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   1 /***************************************************************************
   2  *   Copyright (C) 2008 by Spencer Oliver                                  *
   3  *   spen@spen-soft.co.uk                                                  *
   4  *                                                                         *
   5  *   Copyright (C) 2008 by David T.L. Wong                                 *
   6  *                                                                         *
   7  *   Copyright (C) 2009 by David N. Claffey <dnclaffey@gmail.com>          *
   8  *                                                                         *
   9  *   Copyright (C) 2011 by Drasko DRASKOVIC                                *
  10  *   drasko.draskovic@gmail.com                                            *
  11  *                                                                         *
  12  *   This program is free software; you can redistribute it and/or modify  *
  13  *   it under the terms of the GNU General Public License as published by  *
  14  *   the Free Software Foundation; either version 2 of the License, or     *
  15  *   (at your option) any later version.                                   *
  16  *                                                                         *
  17  *   This program is distributed in the hope that it will be useful,       *
  18  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  19  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  20  *   GNU General Public License for more details.                          *
  21  *                                                                         *
  22  *   You should have received a copy of the GNU General Public License     *
  23  *   along with this program; if not, write to the                         *
  24  *   Free Software Foundation, Inc.,                                       *
  25  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  26  ***************************************************************************/
  27
  28 /*
  29  * This version has optimized assembly routines for 32 bit operations:
  30  * - read word
  31  * - write word
  32  * - write array of words
  33  *
  34  * One thing to be aware of is that the MIPS32 cpu will execute the
  35  * instruction after a branch instruction (one delay slot).
  36  *
  37  * For example:
  38  *  LW $2, ($5 +10)
  39  *  B foo
  40  *  LW $1, ($2 +100)
  41  *
  42  * The LW $1, ($2 +100) instruction is also executed. If this is
  43  * not wanted a NOP can be inserted:
  44  *
  45  *  LW $2, ($5 +10)
  46  *  B foo
  47  *  NOP
  48  *  LW $1, ($2 +100)
  49  *
  50  * or the code can be changed to:
  51  *
  52  *  B foo
  53  *  LW $2, ($5 +10)
  54  *  LW $1, ($2 +100)
  55  *
  56  * The original code contained NOPs. I have removed these and moved
  57  * the branches.
  58  *
  59  * I also moved the PRACC_STACK to 0xFF204000. This allows
  60  * the use of 16 bits offsets to get pointers to the input
  61  * and output area relative to the stack. Note that the stack
  62  * isn't really a stack (the stack pointer is not 'moving')
  63  * but a FIFO simulated in software.
  64  *
  65  * These changes result in a 35% speed increase when programming an
  66  * external flash.
  67  *
  68  * More improvement could be gained if the registers do no need
  69  * to be preserved but in that case the routines should be aware
  70  * OpenOCD is used as a flash programmer or as a debug tool.
  71  *
  72  * Nico Coesel
  73  */
  74
  75 #ifdef HAVE_CONFIG_H
  76 #include "config.h"
  77 #endif
  78
  79 #include <helper/time_support.h>
  80
  81 #include "mips32.h"
  82 #include "mips32_pracc.h"
  83
  84 struct mips32_pracc_context {
  85         uint32_t *local_iparam;
  86         int num_iparam;
  87         uint32_t *local_oparam;
  88         int num_oparam;
  89         const uint32_t *code;
  90         int code_len;
  91         uint32_t stack[32];
  92         int stack_offset;
  93         struct mips_ejtag *ejtag_info;
  94 };
  95
  96 static int mips32_pracc_sync_cache(struct mips_ejtag *ejtag_info,
  97                 uint32_t start_addr, uint32_t end_addr);
  98 static int mips32_pracc_clean_invalidate_cache(struct mips_ejtag *ejtag_info,
  99                 uint32_t start_addr, uint32_t end_addr);
 100
 101 static int wait_for_pracc_rw(struct mips_ejtag *ejtag_info, uint32_t *ctrl)
 102 {
 103         uint32_t ejtag_ctrl;
 104         long long then = timeval_ms();
 105         int timeout;
 106         int retval;
 107
 108         /* wait for the PrAcc to become "1" */
 109         mips_ejtag_set_instr(ejtag_info, EJTAG_INST_CONTROL);
 110
 111         while (1) {
 112                 ejtag_ctrl = ejtag_info->ejtag_ctrl;
 113                 retval = mips_ejtag_drscan_32(ejtag_info, &ejtag_ctrl);
 114                 if (retval != ERROR_OK)
 115                         return retval;
 116
 117                 if (ejtag_ctrl & EJTAG_CTRL_PRACC)
 118                         break;
 119
 120                 timeout = timeval_ms() - then;
 121                 if (timeout > 1000) {
 122                         LOG_DEBUG("DEBUGMODULE: No memory access in progress!");
 123                         return ERROR_JTAG_DEVICE_ERROR;
 124                 }
 125         }
 126
 127         *ctrl = ejtag_ctrl;
 128         return ERROR_OK;
 129 }
 130
 131 static int mips32_pracc_exec_read(struct mips32_pracc_context *ctx, uint32_t address)
 132 {
 133         struct mips_ejtag *ejtag_info = ctx->ejtag_info;
 134         int offset;
 135         uint32_t ejtag_ctrl, data;
 136
 137         if ((address >= MIPS32_PRACC_PARAM_IN)
 138                 && (address < MIPS32_PRACC_PARAM_IN + ctx->num_iparam * 4)) {
 139                 offset = (address - MIPS32_PRACC_PARAM_IN) / 4;
 140                 data = ctx->local_iparam[offset];
 141         } else if ((address >= MIPS32_PRACC_PARAM_OUT)
 142                 && (address < MIPS32_PRACC_PARAM_OUT + ctx->num_oparam * 4)) {
 143                 offset = (address - MIPS32_PRACC_PARAM_OUT) / 4;
 144                 data = ctx->local_oparam[offset];
 145         } else if ((address >= MIPS32_PRACC_TEXT)
 146                 && (address < MIPS32_PRACC_TEXT + ctx->code_len * 4)) {
 147                 offset = (address - MIPS32_PRACC_TEXT) / 4;
 148                 data = ctx->code[offset];
 149         } else if (address == MIPS32_PRACC_STACK) {
 150                 if (ctx->stack_offset <= 0) {
 151                         LOG_ERROR("Error: Pracc stack out of bounds");
