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, write to the                         *
  27  *   Free Software Foundation, Inc.,                                       *
  28  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  29  ***************************************************************************/
  30 #ifdef HAVE_CONFIG_H
  31 #include "config.h"
  32 #endif
  33
  34 #include "jtag.h"
  35 #include "interface.h"
  36
  37 /**
  38  * @see tap_set_state() and tap_get_state() accessors.
  39  * Actual name is not important since accessors hide it.
  40  */
  41 static tap_state_t state_follower = TAP_RESET;
  42
  43 void tap_set_state_impl(tap_state_t new_state)
  44 {
  45         /* this is the state we think the TAPs are in now, was cur_state */
  46         state_follower = new_state;
  47 }
  48
  49 tap_state_t tap_get_state()
  50 {
  51         return state_follower;
  52 }
  53
  54 /**
  55  * @see tap_set_end_state() and tap_get_end_state() accessors.
  56  * Actual name is not important because accessors hide it.
  57  */
  58 static tap_state_t end_state_follower = TAP_RESET;
  59
  60 void tap_set_end_state(tap_state_t new_end_state)
  61 {
  62         /* this is the state we think the TAPs will be in at completion of the
  63            current TAP operation, was end_state
  64         */
  65         end_state_follower = new_end_state;
  66 }
  67
  68 tap_state_t tap_get_end_state()
  69 {
  70         return end_state_follower;
  71 }
  72
  73
  74 int tap_move_ndx(tap_state_t astate)
  75 {
  76         /* given a stable state, return the index into the tms_seqs[]
  77          * array within tap_get_tms_path()
  78          */
  79
  80         int ndx;
  81
  82         switch (astate)
  83         {
  84         case TAP_RESET:         ndx = 0;                        break;
  85         case TAP_IDLE:          ndx = 1;                        break;
  86         case TAP_DRSHIFT:       ndx = 2;                        break;
  87         case TAP_DRPAUSE:       ndx = 3;                        break;
  88         case TAP_IRSHIFT:       ndx = 4;                        break;
  89         case TAP_IRPAUSE:       ndx = 5;                        break;
  90         default:
  91                 LOG_ERROR("FATAL: unstable state \"%s\" in tap_move_ndx()",
  92                                 tap_state_name(astate));
  93                 exit(1);
  94         }
  95
  96         return ndx;
  97 }
  98
  99
 100 /* tap_move[i][j]: tap movement command to go from state i to state j
 101  * encodings of i and j are what tap_move_ndx() reports.
 102  *
 103  * DRSHIFT->DRSHIFT and IRSHIFT->IRSHIFT have to be caught in interface specific code
 104  */
 105 struct tms_sequences
 106 {
 107         uint8_t bits;
 108         uint8_t bit_count;
 109 };
 110
 111 /*
 112  * These macros allow us to specify TMS state transitions by bits rather than hex bytes.
 113  * Read the bits from LSBit first to MSBit last (right-to-left).
 114  */
 115 #define HEX__(n) 0x##n##LU
 116
 117 #define B8__(x) \
 118          (((x) & 0x0000000FLU)?(1 << 0):0) \
 119         +(((x) & 0x000000F0LU)?(1 << 1):0) \
 120         +(((x) & 0x00000F00LU)?(1 << 2):0) \
 121         +(((x) & 0x0000F000LU)?(1 << 3):0) \
 122         +(((x) & 0x000F0000LU)?(1 << 4):0) \
 123         +(((x) & 0x00F00000LU)?(1 << 5):0) \
 124         +(((x) & 0x0F000000LU)?(1 << 6):0) \
 125         +(((x) & 0xF0000000LU)?(1 << 7):0)
 126
 127 #define B8(bits,count)          { ((uint8_t)B8__(HEX__(bits))), (count) }
 128
 129 static const struct tms_sequences old_tms_seqs[6][6] =          /*  [from_state_ndx][to_state_ndx] */
 130 {
 131         /* value clocked to TMS to move from one of six stable states to another.
