src/jtag/drivers/remote_bitbang.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2
   3 /***************************************************************************
   4  *   Copyright (C) 2011 by Richard Uhler                                   *
   5  *   ruhler@mit.edu                                                        *
   6  *                                                                         *
   7  *   Copyright (C) 2021 by Manuel Wick <manuel@matronix.de>                *
   8  ***************************************************************************/
   9
  10 #ifdef HAVE_CONFIG_H
  11 #include "config.h"
  12 #endif
  13
  14 #ifndef _WIN32
  15 #include <sys/un.h>
  16 #include <netdb.h>
  17 #include <netinet/tcp.h>
  18 #endif
  19 #include "helper/system.h"
  20 #include "helper/replacements.h"
  21 #include <jtag/interface.h>
  22 #include "bitbang.h"
  23
  24 /* arbitrary limit on host name length: */
  25 #define REMOTE_BITBANG_HOST_MAX 255
  26
  27 static char *remote_bitbang_host;
  28 static char *remote_bitbang_port;
  29
  30 static int remote_bitbang_fd;
  31 static uint8_t remote_bitbang_send_buf[512];
  32 static unsigned int remote_bitbang_send_buf_used;
  33
  34 static bool use_remote_sleep;
  35
  36 /* Circular buffer. When start == end, the buffer is empty. */
  37 static char remote_bitbang_recv_buf[256];
  38 static unsigned int remote_bitbang_recv_buf_start;
  39 static unsigned int remote_bitbang_recv_buf_end;
  40
  41 static bool remote_bitbang_recv_buf_full(void)
  42 {
  43         return remote_bitbang_recv_buf_end ==
  44                 ((remote_bitbang_recv_buf_start + sizeof(remote_bitbang_recv_buf) - 1) %
  45                  sizeof(remote_bitbang_recv_buf));
  46 }
  47
  48 static bool remote_bitbang_recv_buf_empty(void)
  49 {
  50         return remote_bitbang_recv_buf_start == remote_bitbang_recv_buf_end;
  51 }
  52
  53 static unsigned int remote_bitbang_recv_buf_contiguous_available_space(void)
  54 {
  55         if (remote_bitbang_recv_buf_end >= remote_bitbang_recv_buf_start) {
  56                 unsigned int space = sizeof(remote_bitbang_recv_buf) -
  57                                      remote_bitbang_recv_buf_end;
  58                 if (remote_bitbang_recv_buf_start == 0)
  59                         space -= 1;
  60                 return space;
  61         } else {
  62                 return remote_bitbang_recv_buf_start -
  63                        remote_bitbang_recv_buf_end - 1;
  64         }
  65 }
  66
  67 static int remote_bitbang_flush(void)
  68 {
  69         if (remote_bitbang_send_buf_used <= 0)
  70                 return ERROR_OK;
  71
  72         unsigned int offset = 0;
  73         while (offset < remote_bitbang_send_buf_used) {
  74                 ssize_t written = write_socket(remote_bitbang_fd, remote_bitbang_send_buf + offset,
  75                                                                            remote_bitbang_send_buf_used - offset);
  76                 if (written < 0) {
  77                         log_socket_error("remote_bitbang_putc");
  78                         remote_bitbang_send_buf_used = 0;
  79                         return ERROR_FAIL;
  80                 }
  81                 offset += written;
  82         }
  83         remote_bitbang_send_buf_used = 0;
  84         return ERROR_OK;
  85 }
  86
  87 enum block_bool {
  88         NO_BLOCK,
  89         BLOCK
  90 };
  91
  92 /* Read any incoming data, placing it into the buffer. */
  93 static int remote_bitbang_fill_buf(enum block_bool block)
  94 {
  95         if (remote_bitbang_recv_buf_empty()) {
  96                 /* If the buffer is empty, reset it to 0 so we get more
  97                  * contiguous space. */
  98                 remote_bitbang_recv_buf_start = 0;
  99                 remote_bitbang_recv_buf_end = 0;
