src/jtag/interface.c

   1 /***************************************************************************
   2  *   Copyright (C) 2005 by Dominic Rath                                    *
   3  *   Dominic.Rath@gmx.de                                                   *
   4  *                                                                         *
   5  *   Copyright (C) 2007,2008 Øyvind Harboe                                 *
   6  *   oyvind.harboe@zylin.com                                               *
   7  *                                                                         *
   8  *   Copyright (C) 2009 SoftPLC Corporation                                *
   9  *       http://softplc.com                                                *
  10  *   dick@softplc.com                                                      *
  11  *                                                                         *
  12  *   Copyright (C) 2009 Zachary T Welch                                    *
  13  *   zw@superlucidity.net                                                  *
  14  *                                                                         *
  15  *   This program is free software; you can redistribute it and/or modify  *
  16  *   it under the terms of the GNU General Public License as published by  *
  17  *   the Free Software Foundation; either version 2 of the License, or     *
  18  *   (at your option) any later version.                                   *
  19  *                                                                         *
  20  *   This program is distributed in the hope that it will be useful,       *
  21  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  22  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  23  *   GNU General Public License for more details.                          *
  24  *                                                                         *
  25  *   You should have received a copy of the GNU General Public License     *
  26  *   along with this program.  If not, see <http://www.gnu.org/licenses/>. *
  27  ***************************************************************************/
  28
  29 #ifdef HAVE_CONFIG_H
  30 #include "config.h"
  31 #endif
  32
  33 #include "jtag.h"
  34 #include "interface.h"
  35
  36 /**
  37  * @see tap_set_state() and tap_get_state() accessors.
  38  * Actual name is not important since accessors hide it.
  39  */
  40 static tap_state_t state_follower = TAP_RESET;
  41
  42 void tap_set_state_impl(tap_state_t new_state)
  43 {
  44         /* this is the state we think the TAPs are in now, was cur_state */
  45         state_follower = new_state;
  46 }
  47
  48 tap_state_t tap_get_state()
  49 {
  50         return state_follower;
  51 }
  52
  53 /**
  54  * @see tap_set_end_state() and tap_get_end_state() accessors.
  55  * Actual name is not important because accessors hide it.
  56  */
  57 static tap_state_t end_state_follower = TAP_RESET;
  58
  59 void tap_set_end_state(tap_state_t new_end_state)
  60 {
  61         /* this is the state we think the TAPs will be in at completion of the
  62          * current TAP operation, was end_state
  63         */
  64         end_state_follower = new_end_state;
  65 }
  66
  67 tap_state_t tap_get_end_state()
  68 {
  69         return end_state_follower;
  70 }
  71
  72 int tap_move_ndx(tap_state_t astate)
  73 {
  74         /* given a stable state, return the index into the tms_seqs[]
  75          * array within tap_get_tms_path()
  76          */
  77
  78         int ndx;
  79
  80         switch (astate) {
  81                 case TAP_RESET:
  82                         ndx = 0;
  83                         break;
  84                 case TAP_IDLE:
  85                         ndx = 1;
  86                         break;
  87                 case TAP_DRSHIFT:
  88                         ndx = 2;
  89                         break;
  90                 case TAP_DRPAUSE:
  91                         ndx = 3;
  92                         break;
  93                 case TAP_IRSHIFT:
  94                         ndx = 4;
  95                         break;
  96                 case TAP_IRPAUSE:
  97                         ndx = 5;
  98                         break;
  99                 default:
 100                         LOG_ERROR("FATAL: unstable state \"%s\" in tap_move_ndx()",
 101                                         tap_state_name(astate));
 102                         exit(1);
 103         }
 104
 105         return ndx;
 106 }
 107
 108 /* tap_move[i][j]: tap movement command to go from state i to state j
 109  * encodings of i and j are what tap_move_ndx() reports.
 110  *
 111  * DRSHIFT->DRSHIFT and IRSHIFT->IRSHIFT have to be caught in interface specific code
 112  */
 113 struct tms_sequences {
 114         uint8_t bits;
 115         uint8_t bit_count;
 116 };
 117
 118 /*
 119  * These macros allow us to specify TMS state transitions by bits rather than hex bytes.
 120  * Read the bits from LSBit first to MSBit last (right-to-left).
