aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--configure.ac6
-rw-r--r--contrib/remote_bitbang/remote_bitbang_sysfsgpio.c211
-rw-r--r--doc/manual/jtag/drivers/remote_bitbang.txt36
-rw-r--r--doc/openocd.texi6
-rw-r--r--src/jtag/drivers/remote_bitbang.c31
5 files changed, 230 insertions, 60 deletions
diff --git a/configure.ac b/configure.ac
index a2442d4..c9cf021 100644
--- a/configure.ac
+++ b/configure.ac
@@ -382,7 +382,7 @@ AC_ARG_ENABLE([internal-libjaylink],
[use_internal_libjaylink=$enableval], [use_internal_libjaylink=no])
AC_ARG_ENABLE([remote-bitbang],
- AS_HELP_STRING([--enable-remote-bitbang], [Enable building support for the Remote Bitbang jtag driver]),
+ AS_HELP_STRING([--enable-remote-bitbang], [Enable building support for the Remote Bitbang driver]),
[build_remote_bitbang=$enableval], [build_remote_bitbang=no])
AS_CASE(["${host_cpu}"],
@@ -598,9 +598,9 @@ AS_IF([test "x$use_internal_jimtcl" = "xyes"], [
AS_IF([test "x$build_remote_bitbang" = "xyes"], [
build_bitbang=yes
- AC_DEFINE([BUILD_REMOTE_BITBANG], [1], [1 if you want the Remote Bitbang JTAG driver.])
+ AC_DEFINE([BUILD_REMOTE_BITBANG], [1], [1 if you want the Remote Bitbang driver.])
], [
- AC_DEFINE([BUILD_REMOTE_BITBANG], [0], [0 if you don't want the Remote Bitbang JTAG driver.])
+ AC_DEFINE([BUILD_REMOTE_BITBANG], [0], [0 if you don't want the Remote Bitbang driver.])
])
AS_IF([test "x$build_sysfsgpio" = "xyes"], [
diff --git a/contrib/remote_bitbang/remote_bitbang_sysfsgpio.c b/contrib/remote_bitbang/remote_bitbang_sysfsgpio.c
index 9294837..1588eb9 100644
--- a/contrib/remote_bitbang/remote_bitbang_sysfsgpio.c
+++ b/contrib/remote_bitbang/remote_bitbang_sysfsgpio.c
@@ -1,30 +1,31 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/***************************************************************************
+ * Copyright (C) 2021 by Manuel Wick <manuel@matronix.de> *
* Copyright (C) 2013 Paul Fertser <fercerpav@gmail.com> *
* Copyright (C) 2012 by Creative Product Design, marc @ cpdesign.com.au *
***************************************************************************/
/*
- This is a test application to be used as a remote bitbang server for
- the OpenOCD remote_bitbang interface driver.
-
- To compile run:
- gcc -Wall -ansi -pedantic -std=c99 -o remote_bitbang_sysfsgpio remote_bitbang_sysfsgpio.c
-
-
- Usage example:
-
- On Raspberry Pi run:
- socat TCP6-LISTEN:7777,fork EXEC:"sudo ./remote_bitbang_sysfsgpio tck 11 tms 25 tdo 9 tdi 10"
-
- On host run:
- openocd -c "interface remote_bitbang; remote_bitbang host raspberrypi; remote_bitbang port 7777" \
- -f target/stm32f1x.cfg
-
- Or if you want to test UNIX sockets, run both on Raspberry Pi:
- socat UNIX-LISTEN:/tmp/remotebitbang-socket,fork EXEC:"sudo ./remote_bitbang_sysfsgpio tck 11 tms 25 tdo 9 tdi 10"
- openocd -c "interface remote_bitbang; remote_bitbang host /tmp/remotebitbang-socket" -f target/stm32f1x.cfg
+ * This is a test application to be used as a remote bitbang server for
+ * the OpenOCD remote_bitbang interface driver.