 152                         return ERROR_JTAG_DEVICE_ERROR;
 153                 }
 154                 /* save to our debug stack */
 155                 data = ctx->stack[--ctx->stack_offset];
 156         } else {
 157                 /* TODO: send JMP 0xFF200000 instruction. Hopefully processor jump back
 158                  * to start of debug vector */
 159
 160                 LOG_ERROR("Error reading unexpected address 0x%8.8" PRIx32 "", address);
 161                 return ERROR_JTAG_DEVICE_ERROR;
 162         }
 163
 164         /* Send the data out */
 165         mips_ejtag_set_instr(ctx->ejtag_info, EJTAG_INST_DATA);
 166         mips_ejtag_drscan_32_out(ctx->ejtag_info, data);
 167
 168         /* Clear the access pending bit (let the processor eat!) */
 169         ejtag_ctrl = ejtag_info->ejtag_ctrl & ~EJTAG_CTRL_PRACC;
 170         mips_ejtag_set_instr(ctx->ejtag_info, EJTAG_INST_CONTROL);
 171         mips_ejtag_drscan_32_out(ctx->ejtag_info, ejtag_ctrl);
 172
 173         return jtag_execute_queue();
 174 }
 175
 176 static int mips32_pracc_exec_write(struct mips32_pracc_context *ctx, uint32_t address)
 177 {
 178         uint32_t ejtag_ctrl, data;
 179         int offset;
 180         struct mips_ejtag *ejtag_info = ctx->ejtag_info;
 181         int retval;
 182
 183         mips_ejtag_set_instr(ctx->ejtag_info, EJTAG_INST_DATA);
 184         retval = mips_ejtag_drscan_32(ctx->ejtag_info, &data);
 185         if (retval != ERROR_OK)
 186                 return retval;
 187
 188         /* Clear access pending bit */
 189         ejtag_ctrl = ejtag_info->ejtag_ctrl & ~EJTAG_CTRL_PRACC;
 190         mips_ejtag_set_instr(ctx->ejtag_info, EJTAG_INST_CONTROL);
 191         mips_ejtag_drscan_32_out(ctx->ejtag_info, ejtag_ctrl);
 192
 193         retval = jtag_execute_queue();
 194         if (retval != ERROR_OK)
 195                 return retval;
 196
 197         if ((address >= MIPS32_PRACC_PARAM_IN)
 198                 && (address < MIPS32_PRACC_PARAM_IN + ctx->num_iparam * 4)) {
 199                 offset = (address - MIPS32_PRACC_PARAM_IN) / 4;
 200                 ctx->local_iparam[offset] = data;
 201         } else if ((address >= MIPS32_PRACC_PARAM_OUT)
 202                 && (address < MIPS32_PRACC_PARAM_OUT + ctx->num_oparam * 4)) {
 203                 offset = (address - MIPS32_PRACC_PARAM_OUT) / 4;
 204                 ctx->local_oparam[offset] = data;
 205         } else if (address == MIPS32_PRACC_STACK) {
 206                 if (ctx->stack_offset >= 32) {
 207                         LOG_ERROR("Error: Pracc stack out of bounds");
 208                         return ERROR_JTAG_DEVICE_ERROR;
 209                 }
 210                 /* save data onto our stack */
 211                 ctx->stack[ctx->stack_offset++] = data;
 212         } else {
 213                 LOG_ERROR("Error writing unexpected address 0x%8.8" PRIx32 "", address);
 214                 return ERROR_JTAG_DEVICE_ERROR;
 215         }
 216
 217         return ERROR_OK;
 218 }
 219
 220 int mips32_pracc_exec(struct mips_ejtag *ejtag_info, int code_len, const uint32_t *code,
 221                 int num_param_in, uint32_t *param_in, int num_param_out, uint32_t *param_out, int cycle)
 222 {
 223         uint32_t ejtag_ctrl;
 224         uint32_t address;
 225         struct mips32_pracc_context ctx;
 226         int retval;
 227         int pass = 0;
 228
 229         ctx.local_iparam = param_in;
 230         ctx.local_oparam = param_out;
 231         ctx.num_iparam = num_param_in;
 232         ctx.num_oparam = num_param_out;
 233         ctx.code = code;
 234         ctx.code_len = code_len;
 235         ctx.ejtag_info = ejtag_info;
 236         ctx.stack_offset = 0;
 237
 238         while (1) {
 239                 retval = wait_for_pracc_rw(ejtag_info, &ejtag_ctrl);
 240                 if (retval != ERROR_OK)
 241                         return retval;
 242
 243                 address = 0;
 244                 mips_ejtag_set_instr(ejtag_info, EJTAG_INST_ADDRESS);
 245                 retval = mips_ejtag_drscan_32(ejtag_info, &address);
 246                 if (retval != ERROR_OK)
 247                         return retval;
 248
 249                 /* Check for read or write */
 250                 if (ejtag_ctrl & EJTAG_CTRL_PRNW) {
 251                         retval = mips32_pracc_exec_write(&ctx, address);
 252                         if (retval != ERROR_OK)
 253                                 return retval;
 254                 } else {
 255                         /* Check to see if its reading at the debug vector. The first pass through
 256                          * the module is always read at the vector, so the first one we allow.  When
 257                          * the second read from the vector occurs we are done and just exit. */
 258                         if ((address == MIPS32_PRACC_TEXT) && (pass++))
 259                                 break;
 260
 261                         retval = mips32_pracc_exec_read(&ctx, address);
 262                         if (retval != ERROR_OK)
 263                                 return retval;
 264                 }
 265
 266                 if (cycle == 0)
 267                         break;
 268         }
 269
 270         /* stack sanity check */
 271         if (ctx.stack_offset != 0)
 272                 LOG_DEBUG("Pracc Stack not zero");
 273
 274         return ERROR_OK;
 275 }
 276
 277 static int mips32_pracc_read_u32(struct mips_ejtag *ejtag_info, uint32_t addr, uint32_t *buf)
 278 {
 279         uint32_t code[] = {
 280                                                                                                                 /* start: */
 281                 MIPS32_MTC0(15, 31, 0),                                         /* move $15 to COP0 DeSave */
 282                 MIPS32_LUI(15, PRACC_UPPER_BASE_ADDR),                          /* $15 = MIPS32_PRACC_BASE_ADDR */
 283                 MIPS32_SW(8, PRACC_STACK_OFFSET, 15),                           /* sw $8,PRACC_STACK_OFFSET($15) */
 284
 285                 MIPS32_LUI(8, UPPER16((addr + 0x8000))),                        /* load  $8 with modified upper address */
 286                 MIPS32_LW(8, LOWER16(addr), 8),                                 /* lw $8, LOWER16(addr)($8) */
 287                 MIPS32_SW(8, PRACC_OUT_OFFSET, 15),                             /* sw $8,PRACC_OUT_OFFSET($15) */
 288
 289                 MIPS32_LW(8, PRACC_STACK_OFFSET, 15),                           /* lw $8,PRACC_STACK_OFFSET($15) */
 290                 MIPS32_B(NEG16(8)),                                                     /* b start */