 100         }
 101
 102         if (block == BLOCK) {
 103                 if (remote_bitbang_flush() != ERROR_OK)
 104                         return ERROR_FAIL;
 105                 socket_block(remote_bitbang_fd);
 106         }
 107
 108         bool first = true;
 109         while (!remote_bitbang_recv_buf_full()) {
 110                 unsigned int contiguous_available_space =
 111                                 remote_bitbang_recv_buf_contiguous_available_space();
 112                 ssize_t count = read_socket(remote_bitbang_fd,
 113                                 remote_bitbang_recv_buf + remote_bitbang_recv_buf_end,
 114                                 contiguous_available_space);
 115                 if (first && block == BLOCK)
 116                         socket_nonblock(remote_bitbang_fd);
 117                 first = false;
 118                 if (count > 0) {
 119                         remote_bitbang_recv_buf_end += count;
 120                         if (remote_bitbang_recv_buf_end == sizeof(remote_bitbang_recv_buf))
 121                                 remote_bitbang_recv_buf_end = 0;
 122                 } else if (count == 0) {
 123                         return ERROR_OK;
 124                 } else if (count < 0) {
 125 #ifdef _WIN32
 126                         if (WSAGetLastError() == WSAEWOULDBLOCK) {
 127 #else
 128                         if (errno == EAGAIN) {
 129 #endif
 130                                 return ERROR_OK;
 131                         } else {
 132                                 log_socket_error("remote_bitbang_fill_buf");
 133                                 return ERROR_FAIL;
 134                         }
 135                 }
 136         }
 137
 138         return ERROR_OK;
 139 }
 140
 141 typedef enum {
 142         NO_FLUSH,
 143         FLUSH_SEND_BUF
 144 } flush_bool_t;
 145
 146 static int remote_bitbang_queue(int c, flush_bool_t flush)
 147 {
 148         remote_bitbang_send_buf[remote_bitbang_send_buf_used++] = c;
 149         if (flush == FLUSH_SEND_BUF ||
 150                         remote_bitbang_send_buf_used >= ARRAY_SIZE(remote_bitbang_send_buf))
 151                 return remote_bitbang_flush();
 152         return ERROR_OK;
 153 }
 154
 155 static int remote_bitbang_quit(void)
 156 {
 157         if (remote_bitbang_queue('Q', FLUSH_SEND_BUF) == ERROR_FAIL)
 158                 return ERROR_FAIL;
 159
 160         if (close_socket(remote_bitbang_fd) != 0) {
 161                 log_socket_error("close_socket");
 162                 return ERROR_FAIL;
 163         }
 164
 165         free(remote_bitbang_host);
 166         free(remote_bitbang_port);
 167
 168         LOG_INFO("remote_bitbang interface quit");
 169         return ERROR_OK;
 170 }
 171
 172 static bb_value_t char_to_int(int c)
 173 {
 174         switch (c) {
 175                 case '0':
 176                         return BB_LOW;
 177                 case '1':
 178                         return BB_HIGH;
 179                 default:
 180                         remote_bitbang_quit();
 181                         LOG_ERROR("remote_bitbang: invalid read response: %c(%i)", c, c);
 182                         return BB_ERROR;
 183         }
 184 }
 185
 186 static int remote_bitbang_sample(void)
 187 {
 188         if (remote_bitbang_fill_buf(NO_BLOCK) != ERROR_OK)
 189                 return ERROR_FAIL;
 190         assert(!remote_bitbang_recv_buf_full());
 191         return remote_bitbang_queue('R', NO_FLUSH);
 192 }
 193
 194 static bb_value_t remote_bitbang_read_sample(void)
 195 {
 196         if (remote_bitbang_recv_buf_empty()) {
 197                 if (remote_bitbang_fill_buf(BLOCK) != ERROR_OK)
 198                         return BB_ERROR;
 199         }
 200         assert(!remote_bitbang_recv_buf_empty());
 201         int c = remote_bitbang_recv_buf[remote_bitbang_recv_buf_start];