 121  */
 122 #define HEX__(n) 0x##n##LU
 123
 124 #define B8__(x) \
 125         ((((x) & 0x0000000FLU) ? (1 << 0) : 0) \
 126         +(((x) & 0x000000F0LU) ? (1 << 1) : 0) \
 127         +(((x) & 0x00000F00LU) ? (1 << 2) : 0) \
 128         +(((x) & 0x0000F000LU) ? (1 << 3) : 0) \
 129         +(((x) & 0x000F0000LU) ? (1 << 4) : 0) \
 130         +(((x) & 0x00F00000LU) ? (1 << 5) : 0) \
 131         +(((x) & 0x0F000000LU) ? (1 << 6) : 0) \
 132         +(((x) & 0xF0000000LU) ? (1 << 7) : 0))
 133
 134 #define B8(bits, count) {((uint8_t)B8__(HEX__(bits))), (count)}
 135
 136 static const struct tms_sequences old_tms_seqs[6][6] = {        /* [from_state_ndx][to_state_ndx] */
 137         /* value clocked to TMS to move from one of six stable states to another.
 138          * N.B. OOCD clocks TMS from LSB first, so read these right-to-left.
 139          * N.B. Reset only needs to be 0b11111, but in JLink an even byte of 1's is more stable.
 140          * These extra ones cause no TAP state problem, because we go into reset and stay in reset.
 141          */
 142
 143 /* to state: */
 144 /*      RESET            IDLE                   DRSHIFT                 DRPAUSE                 IRSHIFT                 IRPAUSE         */      /* from state: */
 145 {B8(1111111, 7), B8(0000000, 7), B8(0010111, 7), B8(0001010, 7), B8(0011011, 7), B8(0010110, 7)},/* RESET */
 146 {B8(1111111, 7), B8(0000000, 7), B8(0100101, 7), B8(0000101, 7), B8(0101011, 7), B8(0001011, 7)},/* IDLE */
 147 {B8(1111111, 7), B8(0110001, 7), B8(0000000, 7), B8(0000001, 7), B8(0001111, 7), B8(0101111, 7)},/* DRSHIFT */
 148 {B8(1111111, 7), B8(0110000, 7), B8(0100000, 7), B8(0010111, 7), B8(0011110, 7), B8(0101111, 7)},/* DRPAUSE */
 149 {B8(1111111, 7), B8(0110001, 7), B8(0000111, 7), B8(0010111, 7), B8(0000000, 7), B8(0000001, 7)},/* IRSHIFT */
 150 {B8(1111111, 7), B8(0110000, 7), B8(0011100, 7), B8(0010111, 7), B8(0011110, 7), B8(0101111, 7)},/* IRPAUSE */
 151 };
 152
 153 static const struct tms_sequences short_tms_seqs[6][6] = { /* [from_state_ndx][to_state_ndx] */
 154         /* this is the table submitted by Jeff Williams on 3/30/2009 with this comment:
 155
 156         OK, I added Peter's version of the state table, and it works OK for
 157         me on MC1322x. I've recreated the jlink portion of patch with this
 158         new state table. His changes to my state table are pretty minor in
 159         terms of total transitions, but Peter feels that his version fixes
 160         some long-standing problems.
 161         Jeff
 162
 163         I added the bit count into the table, reduced RESET column to 7 bits from 8.
 164         Dick
 165
 166         state specific comments:
 167         ------------------------
 168         *->RESET                tried the 5 bit reset and it gave me problems, 7 bits seems to
 169                                         work better on ARM9 with ft2232 driver.  (Dick)
 170
 171         RESET->DRSHIFT add 1 extra clock cycles in the RESET state before advancing.
 172                                         needed on ARM9 with ft2232 driver.  (Dick)
 173                                         (For a total of *THREE* extra clocks in RESET; NOP.)
 174
 175         RESET->IRSHIFT add 1 extra clock cycles in the RESET state before advancing.
 176                                         needed on ARM9 with ft2232 driver.  (Dick)
 177                                         (For a total of *TWO* extra clocks in RESET; NOP.)
 178
 179         RESET->*                always adds one or more clocks in the target state,
 180                                         which should be NOPS; except shift states which (as
 181                                         noted above) add those clocks in RESET.