 291                 MIPS32_MFC0(15, 31, 0),                                         /* move COP0 DeSave to $15 */
 292         };
 293
 294         return mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code, 0, NULL, 1, buf, 1);
 295 }
 296
 297 int mips32_pracc_read_mem(struct mips_ejtag *ejtag_info, uint32_t addr, int size, int count, void *buf)
 298 {
 299         if (count == 1 && size == 4)
 300                 return mips32_pracc_read_u32(ejtag_info, addr, (uint32_t *)buf);
 301
 302         int retval = ERROR_FAIL;
 303
 304         uint32_t *code = NULL;
 305         uint32_t *data = NULL;
 306
 307         code = malloc((256 * 2 + 10) * sizeof(uint32_t));
 308         if (code == NULL) {
 309                 LOG_ERROR("Out of memory");
 310                 goto exit;
 311         }
 312
 313         if (size != 4) {
 314                 data = malloc(256 * sizeof(uint32_t));
 315                 if (data == NULL) {
 316                         LOG_ERROR("Out of memory");
 317                         goto exit;
 318                 }
 319         }
 320
 321         uint32_t *buf32 = buf;
 322         uint16_t *buf16 = buf;
 323         uint8_t *buf8 = buf;
 324
 325         int i;
 326         uint32_t upper_base_addr, last_upper_base_addr;
 327         int this_round_count;
 328         int code_len;
 329
 330         while (count) {
 331                 this_round_count = (count > 256) ? 256 : count;
 332                 last_upper_base_addr = UPPER16((addr + 0x8000));
 333                 uint32_t *code_p = code;
 334
 335                 *code_p++ = MIPS32_MTC0(15, 31, 0);                                     /* save $15 in DeSave */
 336                 *code_p++ = MIPS32_LUI(15, PRACC_UPPER_BASE_ADDR);                      /* $15 = MIPS32_PRACC_BASE_ADDR */
 337                 *code_p++ = MIPS32_SW(8, PRACC_STACK_OFFSET, 15);                       /* save $8 and $9 to pracc stack */
 338                 *code_p++ = MIPS32_SW(9, PRACC_STACK_OFFSET, 15);
 339                 *code_p++ = MIPS32_LUI(9, last_upper_base_addr);                        /* load the upper memory address in $9*/
 340                 code_len = 5;
 341
 342                 for (i = 0; i != this_round_count; i++) {               /* Main code loop */
 343                         upper_base_addr = UPPER16((addr + 0x8000));
 344                         if (last_upper_base_addr != upper_base_addr) {
 345                                 *code_p++ = MIPS32_LUI(9, upper_base_addr);             /* if needed, change upper address in $9*/
 346                                 code_len++;
 347                                 last_upper_base_addr = upper_base_addr;
 348                         }
 349
 350                         if (size == 4)
 351                                 *code_p++ = MIPS32_LW(8, LOWER16(addr), 9);             /* load from memory to $8 */
 352                         else if (size == 2)
 353                                 *code_p++ = MIPS32_LHU(8, LOWER16(addr), 9);
 354                         else
 355                                 *code_p++ = MIPS32_LBU(8, LOWER16(addr), 9);
 356
 357                         *code_p++ = MIPS32_SW(8, PRACC_OUT_OFFSET + i * 4, 15);         /* store $8 at param out */
 358
 359                         code_len += 2;
 360                         addr += size;
 361                 }
 362
 363                 *code_p++ = MIPS32_LW(9, PRACC_STACK_OFFSET, 15);                       /* restore $8 and $9 from pracc stack */
 364                 *code_p++ = MIPS32_LW(8, PRACC_STACK_OFFSET, 15);
 365
 366                 code_len += 4;
 367                 *code_p++ = MIPS32_B(NEG16(code_len - 1));                                      /* jump to start */
 368                 *code_p = MIPS32_MFC0(15, 31, 0);                                       /* restore $15 from DeSave */
 369
 370                 if (size == 4) {
 371                         retval = mips32_pracc_exec(ejtag_info, code_len, code, 0, NULL, this_round_count, buf32, 1);
 372                         if (retval != ERROR_OK)
 373                                 goto exit;
 374                         buf32 += this_round_count;
 375                 } else {
 376                         retval = mips32_pracc_exec(ejtag_info, code_len, code, 0, NULL, this_round_count, data, 1);
 377                         if (retval != ERROR_OK)
 378                                 goto exit;
 379                         uint32_t *data_p = data;
 380                         for (i = 0; i != this_round_count; i++) {
 381                                 if (size == 2)
 382                                         *buf16++ = *data_p++;
 383                                 else
 384                                         *buf8++ = *data_p++;
 385                         }
 386                 }
 387                 count -= this_round_count;
 388         }
 389
 390 exit:
 391         if (code)
 392                 free(code);
 393         if (data)
 394                 free(data);
 395         return retval;
 396 }
 397
 398 int mips32_cp0_read(struct mips_ejtag *ejtag_info, uint32_t *val, uint32_t cp0_reg, uint32_t cp0_sel)
 399 {
 400         /**
 401          * Do not make this code static, but regenerate it every time,
 402          * as 3th element has to be changed to add parameters
 403          */
 404         uint32_t code[] = {
 405                                                                                                                 /* start: */
 406                 MIPS32_MTC0(15, 31, 0),                                                 /* move $15 to COP0 DeSave */
 407                 MIPS32_LUI(15, PRACC_UPPER_BASE_ADDR),                                  /* $15 = MIPS32_PRACC_BASE_ADDR */
 408                 MIPS32_SW(8, PRACC_STACK_OFFSET, 15),                                   /* sw $8,PRACC_STACK_OFFSET($15) */
 409
 410                 /* 3 */ MIPS32_MFC0(8, 0, 0),                                           /* move COP0 [cp0_reg select] to $8 */
 411                 MIPS32_SW(8, PRACC_OUT_OFFSET, 15),                                     /* sw $8,PRACC_OUT_OFFSET($15) */
 412
 413                 MIPS32_LW(8, PRACC_STACK_OFFSET, 15),                                   /* lw $8,PRACC_STACK_OFFSET($15) */
 414                 MIPS32_B(NEG16(7)),                                                     /* b start */
 415                 MIPS32_MFC0(15, 31, 0),                                                 /* move COP0 DeSave to $15 */
 416         };
 417
 418         /**
 419          * Note that our input parametes cp0_reg and cp0_sel
 420          * are numbers (not gprs) which make part of mfc0 instruction opcode.