 202         remote_bitbang_recv_buf_start =
 203                 (remote_bitbang_recv_buf_start + 1) % sizeof(remote_bitbang_recv_buf);
 204         return char_to_int(c);
 205 }
 206
 207 static int remote_bitbang_write(int tck, int tms, int tdi)
 208 {
 209         char c = '0' + ((tck ? 0x4 : 0x0) | (tms ? 0x2 : 0x0) | (tdi ? 0x1 : 0x0));
 210         return remote_bitbang_queue(c, NO_FLUSH);
 211 }
 212
 213 static int remote_bitbang_reset(int trst, int srst)
 214 {
 215         char c = 'r' + ((trst ? 0x2 : 0x0) | (srst ? 0x1 : 0x0));
 216         /* Always flush the send buffer on reset, because the reset call need not be
 217          * followed by jtag_execute_queue(). */
 218         return remote_bitbang_queue(c, FLUSH_SEND_BUF);
 219 }
 220
 221 static int remote_bitbang_sleep(unsigned int microseconds)
 222 {
 223         if (!use_remote_sleep) {
 224                 jtag_sleep(microseconds);
 225                 return ERROR_OK;
 226         }
 227
 228         int tmp;
 229         unsigned int ms = microseconds / 1000;
 230         unsigned int us = microseconds % 1000;
 231
 232         for (unsigned int i = 0; i < ms; i++) {
 233                 tmp = remote_bitbang_queue('Z', NO_FLUSH);
 234                 if (tmp != ERROR_OK)
 235                         return tmp;
 236         }
 237
 238         for (unsigned int i = 0; i < us; i++) {
 239                 tmp = remote_bitbang_queue('z', NO_FLUSH);
 240                 if (tmp != ERROR_OK)
 241                         return tmp;
 242         }
 243
 244         return remote_bitbang_flush();
 245 }
 246
 247 static int remote_bitbang_blink(int on)
 248 {
 249         char c = on ? 'B' : 'b';
 250         return remote_bitbang_queue(c, FLUSH_SEND_BUF);
 251 }
 252
 253 static void remote_bitbang_swdio_drive(bool is_output)
 254 {
 255         char c = is_output ? 'O' : 'o';
 256         if (remote_bitbang_queue(c, FLUSH_SEND_BUF) == ERROR_FAIL)
 257                 LOG_ERROR("Error setting direction for swdio");
 258 }
 259
 260 static int remote_bitbang_swdio_read(void)
 261 {
 262         if (remote_bitbang_queue('c', FLUSH_SEND_BUF) != ERROR_FAIL)
 263                 return remote_bitbang_read_sample();
 264         else
 265                 return BB_ERROR;
 266 }
 267
 268 static int remote_bitbang_swd_write(int swclk, int swdio)
 269 {
 270         char c = 'd' + ((swclk ? 0x2 : 0x0) | (swdio ? 0x1 : 0x0));
 271         return remote_bitbang_queue(c, NO_FLUSH);
 272 }
 273
 274 static struct bitbang_interface remote_bitbang_bitbang = {
 275         .buf_size = sizeof(remote_bitbang_recv_buf) - 1,
 276         .sample = &remote_bitbang_sample,
 277         .read_sample = &remote_bitbang_read_sample,
 278         .write = &remote_bitbang_write,
 279         .swdio_read = &remote_bitbang_swdio_read,
 280         .swdio_drive = &remote_bitbang_swdio_drive,
 281         .swd_write = &remote_bitbang_swd_write,
 282         .blink = &remote_bitbang_blink,
 283         .sleep = &remote_bitbang_sleep,
 284         .flush = &remote_bitbang_flush,
 285 };
 286
 287 static int remote_bitbang_init_tcp(void)
 288 {
 289         struct addrinfo hints = { .ai_family = AF_UNSPEC, .ai_socktype = SOCK_STREAM };
 290         struct addrinfo *result, *rp;
 291         int fd = 0;
 292
 293         LOG_INFO("Connecting to %s:%s",
 294                         remote_bitbang_host ? remote_bitbang_host : "localhost",
 295                         remote_bitbang_port);
 296
 297         /* Obtain address(es) matching host/port */
 298         int s = getaddrinfo(remote_bitbang_host, remote_bitbang_port, &hints, &result);
 299         if (s != 0) {
 300                 LOG_ERROR("getaddrinfo: %s\n", gai_strerror(s));
 301                 return ERROR_FAIL;
 302         }
 303
 304         /* getaddrinfo() returns a list of address structures.
