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 #include "binarybuffer.h"
  30 #include "log.h"
  31 #include "jtag.h"
  32
  33 #include <stdlib.h>
  34
  35 int mips_ejtag_set_instr(mips_ejtag_t *ejtag_info, int new_instr, in_handler_t handler)
  36 {
  37         jtag_tap_t *tap;
  38
  39         tap = ejtag_info->tap;
  40         if (tap==NULL)
  41                 return ERROR_FAIL;
  42
  43         if (buf_get_u32(tap->cur_instr, 0, tap->ir_length) != new_instr)
  44         {
  45                 scan_field_t field;
  46                 u8 t[4];
  47
  48                 field.tap = tap;
  49                 field.num_bits = tap->ir_length;
  50                 field.out_value = t;
  51                 buf_set_u32(field.out_value, 0, field.num_bits, new_instr);
  52                 field.out_mask = NULL;
  53                 field.in_value = NULL;
  54                 field.in_check_value = NULL;
  55                 field.in_check_mask = NULL;
  56                 field.in_handler = handler;
  57                 field.in_handler_priv = NULL;
  58                 jtag_add_ir_scan(1, &field, -1);
  59         }
  60
  61         return ERROR_OK;
  62 }
  63
  64 int mips_ejtag_get_idcode(mips_ejtag_t *ejtag_info, u32 *idcode, in_handler_t handler)
  65 {
  66         scan_field_t field;
  67
  68         jtag_add_end_state(TAP_IDLE);
  69
  70         mips_ejtag_set_instr(ejtag_info, EJTAG_INST_IDCODE, NULL);
  71
  72         field.tap = ejtag_info->tap;
  73         field.num_bits = 32;
  74         field.out_value = NULL;
  75         field.out_mask = NULL;
  76         field.in_value = (void*)idcode;
  77         field.in_check_value = NULL;
  78         field.in_check_mask = NULL;
  79         field.in_handler = NULL;
  80         field.in_handler_priv = NULL;
  81         jtag_add_dr_scan(1, &field, -1);
  82
  83         if (jtag_execute_queue() != ERROR_OK)
  84         {
  85                 LOG_ERROR("register read failed");
  86         }
  87
  88         return ERROR_OK;
  89 }
  90
  91 int mips_ejtag_get_impcode(mips_ejtag_t *ejtag_info, u32 *impcode, in_handler_t handler)
  92 {
  93         scan_field_t field;
  94
  95         jtag_add_end_state(TAP_IDLE);
  96
  97         mips_ejtag_set_instr(ejtag_info, EJTAG_INST_IMPCODE, NULL);
  98
  99         field.tap = ejtag_info->tap;
 100         field.num_bits = 32;
 101         field.out_value = NULL;
 102         field.out_mask = NULL;
 103         field.in_value = (void*)impcode;
 104         field.in_check_value = NULL;
 105         field.in_check_mask = NULL;
 106         field.in_handler = NULL;
 107         field.in_handler_priv = NULL;
 108         jtag_add_dr_scan(1, &field, -1);
 109
 110         if (jtag_execute_queue() != ERROR_OK)
 111         {
 112                 LOG_ERROR("register read failed");
 113         }
 114
 115         return ERROR_OK;
 116 }
 117
 118 int mips_ejtag_drscan_32(mips_ejtag_t *ejtag_info, u32 *data)
 119 {
 120         jtag_tap_t *tap;
 121         tap  = ejtag_info->tap;
 122
 123         if (tap==NULL)
 124                 return ERROR_FAIL;
 125         scan_field_t field;
 126         u8 t[4];
 127         int retval;
 128
 129         field.tap = tap;
 130         field.num_bits = 32;
 131         field.out_value = t;
 132         buf_set_u32(field.out_value, 0, field.num_bits, *data);
 133         field.out_mask = NULL;
 134         field.in_value = (u8*)data;
 135         field.in_check_value = NULL;
 136         field.in_check_mask = NULL;
 137         field.in_handler = NULL;
 138         field.in_handler_priv = NULL;
 139         jtag_add_dr_scan(1, &field, -1);
 140
 141         if ((retval = jtag_execute_queue()) != ERROR_OK)
 142         {
 143                 LOG_ERROR("register read failed");
 144                 return retval;
 145         }
 146
