Fw: [PATCH] OpenRD board configuration
[openocd/cortex.git] / src / target / arm_simulator.c
blob93fb3dd9b522b93ec0319d11b4e66f06362202a7
1 /***************************************************************************
2 * Copyright (C) 2006 by Dominic Rath *
3 * Dominic.Rath@gmx.de *
4 * *
5 * Copyright (C) 2008 by Hongtao Zheng *
6 * hontor@126.com *
7 * *
8 * This program is free software; you can redistribute it and/or modify *
9 * it under the terms of the GNU General Public License as published by *
10 * the Free Software Foundation; either version 2 of the License, or *
11 * (at your option) any later version. *
12 * *
13 * This program is distributed in the hope that it will be useful, *
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
16 * GNU General Public License for more details. *
17 * *
18 * You should have received a copy of the GNU General Public License *
19 * along with this program; if not, write to the *
20 * Free Software Foundation, Inc., *
21 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
22 ***************************************************************************/
23 #ifdef HAVE_CONFIG_H
24 #include "config.h"
25 #endif
27 #include "armv4_5.h"
28 #include "arm_disassembler.h"
29 #include "arm_simulator.h"
30 #include "log.h"
31 #include "binarybuffer.h"
34 uint32_t arm_shift(uint8_t shift, uint32_t Rm, uint32_t shift_amount, uint8_t *carry)
36 uint32_t return_value = 0;
37 shift_amount &= 0xff;
39 if (shift == 0x0) /* LSL */
41 if ((shift_amount > 0) && (shift_amount <= 32))
43 return_value = Rm << shift_amount;
44 *carry = Rm >> (32 - shift_amount);
46 else if (shift_amount > 32)
48 return_value = 0x0;
49 *carry = 0x0;
51 else /* (shift_amount == 0) */
53 return_value = Rm;
56 else if (shift == 0x1) /* LSR */
58 if ((shift_amount > 0) && (shift_amount <= 32))
60 return_value = Rm >> shift_amount;
61 *carry = (Rm >> (shift_amount - 1)) & 1;
63 else if (shift_amount > 32)
65 return_value = 0x0;
66 *carry = 0x0;
68 else /* (shift_amount == 0) */
70 return_value = Rm;
73 else if (shift == 0x2) /* ASR */
75 if ((shift_amount > 0) && (shift_amount <= 32))
77 /* right shifts of unsigned values are guaranteed to be logical (shift in zeroes)
78 * simulate an arithmetic shift (shift in signed-bit) by adding the signed-bit manually */
79 return_value = Rm >> shift_amount;
80 if (Rm & 0x80000000)
81 return_value |= 0xffffffff << (32 - shift_amount);
83 else if (shift_amount > 32)
85 if (Rm & 0x80000000)
87 return_value = 0xffffffff;
88 *carry = 0x1;
90 else
92 return_value = 0x0;
93 *carry = 0x0;
96 else /* (shift_amount == 0) */
98 return_value = Rm;
101 else if (shift == 0x3) /* ROR */
103 if (shift_amount == 0)
105 return_value = Rm;
107 else
109 shift_amount = shift_amount % 32;
110 return_value = (Rm >> shift_amount) | (Rm << (32 - shift_amount));
111 *carry = (return_value >> 31) & 0x1;
114 else if (shift == 0x4) /* RRX */
116 return_value = Rm >> 1;
117 if (*carry)
118 Rm |= 0x80000000;
119 *carry = Rm & 0x1;
122 return return_value;
126 uint32_t arm_shifter_operand(struct arm_sim_interface *sim, int variant, union arm_shifter_operand shifter_operand, uint8_t *shifter_carry_out)
128 uint32_t return_value;
129 int instruction_size;
131 if (sim->get_state(sim) == ARMV4_5_STATE_ARM)
132 instruction_size = 4;
133 else
134 instruction_size = 2;
136 *shifter_carry_out = sim->get_cpsr(sim, 29, 1);
138 if (variant == 0) /* 32-bit immediate */
140 return_value = shifter_operand.immediate.immediate;
142 else if (variant == 1) /* immediate shift */
144 uint32_t Rm = sim->get_reg_mode(sim, shifter_operand.immediate_shift.Rm);
146 /* adjust RM in case the PC is being read */
147 if (shifter_operand.immediate_shift.Rm == 15)
148 Rm += 2 * instruction_size;
150 return_value = arm_shift(shifter_operand.immediate_shift.shift, Rm, shifter_operand.immediate_shift.shift_imm, shifter_carry_out);
152 else if (variant == 2) /* register shift */
154 uint32_t Rm = sim->get_reg_mode(sim, shifter_operand.register_shift.Rm);
