt_read(data->buf + data->offset,
+					sizeof(data->buf) - data->offset);
+		data->offset += len;
+		process_data(data);
+	} while (len > 0);
+
+	if (mainloop_modify_timeout(id, 1) < 0)
+		mainloop_exit_failure();
+}
+
+int control_rtt(char *jlink, char *rtt)
+{
+	struct control_data *data;
+
+	if (jlink_init() < 0) {
+		fprintf(stderr, "Failed to initialize J-Link library\n");
+		return -EIO;
+	}
+
+	if (jlink_connect(jlink) < 0) {
+		fprintf(stderr, "Failed to connect to target device\n");
+		return -ENODEV;
+	}
+
+	if (jlink_start_rtt(rtt) < 0) {
+		fprintf(stderr, "Failed to initialize RTT\n");
+		return -ENODEV;
+	}
+
+	printf("--- RTT opened ---\n");
+
+	data = new0(struct control_data, 1);
+	data->channel = HCI_CHANNEL_MONITOR;
+	data->fd = -1;
+
+	if (mainloop_add_timeout(1, rtt_callback, data, free_data) < 0) {
+		free(data);
+		return -EIO;
+	}
+
+	return 0;
+}
+
 bool control_writer(const char *path)
 {
 	btsnoop_file = btsnoop_create(path, BTSNOOP_FORMAT_MONITOR);
diff --git a/monitor/control.h b/monitor/control.h
index 630a852e4..c315eb7db 100644
--- a/monitor/control.h
+++ b/monitor/control.h
@@ -28,6 +28,7 @@ bool control_writer(const char *path);
 void control_reader(const char *path);
 void control_server(const char *path);
 int control_tty(const char *path, unsigned int speed);
+int control_rtt(char *jlink, char *rtt);
 int control_tracing(void);
 void control_disable_decoding(void);
 
diff --git a/monitor/main.c b/monitor/main.c
index 3e61a4661..27132e3c3 100644
--- a/monitor/main.c
+++ b/monitor/main.c
@@ -72,6 +72,10 @@ static void usage(void)
 		"\t-S, --sco              Dump SCO traffic\n"
 		"\t-A, --a2dp             Dump A2DP stream traffic\n"
 		"\t-E, --ellisys [ip]     Send Ellisys HCI Injection\n"
+		"\t-R  --rtt <device>,[<interface>],[<speed>],[<serialno>]\n"
+		"\t                       Read data from RTT\n"
+		"\t-C  --rtt-cb [<address>],[<area>],[<name>]\n"
+		"\t                       RTT control block parameters\n"
 		"\t-h, --help             Show help options\n");
 }
 
@@ -89,6 +93,8 @@ static const struct option main_options[] = {
 	{ "sco",     no_argument,	NULL, 'S' },
 	{ "a2dp",    no_argument,	NULL, 'A' },
 	{ "ellisys", required_argument, NULL, 'E' },
+	{ "jlink",   required_argument, NULL, 'J' },
+	{ "rtt",     required_argument, NULL, 'R' },
 	{ "todo",    no_argument,       NULL, '#' },
 	{ "version", no_argument,       NULL, 'v' },
 	{ "help",    no_argument,       NULL, 'h' },
@@ -106,6 +112,8 @@ int main(int argc, char *argv[])
 	unsigned int tty_speed = B115200;
 	unsigned short ellisys_port = 0;
 	const char *str;
+	char *jlink = NULL;
+	char *rtt = NULL;
 	int exit_status;
 	sigset_t mask;
 
@@ -117,7 +125,7 @@ int main(int argc, char *argv[])
 		int opt;
 		struct sockaddr_un addr;
 
-		opt = getopt_long(argc, argv, "d:r:w:a:s:p:i:tTSAE:vh",
+		opt = getopt_long(argc, argv, "d:r:w:a:s:p:i:tTSAE:J:R:vh",
 						main_options, NULL);
 		if (opt < 0)
 			break;
@@ -182,6 +190,12 @@ int main(int argc, char *argv[])
 			ellisys_server = optarg;
 			ellisys_port = 24352;
 			break;
+		case 'J':
+			jlink = optarg;
+			break;
+		case 'R':
+			rtt = optarg;
+			break;
 		case '#':
 			packet_todo();
 			lmp_todo();
@@ -240,11 +254,19 @@ int main(int argc, char *argv[])
 	if (ellisys_server)
 		ellisys_enable(ellisys_server, ellisys_port);
 
-	if (!tty && control_tracing() < 0)
+	if (tty && jlink)
 		return EXIT_FAILURE;
 
-	if (tty && control_tty(tty, tty_speed) < 0)
-		return EXIT_FAILURE;
+	if (tty) {
+		if (control_tty(tty, tty_speed) < 0)
+			return EXIT_FAILURE;
+	} else if (jlink) {
+		if (control_rtt(jlink, rtt) < 0)
+			return EXIT_FAILURE;
+	} else {
+		if (control_tracing() < 0)
+			return EXIT_FAILURE;
+	}
 
 	exit_status = mainloop_run();
 
-- 
2.16.2

Re: [PATCH BlueZ 0/3] Receiving monitor data stream over RTT

[Luiz Augusto von Dentz]

