src/target/mips_ejtag.c

   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  *   This program is free software; you can redistribute it and/or modify  *
   8  *   it under the terms of the GNU General Public License as published by  *
   9  *   the Free Software Foundation; either version 2 of the License, or     *
  10  *   (at your option) any later version.                                   *
  11  *                                                                         *
  12  *   This program is distributed in the hope that it will be useful,       *
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  15  *   GNU General Public License for more details.                          *
  16  *                                                                         *
  17  *   You should have received a copy of the GNU General Public License     *
  18  *   along with this program; if not, write to the                         *
  19  *   Free Software Foundation, Inc.,                                       *
  20  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  21  ***************************************************************************/
  22 #ifdef HAVE_CONFIG_H
  23 #include "config.h"
  24 #endif
  25
  26 #include "mips32.h"
  27 #include "mips_ejtag.h"
  28
  29
  30 int mips_ejtag_set_instr(mips_ejtag_t *ejtag_info, int new_instr, void *delete_me_and_submit_patch)
  31 {
  32         jtag_tap_t *tap;
  33
  34         tap = ejtag_info->tap;
  35         if (tap == NULL)
  36                 return ERROR_FAIL;
  37
  38         if (buf_get_u32(tap->cur_instr, 0, tap->ir_length) != (uint32_t)new_instr)
  39         {
  40                 scan_field_t field;
  41                 uint8_t t[4];
  42
  43                 field.tap = tap;
  44                 field.num_bits = tap->ir_length;
  45                 field.out_value = t;
  46                 buf_set_u32(field.out_value, 0, field.num_bits, new_instr);
  47                 field.in_value = NULL;
  48
  49                 jtag_add_ir_scan(1, &field, jtag_get_end_state());
  50         }
  51
  52         return ERROR_OK;
  53 }
  54
  55 int mips_ejtag_get_idcode(mips_ejtag_t *ejtag_info, uint32_t *idcode)
  56 {
  57         scan_field_t field;
  58
  59         jtag_set_end_state(TAP_IDLE);
  60
  61         mips_ejtag_set_instr(ejtag_info, EJTAG_INST_IDCODE, NULL);
  62
  63         field.tap = ejtag_info->tap;
  64         field.num_bits = 32;
  65         field.out_value = NULL;
  66         field.in_value = (void*)idcode;
  67
  68         jtag_add_dr_scan(1, &field, jtag_get_end_state());
  69
  70         if (jtag_execute_queue() != ERROR_OK)
  71         {
  72                 LOG_ERROR("register read failed");
  73         }
  74
  75         return ERROR_OK;
  76 }
  77
  78 int mips_ejtag_get_impcode(mips_ejtag_t *ejtag_info, uint32_t *impcode)
  79 {
  80         scan_field_t field;
  81
  82         jtag_set_end_state(TAP_IDLE);
  83
  84         mips_ejtag_set_instr(ejtag_info, EJTAG_INST_IMPCODE, NULL);
  85
  86         field.tap = ejtag_info->tap;
  87         field.num_bits = 32;
  88         field.out_value = NULL;
  89         field.in_value = (void*)impcode;
  90
  91         jtag_add_dr_scan(1, &field, jtag_get_end_state());
  92
  93         if (jtag_execute_queue() != ERROR_OK)
  94         {
  95                 LOG_ERROR("register read failed");
  96         }
  97
  98         return ERROR_OK;
  99 }
 100
 101 int mips_ejtag_drscan_32(mips_ejtag_t *ejtag_info, uint32_t *data)
 102 {
 103         jtag_tap_t *tap;
 104         tap  = ejtag_info->tap;
 105
 106         if (tap == NULL)
 107                 return ERROR_FAIL;
 108         scan_field_t field;
 109         uint8_t t[4], r[4];
 110         int retval;
 111
 112         field.tap = tap;
 113         field.num_bits = 32;
 114         field.out_value = t;
 115         buf_set_u32(field.out_value, 0, field.num_bits, *data);
 116         field.in_value = r;
 117