 421          *
 422          * These are not fix, but can be different for each mips32_cp0_read() function call,
 423          * and that is why we must insert them directly into opcode,
 424          * i.e. we can not pass it on EJTAG microprogram stack (via param_in),
 425          * and put them into the gprs later from MIPS32_PRACC_STACK
 426          * because mfc0 do not use gpr as a parameter for the cp0_reg and select part,
 427          * but plain (immediate) number.
 428          *
 429          * MIPS32_MTC0 is implemented via MIPS32_R_INST macro.
 430          * In order to insert our parameters, we must change rd and funct fields.
 431          */
 432         code[3] |= (cp0_reg << 11) | cp0_sel;  /* change rd and funct of MIPS32_R_INST macro */
 433
 434         return mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code, 0, NULL, 1, val, 1);
 435 }
 436
 437 int mips32_cp0_write(struct mips_ejtag *ejtag_info, uint32_t val, uint32_t cp0_reg, uint32_t cp0_sel)
 438 {
 439         uint32_t code[] = {
 440                                                                                                                         /* start: */
 441                 MIPS32_MTC0(15, 31, 0),                                                 /* move $15 to COP0 DeSave */
 442                 MIPS32_LUI(15, UPPER16(val)),                                           /* Load val to $15 */
 443                 MIPS32_ORI(15, 15, LOWER16(val)),
 444
 445                 /* 3 */ MIPS32_MTC0(15, 0, 0),                                          /* move $15 to COP0 [cp0_reg select] */
 446
 447                 MIPS32_B(NEG16(5)),                                                     /* b start */
 448                 MIPS32_MFC0(15, 31, 0),                                                 /* move COP0 DeSave to $15 */
 449         };
 450
 451         /**
 452          * Note that MIPS32_MTC0 macro is implemented via MIPS32_R_INST macro.
 453          * In order to insert our parameters, we must change rd and funct fields.
 454          */
 455         code[3] |= (cp0_reg << 11) | cp0_sel;  /* change rd and funct fields of MIPS32_R_INST macro */
 456
 457         return mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code, 0, NULL, 0, NULL, 1);
 458 }
 459
 460 /**
 461  * \b mips32_pracc_sync_cache
 462  *
 463  * Synchronize Caches to Make Instruction Writes Effective
 464  * (ref. doc. MIPS32 Architecture For Programmers Volume II: The MIPS32 Instruction Set,
 465  *  Document Number: MD00086, Revision 2.00, June 9, 2003)
 466  *
 467  * When the instruction stream is written, the SYNCI instruction should be used
 468  * in conjunction with other instructions to make the newly-written instructions effective.
 469  *
 470  * Explanation :
 471  * A program that loads another program into memory is actually writing the D- side cache.
 472  * The instructions it has loaded can't be executed until they reach the I-cache.
 473  *
 474  * After the instructions have been written, the loader should arrange
 475  * to write back any containing D-cache line and invalidate any locations
 476  * already in the I-cache.
 477  *
 478  * You can do that with cache instructions, but those instructions are only available in kernel mode,
 479  * and a loader writing instructions for the use of its own process need not be privileged software.
 480  *
 481  * In the latest MIPS32/64 CPUs, MIPS provides the synci instruction,
 482  * which does the whole job for a cache-line-sized chunk of the memory you just loaded:
 483  * That is, it arranges a D-cache write-back and an I-cache invalidate.
 484  *
 485  * To employ synci at user level, you need to know the size of a cache line,
 486  * and that can be obtained with a rdhwr SYNCI_Step
 487  * from one of the standard “hardware registers”.
 488  */
 489 static int mips32_pracc_sync_cache(struct mips_ejtag *ejtag_info,
 490                 uint32_t start_addr, uint32_t end_addr)
 491 {
 492         static const uint32_t code[] = {
 493                                                                                                                         /* start: */
 494                 MIPS32_MTC0(15, 31, 0),                                                         /* move $15 to COP0 DeSave */
 495                 MIPS32_LUI(15, UPPER16(MIPS32_PRACC_STACK)),            /* $15 = MIPS32_PRACC_STACK */
 496                 MIPS32_ORI(15, 15, LOWER16(MIPS32_PRACC_STACK)),
 497                 MIPS32_SW(8, 0, 15),                                                            /* sw $8,($15) */
 498                 MIPS32_SW(9, 0, 15),                                                            /* sw $9,($15) */
 499                 MIPS32_SW(10, 0, 15),                                                           /* sw $10,($15) */
 500                 MIPS32_SW(11, 0, 15),                                                           /* sw $11,($15) */
 501
 502                 MIPS32_LUI(8, UPPER16(MIPS32_PRACC_PARAM_IN)),          /* $8 = MIPS32_PRACC_PARAM_IN */
 503                 MIPS32_ORI(8, 8, LOWER16(MIPS32_PRACC_PARAM_IN)),
 504                 MIPS32_LW(9, 0, 8),                                                                     /* Load write start_addr to $9 */
 505                 MIPS32_LW(10, 4, 8),                                                            /* Load write end_addr to $10 */
 506
 507                 MIPS32_RDHWR(11, MIPS32_SYNCI_STEP),                            /* $11 = MIPS32_SYNCI_STEP */
 508                 MIPS32_BEQ(11, 0, 6),                                                           /* beq $11, $0, end */
 509                 MIPS32_NOP,
 510                                                                                                                         /* synci_loop : */
 511                 MIPS32_SYNCI(0, 9),                                                                     /* synci 0($9) */
 512                 MIPS32_SLTU(8, 10, 9),                                                          /* sltu $8, $10, $9  # $8 = $10 < $9 ? 1 : 0 */
 513                 MIPS32_BNE(8, 0, NEG16(3)),                                                     /* bne $8, $0, synci_loop */
 514                 MIPS32_ADDU(9, 9, 11),                                                          /* $9 += MIPS32_SYNCI_STEP */