 182
 183         The X-to-X transitions always add clocks; from *SHIFT, they go
 184         via IDLE and thus *DO HAVE SIDE EFFECTS* (capture and update).
 185 */
 186
 187 /* to state: */
 188 /*      RESET           IDLE                    DRSHIFT                 DRPAUSE                 IRSHIFT                 IRPAUSE */ /* from state: */
 189 {B8(1111111, 7), B8(0000000, 7), B8(0010111, 7), B8(0001010, 7), B8(0011011, 7), B8(0010110, 7)}, /* RESET */
 190 {B8(1111111, 7), B8(0000000, 7), B8(001, 3),     B8(0101, 4),    B8(0011, 4),    B8(01011, 5)}, /* IDLE */
 191 {B8(1111111, 7), B8(011, 3),     B8(00111, 5),   B8(01, 2),              B8(001111, 6),  B8(0101111, 7)}, /* DRSHIFT */
 192 {B8(1111111, 7), B8(011, 3),     B8(01, 2),              B8(0, 1),               B8(001111, 6),  B8(0101111, 7)}, /* DRPAUSE */
 193 {B8(1111111, 7), B8(011, 3),     B8(00111, 5),   B8(010111, 6),  B8(001111, 6),  B8(01, 2)}, /* IRSHIFT */
 194 {B8(1111111, 7), B8(011, 3),     B8(00111, 5),   B8(010111, 6),  B8(01, 2),              B8(0, 1)} /* IRPAUSE */
 195 };
 196
 197 typedef const struct tms_sequences tms_table[6][6];
 198
 199 static tms_table *tms_seqs = &short_tms_seqs;
 200
 201 int tap_get_tms_path(tap_state_t from, tap_state_t to)
 202 {
 203         return (*tms_seqs)[tap_move_ndx(from)][tap_move_ndx(to)].bits;
 204 }
 205
 206 int tap_get_tms_path_len(tap_state_t from, tap_state_t to)
 207 {
 208         return (*tms_seqs)[tap_move_ndx(from)][tap_move_ndx(to)].bit_count;
 209 }
 210
 211 bool tap_is_state_stable(tap_state_t astate)
 212 {
 213         bool is_stable;
 214
 215         /*      A switch () is used because it is symbol dependent
 216          * (not value dependent like an array), and can also check bounds.
 217         */
 218         switch (astate) {
 219                 case TAP_RESET:
 220                 case TAP_IDLE:
 221                 case TAP_DRSHIFT:
 222                 case TAP_DRPAUSE:
 223                 case TAP_IRSHIFT:
 224                 case TAP_IRPAUSE:
 225                         is_stable = true;
 226                         break;
 227                 default:
 228                         is_stable = false;
 229         }
 230
 231         return is_stable;
 232 }
 233
 234 tap_state_t tap_state_transition(tap_state_t cur_state, bool tms)
 235 {
 236         tap_state_t new_state;
 237
 238         /*      A switch is used because it is symbol dependent and not value dependent
 239          * like an array.  Also it can check for out of range conditions.