 305          Try each address until we successfully connect(2).
 306          If socket(2) (or connect(2)) fails, we (close the socket
 307          and) try the next address. */
 308
 309         for (rp = result; rp ; rp = rp->ai_next) {
 310                 fd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
 311                 if (fd == -1)
 312                         continue;
 313
 314                 if (connect(fd, rp->ai_addr, rp->ai_addrlen) != -1)
 315                         break; /* Success */
 316
 317                 close(fd);
 318         }
 319
 320         /* We work hard to collapse the writes into the minimum number, so when
 321          * we write something we want to get it to the other end of the
 322          * connection as fast as possible. */
 323         int one = 1;
 324         /* On Windows optval has to be a const char *. */
 325         setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, (const char *)&one, sizeof(one));
 326
 327         freeaddrinfo(result); /* No longer needed */
 328
 329         if (!rp) { /* No address succeeded */
 330                 log_socket_error("Failed to connect");
 331                 return ERROR_FAIL;
 332         }
 333
 334         return fd;
 335 }
 336
 337 static int remote_bitbang_init_unix(void)
 338 {
 339         if (!remote_bitbang_host) {
 340                 LOG_ERROR("host/socket not specified");
 341                 return ERROR_FAIL;
 342         }
 343
 344         LOG_INFO("Connecting to unix socket %s", remote_bitbang_host);
 345         int fd = socket(PF_UNIX, SOCK_STREAM, 0);
 346         if (fd < 0) {
 347                 log_socket_error("socket");
 348                 return ERROR_FAIL;
 349         }
 350
 351         struct sockaddr_un addr;
 352         addr.sun_family = AF_UNIX;
 353         strncpy(addr.sun_path, remote_bitbang_host, sizeof(addr.sun_path));
 354         addr.sun_path[sizeof(addr.sun_path)-1] = '\0';
 355
 356         if (connect(fd, (struct sockaddr *)&addr, sizeof(struct sockaddr_un)) < 0) {
 357                 log_socket_error("connect");
 358                 return ERROR_FAIL;
 359         }
 360
 361         return fd;
 362 }
 363
 364 static int remote_bitbang_init(void)
 365 {
 366         bitbang_interface = &remote_bitbang_bitbang;
 367
 368         remote_bitbang_recv_buf_start = 0;
 369         remote_bitbang_recv_buf_end = 0;
 370
 371         LOG_INFO("Initializing remote_bitbang driver");
 372         if (!remote_bitbang_port)
 373                 remote_bitbang_fd = remote_bitbang_init_unix();
 374         else
 375                 remote_bitbang_fd = remote_bitbang_init_tcp();
 376
 377         if (remote_bitbang_fd < 0)
 378                 return remote_bitbang_fd;
 379
 380         socket_nonblock(remote_bitbang_fd);
 381
 382         LOG_INFO("remote_bitbang driver initialized");
 383         return ERROR_OK;
 384 }
 385
 386 COMMAND_HANDLER(remote_bitbang_handle_remote_bitbang_port_command)
 387 {
 388         if (CMD_ARGC == 1) {
 389                 uint16_t port;
 390                 COMMAND_PARSE_NUMBER(u16, CMD_ARGV[0], port);
 391                 free(remote_bitbang_port);
 392                 remote_bitbang_port = port == 0 ? NULL : strdup(CMD_ARGV[0]);
 393                 return ERROR_OK;
 394         }
 395         return ERROR_COMMAND_SYNTAX_ERROR;
 396 }
 397
 398 COMMAND_HANDLER(remote_bitbang_handle_remote_bitbang_host_command)
 399 {
 400         if (CMD_ARGC == 1) {
 401                 free(remote_bitbang_host);