 515                 MIPS32_SYNC,
 516                                                                                                                         /* end: */
 517                 MIPS32_LW(11, 0, 15),                                                           /* lw $11,($15) */
 518                 MIPS32_LW(10, 0, 15),                                                           /* lw $10,($15) */
 519                 MIPS32_LW(9, 0, 15),                                                            /* lw $9,($15) */
 520                 MIPS32_LW(8, 0, 15),                                                            /* lw $8,($15) */
 521                 MIPS32_B(NEG16(24)),                                                            /* b start */
 522                 MIPS32_MFC0(15, 31, 0),                                                         /* move COP0 DeSave to $15 */
 523         };
 524
 525         /* TODO remove array */
 526         uint32_t *param_in = malloc(2 * sizeof(uint32_t));
 527         int retval;
 528         param_in[0] = start_addr;
 529         param_in[1] = end_addr;
 530
 531         retval = mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code, 2, param_in, 0, NULL, 1);
 532
 533         free(param_in);
 534
 535         return retval;
 536 }
 537
 538 /**
 539  * \b mips32_pracc_clean_invalidate_cache
 540  *
 541  * Writeback D$ and Invalidate I$
 542  * so that the instructions written can be visible to CPU
 543  */
 544 static int mips32_pracc_clean_invalidate_cache(struct mips_ejtag *ejtag_info,
 545                                                                                                         uint32_t start_addr, uint32_t end_addr)
 546 {
 547         static const uint32_t code[] = {
 548                                                                                                                         /* start: */
 549                 MIPS32_MTC0(15, 31, 0),                                                         /* move $15 to COP0 DeSave */
 550                 MIPS32_LUI(15, UPPER16(MIPS32_PRACC_STACK)),            /* $15 = MIPS32_PRACC_STACK */
 551                 MIPS32_ORI(15, 15, LOWER16(MIPS32_PRACC_STACK)),
 552                 MIPS32_SW(8, 0, 15),                                                            /* sw $8,($15) */
 553                 MIPS32_SW(9, 0, 15),                                                            /* sw $9,($15) */
 554                 MIPS32_SW(10, 0, 15),                                                           /* sw $10,($15) */
 555                 MIPS32_SW(11, 0, 15),                                                           /* sw $11,($15) */
 556
 557                 MIPS32_LUI(8, UPPER16(MIPS32_PRACC_PARAM_IN)),          /* $8 = MIPS32_PRACC_PARAM_IN */
 558                 MIPS32_ORI(8, 8, LOWER16(MIPS32_PRACC_PARAM_IN)),
 559                 MIPS32_LW(9, 0, 8),                                                                     /* Load write start_addr to $9 */
 560                 MIPS32_LW(10, 4, 8),                                                            /* Load write end_addr to $10 */
 561                 MIPS32_LW(11, 8, 8),                                                            /* Load write clsiz to $11 */
 562
 563                                                                                                                         /* cache_loop: */
 564                 MIPS32_SLTU(8, 10, 9),                                                          /* sltu $8, $10, $9  :  $8 <- $10 < $9 ? */
 565                 MIPS32_BGTZ(8, 6),                                                                      /* bgtz $8, end */
 566                 MIPS32_NOP,
 567
 568                 MIPS32_CACHE(MIPS32_CACHE_D_HIT_WRITEBACK, 0, 9),               /* cache Hit_Writeback_D, 0($9) */
 569                 MIPS32_CACHE(MIPS32_CACHE_I_HIT_INVALIDATE, 0, 9),      /* cache Hit_Invalidate_I, 0($9) */
 570
 571                 MIPS32_ADDU(9, 9, 11),                                                          /* $9 += $11 */
 572
 573                 MIPS32_B(NEG16(7)),                                                                     /* b cache_loop */
 574                 MIPS32_NOP,
 575                                                                                                                         /* end: */
 576                 MIPS32_LW(11, 0, 15),                                                           /* lw $11,($15) */
 577                 MIPS32_LW(10, 0, 15),                                                           /* lw $10,($15) */
 578                 MIPS32_LW(9, 0, 15),                                                            /* lw $9,($15) */
 579                 MIPS32_LW(8, 0, 15),                                                            /* lw $8,($15) */
 580                 MIPS32_B(NEG16(25)),                                                            /* b start */
 581                 MIPS32_MFC0(15, 31, 0),                                                         /* move COP0 DeSave to $15 */
 582         };
 583
 584         /**
 585          * Find cache line size in bytes
 586          */
 587         uint32_t conf;
 588         uint32_t dl, clsiz;
 589
 590         mips32_cp0_read(ejtag_info, &conf, 16, 1);
 591         dl = (conf & MIPS32_CONFIG1_DL_MASK) >> MIPS32_CONFIG1_DL_SHIFT;
 592
 593         /* dl encoding : dl=1 => 4 bytes, dl=2 => 8 bytes, etc... */
 594         clsiz = 0x2 << dl;
 595
 596         /* TODO remove array */
 597         uint32_t *param_in = malloc(3 * sizeof(uint32_t));
 598         int retval;
 599         param_in[0] = start_addr;
 600         param_in[1] = end_addr;
 601         param_in[2] = clsiz;
 602
 603         retval = mips32_pracc_exec(ejtag_info, ARRAY_SIZE(code), code, 3, param_in, 0, NULL, 1);
 604
 605         free(param_in);
 606
 607         return retval;
 608 }
 609
 610 static int mips32_pracc_write_mem_generic(struct mips_ejtag *ejtag_info, uint32_t addr, int size, int count, void *buf)
 611 {
 612         uint32_t *code;
 613         code = malloc((128 * 3 + 9) * sizeof(uint32_t));        /* alloc memory for the worst case */
 614         if (code == NULL) {
 615                 LOG_ERROR("Out of memory");