 132          * N.B. OOCD clocks TMS from LSB first, so read these right-to-left.
 133          * N.B. Reset only needs to be 0b11111, but in JLink an even byte of 1's is more stable.
 134          * These extra ones cause no TAP state problem, because we go into reset and stay in reset.
 135          */
 136
 137         /* to state: */
 138         /*      RESET                   IDLE                    DRSHIFT                 DRPAUSE                 IRSHIFT                 IRPAUSE         */              /* from state: */
 139         {       B8(1111111,7),  B8(0000000,7),  B8(0010111,7),  B8(0001010,7),  B8(0011011,7),  B8(0010110,7) },        /* RESET */
 140         {       B8(1111111,7),  B8(0000000,7),  B8(0100101,7),  B8(0000101,7),  B8(0101011,7),  B8(0001011,7) },        /* IDLE */
 141         {       B8(1111111,7),  B8(0110001,7),  B8(0000000,7),  B8(0000001,7),  B8(0001111,7),  B8(0101111,7) },        /* DRSHIFT */
 142         {       B8(1111111,7),  B8(0110000,7),  B8(0100000,7),  B8(0010111,7),  B8(0011110,7),  B8(0101111,7) },        /* DRPAUSE */
 143         {       B8(1111111,7),  B8(0110001,7),  B8(0000111,7),  B8(0010111,7),  B8(0000000,7),  B8(0000001,7) },        /* IRSHIFT */
 144         {       B8(1111111,7),  B8(0110000,7),  B8(0011100,7),  B8(0010111,7),  B8(0011110,7),  B8(0101111,7) },        /* IRPAUSE */
 145 };
 146
 147
 148
 149 static const struct tms_sequences short_tms_seqs[6][6] =                /*  [from_state_ndx][to_state_ndx] */
 150 {
 151         /* this is the table submitted by Jeff Williams on 3/30/2009 with this comment:
 152
 153                 OK, I added Peter's version of the state table, and it works OK for
 154                 me on MC1322x. I've recreated the jlink portion of patch with this
 155                 new state table. His changes to my state table are pretty minor in
 156                 terms of total transitions, but Peter feels that his version fixes
 157                 some long-standing problems.
 158                 Jeff
 159
 160                 I added the bit count into the table, reduced RESET column to 7 bits from 8.
 161                 Dick
 162
 163                 state specific comments:
 164                 ------------------------
 165                 *->RESET           tried the 5 bit reset and it gave me problems, 7 bits seems to
 166                                            work better on ARM9 with ft2232 driver.  (Dick)
 167
 168                 RESET->DRSHIFT add 1 extra clock cycles in the RESET state before advancing.
 169                                                 needed on ARM9 with ft2232 driver.  (Dick)
 170                                                 (For a total of *THREE* extra clocks in RESET; NOP.)
 171
 172                 RESET->IRSHIFT add 1 extra clock cycles in the RESET state before advancing.
 173                                                 needed on ARM9 with ft2232 driver.  (Dick)
 174                                                 (For a total of *TWO* extra clocks in RESET; NOP.)
 175
 176                 RESET->*                always adds one or more clocks in the target state,
 177                                                 which should be NOPS; except shift states which (as
 178                                                 noted above) add those clocks in RESET.
 179
 180                 The X-to-X transitions always add clocks; from *SHIFT, they go
 181                 via IDLE and thus *DO HAVE SIDE EFFECTS* (capture and update).