 147         keep_alive();
 148
 149         return ERROR_OK;
 150 }
 151
 152 int mips_ejtag_step_enable(mips_ejtag_t *ejtag_info)
 153 {
 154         u32 code[] = {
 155                         MIPS32_MTC0(1,31,0),                    /* move $1 to COP0 DeSave */
 156                         MIPS32_MFC0(1,23,0),                    /* move COP0 Debug to $1 */
 157                         MIPS32_ORI(1,1,0x0100),                 /* set SSt bit in debug reg */
 158                         MIPS32_MTC0(1,23,0),                    /* move $1 to COP0 Debug */
 159                         MIPS32_MFC0(1,31,0),                    /* move COP0 DeSave to $1 */
 160                         MIPS32_NOP,
 161                         MIPS32_B(NEG16(7)),
 162                         MIPS32_NOP,
 163         };
 164
 165         mips32_pracc_exec(ejtag_info, sizeof(code)/sizeof(code[0]), code, \
 166                 0, NULL, 0, NULL, 1);
 167
 168         return ERROR_OK;
 169 }
 170 int mips_ejtag_step_disable(mips_ejtag_t *ejtag_info)
 171 {
 172         u32 code[] = {
 173                         MIPS32_MTC0(15,31,0),                                                   /* move $15 to COP0 DeSave */
 174                         MIPS32_LUI(15,UPPER16(MIPS32_PRACC_STACK)),     /* $15 = MIPS32_PRACC_STACK */
 175                         MIPS32_ORI(15,15,LOWER16(MIPS32_PRACC_STACK)),
 176                         MIPS32_SW(1,0,15),                                                              /* sw $1,($15) */
 177                         MIPS32_SW(2,0,15),                                                              /* sw $2,($15) */
 178                         MIPS32_MFC0(1,23,0),                                                    /* move COP0 Debug to $1 */
 179                         MIPS32_LUI(2,0xFFFF),                                                   /* $2 = 0xfffffeff */
 180                         MIPS32_ORI(2,2,0xFEFF),
 181                         MIPS32_AND(1,1,2),
 182                         MIPS32_MTC0(1,23,0),                                                    /* move $1 to COP0 Debug */
 183                         MIPS32_LW(2,0,15),
 184                         MIPS32_LW(1,0,15),
 185                         MIPS32_MFC0(15,31,0),                                                   /* move COP0 DeSave to $15 */
 186                         MIPS32_NOP,
 187                         MIPS32_B(NEG16(15)),
 188                         MIPS32_NOP,
 189         };
 190
 191         mips32_pracc_exec(ejtag_info, sizeof(code)/sizeof(code[0]), code, \
 192                 0, NULL, 0, NULL, 1);
 193
 194         return ERROR_OK;
 195 }
 196
 197 int mips_ejtag_config_step(mips_ejtag_t *ejtag_info, int enable_step)
 198 {
 199         if (enable_step)
 200                 return mips_ejtag_step_enable(ejtag_info);
 201         return mips_ejtag_step_disable(ejtag_info);
 202 }
 203
 204 int mips_ejtag_enter_debug(mips_ejtag_t *ejtag_info)
 205 {
 206         u32 ejtag_ctrl;
 207         jtag_add_end_state(TAP_IDLE);
 208         mips_ejtag_set_instr(ejtag_info, EJTAG_INST_CONTROL, NULL);
 209
 210         /* set debug break bit */
 211         ejtag_ctrl = ejtag_info->ejtag_ctrl | EJTAG_CTRL_JTAGBRK;
 212         mips_ejtag_drscan_32(ejtag_info, &ejtag_ctrl);
 213
 214         /* break bit will be cleared by hardware */
 215         ejtag_ctrl = ejtag_info->ejtag_ctrl;
 216         mips_ejtag_drscan_32(ejtag_info, &ejtag_ctrl);
 217         LOG_DEBUG("ejtag_ctrl: 0x%8.8x", ejtag_ctrl);
 218         if((ejtag_ctrl & EJTAG_CTRL_BRKST) == 0)
 219                 LOG_DEBUG("Failed to enter Debug Mode!");
 220
 221         return ERROR_OK;
 222 }
 223
 224 int mips_ejtag_exit_debug(mips_ejtag_t *ejtag_info, int enable_interrupts)
 225 {
 226         u32 inst;
 227         inst = MIPS32_DRET;
 228