Hi Andrzej,

On Thu, Feb 22, 2018 at 11:20 AM, Andrzej Kaczmarek
<andrzej.kaczmarek@codecoup.pl> wrote:
> Hi,
>
> Here's patch series which adds support for receiving monitor data stream over
> Segger RTT channel. This allows to stream data from embedded device without
> need to spare a UART for monitor data and is also much faster. It is now
> supported by Apache Mynewt (NimBLE stack), but I believe it can be also added
> to other RTOS-es like Zephyr Project.
>
> RTT is handled natively by talking to J-Link via libjlinkarm.so. Since there
> is no public documentation for this library, interface was done mostly by
> trial and error so it may be lacking something - I tried it with few Cortex-M
> devices and it works smoothly.
>
> Both J-Link and RTT needs few configuration parameters to work so I combined
> them into two command line options:
>   -J --jlink <device>,<interface>,<speed>,<serialno>
>   -R --rtt <address>,<area>,<buffer>
>
> <device> - one of devices supported by J-Link (no default)
> <interface> - only 'swd' supported for now (default: swd)
> <speed> - interface speed (default: 1000)
> <serialno> - emu serial number or 0 if not used (detault: 0)
> <address> - RTT control block address (default: 0)
> <area> - RTT control block search area length (default: 0)
> <buffer> - RTT buffer name with monitor data stream (default: monitor)

Given that the device has no default I suppose it is not able to
auto-detect it, wouldn't it be possible to add support for that? At
least the tools for flashing, etc, do seems to be able to detect when
using a j-tag.

>
> Andrzej Kaczmarek (3):
>   monitor: Extract TTY data processing to separate function
>   monitor: Add interface for J-Link library
>   monitor: Add support for reading over J-Link RTT
>
>  Makefile.tools    |   3 +-
>  monitor/control.c |  87 +++++++++++++----
>  monitor/control.h |   1 +
>  monitor/jlink.c   | 282 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  monitor/jlink.h   |  27 ++++++
>  monitor/main.c    |  30 +++++-
>  6 files changed, 409 insertions(+), 21 deletions(-)
>  create mode 100644 monitor/jlink.c
>  create mode 100644 monitor/jlink.h
>
> --
> 2.16.2
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html



-- 
Luiz Augusto von Dentz

Re: [PATCH BlueZ 0/3] Receiving monitor data stream over RTT

[Andrzej Kaczmarek]

Hi Luiz,

On Thu, Feb 22, 2018 at 12:14 PM, Luiz Augusto von Dentz
<luiz.dentz@gmail.com> wrote:
> Hi Andrzej,
>
> On Thu, Feb 22, 2018 at 11:20 AM, Andrzej Kaczmarek
> <andrzej.kaczmarek@codecoup.pl> wrote:
>> Hi,
>>
>> Here's patch series which adds support for receiving monitor data stream over
>> Segger RTT channel. This allows to stream data from embedded device without
>> need to spare a UART for monitor data and is also much faster. It is now
>> supported by Apache Mynewt (NimBLE stack), but I believe it can be also added
>> to other RTOS-es like Zephyr Project.
>>
>> RTT is handled natively by talking to J-Link via libjlinkarm.so. Since there
>> is no public documentation for this library, interface was done mostly by
>> trial and error so it may be lacking something - I tried it with few Cortex-M
>> devices and it works smoothly.
>>
>> Both J-Link and RTT needs few configuration parameters to work so I combined
>> them into two command line options:
>>   -J --jlink <device>,<interface>,<speed>,<serialno>
>>   -R --rtt <address>,<area>,<buffer>
>>
>> <device> - one of devices supported by J-Link (no default)
>> <interface> - only 'swd' supported for now (default: swd)
>> <speed> - interface speed (default: 1000)
>> <serialno> - emu serial number or 0 if not used (detault: 0)
>> <address> - RTT control block address (default: 0)
>> <area> - RTT control block search area length (default: 0)
>> <buffer> - RTT buffer name with monitor data stream (default: monitor)
>
> Given that the device has no default I suppose it is not able to
> auto-detect it, wouldn't it be possible to add support for that? At
> least the tools for flashing, etc, do seems to be able to detect when
> using a j-tag.

I'm not sure if it is any different over JTAG, but I don't think
J-Link can autodetect device over SWD (which I only implemented now) -
you need to specify at least core in order to be able to connect to
target.

>>
>> Andrzej Kaczmarek (3):
>>   monitor: Extract TTY data processing to separate function
>>   monitor: Add interface for J-Link library
>>   monitor: Add support for reading over J-Link RTT
>>
>>  Makefile.tools    |   3 +-
>>  monitor/control.c |  87 +++++++++++++----
>>  monitor/control.h |   1 +
>>  monitor/jlink.c   | 282 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>  monitor/jlink.h   |  27 ++++++
>>  monitor/main.c    |  30 +++++-
>>  6 files changed, 409 insertions(+), 21 deletions(-)
>>  create mode 100644 monitor/jlink.c
>>  create mode 100644 monitor/jlink.h
>>
>> --
>> 2.16.2
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>
>
> --
> Luiz Augusto von Dentz

Best regards,
Andrzej

Re: [PATCH BlueZ 3/3] monitor: Add support for reading over J-Link RTT

[ERAMOTO Masaya]