+ *
+ * To compile run:
+ * gcc -Wall -ansi -pedantic -std=c99 -o remote_bitbang_sysfsgpio remote_bitbang_sysfsgpio.c
+ *
+ *
+ * Usage example:
+ *
+ * On Raspberry Pi run:
+ * socat TCP6-LISTEN:7777,fork EXEC:"sudo ./remote_bitbang_sysfsgpio tck 11 tms 25 tdo 9 tdi 10"
+ *
+ * On host run:
+ * openocd -c "adapter driver remote_bitbang; remote_bitbang host raspberrypi; remote_bitbang port 7777" \
+ * -f target/stm32f1x.cfg
+ *
+ * Or if you want to test UNIX sockets, run both on Raspberry Pi:
+ * socat UNIX-LISTEN:/tmp/remotebitbang-socket,fork EXEC:"sudo ./remote_bitbang_sysfsgpio tck 11 tms 25 tdo 9 tdi 10"
+ * openocd -c "adapter driver remote_bitbang; remote_bitbang host /tmp/remotebitbang-socket" -f target/stm32f1x.cfg
*/
#include <sys/types.h>
@@ -97,11 +98,14 @@ static void unexport_sysfs_gpio(int gpio)
* If the gpio is an output, it is initialized according to init_high,
* otherwise it is ignored.
*
+ * When open_rw is set, the file descriptor will be open as read and write,
+ * e.g. for SWDIO (TMS) that is used as input and output.
+ *
* If the gpio is already exported we just show a warning and continue; if
* openocd happened to crash (or was killed by user) then the gpios will not
* have been cleaned up.
*/
-static int setup_sysfs_gpio(int gpio, int is_output, int init_high)
+static int setup_sysfs_gpio(int gpio, int is_output, int init_high, int open_rw)
{
char buf[40];
char gpiostr[4];
@@ -132,7 +136,9 @@ static int setup_sysfs_gpio(int gpio, int is_output, int init_high)
}
snprintf(buf, sizeof(buf), "/sys/class/gpio/gpio%d/value", gpio);
- if (is_output)
+ if (open_rw)
+ ret = open(buf, O_RDWR | O_NONBLOCK | O_SYNC);
+ else if (is_output)
ret = open(buf, O_WRONLY | O_NONBLOCK | O_SYNC);
else
ret = open(buf, O_RDONLY | O_NONBLOCK | O_SYNC);
@@ -144,6 +150,37 @@ static int setup_sysfs_gpio(int gpio, int is_output, int init_high)
}
/*
+ * Change direction for gpio.
+ */
+static int change_dir_sysfs_gpio(int gpio, int is_output, int init_high)
+{
+ char buf[40];
+ int ret;
+
+ if (!is_gpio_valid(gpio))
+ return ERROR_OK;
+
+ snprintf(buf, sizeof(buf), "/sys/class/gpio/gpio%d/direction", gpio);
+ ret = open_write_close(buf, is_output ? (init_high ? "high" : "low") : "in");
+ if (ret < 0) {
+ LOG_ERROR("Couldn't set direction for gpio %d", gpio);
+ perror("sysfsgpio: ");
+ unexport_sysfs_gpio(gpio);
+ return ERROR_FAIL;
+ }
+
+ return ERROR_OK;
+}
+
+/* gpio numbers for each gpio. Negative values are invalid */
+static int tck_gpio = -1;
+static int tms_gpio = -1;
+static int tdi_gpio = -1;
+static int tdo_gpio = -1;
+static int trst_gpio = -1;
+static int srst_gpio = -1;
+
+/*
* file descriptors for /sys/class/gpio/gpioXX/value
* Set up during init.
*/
@@ -155,6 +192,15 @@ static int trst_fd = -1;
static int srst_fd = -1;
/*
+ * GPIO state of /sys/class/gpio/gpioXX/value
+ */
+static int last_tck = -1;
+static int last_tms = -1;
+static int last_tms_drive = -1;
+static int last_tdi = -1;
+static int last_initialized = -1;
+
+/*
* Bitbang interface read of TDO
*
* The sysfs value will read back either '0' or '1'. The trick here is to call
@@ -179,26 +225,22 @@ static int sysfsgpio_read(void)
/*
* Bitbang interface write of TCK, TMS, TDI
*
- * Seeing as this is the only function where the outputs are changed,
- * we can cache the old value to avoid needlessly writing it.
+ * Output states are changed here and in sysfsgpio_write_swd,
+ * which are not used simultaneously, so we can cache the old
+ * value to avoid needlessly writing it.