 229         /* TODO : enable/disable interrrupts */
 230
 231         /* execute our dret instruction */
 232         mips32_pracc_exec(ejtag_info, 1, &inst, 0, NULL, 0, NULL, 0);
 233
 234         return ERROR_OK;
 235 }
 236
 237 int mips_ejtag_read_debug(mips_ejtag_t *ejtag_info, u32* debug_reg)
 238 {
 239         /* read ejtag ECR */
 240         u32 code[] = {
 241                         MIPS32_MTC0(15,31,0),                                                   /* move $15 to COP0 DeSave */
 242                         MIPS32_LUI(15,UPPER16(MIPS32_PRACC_STACK)),     /* $15 = MIPS32_PRACC_STACK */
 243                         MIPS32_ORI(15,15,LOWER16(MIPS32_PRACC_STACK)),
 244                         MIPS32_SW(1,0,15),                                                              /* sw $1,($15) */
 245                         MIPS32_SW(2,0,15),                                                              /* sw $2,($15) */
 246                         MIPS32_LUI(1,UPPER16(MIPS32_PRACC_PARAM_OUT)),  /* $1 = MIPS32_PRACC_PARAM_OUT */
 247                         MIPS32_ORI(1,1,LOWER16(MIPS32_PRACC_PARAM_OUT)),
 248                         MIPS32_MFC0(2,23,0),                                                    /* move COP0 Debug to $2 */
 249                         MIPS32_SW(2,0,1),
 250                         MIPS32_LW(2,0,15),
 251                         MIPS32_LW(1,0,15),
 252                         MIPS32_MFC0(15,31,0),                                                   /* move COP0 DeSave to $15 */
 253                         MIPS32_NOP,
 254                         MIPS32_B(NEG16(14)),
 255                         MIPS32_NOP,
 256         };
 257
 258         mips32_pracc_exec(ejtag_info, sizeof(code)/sizeof(code[0]), code, \
 259                 0, NULL, 1, debug_reg, 1);
 260
 261         return ERROR_OK;
 262 }
 263
 264 int mips_ejtag_init(mips_ejtag_t *ejtag_info)
 265 {
 266         u32 ejtag_version;
 267
 268         mips_ejtag_get_impcode(ejtag_info, &ejtag_info->impcode, NULL);
 269         LOG_DEBUG("impcode: 0x%8.8x", ejtag_info->impcode);
 270
 271         /* get ejtag version */
 272         ejtag_version = ((ejtag_info->impcode >> 29) & 0x07);
 273
 274         switch (ejtag_version)
 275         {
 276                 case 0:
 277                         LOG_DEBUG("EJTAG: Version 1 or 2.0 Detected");
 278                         break;
 279                 case 1:
 280                         LOG_DEBUG("EJTAG: Version 2.5 Detected");
 281                         break;
 282                 case 2:
 283                         LOG_DEBUG("EJTAG: Version 2.6 Detected");
 284                         break;
 285                 case 3:
 286                         LOG_DEBUG("EJTAG: Version 3.1 Detected");
 287                         break;
 288                 default:
 289                         LOG_DEBUG("EJTAG: Unknown Version Detected");
 290                         break;
 291         }
 292         LOG_DEBUG("EJTAG: features:%s%s%s%s%s%s%s",
 293                 ejtag_info->impcode & (1<<28) ? " R3k":    " R4k",
 294                 ejtag_info->impcode & (1<<24) ? " DINT":   "",
 295                 ejtag_info->impcode & (1<<22) ? " ASID_8": "",
 296                 ejtag_info->impcode & (1<<21) ? " ASID_6": "",
 297                 ejtag_info->impcode & (1<<16) ? " MIPS16": "",
 298                 ejtag_info->impcode & (1<<14) ? " noDMA":  " DMA",
 299                 ejtag_info->impcode & (1<<0)  ? " MIPS64": " MIPS32"
 300         );
 301
 302         if((ejtag_info->impcode & (1<<14)) == 0)
 303                 LOG_DEBUG("EJTAG: DMA Access Mode Support Enabled");
 304
 305         /* set initial state for ejtag control reg */
 306         ejtag_info->ejtag_ctrl = EJTAG_CTRL_ROCC | EJTAG_CTRL_PRACC | EJTAG_CTRL_PROBEN | EJTAG_CTRL_SETDEV;
 307
 308         return ERROR_OK;
 309 }