Hi Andrzej,


On 02/22/2018 06:20 PM, Andrzej Kaczmarek wrote:
> This patch adds support for reading data over J-Link RTT. It can be
> used as replacement for TTY when reading from embedded devices since
> it's much faster and does block a UART. Data format is the same as
> for TTY. At the moment monitor over RTT is only supported by Apache
> Mynewt project.
> 
> Reading data is done by polling RTT every 1 msec since there is no
> blocking API to read something from RTT buffer.
> 
> To enable reading from RTT, J-Link and RTT configuration needs to be
> passed via command line:
>   -J --jlink <device>,<interface>,<speed>,<serialno>
>   -R --rtt <address>,<area>,<buffer>
> 
> <device> - one of devices supported by J-Link (no default)
> <interface> - only 'swd' supported for now (default: swd)
> <speed> - interface speed (default: 1000)
> <serialno> - emu serial number or 0 if not used (detault: 0)
> <address> - RTT control block address (default: 0)
> <area> - RTT control block search area length (default: 0)
> <buffer> - RTT buffer name with monitor data stream (default: monitor)
> 
> Parameters with default values can be omitted.
> 
> For example, to read from default nRF52 device and look for RTT buffer
> with default name over entire RAM area use:
>   btmon -J nrf52 -R 0x20000000,0x10000
> ---
>  Makefile.tools    |  3 ++-
>  monitor/control.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  monitor/control.h |  1 +
>  monitor/main.c    | 30 ++++++++++++++++++++++++++----
>  4 files changed, 79 insertions(+), 5 deletions(-)
> 
> diff --git a/Makefile.tools b/Makefile.tools
> index 71d083e71..7466633bb 100644
> --- a/Makefile.tools
> +++ b/Makefile.tools
> @@ -59,9 +59,10 @@ monitor_btmon_SOURCES = monitor/main.c monitor/bt.h \
>  				monitor/analyze.h monitor/analyze.c \
>  				monitor/intel.h monitor/intel.c \
>  				monitor/broadcom.h monitor/broadcom.c \
> +				monitor/jlink.h monitor/jlink.c \
>  				monitor/tty.h
>  monitor_btmon_LDADD = lib/libbluetooth-internal.la \
> -				src/libshared-mainloop.la @UDEV_LIBS@
> +				src/libshared-mainloop.la @UDEV_LIBS@ -ldl
>  endif
>  
>  if TESTING
> diff --git a/monitor/control.c b/monitor/control.c
> index 98f414be9..73462be42 100644
> --- a/monitor/control.c
> +++ b/monitor/control.c
> @@ -54,6 +54,7 @@
>  #include "ellisys.h"
>  #include "tty.h"
>  #include "control.h"
> +#include "jlink.h"
>  
>  static struct btsnoop *btsnoop_file = NULL;
>  static bool hcidump_fallback = false;
> @@ -1376,6 +1377,55 @@ int control_tty(const char *path, unsigned int speed)
>  	return 0;
>  }
>  
> +static void rtt_callback(int id, void *user_data)
> +{
> +	struct control_data *data = user_data;
> +	ssize_t len;
> +
> +	do {
> +		len = jlink_rtt_read(data->buf + data->offset,
> +					sizeof(data->buf) - data->offset);
> +		data->offset += len;
> +		process_data(data);
> +	} while (len > 0);
> +
> +	if (mainloop_modify_timeout(id, 1) < 0)
> +		mainloop_exit_failure();
> +}
> +
> +int control_rtt(char *jlink, char *rtt)
> +{
> +	struct control_data *data;
> +
> +	if (jlink_init() < 0) {
> +		fprintf(stderr, "Failed to initialize J-Link library\n");
> +		return -EIO;
> +	}
> +
> +	if (jlink_connect(jlink) < 0) {
> +		fprintf(stderr, "Failed to connect to target device\n");
> +		return -ENODEV;
> +	}
> +
> +	if (jlink_start_rtt(rtt) < 0) {
> +		fprintf(stderr, "Failed to initialize RTT\n");
> +		return -ENODEV;
> +	}
> +
> +	printf("--- RTT opened ---\n");
> +
> +	data = new0(struct control_data, 1);
> +	data->channel = HCI_CHANNEL_MONITOR;
> +	data->fd = -1;
> +
> +	if (mainloop_add_timeout(1, rtt_callback, data, free_data) < 0) {
> +		free(data);
> +		return -EIO;
> +	}
> +
> +	return 0;
> +}
> +
>  bool control_writer(const char *path)
>  {
>  	btsnoop_file = btsnoop_create(path, BTSNOOP_FORMAT_MONITOR);
> diff --git a/monitor/control.h b/monitor/control.h
> index 630a852e4..c315eb7db 100644
> --- a/monitor/control.h
> +++ b/monitor/control.h
> @@ -28,6 +28,7 @@ bool control_writer(const char *path);
>  void control_reader(const char *path);
>  void control_server(const char *path);
>  int control_tty(const char *path, unsigned int speed);
> +int control_rtt(char *jlink, char *rtt);
>  int control_tracing(void);
>  void control_disable_decoding(void);
>  
> diff --git a/monitor/main.c b/monitor/main.c
> index 3e61a4661..27132e3c3 100644
> --- a/monitor/main.c
> +++ b/monitor/main.c
> @@ -72,6 +72,10 @@ static void usage(void)
>  		"\t-S, --sco              Dump SCO traffic\n"
>  		"\t-A, --a2dp             Dump A2DP stream traffic\n"
>  		"\t-E, --ellisys [ip]     Send Ellisys HCI Injection\n"
> +		"\t-R  --rtt <device>,[<interface>],[<speed>],[<serialno>]\n"
> +		"\t                       Read data from RTT\n"
> +		"\t-C  --rtt-cb [<address>],[<area>],[<name>]\n"
> +		"\t                       RTT control block parameters\n"

The description of two options is incorrect since it is different from
the commit message and the implementation of this patch.