 402                 remote_bitbang_host = strdup(CMD_ARGV[0]);
 403                 return ERROR_OK;
 404         }
 405         return ERROR_COMMAND_SYNTAX_ERROR;
 406 }
 407
 408 static const char * const remote_bitbang_transports[] = { "jtag", "swd", NULL };
 409
 410 COMMAND_HANDLER(remote_bitbang_handle_remote_bitbang_use_remote_sleep_command)
 411 {
 412         if (CMD_ARGC != 1)
 413                 return ERROR_COMMAND_SYNTAX_ERROR;
 414
 415         COMMAND_PARSE_ON_OFF(CMD_ARGV[0], use_remote_sleep);
 416
 417         return ERROR_OK;
 418 }
 419
 420 static const struct command_registration remote_bitbang_subcommand_handlers[] = {
 421         {
 422                 .name = "port",
 423                 .handler = remote_bitbang_handle_remote_bitbang_port_command,
 424                 .mode = COMMAND_CONFIG,
 425                 .help = "Set the port to use to connect to the remote jtag.\n"
 426                         "  if 0 or unset, use unix sockets to connect to the remote jtag.",
 427                 .usage = "port_number",
 428         },
 429         {
 430                 .name = "host",
 431                 .handler = remote_bitbang_handle_remote_bitbang_host_command,
 432                 .mode = COMMAND_CONFIG,
 433                 .help = "Set the host to use to connect to the remote jtag.\n"
 434                         "  if port is 0 or unset, this is the name of the unix socket to use.",
 435                 .usage = "host_name",
 436         },
 437         {
 438                 .name = "use_remote_sleep",
 439                 .handler = remote_bitbang_handle_remote_bitbang_use_remote_sleep_command,
 440                 .mode = COMMAND_CONFIG,
 441                 .help = "Rather than executing sleep locally, include delays in the "
 442                         "instruction stream for the remote host.",
 443                 .usage = "(on|off)",
 444         },
 445         COMMAND_REGISTRATION_DONE
 446 };
 447
 448 static const struct command_registration remote_bitbang_command_handlers[] = {
 449         {
 450                 .name = "remote_bitbang",
 451                 .mode = COMMAND_ANY,
 452                 .help = "perform remote_bitbang management",
 453                 .chain = remote_bitbang_subcommand_handlers,
 454                 .usage = "",
 455         },
 456         COMMAND_REGISTRATION_DONE
 457 };
 458
 459 static int remote_bitbang_execute_queue(struct jtag_command *cmd_queue)
 460 {
 461         /* safety: the send buffer must be empty, no leftover characters from
 462          * previous transactions */
 463         assert(remote_bitbang_send_buf_used == 0);
 464
 465         /* process the JTAG command queue */
 466         int ret = bitbang_execute_queue(cmd_queue);
 467         if (ret != ERROR_OK)
 468                 return ret;
 469
 470         /* flush not-yet-sent characters, if any */
 471         return remote_bitbang_flush();
 472 }
 473
 474 static struct jtag_interface remote_bitbang_interface = {
 475         .execute_queue = &remote_bitbang_execute_queue,
 476 };
 477
 478 struct adapter_driver remote_bitbang_adapter_driver = {
 479         .name = "remote_bitbang",
 480         .transports = remote_bitbang_transports,
 481         .commands = remote_bitbang_command_handlers,
 482
 483         .init = &remote_bitbang_init,
 484         .quit = &remote_bitbang_quit,
 485         .reset = &remote_bitbang_reset,
 486
 487         .jtag_ops = &remote_bitbang_interface,
 488         .swd_ops = &bitbang_swd,
 489 };