 182         */
 183
 184         /* to state: */
 185         /*      RESET                   IDLE                    DRSHIFT                 DRPAUSE                 IRSHIFT                 IRPAUSE */                      /* from state: */
 186         {       B8(1111111,7),  B8(0000000,7),  B8(0010111,7),  B8(0001010,7),  B8(0011011,7),  B8(0010110,7) },        /* RESET */
 187         {       B8(1111111,7),  B8(0000000,7),  B8(001,3),              B8(0101,4),             B8(0011,4),             B8(01011,5) },          /* IDLE */
 188         {       B8(1111111,7),  B8(011,3),              B8(00111,5),    B8(01,2),               B8(001111,6),   B8(0101111,7) },        /* DRSHIFT */
 189         {       B8(1111111,7),  B8(011,3),              B8(01,2),               B8(0,1),                B8(001111,6),   B8(0101111,7) },        /* DRPAUSE */
 190         {       B8(1111111,7),  B8(011,3),              B8(00111,5),    B8(010111,6),   B8(001111,6),   B8(01,2) },                     /* IRSHIFT */
 191         {       B8(1111111,7),  B8(011,3),              B8(00111,5),    B8(010111,6),   B8(01,2),               B8(0,1)}                        /* IRPAUSE */
 192
 193 };
 194
 195 typedef const struct tms_sequences tms_table[6][6];
 196
 197 static tms_table *tms_seqs=&short_tms_seqs;
 198
 199 int tap_get_tms_path(tap_state_t from, tap_state_t to)
 200 {
 201         return (*tms_seqs)[tap_move_ndx(from)][tap_move_ndx(to)].bits;
 202 }
 203
 204
 205 int tap_get_tms_path_len(tap_state_t from, tap_state_t to)
 206 {
 207         return (*tms_seqs)[tap_move_ndx(from)][tap_move_ndx(to)].bit_count;
 208 }
 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         {
 220         case TAP_RESET:
 221         case TAP_IDLE:
 222         case TAP_DRSHIFT:
 223         case TAP_DRPAUSE:
 224         case TAP_IRSHIFT:
 225         case TAP_IRPAUSE:
 226                 is_stable = true;
 227                 break;
 228         default:
 229                 is_stable = false;
 230         }
 231
 232         return is_stable;
 233 }
 234
 235 tap_state_t tap_state_transition(tap_state_t cur_state, bool tms)
 236 {
 237         tap_state_t new_state;
 238
 239         /*      A switch is used because it is symbol dependent and not value dependent
 240                 like an array.  Also it can check for out of range conditions.
 241         */
 242
 243         if (tms)
 244         {
 245                 switch (cur_state)
 246                 {
 247                 case TAP_RESET:
 248                         new_state = cur_state;
 249                         break;
 250                 case TAP_IDLE:
 251                 case TAP_DRUPDATE:
 252                 case TAP_IRUPDATE:
 253                         new_state = TAP_DRSELECT;
 254                         break;
 255                 case TAP_DRSELECT:
 256                         new_state = TAP_IRSELECT;
 257                         break;
 258                 case TAP_DRCAPTURE:
 259                 case TAP_DRSHIFT:
 260                         new_state = TAP_DREXIT1;
 261                         break;
 262                 case TAP_DREXIT1:
 263                 case TAP_DREXIT2:
 264                         new_state = TAP_DRUPDATE;
 265                         break;
 266                 case TAP_DRPAUSE:
 267                         new_state = TAP_DREXIT2;
 268                         break;
 269                 case TAP_IRSELECT:
 270                         new_state = TAP_RESET;
 271                         break;
 272                 case TAP_IRCAPTURE:
 273                 case TAP_IRSHIFT:
 274                         new_state = TAP_IREXIT1;
 275                         break;
 276                 case TAP_IREXIT1:
 277                 case TAP_IREXIT2:
 278                         new_state = TAP_IRUPDATE;
 279                         break;