Regards,
Eramoto

>  		"\t-h, --help             Show help options\n");
>  }
>  
> @@ -89,6 +93,8 @@ static const struct option main_options[] = {
>  	{ "sco",     no_argument,	NULL, 'S' },
>  	{ "a2dp",    no_argument,	NULL, 'A' },
>  	{ "ellisys", required_argument, NULL, 'E' },
> +	{ "jlink",   required_argument, NULL, 'J' },
> +	{ "rtt",     required_argument, NULL, 'R' },
>  	{ "todo",    no_argument,       NULL, '#' },
>  	{ "version", no_argument,       NULL, 'v' },
>  	{ "help",    no_argument,       NULL, 'h' },
> @@ -106,6 +112,8 @@ int main(int argc, char *argv[])
>  	unsigned int tty_speed = B115200;
>  	unsigned short ellisys_port = 0;
>  	const char *str;
> +	char *jlink = NULL;
> +	char *rtt = NULL;
>  	int exit_status;
>  	sigset_t mask;
>  
> @@ -117,7 +125,7 @@ int main(int argc, char *argv[])
>  		int opt;
>  		struct sockaddr_un addr;
>  
> -		opt = getopt_long(argc, argv, "d:r:w:a:s:p:i:tTSAE:vh",
> +		opt = getopt_long(argc, argv, "d:r:w:a:s:p:i:tTSAE:J:R:vh",
>  						main_options, NULL);
>  		if (opt < 0)
>  			break;
> @@ -182,6 +190,12 @@ int main(int argc, char *argv[])
>  			ellisys_server = optarg;
>  			ellisys_port = 24352;
>  			break;
> +		case 'J':
> +			jlink = optarg;
> +			break;
> +		case 'R':
> +			rtt = optarg;
> +			break;
>  		case '#':
>  			packet_todo();
>  			lmp_todo();
> @@ -240,11 +254,19 @@ int main(int argc, char *argv[])
>  	if (ellisys_server)
>  		ellisys_enable(ellisys_server, ellisys_port);
>  
> -	if (!tty && control_tracing() < 0)
> +	if (tty && jlink)
>  		return EXIT_FAILURE;
>  
> -	if (tty && control_tty(tty, tty_speed) < 0)
> -		return EXIT_FAILURE;
> +	if (tty) {
> +		if (control_tty(tty, tty_speed) < 0)
> +			return EXIT_FAILURE;
> +	} else if (jlink) {
> +		if (control_rtt(jlink, rtt) < 0)
> +			return EXIT_FAILURE;
> +	} else {
> +		if (control_tracing() < 0)
> +			return EXIT_FAILURE;
> +	}
>  
>  	exit_status = mainloop_run();
>  
> 

Re: [PATCH BlueZ 3/3] monitor: Add support for reading over J-Link RTT

[Andrzej Kaczmarek]