 240         */
 241
 242         if (tms) {
 243                 switch (cur_state) {
 244                         case TAP_RESET:
 245                                 new_state = cur_state;
 246                                 break;
 247                         case TAP_IDLE:
 248                         case TAP_DRUPDATE:
 249                         case TAP_IRUPDATE:
 250                                 new_state = TAP_DRSELECT;
 251                                 break;
 252                         case TAP_DRSELECT:
 253                                 new_state = TAP_IRSELECT;
 254                                 break;
 255                         case TAP_DRCAPTURE:
 256                         case TAP_DRSHIFT:
 257                                 new_state = TAP_DREXIT1;
 258                                 break;
 259                         case TAP_DREXIT1:
 260                         case TAP_DREXIT2:
 261                                 new_state = TAP_DRUPDATE;
 262                                 break;
 263                         case TAP_DRPAUSE:
 264                                 new_state = TAP_DREXIT2;
 265                                 break;
 266                         case TAP_IRSELECT:
 267                                 new_state = TAP_RESET;
 268                                 break;
 269                         case TAP_IRCAPTURE:
 270                         case TAP_IRSHIFT:
 271                                 new_state = TAP_IREXIT1;
 272                                 break;
 273                         case TAP_IREXIT1:
 274                         case TAP_IREXIT2:
 275                                 new_state = TAP_IRUPDATE;
 276                                 break;
 277                         case TAP_IRPAUSE:
 278                                 new_state = TAP_IREXIT2;
 279                                 break;
 280                         default:
 281                                 LOG_ERROR("fatal: invalid argument cur_state=%d", cur_state);
 282                                 exit(1);
 283                                 break;
 284                 }
 285         } else {
 286                 switch (cur_state) {
 287                         case TAP_RESET:
 288                         case TAP_IDLE:
 289                         case TAP_DRUPDATE:
 290                         case TAP_IRUPDATE:
 291                                 new_state = TAP_IDLE;
 292                                 break;
 293                         case TAP_DRSELECT:
 294                                 new_state = TAP_DRCAPTURE;
 295                                 break;
 296                         case TAP_DRCAPTURE:
 297                         case TAP_DRSHIFT:
 298                         case TAP_DREXIT2:
 299                                 new_state = TAP_DRSHIFT;
 300                                 break;
 301                         case TAP_DREXIT1:
 302                         case TAP_DRPAUSE:
 303                                 new_state = TAP_DRPAUSE;
 304                                 break;
 305                         case TAP_IRSELECT:
 306                                 new_state = TAP_IRCAPTURE;
 307                                 break;
 308                         case TAP_IRCAPTURE:
 309                         case TAP_IRSHIFT:
 310                         case TAP_IREXIT2:
 311                                 new_state = TAP_IRSHIFT;
 312                                 break;
 313                         case TAP_IREXIT1:
 314                         case TAP_IRPAUSE:
 315                                 new_state = TAP_IRPAUSE;
 316                                 break;
 317                         default:
 318                                 LOG_ERROR("fatal: invalid argument cur_state=%d", cur_state);
 319                                 exit(1);
 320                                 break;
 321                 }
 322         }
 323
 324         return new_state;
 325 }
 326
 327 /* NOTE:  do not change these state names.  They're documented,
 328  * and we rely on them to match SVF input (except for "RUN/IDLE").
 329  */
 330 static const struct name_mapping {
 331         enum tap_state symbol;
 332         const char *name;
 333 } tap_name_mapping[] = {
 334         { TAP_RESET, "RESET", },
 335         { TAP_IDLE, "RUN/IDLE", },
 336         { TAP_DRSELECT, "DRSELECT", },
 337         { TAP_DRCAPTURE, "DRCAPTURE", },
 338         { TAP_DRSHIFT, "DRSHIFT", },
 339         { TAP_DREXIT1, "DREXIT1", },
 340         { TAP_DRPAUSE, "DRPAUSE", },
 341         { TAP_DREXIT2, "DREXIT2", },
 342         { TAP_DRUPDATE, "DRUPDATE", },
 343         { TAP_IRSELECT, "IRSELECT", },
 344         { TAP_IRCAPTURE, "IRCAPTURE", },
 345         { TAP_IRSHIFT, "IRSHIFT", },
 346         { TAP_IREXIT1, "IREXIT1", },