 118         jtag_add_dr_scan(1, &field, jtag_get_end_state());
 119
 120         if ((retval = jtag_execute_queue()) != ERROR_OK)
 121         {
 122                 LOG_ERROR("register read failed");
 123                 return retval;
 124         }
 125
 126         *data = buf_get_u32(field.in_value, 0, 32);
 127
 128         keep_alive();
 129
 130         return ERROR_OK;
 131 }
 132
 133 int mips_ejtag_step_enable(mips_ejtag_t *ejtag_info)
 134 {
 135         uint32_t code[] = {
 136                         MIPS32_MTC0(1,31,0),                    /* move $1 to COP0 DeSave */
 137                         MIPS32_MFC0(1,23,0),                    /* move COP0 Debug to $1 */
 138                         MIPS32_ORI(1,1,0x0100),                 /* set SSt bit in debug reg */
 139                         MIPS32_MTC0(1,23,0),                    /* move $1 to COP0 Debug */
 140                         MIPS32_MFC0(1,31,0),                    /* move COP0 DeSave to $1 */
 141                         MIPS32_NOP,
 142                         MIPS32_B(NEG16(7)),
 143                         MIPS32_NOP,
 144         };
 145
 146         mips32_pracc_exec(ejtag_info, sizeof(code)/sizeof(code[0]), code, \
 147                 0, NULL, 0, NULL, 1);
 148
 149         return ERROR_OK;
 150 }
 151 int mips_ejtag_step_disable(mips_ejtag_t *ejtag_info)
 152 {
 153         uint32_t code[] = {
 154                         MIPS32_MTC0(15,31,0),                                                   /* move $15 to COP0 DeSave */
 155                         MIPS32_LUI(15,UPPER16(MIPS32_PRACC_STACK)),     /* $15 = MIPS32_PRACC_STACK */
 156                         MIPS32_ORI(15,15,LOWER16(MIPS32_PRACC_STACK)),
 157                         MIPS32_SW(1,0,15),                                                              /* sw $1,($15) */
 158                         MIPS32_SW(2,0,15),                                                              /* sw $2,($15) */
 159                         MIPS32_MFC0(1,23,0),                                                    /* move COP0 Debug to $1 */
 160                         MIPS32_LUI(2,0xFFFF),                                                   /* $2 = 0xfffffeff */
 161                         MIPS32_ORI(2,2,0xFEFF),
 162                         MIPS32_AND(1,1,2),
 163                         MIPS32_MTC0(1,23,0),                                                    /* move $1 to COP0 Debug */
 164                         MIPS32_LW(2,0,15),
 165                         MIPS32_LW(1,0,15),
 166                         MIPS32_MFC0(15,31,0),                                                   /* move COP0 DeSave to $15 */
 167                         MIPS32_NOP,
 168                         MIPS32_B(NEG16(15)),
 169                         MIPS32_NOP,
 170         };
 171
 172         mips32_pracc_exec(ejtag_info, sizeof(code)/sizeof(code[0]), code, \
 173                 0, NULL, 0, NULL, 1);
 174
 175         return ERROR_OK;
 176 }
 177
 178 int mips_ejtag_config_step(mips_ejtag_t *ejtag_info, int enable_step)
 179 {
 180         if (enable_step)
 181                 return mips_ejtag_step_enable(ejtag_info);
 182         return mips_ejtag_step_disable(ejtag_info);
 183 }
 184
 185 int mips_ejtag_enter_debug(mips_ejtag_t *ejtag_info)
 186 {
 187         uint32_t ejtag_ctrl;
 188         jtag_set_end_state(TAP_IDLE);
 189         mips_ejtag_set_instr(ejtag_info, EJTAG_INST_CONTROL, NULL);
 190
 191         /* set debug break bit */
 192         ejtag_ctrl = ejtag_info->ejtag_ctrl | EJTAG_CTRL_JTAGBRK;
 193         mips_ejtag_drscan_32(ejtag_info, &ejtag_ctrl);
 194
 195         /* break bit will be cleared by hardware */
 196         ejtag_ctrl = ejtag_info->ejtag_ctrl;
 197         mips_ejtag_drscan_32(ejtag_info, &ejtag_ctrl);
 198         LOG_DEBUG("ejtag_ctrl: 0x%8.8" PRIx32 "", ejtag_ctrl);
 199         if ((ejtag_ctrl & EJTAG_CTRL_BRKST) == 0)
 200                 LOG_DEBUG("Failed to enter Debug Mode!");
 201
 202         return ERROR_OK;