Hi Eramoto,

On Fri, Feb 23, 2018 at 8:00 AM, ERAMOTO Masaya
<eramoto.masaya@jp.fujitsu.com> wrote:
> Hi Andrzej,
>
>
> On 02/22/2018 06:20 PM, Andrzej Kaczmarek wrote:
>> This patch adds support for reading data over J-Link RTT. It can be
>> used as replacement for TTY when reading from embedded devices since
>> it's much faster and does block a UART. Data format is the same as
>> for TTY. At the moment monitor over RTT is only supported by Apache
>> Mynewt project.
>>
>> Reading data is done by polling RTT every 1 msec since there is no
>> blocking API to read something from RTT buffer.
>>
>> To enable reading from RTT, J-Link and RTT configuration needs to be
>> passed via command line:
>>   -J --jlink <device>,<interface>,<speed>,<serialno>
>>   -R --rtt <address>,<area>,<buffer>
>>
>> <device> - one of devices supported by J-Link (no default)
>> <interface> - only 'swd' supported for now (default: swd)
>> <speed> - interface speed (default: 1000)
>> <serialno> - emu serial number or 0 if not used (detault: 0)
>> <address> - RTT control block address (default: 0)
>> <area> - RTT control block search area length (default: 0)
>> <buffer> - RTT buffer name with monitor data stream (default: monitor)
>>
>> Parameters with default values can be omitted.
>>
>> For example, to read from default nRF52 device and look for RTT buffer
>> with default name over entire RAM area use:
>>   btmon -J nrf52 -R 0x20000000,0x10000
>> ---
>>  Makefile.tools    |  3 ++-
>>  monitor/control.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
>>  monitor/control.h |  1 +
>>  monitor/main.c    | 30 ++++++++++++++++++++++++++----
>>  4 files changed, 79 insertions(+), 5 deletions(-)
>>
>> diff --git a/Makefile.tools b/Makefile.tools
>> index 71d083e71..7466633bb 100644
>> --- a/Makefile.tools
>> +++ b/Makefile.tools
>> @@ -59,9 +59,10 @@ monitor_btmon_SOURCES = monitor/main.c monitor/bt.h \
>>                               monitor/analyze.h monitor/analyze.c \
>>                               monitor/intel.h monitor/intel.c \
>>                               monitor/broadcom.h monitor/broadcom.c \
>> +                             monitor/jlink.h monitor/jlink.c \
>>                               monitor/tty.h
>>  monitor_btmon_LDADD = lib/libbluetooth-internal.la \
>> -                             src/libshared-mainloop.la @UDEV_LIBS@
>> +                             src/libshared-mainloop.la @UDEV_LIBS@ -ldl
>>  endif
>>
>>  if TESTING
>> diff --git a/monitor/control.c b/monitor/control.c
>> index 98f414be9..73462be42 100644
>> --- a/monitor/control.c
>> +++ b/monitor/control.c
>> @@ -54,6 +54,7 @@
>>  #include "ellisys.h"
>>  #include "tty.h"
>>  #include "control.h"
>> +#include "jlink.h"
>>
>>  static struct btsnoop *btsnoop_file = NULL;
>>  static bool hcidump_fallback = false;
>> @@ -1376,6 +1377,55 @@ int control_tty(const char *path, unsigned int speed)
>>       return 0;
>>  }
>>
>> +static void rtt_callback(int id, void *user_data)
>> +{
>> +     struct control_data *data = user_data;
>> +     ssize_t len;
>> +
>> +     do {
>> +             len = jlink_rtt_read(data->buf + data->offset,
>> +                                     sizeof(data->buf) - data->offset);
>> +             data->offset += len;
>> +             process_data(data);
>> +     } while (len > 0);
>> +
>> +     if (mainloop_modify_timeout(id, 1) < 0)
>> +             mainloop_exit_failure();
>> +}
>> +
>> +int control_rtt(char *jlink, char *rtt)
>> +{
>> +     struct control_data *data;
>> +
>> +     if (jlink_init() < 0) {
>> +             fprintf(stderr, "Failed to initialize J-Link library\n");
>> +             return -EIO;
>> +     }
>> +
>> +     if (jlink_connect(jlink) < 0) {
>> +             fprintf(stderr, "Failed to connect to target device\n");
>> +             return -ENODEV;
>> +     }
>> +
>> +     if (jlink_start_rtt(rtt) < 0) {
>> +             fprintf(stderr, "Failed to initialize RTT\n");
>> +             return -ENODEV;
>> +     }
>> +
>> +     printf("--- RTT opened ---\n");
>> +
>> +     data = new0(struct control_data, 1);
>> +     data->channel = HCI_CHANNEL_MONITOR;
>> +     data->fd = -1;
>> +
>> +     if (mainloop_add_timeout(1, rtt_callback, data, free_data) < 0) {
>> +             free(data);
>> +             return -EIO;
>> +     }
>> +
>> +     return 0;
>> +}
>> +
>>  bool control_writer(const char *path)
>>  {
>>       btsnoop_file = btsnoop_create(path, BTSNOOP_FORMAT_MONITOR);
>> diff --git a/monitor/control.h b/monitor/control.h
>> index 630a852e4..c315eb7db 100644
>> --- a/monitor/control.h
>> +++ b/monitor/control.h
>> @@ -28,6 +28,7 @@ bool control_writer(const char *path);
>>  void control_reader(const char *path);
>>  void control_server(const char *path);
>>  int control_tty(const char *path, unsigned int speed);
>> +int control_rtt(char *jlink, char *rtt);
>>  int control_tracing(void);
>>  void control_disable_decoding(void);
>>
>> diff --git a/monitor/main.c b/monitor/main.c
>> index 3e61a4661..27132e3c3 100644
>> --- a/monitor/main.c
>> +++ b/monitor/main.c
>> @@ -72,6 +72,10 @@ static void usage(void)
>>               "\t-S, --sco              Dump SCO traffic\n"
>>               "\t-A, --a2dp             Dump A2DP stream traffic\n"
>>               "\t-E, --ellisys [ip]     Send Ellisys HCI Injection\n"
>> +             "\t-R  --rtt <device>,[<interface>],[<speed>],[<serialno>]\n"
>> +             "\t                       Read data from RTT\n"
>> +             "\t-C  --rtt-cb [<address>],[<area>],[<name>]\n"
>> +             "\t                       RTT control block parameters\n"
>
> The description of two options is incorrect since it is different from
> the commit message and the implementation of this patch.

Ah, I forgot to update this message after changing option names -
thanks, will fix later in v2.

> Regards,
> Eramoto

Best regards,
Andrzej

Re: [PATCH BlueZ 3/3] monitor: Add support for reading over J-Link RTT

[Marcel Holtmann]

Hi Andrzej,

> This patch adds support for reading data over J-Link RTT. It can be
> used as replacement for TTY when reading from embedded devices since
> it's much faster and does block a UART. Data format is the same as
> for TTY. At the moment monitor over RTT is only supported by Apache
> Mynewt project.
> 
> Reading data is done by polling RTT every 1 msec since there is no
> blocking API to read something from RTT buffer.

have you check with top or something that you are not causing massive load on your system by polling every 1 msec. And frankly such interfaces are horrible. How is the RTT actually exposed? Is that via HID reports or what. Have you tried usbmon and see if you see packets when using the library.