*/
static void sysfsgpio_write(int tck, int tms, int tdi)
{
const char one[] = "1";
const char zero[] = "0";
- static int last_tck;
- static int last_tms;
- static int last_tdi;
-
- static int first_time;
size_t bytes_written;
- if (!first_time) {
+ if (!last_initialized) {
last_tck = !tck;
last_tms = !tms;
last_tdi = !tdi;
- first_time = 1;
+ last_initialized = 1;
}
if (tdi != last_tdi) {
@@ -251,13 +293,81 @@ static void sysfsgpio_reset(int trst, int srst)
}
}
-/* gpio numbers for each gpio. Negative values are invalid */
-static int tck_gpio = -1;
-static int tms_gpio = -1;
-static int tdi_gpio = -1;
-static int tdo_gpio = -1;
-static int trst_gpio = -1;
-static int srst_gpio = -1;
+/*
+ * Bitbang interface set direction of SWDIO (TMS)
+ */
+static void sysfsgpio_swdio_drive(int is_output)
+{
+ int ret;
+
+ if (is_output != 0 && last_tms == -1)
+ last_tms = 0;
+
+ ret = change_dir_sysfs_gpio(tms_gpio, (is_output != 0) ? 1 : 0, last_tms);
+ if (ret != ERROR_OK)
+ LOG_WARNING("Failed to change SWDIO (TMS) direction to output");
+ else
+ last_tms_drive = (is_output != 0) ? 1 : 0;
+}
+
+/*
+ * Bitbang interface read of SWDIO (TMS)
+ *
+ * The sysfs value will read back either '0' or '1'. The trick here is to call
+ * lseek to bypass buffering in the sysfs kernel driver.
+ */
+static int sysfsgpio_swdio_read(void)
+{
+ char buf[1];
+
+ /* important to seek to signal sysfs of new read */
+ lseek(tms_fd, 0, SEEK_SET);
+ int ret = read(tms_fd, &buf, sizeof(buf));
+
+ if (ret < 0) {
+ LOG_WARNING("reading swdio (tms) failed");
+ return 0;
+ }
+
+ return buf[0];
+}
+
+/*
+ * Bitbang interface write of SWCLK (TCK) and SWDIO (TMS)
+ *
+ * Output states are changed here and in sysfsgpio_write, which
+ * are not used simultaneously, so we can cache the old value
+ * to avoid needlessly writing it.
+ */
+static void sysfsgpio_swd_write(int swclk, int swdio)
+{
+ static const char one[] = "1";
+ static const char zero[] = "0";
+
+ size_t bytes_written;
+
+ if (!last_initialized) {
+ last_tck = !swclk;
+ last_tms = !swdio;
+ last_initialized = 1;
+ }
+
+ if (last_tms_drive == 1 && swdio != last_tms) {
+ bytes_written = write(tms_fd, swdio ? &one : &zero, 1);
+ if (bytes_written != 1)
+ LOG_WARNING("writing swdio (tms) failed");
+ }
+
+ /* write clk last */
+ if (swclk != last_tck) {
+ bytes_written = write(tck_fd, swclk ? &one : &zero, 1);
+ if (bytes_written != 1)
+ LOG_WARNING("writing swclk (tck) failed");
+ }
+
+ last_tms = swdio;
+ last_tck = swclk;
+}
/* helper func to close and cleanup files only if they were valid/ used */
static void cleanup_fd(int fd, int gpio)
@@ -293,13 +403,21 @@ static void process_remote_protocol(void)
char d = c - 'r';
sysfsgpio_reset(!!(d & 2),
(d & 1));
- } else if (c >= '0' && c <= '0' + 7) {/* Write */
+ } else if (c >= '0' && c <= '0' + 7) { /* Write */
char d = c - '0';
sysfsgpio_write(!!(d & 4),
!!(d & 2),
(d & 1));
} else if (c == 'R')
putchar(sysfsgpio_read());
+ else if (c == 'c') /* SWDIO read */
+ putchar(sysfsgpio_swdio_read());
+ else if (c == 'o' || c == 'O') /* SWDIO drive */
+ sysfsgpio_swdio_drive(c == 'o' ? 0 : 1);
+ else if (c >= 'd' && c <= 'g') { /* SWD write */
+ char d = c - 'd';
+ sysfsgpio_swd_write((d & 2), (d & 1));
+ }
else
LOG_ERROR("Unknown command '%c' received", c);
}
@@ -307,7 +425,7 @@ static void process_remote_protocol(void)
int main(int argc, char *argv[])
{
- LOG_WARNING("SysfsGPIO remote_bitbang JTAG driver\n");
+ LOG_WARNING("SysfsGPIO remote_bitbang JTAG+SWD driver\n");
for (int i = 1; i < argc; i++) {
if (!strcmp(argv[i], "tck"))
@@ -349,36 +467,39 @@ int main(int argc, char *argv[])
* Configure TDO as an input, and TDI, TCK, TMS, TRST, SRST
* as outputs. Drive TDI and TCK low, and TMS/TRST/SRST high.