 203 }
 204
 205 int mips_ejtag_exit_debug(mips_ejtag_t *ejtag_info)
 206 {
 207         uint32_t inst;
 208         inst = MIPS32_DRET;
 209
 210         /* execute our dret instruction */
 211         mips32_pracc_exec(ejtag_info, 1, &inst, 0, NULL, 0, NULL, 0);
 212
 213         return ERROR_OK;
 214 }
 215
 216 int mips_ejtag_read_debug(mips_ejtag_t *ejtag_info, uint32_t* debug_reg)
 217 {
 218         /* read ejtag ECR */
 219         uint32_t code[] = {
 220                         MIPS32_MTC0(15,31,0),                                                   /* move $15 to COP0 DeSave */
 221                         MIPS32_LUI(15,UPPER16(MIPS32_PRACC_STACK)),     /* $15 = MIPS32_PRACC_STACK */
 222                         MIPS32_ORI(15,15,LOWER16(MIPS32_PRACC_STACK)),
 223                         MIPS32_SW(1,0,15),                                                              /* sw $1,($15) */
 224                         MIPS32_SW(2,0,15),                                                              /* sw $2,($15) */
 225                         MIPS32_LUI(1,UPPER16(MIPS32_PRACC_PARAM_OUT)),  /* $1 = MIPS32_PRACC_PARAM_OUT */
 226                         MIPS32_ORI(1,1,LOWER16(MIPS32_PRACC_PARAM_OUT)),
 227                         MIPS32_MFC0(2,23,0),                                                    /* move COP0 Debug to $2 */
 228                         MIPS32_SW(2,0,1),
 229                         MIPS32_LW(2,0,15),
 230                         MIPS32_LW(1,0,15),
 231                         MIPS32_MFC0(15,31,0),                                                   /* move COP0 DeSave to $15 */
 232                         MIPS32_NOP,
 233                         MIPS32_B(NEG16(14)),
 234                         MIPS32_NOP,
 235         };
 236
 237         mips32_pracc_exec(ejtag_info, sizeof(code)/sizeof(code[0]), code, \
 238                 0, NULL, 1, debug_reg, 1);
 239
 240         return ERROR_OK;
 241 }
 242
 243 int mips_ejtag_init(mips_ejtag_t *ejtag_info)
 244 {
 245         uint32_t ejtag_version;
 246
 247         mips_ejtag_get_impcode(ejtag_info, &ejtag_info->impcode);
 248         LOG_DEBUG("impcode: 0x%8.8" PRIx32 "", ejtag_info->impcode);
 249
 250         /* get ejtag version */
 251         ejtag_version = ((ejtag_info->impcode >> 29) & 0x07);
 252
 253         switch (ejtag_version)
 254         {
 255                 case 0:
 256                         LOG_DEBUG("EJTAG: Version 1 or 2.0 Detected");
 257                         break;
 258                 case 1:
 259                         LOG_DEBUG("EJTAG: Version 2.5 Detected");
 260                         break;
 261                 case 2:
 262                         LOG_DEBUG("EJTAG: Version 2.6 Detected");
 263                         break;
 264                 case 3:
 265                         LOG_DEBUG("EJTAG: Version 3.1 Detected");
 266                         break;
 267                 default:
 268                         LOG_DEBUG("EJTAG: Unknown Version Detected");
 269                         break;
 270         }
 271         LOG_DEBUG("EJTAG: features:%s%s%s%s%s%s%s",
 272                 ejtag_info->impcode & (1 << 28) ? " R3k":    " R4k",
 273                 ejtag_info->impcode & (1 << 24) ? " DINT":   "",
 274                 ejtag_info->impcode & (1 << 22) ? " ASID_8": "",
 275                 ejtag_info->impcode & (1 << 21) ? " ASID_6": "",
 276                 ejtag_info->impcode & (1 << 16) ? " MIPS16": "",
 277                 ejtag_info->impcode & (1 << 14) ? " noDMA":  " DMA",
 278                 ejtag_info->impcode & (1 << 0)  ? " MIPS64": " MIPS32"
 279 );
 280
 281         if ((ejtag_info->impcode & (1 << 14)) == 0)
 282                 LOG_DEBUG("EJTAG: DMA Access Mode Support Enabled");
 283
 284         /* set initial state for ejtag control reg */
 285         ejtag_info->ejtag_ctrl = EJTAG_CTRL_ROCC | EJTAG_CTRL_PRACC | EJTAG_CTRL_PROBEN | EJTAG_CTRL_SETDEV;
 286
 287         return ERROR_OK;
 288 }