> 
> To enable reading from RTT, J-Link and RTT configuration needs to be
> passed via command line:
> -J --jlink <device>,<interface>,<speed>,<serialno>
> -R --rtt <address>,<area>,<buffer>
> 
> <device> - one of devices supported by J-Link (no default)
> <interface> - only 'swd' supported for now (default: swd)
> <speed> - interface speed (default: 1000)
> <serialno> - emu serial number or 0 if not used (detault: 0)
> <address> - RTT control block address (default: 0)
> <area> - RTT control block search area length (default: 0)
> <buffer> - RTT buffer name with monitor data stream (default: monitor)
> 
> Parameters with default values can be omitted.
> 
> For example, to read from default nRF52 device and look for RTT buffer
> with default name over entire RAM area use:
> btmon -J nrf52 -R 0x20000000,0x10000
> ---
> Makefile.tools    |  3 ++-
> monitor/control.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
> monitor/control.h |  1 +
> monitor/main.c    | 30 ++++++++++++++++++++++++++----
> 4 files changed, 79 insertions(+), 5 deletions(-)
> 
> diff --git a/Makefile.tools b/Makefile.tools
> index 71d083e71..7466633bb 100644
> --- a/Makefile.tools
> +++ b/Makefile.tools
> @@ -59,9 +59,10 @@ monitor_btmon_SOURCES = monitor/main.c monitor/bt.h \
> 				monitor/analyze.h monitor/analyze.c \
> 				monitor/intel.h monitor/intel.c \
> 				monitor/broadcom.h monitor/broadcom.c \
> +				monitor/jlink.h monitor/jlink.c \
> 				monitor/tty.h
> monitor_btmon_LDADD = lib/libbluetooth-internal.la \
> -				src/libshared-mainloop.la @UDEV_LIBS@
> +				src/libshared-mainloop.la @UDEV_LIBS@ -ldl
> endif
> 
> if TESTING
> diff --git a/monitor/control.c b/monitor/control.c
> index 98f414be9..73462be42 100644
> --- a/monitor/control.c
> +++ b/monitor/control.c
> @@ -54,6 +54,7 @@
> #include "ellisys.h"
> #include "tty.h"
> #include "control.h"
> +#include "jlink.h"
> 
> static struct btsnoop *btsnoop_file = NULL;
> static bool hcidump_fallback = false;
> @@ -1376,6 +1377,55 @@ int control_tty(const char *path, unsigned int speed)
> 	return 0;
> }
> 
> +static void rtt_callback(int id, void *user_data)
> +{
> +	struct control_data *data = user_data;
> +	ssize_t len;
> +
> +	do {
> +		len = jlink_rtt_read(data->buf + data->offset,
> +					sizeof(data->buf) - data->offset);
> +		data->offset += len;
> +		process_data(data);
> +	} while (len > 0);
> +
> +	if (mainloop_modify_timeout(id, 1) < 0)
> +		mainloop_exit_failure();
> +}
> +
> +int control_rtt(char *jlink, char *rtt)
> +{
> +	struct control_data *data;
> +
> +	if (jlink_init() < 0) {
> +		fprintf(stderr, "Failed to initialize J-Link library\n");
> +		return -EIO;
> +	}
> +
> +	if (jlink_connect(jlink) < 0) {
> +		fprintf(stderr, "Failed to connect to target device\n");
> +		return -ENODEV;
> +	}
> +
> +	if (jlink_start_rtt(rtt) < 0) {
> +		fprintf(stderr, "Failed to initialize RTT\n");
> +		return -ENODEV;
> +	}
> +
> +	printf("--- RTT opened ---\n”);

What is this? Debugging code?

> +
> +	data = new0(struct control_data, 1);
> +	data->channel = HCI_CHANNEL_MONITOR;
> +	data->fd = -1;
> +
> +	if (mainloop_add_timeout(1, rtt_callback, data, free_data) < 0) {
> +		free(data);
> +		return -EIO;
> +	}
> +
> +	return 0;
> +}
> +
> bool control_writer(const char *path)
> {
> 	btsnoop_file = btsnoop_create(path, BTSNOOP_FORMAT_MONITOR);
> diff --git a/monitor/control.h b/monitor/control.h
> index 630a852e4..c315eb7db 100644
> --- a/monitor/control.h
> +++ b/monitor/control.h
> @@ -28,6 +28,7 @@ bool control_writer(const char *path);
> void control_reader(const char *path);
> void control_server(const char *path);
> int control_tty(const char *path, unsigned int speed);
> +int control_rtt(char *jlink, char *rtt);
> int control_tracing(void);
> void control_disable_decoding(void);
> 
> diff --git a/monitor/main.c b/monitor/main.c
> index 3e61a4661..27132e3c3 100644
> --- a/monitor/main.c
> +++ b/monitor/main.c
> @@ -72,6 +72,10 @@ static void usage(void)
> 		"\t-S, --sco              Dump SCO traffic\n"
> 		"\t-A, --a2dp             Dump A2DP stream traffic\n"
> 		"\t-E, --ellisys [ip]     Send Ellisys HCI Injection\n"
> +		"\t-R  --rtt <device>,[<interface>],[<speed>],[<serialno>]\n"
> +		"\t                       Read data from RTT\n"
> +		"\t-C  --rtt-cb [<address>],[<area>],[<name>]\n"
> +		"\t                       RTT control block parameters\n"
> 		"\t-h, --help             Show help options\n");
> }
> 
> @@ -89,6 +93,8 @@ static const struct option main_options[] = {
> 	{ "sco",     no_argument,	NULL, 'S' },
> 	{ "a2dp",    no_argument,	NULL, 'A' },
> 	{ "ellisys", required_argument, NULL, 'E' },
> +	{ "jlink",   required_argument, NULL, 'J' },
> +	{ "rtt",     required_argument, NULL, 'R' },
> 	{ "todo",    no_argument,       NULL, '#' },
> 	{ "version", no_argument,       NULL, 'v' },
> 	{ "help",    no_argument,       NULL, 'h' },
> @@ -106,6 +112,8 @@ int main(int argc, char *argv[])
> 	unsigned int tty_speed = B115200;
> 	unsigned short ellisys_port = 0;
> 	const char *str;
> +	char *jlink = NULL;
> +	char *rtt = NULL;
> 	int exit_status;
> 	sigset_t mask;
> 
> @@ -117,7 +125,7 @@ int main(int argc, char *argv[])
> 		int opt;
> 		struct sockaddr_un addr;
> 
> -		opt = getopt_long(argc, argv, "d:r:w:a:s:p:i:tTSAE:vh",
> +		opt = getopt_long(argc, argv, "d:r:w:a:s:p:i:tTSAE:J:R:vh",
> 						main_options, NULL);
> 		if (opt < 0)
> 			break;
> @@ -182,6 +190,12 @@ int main(int argc, char *argv[])
> 			ellisys_server = optarg;
> 			ellisys_port = 24352;
> 			break;
> +		case 'J':
> +			jlink = optarg;
> +			break;
> +		case 'R':
> +			rtt = optarg;
> +			break;
> 		case '#':
> 			packet_todo();
> 			lmp_todo();
> @@ -240,11 +254,19 @@ int main(int argc, char *argv[])
> 	if (ellisys_server)
> 		ellisys_enable(ellisys_server, ellisys_port);
> 
> -	if (!tty && control_tracing() < 0)
> +	if (tty && jlink)
> 		return EXIT_FAILURE;
> 
> -	if (tty && control_tty(tty, tty_speed) < 0)
> -		return EXIT_FAILURE;
> +	if (tty) {
> +		if (control_tty(tty, tty_speed) < 0)
> +			return EXIT_FAILURE;
> +	} else if (jlink) {
> +		if (control_rtt(jlink, rtt) < 0)
> +			return EXIT_FAILURE;
> +	} else {
> +		if (control_tracing() < 0)
> +			return EXIT_FAILURE;
> +	}