 280                 case TAP_IRPAUSE:
 281                         new_state = TAP_IREXIT2;
 282                         break;
 283                 default:
 284                         LOG_ERROR("fatal: invalid argument cur_state=%d", cur_state);
 285                         exit(1);
 286                         break;
 287                 }
 288         }
 289         else
 290         {
 291                 switch (cur_state)
 292                 {
 293                 case TAP_RESET:
 294                 case TAP_IDLE:
 295                 case TAP_DRUPDATE:
 296                 case TAP_IRUPDATE:
 297                         new_state = TAP_IDLE;
 298                         break;
 299                 case TAP_DRSELECT:
 300                         new_state = TAP_DRCAPTURE;
 301                         break;
 302                 case TAP_DRCAPTURE:
 303                 case TAP_DRSHIFT:
 304                 case TAP_DREXIT2:
 305                         new_state = TAP_DRSHIFT;
 306                         break;
 307                 case TAP_DREXIT1:
 308                 case TAP_DRPAUSE:
 309                         new_state = TAP_DRPAUSE;
 310                         break;
 311                 case TAP_IRSELECT:
 312                         new_state = TAP_IRCAPTURE;
 313                         break;
 314                 case TAP_IRCAPTURE:
 315                 case TAP_IRSHIFT:
 316                 case TAP_IREXIT2:
 317                         new_state = TAP_IRSHIFT;
 318                         break;
 319                 case TAP_IREXIT1:
 320                 case TAP_IRPAUSE:
 321                         new_state = TAP_IRPAUSE;
 322                         break;
 323                 default:
 324                         LOG_ERROR("fatal: invalid argument cur_state=%d", cur_state);
 325                         exit(1);
 326                         break;
 327                 }
 328         }
 329
 330         return new_state;
 331 }
 332
 333
 334 /* NOTE:  do not change these state names.  They're documented,
 335  * and we rely on them to match SVF input (except for "RUN/IDLE").
 336  */
 337 static const struct name_mapping {
 338         enum tap_state  symbol;
 339         const char      *name;
 340 } tap_name_mapping[] = {
 341         { TAP_RESET,    "RESET", },
 342         { TAP_IDLE,     "RUN/IDLE", },
 343         { TAP_DRSELECT, "DRSELECT", },
 344         { TAP_DRCAPTURE,"DRCAPTURE", },
 345         { TAP_DRSHIFT,  "DRSHIFT", },
 346         { TAP_DREXIT1,  "DREXIT1", },
 347         { TAP_DRPAUSE,  "DRPAUSE", },
 348         { TAP_DREXIT2,  "DREXIT2", },
 349         { TAP_DRUPDATE, "DRUPDATE", },
 350         { TAP_IRSELECT, "IRSELECT", },
 351         { TAP_IRCAPTURE,"IRCAPTURE", },
 352         { TAP_IRSHIFT,  "IRSHIFT", },
 353         { TAP_IREXIT1,  "IREXIT1", },
 354         { TAP_IRPAUSE,  "IRPAUSE", },
 355         { TAP_IREXIT2,  "IREXIT2", },
 356         { TAP_IRUPDATE, "IRUPDATE", },
 357
 358         /* only for input:  accept standard SVF name */
 359         { TAP_IDLE,     "IDLE", },
 360 };
 361
 362 const char *tap_state_name(tap_state_t state)
 363 {
 364         unsigned i;
 365
 366         for (i = 0; i < ARRAY_SIZE(tap_name_mapping); i++) {
 367                 if (tap_name_mapping[i].symbol == state)
 368                         return tap_name_mapping[i].name;
 369         }
 370         return "???";
 371 }
 372
 373 tap_state_t tap_state_by_name(const char *name)
 374 {
 375         unsigned i;
 376
 377         for (i = 0; i < ARRAY_SIZE(tap_name_mapping); i++) {
 378                 /* be nice to the human */
 379                 if (strcasecmp(name, tap_name_mapping[i].name) == 0)
 380                         return tap_name_mapping[i].symbol;
 381         }
 382         /* not found */
 383         return TAP_INVALID;
 384 }
 385
 386 #ifdef _DEBUG_JTAG_IO_