*/
- tck_fd = setup_sysfs_gpio(tck_gpio, 1, 0);
+ tck_fd = setup_sysfs_gpio(tck_gpio, 1, 0, 0);
if (tck_fd < 0)
goto out_error;
- tms_fd = setup_sysfs_gpio(tms_gpio, 1, 1);
+ tms_fd = setup_sysfs_gpio(tms_gpio, 1, 1, 1);
if (tms_fd < 0)
goto out_error;
+ last_tms_drive = 0;
- tdi_fd = setup_sysfs_gpio(tdi_gpio, 1, 0);
+ tdi_fd = setup_sysfs_gpio(tdi_gpio, 1, 0, 0);
if (tdi_fd < 0)
goto out_error;
- tdo_fd = setup_sysfs_gpio(tdo_gpio, 0, 0);
+ tdo_fd = setup_sysfs_gpio(tdo_gpio, 0, 0, 0);
if (tdo_fd < 0)
goto out_error;
/* assume active low */
if (trst_gpio > 0) {
- trst_fd = setup_sysfs_gpio(trst_gpio, 1, 1);
+ trst_fd = setup_sysfs_gpio(trst_gpio, 1, 1, 0);
if (trst_fd < 0)
goto out_error;
}
/* assume active low */
if (srst_gpio > 0) {
- srst_fd = setup_sysfs_gpio(srst_gpio, 1, 1);
+ srst_fd = setup_sysfs_gpio(srst_gpio, 1, 1, 0);
if (srst_fd < 0)
goto out_error;
}
+ last_initialized = 0;
+
LOG_WARNING("SysfsGPIO nums: tck = %d, tms = %d, tdi = %d, tdo = %d",
tck_gpio, tms_gpio, tdi_gpio, tdo_gpio);
LOG_WARNING("SysfsGPIO num: srst = %d", srst_gpio);
diff --git a/doc/manual/jtag/drivers/remote_bitbang.txt b/doc/manual/jtag/drivers/remote_bitbang.txt
index f394d73..7c8eee2 100644
--- a/doc/manual/jtag/drivers/remote_bitbang.txt
+++ b/doc/manual/jtag/drivers/remote_bitbang.txt
@@ -1,15 +1,19 @@
/** @remote_bitbangpage OpenOCD Developer's Guide
-The remote_bitbang JTAG driver is used to drive JTAG from a remote process. The
-remote_bitbang driver communicates via TCP or UNIX sockets with some remote
-process using an ASCII encoding of the bitbang interface. The remote process
-presumably then drives the JTAG however it pleases. The remote process should
-act as a server, listening for connections from the openocd remote_bitbang
-driver.
+The remote_bitbang JTAG+SWD driver is used to drive JTAG and/or SWD from a
+remote process. The remote_bitbang driver communicates via TCP or UNIX
+sockets with some remote process using an ASCII encoding of the bitbang
+interface. The remote process presumably then drives the JTAG/SWD however
+it pleases. The remote process should act as a server, listening for
+connections from the openocd remote_bitbang driver.
The remote bitbang driver is useful for debugging software running on
processors which are being simulated.
+There also is an implementation of the server-side protocol for the
+Glasgow Debug Tool (https://github.com/glasgowEmbedded/Glasgow) through
+the jtag-openocd applet.
+
The bitbang interface consists of the following functions.
blink on
@@ -24,11 +28,20 @@ write tck tms tdi
reset trst srst
Set the value of trst, srst.
+swdio_drive
+ Set the output enable of the bidirectional swdio (tms) pin
+
+swdio_read
+ Sample the value of swdio (tms).
+
+swd_write
+ Set the value of swclk (tck) and swdio (tms).
+
An additional function, quit, is added to the remote_bitbang interface to
indicate there will be no more requests and the connection with the remote
driver should be closed.