This is getting to complicated and needs a cleanup first.

Regards

Marcel

Re: [PATCH BlueZ 3/3] monitor: Add support for reading over J-Link RTT

[Andrzej Kaczmarek]

Hi Marcel,

On Mon, Feb 26, 2018 at 2:59 PM, Marcel Holtmann <marcel@holtmann.org> wrot=
e:
> Hi Andrzej,
>
>> This patch adds support for reading data over J-Link RTT. It can be
>> used as replacement for TTY when reading from embedded devices since
>> it's much faster and does block a UART. Data format is the same as
>> for TTY. At the moment monitor over RTT is only supported by Apache
>> Mynewt project.
>>
>> Reading data is done by polling RTT every 1 msec since there is no
>> blocking API to read something from RTT buffer.
>
> have you check with top or something that you are not causing massive loa=
d on your system by polling every 1 msec. And frankly such interfaces are h=
orrible. How is the RTT actually exposed? Is that via HID reports or what. =
Have you tried usbmon and see if you see packets when using the library.

RTT works over J-Link connection and every time you want to read
something it just reads it directly from MCU memory - it just works
like this.
Polling every 1 msec adds a bit of load (few % perhaps when system is
in idle) but it is not something that you will have running all the
time, just when you need it. I use this quite often and honestly don't
even notice that it is running.

>> To enable reading from RTT, J-Link and RTT configuration needs to be
>> passed via command line:
>> -J --jlink <device>,<interface>,<speed>,<serialno>
>> -R --rtt <address>,<area>,<buffer>
>>
>> <device> - one of devices supported by J-Link (no default)
>> <interface> - only 'swd' supported for now (default: swd)
>> <speed> - interface speed (default: 1000)
>> <serialno> - emu serial number or 0 if not used (detault: 0)
>> <address> - RTT control block address (default: 0)
>> <area> - RTT control block search area length (default: 0)
>> <buffer> - RTT buffer name with monitor data stream (default: monitor)
>>
>> Parameters with default values can be omitted.
>>
>> For example, to read from default nRF52 device and look for RTT buffer
>> with default name over entire RAM area use:
>> btmon -J nrf52 -R 0x20000000,0x10000
>> ---
>> Makefile.tools    |  3 ++-
>> monitor/control.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++=
+
>> monitor/control.h |  1 +
>> monitor/main.c    | 30 ++++++++++++++++++++++++++----
>> 4 files changed, 79 insertions(+), 5 deletions(-)
>>
>> diff --git a/Makefile.tools b/Makefile.tools
>> index 71d083e71..7466633bb 100644
>> --- a/Makefile.tools
>> +++ b/Makefile.tools
>> @@ -59,9 +59,10 @@ monitor_btmon_SOURCES =3D monitor/main.c monitor/bt.h=
 \
>>                               monitor/analyze.h monitor/analyze.c \
>>                               monitor/intel.h monitor/intel.c \
>>                               monitor/broadcom.h monitor/broadcom.c \
>> +                             monitor/jlink.h monitor/jlink.c \
>>                               monitor/tty.h
>> monitor_btmon_LDADD =3D lib/libbluetooth-internal.la \
>> -                             src/libshared-mainloop.la @UDEV_LIBS@
>> +                             src/libshared-mainloop.la @UDEV_LIBS@ -ldl
>> endif
>>
>> if TESTING
>> diff --git a/monitor/control.c b/monitor/control.c
>> index 98f414be9..73462be42 100644
>> --- a/monitor/control.c
>> +++ b/monitor/control.c
>> @@ -54,6 +54,7 @@
>> #include "ellisys.h"
>> #include "tty.h"
>> #include "control.h"
>> +#include "jlink.h"
>>
>> static struct btsnoop *btsnoop_file =3D NULL;
>> static bool hcidump_fallback =3D false;
>> @@ -1376,6 +1377,55 @@ int control_tty(const char *path, unsigned int sp=
eed)
>>       return 0;
>> }
>>
>> +static void rtt_callback(int id, void *user_data)
>> +{
>> +     struct control_data *data =3D user_data;
>> +     ssize_t len;
>> +
>> +     do {
>> +             len =3D jlink_rtt_read(data->buf + data->offset,
>> +                                     sizeof(data->buf) - data->offset);
>> +             data->offset +=3D len;
>> +             process_data(data);
>> +     } while (len > 0);
>> +
>> +     if (mainloop_modify_timeout(id, 1) < 0)
>> +             mainloop_exit_failure();
>> +}
>> +
>> +int control_rtt(char *jlink, char *rtt)
>> +{
>> +     struct control_data *data;
>> +
>> +     if (jlink_init() < 0) {
>> +             fprintf(stderr, "Failed to initialize J-Link library\n");
>> +             return -EIO;
>> +     }
>> +
>> +     if (jlink_connect(jlink) < 0) {
>> +             fprintf(stderr, "Failed to connect to target device\n");
>> +             return -ENODEV;
>> +     }
>> +
>> +     if (jlink_start_rtt(rtt) < 0) {
>> +             fprintf(stderr, "Failed to initialize RTT\n");
>> +             return -ENODEV;
>> +     }
>> +
>> +     printf("--- RTT opened ---\n=E2=80=9D);
>
> What is this? Debugging code?