 616                 return ERROR_FAIL;
 617         }
 618
 619         uint32_t *buf32 = buf;
 620         uint16_t *buf16 = buf;
 621         uint8_t *buf8 = buf;
 622
 623         int i;
 624         int retval = ERROR_FAIL;
 625         uint32_t *code_p;
 626         uint32_t upper_base_addr, last_upper_base_addr;
 627         int this_round_count;
 628         int code_len;
 629
 630         while (count) {
 631                 this_round_count = (count > 128) ? 128 : count;
 632                 last_upper_base_addr = UPPER16((addr + 0x8000));
 633                 code_p = code;
 634
 635                 *code_p++ = MIPS32_MTC0(15, 31, 0);                                     /* save $15 in DeSave */
 636                 *code_p++ = MIPS32_LUI(15, PRACC_UPPER_BASE_ADDR);                      /* $15 = MIPS32_PRACC_BASE_ADDR */
 637                 *code_p++ = MIPS32_SW(8, PRACC_STACK_OFFSET, 15);                       /* save $8 to pracc stack */
 638                 *code_p++ = MIPS32_LUI(15, last_upper_base_addr);                       /* reuse $15 as memory base address */
 639                 code_len = 4;
 640
 641                 for (i = 0; i != this_round_count; i++) {
 642                         upper_base_addr = UPPER16((addr + 0x8000));
 643                         if (last_upper_base_addr != upper_base_addr) {
 644                                 *code_p++ = MIPS32_LUI(15, upper_base_addr);            /* if needed, change upper address in $15*/
 645                                 code_len++;
 646                                 last_upper_base_addr = upper_base_addr;
 647                         }
 648
 649                         if (size == 4) {        /* for word write check if one half word is 0 and load it accordingly */
 650                                 if (LOWER16(*buf32) == 0) {
 651                                         *code_p++ = MIPS32_LUI(8, UPPER16(*buf32));             /* load only upper value */
 652                                         code_len++;
 653                                 } else if (UPPER16(*buf32) == 0) {
 654                                         *code_p++ = MIPS32_ORI(8, 0, LOWER16(*buf32));          /* load only lower value */
 655                                         code_len++;
 656                                 } else {
 657                                         *code_p++ = MIPS32_LUI(8, UPPER16(*buf32));             /* load upper and lower */
 658                                         *code_p++ = MIPS32_ORI(8, 8, LOWER16(*buf32));
 659                                         code_len += 2;
 660                                 }
 661                                 *code_p++ = MIPS32_SW(8, LOWER16(addr), 15);                    /* store word to memory */
 662                                 code_len++;
 663                                 buf32++;
 664
 665                         } else if (size == 2) {
 666                                 *code_p++ = MIPS32_ORI(8, 0, *buf16);                           /* load lower value */
 667                                 *code_p++ = MIPS32_SH(8, LOWER16(addr), 15);            /* store half word to memory */
 668                                 code_len += 2;
 669                                 buf16++;
 670
 671                         } else {
 672                                 *code_p++ = MIPS32_ORI(8, 0, *buf8);                            /* load lower value */
 673                                 *code_p++ = MIPS32_SB(8, LOWER16(addr), 15);                    /* store byte to memory */
 674                                 code_len += 2;
 675                                 buf8++;
 676                         }
 677
 678                         addr += size;
 679                 }
 680
 681                 *code_p++ = MIPS32_LUI(15, PRACC_UPPER_BASE_ADDR);                      /* $15 = MIPS32_PRACC_BASE_ADDR */
 682                 *code_p++ = MIPS32_LW(8, PRACC_STACK_OFFSET, 15);                       /* restore $8 from pracc stack */
 683
 684                 code_len += 4;
 685                 *code_p++ = MIPS32_B(NEG16(code_len - 1));                                      /* jump to start */
 686                 *code_p = MIPS32_MFC0(15, 31, 0);                                       /* restore $15 from DeSave */
 687
 688                 retval = mips32_pracc_exec(ejtag_info, code_len, code, 0, NULL, 0, NULL, 1);
 689                 if (retval != ERROR_OK)
 690                         goto exit;
 691
 692                 count -= this_round_count;
 693         }
 694
 695 exit:
 696         free(code);
 697         return retval;
 698 }
 699
 700 int mips32_pracc_write_mem(struct mips_ejtag *ejtag_info, uint32_t addr, int size, int count, void *buf)
 701 {
 702         int retval = mips32_pracc_write_mem_generic(ejtag_info, addr, size, count, buf);
 703         if (retval != ERROR_OK)
 704                 return retval;
 705
 706         /**
 707          * If we are in the cachable regoion and cache is activated,
 708          * we must clean D$ + invalidate I$ after we did the write,
 709          * so that changes do not continue to live only in D$, but to be
 710          * replicated in I$ also (maybe we wrote the istructions)
 711          */
 712         uint32_t conf = 0;
 713         int cached = 0;
 714
 715         if ((KSEGX(addr) == KSEG1) || ((addr >= 0xff200000) && (addr <= 0xff3fffff)))
 716                 return retval; /*Nothing to do*/
 717
 718         mips32_cp0_read(ejtag_info, &conf, 16, 0);
 719
 720         switch (KSEGX(addr)) {
 721                 case KUSEG:
 722                         cached = (conf & MIPS32_CONFIG0_KU_MASK) >> MIPS32_CONFIG0_KU_SHIFT;
 723                         break;
 724                 case KSEG0:
 725                         cached = (conf & MIPS32_CONFIG0_K0_MASK) >> MIPS32_CONFIG0_K0_SHIFT;
 726                         break;
 727                 case KSEG2:
 728                 case KSEG3:
 729                         cached = (conf & MIPS32_CONFIG0_K23_MASK) >> MIPS32_CONFIG0_K23_SHIFT;
 730                         break;
 731                 default:
 732                         /* what ? */
 733                         break;
 734         }
 735
 736         /**
 737          * Check cachablitiy bits coherency algorithm -
 738          * is the region cacheable or uncached.