 387
 388 #define JTAG_DEBUG_STATE_APPEND(buf, len, bit) \
 389                 do { buf[len] = bit ? '1' : '0'; } while (0)
 390 #define JTAG_DEBUG_STATE_PRINT(a, b, astr, bstr) \
 391                 DEBUG_JTAG_IO("TAP/SM: %9s -> %5s\tTMS: %s\tTDI: %s", \
 392                         tap_state_name(a), tap_state_name(b), astr, bstr)
 393
 394 tap_state_t jtag_debug_state_machine(const void *tms_buf, const void *tdi_buf,
 395                 unsigned tap_bits, tap_state_t next_state)
 396 {
 397         const uint8_t *tms_buffer;
 398         const uint8_t *tdi_buffer;
 399         unsigned tap_bytes;
 400         unsigned cur_byte;
 401         unsigned cur_bit;
 402
 403         unsigned tap_out_bits;
 404         char tms_str[33];
 405         char tdi_str[33];
 406
 407         tap_state_t last_state;
 408
 409         // set startstate (and possibly last, if tap_bits == 0)
 410         last_state = next_state;
 411         DEBUG_JTAG_IO("TAP/SM: START state: %s", tap_state_name(next_state));
 412
 413         tms_buffer = (const uint8_t *)tms_buf;
 414         tdi_buffer = (const uint8_t *)tdi_buf;
 415
 416         tap_bytes = DIV_ROUND_UP(tap_bits, 8);
 417         DEBUG_JTAG_IO("TAP/SM: TMS bits: %u (bytes: %u)", tap_bits, tap_bytes);
 418
 419         tap_out_bits = 0;
 420         for (cur_byte = 0; cur_byte < tap_bytes; cur_byte++)
 421         {
 422                 for (cur_bit = 0; cur_bit < 8; cur_bit++)
 423                 {
 424                         // make sure we do not run off the end of the buffers
 425                         unsigned tap_bit = cur_byte * 8 + cur_bit;
 426                         if (tap_bit == tap_bits)
 427                                 break;
 428
 429                         // check and save TMS bit
 430                         tap_bit = !!(tms_buffer[cur_byte] & (1 << cur_bit));
 431                         JTAG_DEBUG_STATE_APPEND(tms_str, tap_out_bits, tap_bit);
 432
 433                         // use TMS bit to find the next TAP state
 434                         next_state = tap_state_transition(last_state, tap_bit);
 435
 436                         // check and store TDI bit
 437                         tap_bit = !!(tdi_buffer[cur_byte] & (1 << cur_bit));
 438                         JTAG_DEBUG_STATE_APPEND(tdi_str, tap_out_bits, tap_bit);
 439
 440                         // increment TAP bits
 441                         tap_out_bits++;
 442
 443                         // Only show TDO bits on state transitions, or
 444                         // after some number of bits in the same state.
 445                         if ((next_state == last_state) && (tap_out_bits < 32))
 446                                 continue;
 447
 448                         // terminate strings and display state transition
 449                         tms_str[tap_out_bits] = tdi_str[tap_out_bits] = 0;
 450                         JTAG_DEBUG_STATE_PRINT(last_state, next_state, tms_str, tdi_str);
 451
 452                         // reset state
 453                         last_state = next_state;
 454                         tap_out_bits = 0;
 455                 }
 456         }
 457
 458         if (tap_out_bits)
 459         {
 460                 // terminate strings and display state transition
 461                 tms_str[tap_out_bits] = tdi_str[tap_out_bits] = 0;
 462                 JTAG_DEBUG_STATE_PRINT(last_state, next_state, tms_str, tdi_str);
 463         }
 464
 465         DEBUG_JTAG_IO("TAP/SM: FINAL state: %s", tap_state_name(next_state));
 466
 467         return next_state;
 468 }
 469 #endif // _DEBUG_JTAG_IO_
 470
 471 void tap_use_new_tms_table(bool use_new)
 472 {
 473         tms_seqs = use_new ? &short_tms_seqs : &old_tms_seqs;
 474 }
 475 bool tap_uses_new_tms_table(void)
 476 {
 477         return tms_seqs == &short_tms_seqs;
 478 }
 479