A printout when RTT is opened - the same as for TTY when connected and
for socket on incoming connection.

>> +
>> +     data =3D new0(struct control_data, 1);
>> +     data->channel =3D HCI_CHANNEL_MONITOR;
>> +     data->fd =3D -1;
>> +
>> +     if (mainloop_add_timeout(1, rtt_callback, data, free_data) < 0) {
>> +             free(data);
>> +             return -EIO;
>> +     }
>> +
>> +     return 0;
>> +}
>> +
>> bool control_writer(const char *path)
>> {
>>       btsnoop_file =3D btsnoop_create(path, BTSNOOP_FORMAT_MONITOR);
>> diff --git a/monitor/control.h b/monitor/control.h
>> index 630a852e4..c315eb7db 100644
>> --- a/monitor/control.h
>> +++ b/monitor/control.h
>> @@ -28,6 +28,7 @@ bool control_writer(const char *path);
>> void control_reader(const char *path);
>> void control_server(const char *path);
>> int control_tty(const char *path, unsigned int speed);
>> +int control_rtt(char *jlink, char *rtt);
>> int control_tracing(void);
>> void control_disable_decoding(void);
>>
>> diff --git a/monitor/main.c b/monitor/main.c
>> index 3e61a4661..27132e3c3 100644
>> --- a/monitor/main.c
>> +++ b/monitor/main.c
>> @@ -72,6 +72,10 @@ static void usage(void)
>>               "\t-S, --sco              Dump SCO traffic\n"
>>               "\t-A, --a2dp             Dump A2DP stream traffic\n"
>>               "\t-E, --ellisys [ip]     Send Ellisys HCI Injection\n"
>> +             "\t-R  --rtt <device>,[<interface>],[<speed>],[<serialno>]=
\n"
>> +             "\t                       Read data from RTT\n"
>> +             "\t-C  --rtt-cb [<address>],[<area>],[<name>]\n"
>> +             "\t                       RTT control block parameters\n"
>>               "\t-h, --help             Show help options\n");
>> }
>>
>> @@ -89,6 +93,8 @@ static const struct option main_options[] =3D {
>>       { "sco",     no_argument,       NULL, 'S' },
>>       { "a2dp",    no_argument,       NULL, 'A' },
>>       { "ellisys", required_argument, NULL, 'E' },
>> +     { "jlink",   required_argument, NULL, 'J' },
>> +     { "rtt",     required_argument, NULL, 'R' },
>>       { "todo",    no_argument,       NULL, '#' },
>>       { "version", no_argument,       NULL, 'v' },
>>       { "help",    no_argument,       NULL, 'h' },
>> @@ -106,6 +112,8 @@ int main(int argc, char *argv[])
>>       unsigned int tty_speed =3D B115200;
>>       unsigned short ellisys_port =3D 0;
>>       const char *str;
>> +     char *jlink =3D NULL;
>> +     char *rtt =3D NULL;
>>       int exit_status;
>>       sigset_t mask;
>>
>> @@ -117,7 +125,7 @@ int main(int argc, char *argv[])
>>               int opt;
>>               struct sockaddr_un addr;
>>
>> -             opt =3D getopt_long(argc, argv, "d:r:w:a:s:p:i:tTSAE:vh",
>> +             opt =3D getopt_long(argc, argv, "d:r:w:a:s:p:i:tTSAE:J:R:v=
h",
>>                                               main_options, NULL);
>>               if (opt < 0)
>>                       break;
>> @@ -182,6 +190,12 @@ int main(int argc, char *argv[])
>>                       ellisys_server =3D optarg;
>>                       ellisys_port =3D 24352;
>>                       break;
>> +             case 'J':
>> +                     jlink =3D optarg;
>> +                     break;
>> +             case 'R':
>> +                     rtt =3D optarg;
>> +                     break;
>>               case '#':
>>                       packet_todo();
>>                       lmp_todo();
>> @@ -240,11 +254,19 @@ int main(int argc, char *argv[])
>>       if (ellisys_server)
>>               ellisys_enable(ellisys_server, ellisys_port);
>>
>> -     if (!tty && control_tracing() < 0)
>> +     if (tty && jlink)
>>               return EXIT_FAILURE;
>>
>> -     if (tty && control_tty(tty, tty_speed) < 0)
>> -             return EXIT_FAILURE;
>> +     if (tty) {
>> +             if (control_tty(tty, tty_speed) < 0)
>> +                     return EXIT_FAILURE;
>> +     } else if (jlink) {
>> +             if (control_rtt(jlink, rtt) < 0)
>> +                     return EXIT_FAILURE;
>> +     } else {
>> +             if (control_tracing() < 0)
>> +                     return EXIT_FAILURE;
>> +     }
>
> This is getting to complicated and needs a cleanup first.

Any idea how to clean this up? It's pretty clean for me.

> Regards
>
> Marcel

Best regards,
Andrzej