 739          * If cacheable we have to synchronize the cache
 740          */
 741         if (cached == 0x3) {
 742                 uint32_t start_addr, end_addr;
 743                 uint32_t rel;
 744
 745                 start_addr = addr;
 746                 end_addr = addr + count * size;
 747
 748                 /** select cache synchronisation mechanism based on Architecture Release */
 749                 rel = (conf & MIPS32_CONFIG0_AR_MASK) >> MIPS32_CONFIG0_AR_SHIFT;
 750                 switch (rel) {
 751                         case MIPS32_ARCH_REL1:
 752                                 /* MIPS32/64 Release 1 - we must use cache instruction */
 753                                 mips32_pracc_clean_invalidate_cache(ejtag_info, start_addr, end_addr);
 754                                 break;
 755                         case MIPS32_ARCH_REL2:
 756                                 /* MIPS32/64 Release 2 - we can use synci instruction */
 757                                 mips32_pracc_sync_cache(ejtag_info, start_addr, end_addr);
 758                                 break;
 759                         default:
 760                                 /* what ? */
 761                                 break;
 762                 }
 763         }
 764
 765         return retval;
 766 }
 767
 768 int mips32_pracc_write_regs(struct mips_ejtag *ejtag_info, uint32_t *regs)
 769 {
 770         static const uint32_t cp0_write_code[] = {
 771                 MIPS32_MTC0(1, 12, 0),                                                  /* move $1 to status */
 772                 MIPS32_MTLO(1),                                                                 /* move $1 to lo */
 773                 MIPS32_MTHI(1),                                                                 /* move $1 to hi */
 774                 MIPS32_MTC0(1, 8, 0),                                                   /* move $1 to badvaddr */
 775                 MIPS32_MTC0(1, 13, 0),                                                  /* move $1 to cause*/
 776                 MIPS32_MTC0(1, 24, 0),                                                  /* move $1 to depc (pc) */
 777         };
 778
 779         uint32_t *code;
 780         code = malloc((37 * 2 + 6 + 1) * sizeof(uint32_t));     /* alloc memory for the worst case */
 781         if (code == NULL) {
 782                 LOG_ERROR("Out of memory");
 783                 return ERROR_FAIL;
 784         }
 785
 786         uint32_t *code_p = code;
 787         int code_len = 0;
 788         /* load registers 2 to 31 with lui an ori instructions, check if same instructions can be saved */
 789         for (int i = 2; i < 32; i++) {
 790                 if (LOWER16((regs[i])) == 0) {
 791                         *code_p++ = MIPS32_LUI(i, UPPER16((regs[i])));          /* if lower half word is 0, lui instruction only */
 792                         code_len++;
 793                 } else if (UPPER16((regs[i])) == 0) {
 794                         *code_p++ = MIPS32_ORI(i, 0, LOWER16((regs[i])));       /* if upper half word is 0, ori with $0 only*/
 795                         code_len++;
 796                 } else {
 797                         *code_p++ = MIPS32_LUI(i, UPPER16((regs[i])));          /* default, load with lui and ori instructions */
 798                         *code_p++ = MIPS32_ORI(i, i, LOWER16((regs[i])));
 799                         code_len += 2;
 800                 }
 801         }
 802
 803         for (int i = 0; i != 6; i++) {
 804                 *code_p++ = MIPS32_LUI(1, UPPER16((regs[i + 32])));             /* load CPO value in $1, with lui and ori */
 805                 *code_p++ = MIPS32_ORI(1, 1, LOWER16((regs[i + 32])));
 806                 *code_p++ = cp0_write_code[i];                                  /* write value from $1 to CPO register */
 807                 code_len += 3;
 808         }
 809
 810         *code_p++ = MIPS32_LUI(1, UPPER16((regs[1])));                          /* load upper half word in $1 */
 811         code_len += 3;
 812         *code_p++ = MIPS32_B(NEG16(code_len - 1)),                                                      /* b start */
 813         *code_p = MIPS32_ORI(1, 1, LOWER16((regs[1])));                         /* load lower half word in $1 */
 814
 815         int retval = mips32_pracc_exec(ejtag_info, code_len, code, 0, NULL, 0, NULL, 1);
 816         free(code);
 817         return retval;
 818 }
 819
 820 int mips32_pracc_read_regs(struct mips_ejtag *ejtag_info, uint32_t *regs)
 821 {
 822         static int cp0_read_code[] = {
 823                 MIPS32_MFC0(2, 12, 0),                                                  /* move status to $2 */
 824                 MIPS32_MFLO(2),                                                                 /* move lo to $2 */
 825                 MIPS32_MFHI(2),                                                                 /* move hi to $2 */
 826                 MIPS32_MFC0(2, 8, 0),                                                   /* move badvaddr to $2 */
 827                 MIPS32_MFC0(2, 13, 0),                                                  /* move cause to $2 */
 828                 MIPS32_MFC0(2, 24, 0),                                                  /* move depc (pc) to $2 */
 829         };
 830
 831         uint32_t *code;
 832         code = malloc(49 * sizeof(uint32_t));
 833         if (code == NULL) {
 834                 LOG_ERROR("Out of memory");
 835                 return ERROR_FAIL;
 836         }
 837
 838         uint32_t *code_p = code;
 839
 840         *code_p++ = MIPS32_MTC0(1, 31, 0),                                              /* move $1 to COP0 DeSave */
 841         *code_p++ = MIPS32_LUI(1, PRACC_UPPER_BASE_ADDR);                               /* $1 = MIP32_PRACC_BASE_ADDR */
 842
 843         for (int i = 2; i != 32; i++)
 844                 *code_p++ = MIPS32_SW(i, PRACC_OUT_OFFSET + (i * 4), 1);                /* store GPR's 2 to 31 */
 845
 846         for (int i = 0; i != 6; i++) {
 847                 *code_p++ = cp0_read_code[i];                                           /* load COP0 needed registers to $2 */
 848                 *code_p++ = MIPS32_SW(2, PRACC_OUT_OFFSET + (i + 32) * 4, 1);   /* store COP0 registers from $2 to param out */
 849         }
 850
 851         *code_p++ = MIPS32_MFC0(2, 31, 0),                                              /* move DeSave to $2, reg1 value */
 852         *code_p++ = MIPS32_SW(2, PRACC_OUT_OFFSET + 4, 1);                              /* store reg1 value from $2 to param out */
 853
 854         *code_p++ = MIPS32_LW(2, PRACC_OUT_OFFSET + 8, 1);                              /* restore $2 from param out (singularity) */
 855         *code_p++ = MIPS32_B(NEG16(48));                                                /* b start */
 856         *code_p = MIPS32_MFC0(1, 31, 0);                                                /* move COP0 DeSave to $1 */
 857
 858         int retval = mips32_pracc_exec(ejtag_info, 49, code, 0, NULL, MIPS32NUMCOREREGS, regs, 1);
 859
 860         free(code);
 861         return retval;
 862 }
 863
 864 /* fastdata upload/download requires an initialized working area
 865  * to load the download code; it should not be called otherwise
 866  * fetch order from the fastdata area
 867  * 1. start addr
 868  * 2. end addr
 869  * 3. data ...