-These five functions are encoded in ASCII by assigning a single character to
+These eight functions are encoded in ASCII by assigning a single character to
each possible request. The assignments are:
B - Blink on
@@ -47,7 +60,14 @@ each possible request. The assignments are:
s - Reset 0 1
t - Reset 1 0
u - Reset 1 1
+ O - SWDIO drive 1
+ o - SWDIO drive 0
+ c - SWDIO read request
+ d - SWD write 0 0
+ e - SWD write 0 1
+ f - SWD write 1 0
+ g - SWD write 1 1
-The read response is encoded in ASCII as either digit 0 or 1.
+The read responses are encoded in ASCII as either digit 0 or 1.
*/
diff --git a/doc/openocd.texi b/doc/openocd.texi
index c14ee9c..de990c5 100644
--- a/doc/openocd.texi
+++ b/doc/openocd.texi
@@ -2810,9 +2810,9 @@ If not specified, default 0xFFFF is used.
@end deffn
@deffn {Interface Driver} {remote_bitbang}
-Drive JTAG from a remote process. This sets up a UNIX or TCP socket connection
-with a remote process and sends ASCII encoded bitbang requests to that process
-instead of directly driving JTAG.
+Drive JTAG and SWD from a remote process. This sets up a UNIX or TCP socket
+connection with a remote process and sends ASCII encoded bitbang requests to
+that process instead of directly driving JTAG and SWD.
The remote_bitbang driver is useful for debugging software running on
processors which are being simulated.
diff --git a/src/jtag/drivers/remote_bitbang.c b/src/jtag/drivers/remote_bitbang.c
index 36bcbe1..261c30d 100644
--- a/src/jtag/drivers/remote_bitbang.c
+++ b/src/jtag/drivers/remote_bitbang.c
@@ -3,6 +3,8 @@
/***************************************************************************
* Copyright (C) 2011 by Richard Uhler *
* ruhler@mit.edu *
+ * *
+ * Copyright (C) 2021 by Manuel Wick <manuel@matronix.de> *
***************************************************************************/
#ifdef HAVE_CONFIG_H
@@ -220,11 +222,35 @@ static int remote_bitbang_blink(int on)
return remote_bitbang_queue(c, FLUSH_SEND_BUF);
}
+static void remote_bitbang_swdio_drive(bool is_output)
+{
+ char c = is_output ? 'O' : 'o';
+ if (remote_bitbang_queue(c, FLUSH_SEND_BUF) == ERROR_FAIL)
+ LOG_ERROR("Error setting direction for swdio");
+}
+
+static int remote_bitbang_swdio_read(void)
+{
+ if (remote_bitbang_queue('c', FLUSH_SEND_BUF) != ERROR_FAIL)
+ return remote_bitbang_read_sample();
+ else
+ return BB_ERROR;
+}
+
+static int remote_bitbang_swd_write(int swclk, int swdio)
+{
+ char c = 'd' + ((swclk ? 0x2 : 0x0) | (swdio ? 0x1 : 0x0));
+ return remote_bitbang_queue(c, NO_FLUSH);
+}
+
static struct bitbang_interface remote_bitbang_bitbang = {
.buf_size = sizeof(remote_bitbang_recv_buf) - 1,
.sample = &remote_bitbang_sample,
.read_sample = &remote_bitbang_read_sample,
.write = &remote_bitbang_write,
+ .swdio_read = &remote_bitbang_swdio_read,
+ .swdio_drive = &remote_bitbang_swdio_drive,
+ .swd_write = &remote_bitbang_swd_write,
.blink = &remote_bitbang_blink,
};
@@ -349,6 +375,8 @@ COMMAND_HANDLER(remote_bitbang_handle_remote_bitbang_host_command)
return ERROR_COMMAND_SYNTAX_ERROR;
}
+static const char * const remote_bitbang_transports[] = { "jtag", "swd", NULL };
+
static const struct command_registration remote_bitbang_subcommand_handlers[] = {
{
.name = "port",
@@ -401,7 +429,7 @@ static struct jtag_interface remote_bitbang_interface = {
struct adapter_driver remote_bitbang_adapter_driver = {
.name = "remote_bitbang",
- .transports = jtag_only,
+ .transports = remote_bitbang_transports,
.commands = remote_bitbang_command_handlers,
.init = &remote_bitbang_init,
@@ -409,4 +437,5 @@ struct adapter_driver remote_bitbang_adapter_driver = {
.reset = &remote_bitbang_reset,
.jtag_ops = &remote_bitbang_interface,
+ .swd_ops = &bitbang_swd,
};
generated by cgit v1.1 at 2024-08-15 22:45:16 +0000