From 0f70c6c325785517f35bbbb9316801bef7a79d8b Mon Sep 17 00:00:00 2001 From: Manuel Wick Date: Sat, 30 Jan 2021 22:46:50 +0100 Subject: [PATCH] remote_bitbang: Add SWD support This adds new command characters to make SWD work with the new split jtag and swd operations of bitbang. The command characters are as follows: 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 Documentation has been updated accordingly. The new commands will be used by an adapted version of the jtag-openocd applet of the "Glasgow Debug Tool" (https://github.com/glasgowEmbedded/Glasgow). It has been tested against an stm32f103 and an at91samd21 target. contrib/remote/bitbang/remote_bitbang_sysfsgpio.c has also been adapted to support SWD via the new command set. Some limited testing has been done using a Raspberry Pi 2 with an stm32f103 and an at91samd21 target attached. Change-Id: I8e998a2cb36905142cb16e534483094cd99e8fa7 Signed-off-by: Manuel Wick Signed-off-by: David Ryskalczyk Reviewed-on: https://review.openocd.org/c/openocd/+/6044 Tested-by: jenkins Reviewed-by: Tomas Vanek Reviewed-by: Antonio Borneo --- configure.ac | 6 +- .../remote_bitbang/remote_bitbang_sysfsgpio.c | 211 ++++++++++++++---- doc/manual/jtag/drivers/remote_bitbang.txt | 36 ++- doc/openocd.texi | 6 +- src/jtag/drivers/remote_bitbang.c | 31 ++- 5 files changed, 230 insertions(+), 60 deletions(-) diff --git a/configure.ac b/configure.ac index a2442d40b5..c9cf0214e3 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 9294837e3c..1588eb9a3c 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 * * Copyright (C) 2013 Paul Fertser * * 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 @@ -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); @@ -143,6 +149,37 @@ static int setup_sysfs_gpio(int gpio, int is_output, int init_high) return ret; } +/* + * 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. @@ -154,6 +191,15 @@ static int tdo_fd = -1; 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 * @@ -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 f394d736af..7c8eee289e 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 c14ee9cb6a..de990c5381 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 36bcbe19ca..261c30df2d 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 * ***************************************************************************/ #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, }; -- 2.30.2