 870  */
 871 int mips32_pracc_fastdata_xfer(struct mips_ejtag *ejtag_info, struct working_area *source,
 872                 int write_t, uint32_t addr, int count, uint32_t *buf)
 873 {
 874         uint32_t handler_code[] = {
 875                 /* caution when editing, table is modified below */
 876                 /* r15 points to the start of this code */
 877                 MIPS32_SW(8, MIPS32_FASTDATA_HANDLER_SIZE - 4, 15),
 878                 MIPS32_SW(9, MIPS32_FASTDATA_HANDLER_SIZE - 8, 15),
 879                 MIPS32_SW(10, MIPS32_FASTDATA_HANDLER_SIZE - 12, 15),
 880                 MIPS32_SW(11, MIPS32_FASTDATA_HANDLER_SIZE - 16, 15),
 881                 /* start of fastdata area in t0 */
 882                 MIPS32_LUI(8, UPPER16(MIPS32_PRACC_FASTDATA_AREA)),
 883                 MIPS32_ORI(8, 8, LOWER16(MIPS32_PRACC_FASTDATA_AREA)),
 884                 MIPS32_LW(9, 0, 8),                                                             /* start addr in t1 */
 885                 MIPS32_LW(10, 0, 8),                                                    /* end addr to t2 */
 886                                                                                                                 /* loop: */
 887                 /* 8 */ MIPS32_LW(11, 0, 0),                                    /* lw t3,[t8 | r9] */
 888                 /* 9 */ MIPS32_SW(11, 0, 0),                                    /* sw t3,[r9 | r8] */
 889                 MIPS32_BNE(10, 9, NEG16(3)),                                    /* bne $t2,t1,loop */
 890                 MIPS32_ADDI(9, 9, 4),                                                   /* addi t1,t1,4 */
 891
 892                 MIPS32_LW(8, MIPS32_FASTDATA_HANDLER_SIZE - 4, 15),
 893                 MIPS32_LW(9, MIPS32_FASTDATA_HANDLER_SIZE - 8, 15),
 894                 MIPS32_LW(10, MIPS32_FASTDATA_HANDLER_SIZE - 12, 15),
 895                 MIPS32_LW(11, MIPS32_FASTDATA_HANDLER_SIZE - 16, 15),
 896
 897                 MIPS32_LUI(15, UPPER16(MIPS32_PRACC_TEXT)),
 898                 MIPS32_ORI(15, 15, LOWER16(MIPS32_PRACC_TEXT)),
 899                 MIPS32_JR(15),                                                          /* jr start */
 900                 MIPS32_MFC0(15, 31, 0),                                         /* move COP0 DeSave to $15 */
 901         };
 902
 903         uint32_t jmp_code[] = {
 904                 MIPS32_MTC0(15, 31, 0),                 /* move $15 to COP0 DeSave */
 905                 /* 1 */ MIPS32_LUI(15, 0),              /* addr of working area added below */
 906                 /* 2 */ MIPS32_ORI(15, 15, 0),  /* addr of working area added below */
 907                 MIPS32_JR(15),                                  /* jump to ram program */
 908                 MIPS32_NOP,
 909         };
 910
 911         int retval, i;
 912         uint32_t val, ejtag_ctrl, address;
 913
 914         if (source->size < MIPS32_FASTDATA_HANDLER_SIZE)
 915                 return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
 916
 917         if (write_t) {
 918                 handler_code[8] = MIPS32_LW(11, 0, 8);  /* load data from probe at fastdata area */
 919                 handler_code[9] = MIPS32_SW(11, 0, 9);  /* store data to RAM @ r9 */
 920         } else {
 921                 handler_code[8] = MIPS32_LW(11, 0, 9);  /* load data from RAM @ r9 */
 922                 handler_code[9] = MIPS32_SW(11, 0, 8);  /* store data to probe at fastdata area */
 923         }
 924
 925         /* write program into RAM */
 926         if (write_t != ejtag_info->fast_access_save) {
 927                 mips32_pracc_write_mem_generic(ejtag_info, source->address, 4, ARRAY_SIZE(handler_code), handler_code);
 928                 /* save previous operation to speed to any consecutive read/writes */
 929                 ejtag_info->fast_access_save = write_t;
 930         }
 931
 932         LOG_DEBUG("%s using 0x%.8" PRIx32 " for write handler", __func__, source->address);
 933
 934         jmp_code[1] |= UPPER16(source->address);
 935         jmp_code[2] |= LOWER16(source->address);
 936
 937         for (i = 0; i < (int) ARRAY_SIZE(jmp_code); i++) {
 938                 retval = wait_for_pracc_rw(ejtag_info, &ejtag_ctrl);
 939                 if (retval != ERROR_OK)
 940                         return retval;
 941
 942                 mips_ejtag_set_instr(ejtag_info, EJTAG_INST_DATA);
 943                 mips_ejtag_drscan_32_out(ejtag_info, jmp_code[i]);
 944
 945                 /* Clear the access pending bit (let the processor eat!) */
 946                 ejtag_ctrl = ejtag_info->ejtag_ctrl & ~EJTAG_CTRL_PRACC;
 947                 mips_ejtag_set_instr(ejtag_info, EJTAG_INST_CONTROL);
 948                 mips_ejtag_drscan_32_out(ejtag_info, ejtag_ctrl);
 949         }
 950
 951         retval = wait_for_pracc_rw(ejtag_info, &ejtag_ctrl);
 952         if (retval != ERROR_OK)
 953                 return retval;
 954
 955         /* next fetch to dmseg should be in FASTDATA_AREA, check */
 956         address = 0;
 957         mips_ejtag_set_instr(ejtag_info, EJTAG_INST_ADDRESS);
 958         retval = mips_ejtag_drscan_32(ejtag_info, &address);
 959         if (retval != ERROR_OK)
 960                 return retval;
 961
 962         if (address != MIPS32_PRACC_FASTDATA_AREA)
 963                 return ERROR_FAIL;
 964
 965         /* wait PrAcc pending bit for FASTDATA write */
 966         retval = wait_for_pracc_rw(ejtag_info, &ejtag_ctrl);
 967         if (retval != ERROR_OK)
 968                 return retval;
 969
 970         /* Send the load start address */
 971         val = addr;
 972         mips_ejtag_set_instr(ejtag_info, EJTAG_INST_FASTDATA);
 973         mips_ejtag_fastdata_scan(ejtag_info, 1, &val);
 974
 975         /* Send the load end address */
 976         val = addr + (count - 1) * 4;
 977         mips_ejtag_fastdata_scan(ejtag_info, 1, &val);
 978
 979         for (i = 0; i < count; i++) {
 980                 retval = mips_ejtag_fastdata_scan(ejtag_info, write_t, buf++);
 981                 if (retval != ERROR_OK)
 982                         return retval;
 983         }
 984
 985         retval = jtag_execute_queue();
 986         if (retval != ERROR_OK) {
 987                 LOG_ERROR("fastdata load failed");
 988                 return retval;
 989         }
 990
 991         retval = wait_for_pracc_rw(ejtag_info, &ejtag_ctrl);
 992         if (retval != ERROR_OK)
 993                 return retval;
 994
 995         address = 0;
 996         mips_ejtag_set_instr(ejtag_info, EJTAG_INST_ADDRESS);
 997         retval = mips_ejtag_drscan_32(ejtag_info, &address);
 998         if (retval != ERROR_OK)
 999                 return retval;
1000
1001         if (address != MIPS32_PRACC_TEXT)
1002                 LOG_ERROR("mini program did not return to start");
1003
1004         return retval;
1005 }