 347         { TAP_IRPAUSE, "IRPAUSE", },
 348         { TAP_IREXIT2, "IREXIT2", },
 349         { TAP_IRUPDATE, "IRUPDATE", },
 350
 351         /* only for input:  accept standard SVF name */
 352         { TAP_IDLE, "IDLE", },
 353 };
 354
 355 const char *tap_state_name(tap_state_t state)
 356 {
 357         unsigned i;
 358
 359         for (i = 0; i < ARRAY_SIZE(tap_name_mapping); i++) {
 360                 if (tap_name_mapping[i].symbol == state)
 361                         return tap_name_mapping[i].name;
 362         }
 363         return "???";
 364 }
 365
 366 tap_state_t tap_state_by_name(const char *name)
 367 {
 368         unsigned i;
 369
 370         for (i = 0; i < ARRAY_SIZE(tap_name_mapping); i++) {
 371                 /* be nice to the human */
 372                 if (strcasecmp(name, tap_name_mapping[i].name) == 0)
 373                         return tap_name_mapping[i].symbol;
 374         }
 375         /* not found */
 376         return TAP_INVALID;
 377 }
 378
 379 #ifdef _DEBUG_JTAG_IO_
 380
 381 #define JTAG_DEBUG_STATE_APPEND(buf, len, bit) \
 382         do { buf[len] = bit ? '1' : '0'; } while (0)
 383 #define JTAG_DEBUG_STATE_PRINT(a, b, astr, bstr) \
 384         DEBUG_JTAG_IO("TAP/SM: %9s -> %5s\tTMS: %s\tTDI: %s", \
 385         tap_state_name(a), tap_state_name(b), astr, bstr)
 386
 387 tap_state_t jtag_debug_state_machine(const void *tms_buf, const void *tdi_buf,
 388         unsigned tap_bits, tap_state_t next_state)
 389 {
 390         const uint8_t *tms_buffer;
 391         const uint8_t *tdi_buffer;
 392         unsigned tap_bytes;
 393         unsigned cur_byte;
 394         unsigned cur_bit;
 395
 396         unsigned tap_out_bits;
 397         char tms_str[33];
 398         char tdi_str[33];
 399
 400         tap_state_t last_state;
 401
 402         /* set startstate (and possibly last, if tap_bits == 0) */
 403         last_state = next_state;
 404         DEBUG_JTAG_IO("TAP/SM: START state: %s", tap_state_name(next_state));
 405
 406         tms_buffer = (const uint8_t *)tms_buf;
 407         tdi_buffer = (const uint8_t *)tdi_buf;
 408
 409         tap_bytes = DIV_ROUND_UP(tap_bits, 8);
 410         DEBUG_JTAG_IO("TAP/SM: TMS bits: %u (bytes: %u)", tap_bits, tap_bytes);
 411
 412         tap_out_bits = 0;
 413         for (cur_byte = 0; cur_byte < tap_bytes; cur_byte++) {
 414                 for (cur_bit = 0; cur_bit < 8; cur_bit++) {
 415                         /* make sure we do not run off the end of the buffers */
 416                         unsigned tap_bit = cur_byte * 8 + cur_bit;
 417                         if (tap_bit == tap_bits)
 418                                 break;
 419
 420                         /* check and save TMS bit */
 421                         tap_bit = !!(tms_buffer[cur_byte] & (1 << cur_bit));
 422                         JTAG_DEBUG_STATE_APPEND(tms_str, tap_out_bits, tap_bit);
 423
 424                         /* use TMS bit to find the next TAP state */
 425                         next_state = tap_state_transition(last_state, tap_bit);
 426
 427                         /* check and store TDI bit */
 428                         tap_bit = !!(tdi_buffer[cur_byte] & (1 << cur_bit));
 429                         JTAG_DEBUG_STATE_APPEND(tdi_str, tap_out_bits, tap_bit);
 430
 431                         /* increment TAP bits */
 432                         tap_out_bits++;
 433
 434                         /* Only show TDO bits on state transitions, or */
 435                         /* after some number of bits in the same state. */
 436                         if ((next_state == last_state) && (tap_out_bits < 32))
 437                                 continue;
 438
 439                         /* terminate strings and display state transition */
 440                         tms_str[tap_out_bits] = tdi_str[tap_out_bits] = 0;
 441                         JTAG_DEBUG_STATE_PRINT(last_state, next_state, tms_str, tdi_str);
 442
 443                         /* reset state */
 444                         last_state = next_state;
 445                         tap_out_bits = 0;
 446                 }
 447         }
 448
 449         if (tap_out_bits) {
 450                 /* terminate strings and display state transition */
 451                 tms_str[tap_out_bits] = tdi_str[tap_out_bits] = 0;
 452                 JTAG_DEBUG_STATE_PRINT(last_state, next_state, tms_str, tdi_str);
 453         }
 454
 455         DEBUG_JTAG_IO("TAP/SM: FINAL state: %s", tap_state_name(next_state));
 456
 457         return next_state;
 458 }
 459 #endif  /* _DEBUG_JTAG_IO_ */
 460
 461 void tap_use_new_tms_table(bool use_new)
 462 {
 463         tms_seqs = use_new ? &short_tms_seqs : &old_tms_seqs;
 464 }
 465 bool tap_uses_new_tms_table(void)
 466 {
 467         return tms_seqs == &short_tms_seqs;
 468 }