155 uint32_t Rs = sim->get_reg_mode(sim, shifter_operand.register_shift.Rs);
157 /* adjust RM in case the PC is being read */
158 if (shifter_operand.register_shift.Rm == 15)
159 Rm += 2 * instruction_size;
161 return_value = arm_shift(shifter_operand.immediate_shift.shift, Rm, Rs, shifter_carry_out);
163 else
165 LOG_ERROR("BUG: shifter_operand.variant not 0, 1 or 2");
166 return_value = 0xffffffff;
169 return return_value;
172 int pass_condition(uint32_t cpsr, uint32_t opcode)
174 switch ((opcode & 0xf0000000) >> 28)
176 case 0x0: /* EQ */
177 if (cpsr & 0x40000000)
178 return 1;
179 else
180 return 0;
181 case 0x1: /* NE */
182 if (!(cpsr & 0x40000000))
183 return 1;
184 else
185 return 0;
186 case 0x2: /* CS */
187 if (cpsr & 0x20000000)
188 return 1;
189 else
190 return 0;
191 case 0x3: /* CC */
192 if (!(cpsr & 0x20000000))
193 return 1;
194 else
195 return 0;
196 case 0x4: /* MI */
197 if (cpsr & 0x80000000)
198 return 1;
199 else
200 return 0;
201 case 0x5: /* PL */
202 if (!(cpsr & 0x80000000))
203 return 1;
204 else
205 return 0;
206 case 0x6: /* VS */
207 if (cpsr & 0x10000000)
208 return 1;
209 else
210 return 0;
211 case 0x7: /* VC */
212 if (!(cpsr & 0x10000000))
213 return 1;
214 else
215 return 0;
216 case 0x8: /* HI */
217 if ((cpsr & 0x20000000) && !(cpsr & 0x40000000))
218 return 1;
219 else
220 return 0;
221 case 0x9: /* LS */
222 if (!(cpsr & 0x20000000) || (cpsr & 0x40000000))
223 return 1;
224 else
225 return 0;
226 case 0xa: /* GE */
227 if (((cpsr & 0x80000000) && (cpsr & 0x10000000))
228 || (!(cpsr & 0x80000000) && !(cpsr & 0x10000000)))
229 return 1;
230 else
231 return 0;
232 case 0xb: /* LT */
233 if (((cpsr & 0x80000000) && !(cpsr & 0x10000000))
234 || (!(cpsr & 0x80000000) && (cpsr & 0x10000000)))
235 return 1;
236 else
237 return 0;
238 case 0xc: /* GT */
239 if (!(cpsr & 0x40000000) &&
240 (((cpsr & 0x80000000) && (cpsr & 0x10000000))
241 || (!(cpsr & 0x80000000) && !(cpsr & 0x10000000))))
242 return 1;
243 else
244 return 0;
245 case 0xd: /* LE */
246 if ((cpsr & 0x40000000) ||
247 ((cpsr & 0x80000000) && !(cpsr & 0x10000000))
248 || (!(cpsr & 0x80000000) && (cpsr & 0x10000000)))
249 return 1;
250 else
251 return 0;
252 case 0xe:
253 case 0xf:
254 return 1;
258 LOG_ERROR("BUG: should never get here");
259 return 0;
262 int thumb_pass_branch_condition(uint32_t cpsr, uint16_t opcode)
264 return pass_condition(cpsr, (opcode & 0x0f00) << 20);
267 /* simulate a single step (if possible)
268 * if the dry_run_pc argument is provided, no state is changed,
269 * but the new pc is stored in the variable pointed at by the argument
271 int arm_simulate_step_core(target_t *target, uint32_t *dry_run_pc, struct arm_sim_interface *sim)
273 uint32_t current_pc = sim->get_reg(sim, 15);
274 arm_instruction_t instruction;
275 int instruction_size;
276 int retval = ERROR_OK;
278 if (sim->get_state(sim) == ARMV4_5_STATE_ARM)
280 uint32_t opcode;
282 /* get current instruction, and identify it */
283 if ((retval = target_read_u32(target, current_pc, &opcode)) != ERROR_OK)
285 return retval;
287 if ((retval = arm_evaluate_opcode(opcode, current_pc, &instruction)) != ERROR_OK)
289 return retval;
291 instruction_size = 4;
293 /* check condition code (for all instructions) */
294 if (!pass_condition(sim->get_cpsr(sim, 0, 32), opcode))
296 if (dry_run_pc)
298 *dry_run_pc = current_pc + instruction_size;
300 else
302 sim->set_reg(sim, 15, current_pc + instruction_size);
305 return ERROR_OK;
308 else
310 uint16_t opcode;
312 if ((retval = target_read_u16(target, current_pc, &opcode)) != ERROR_OK)
314 return retval;
316 if ((retval = thumb_evaluate_opcode(opcode, current_pc, &instruction)) != ERROR_OK)
318 return retval;
320 instruction_size = 2;
322 /* check condition code (only for branch instructions) */
323 if ((!thumb_pass_branch_condition(sim->get_cpsr(sim, 0, 32), opcode)) &&
324 (instruction.type == ARM_B))
326 if (dry_run_pc)
328 *dry_run_pc = current_pc + instruction_size;
330 else
332 sim->set_reg(sim, 15, current_pc + instruction_size);
335 return ERROR_OK;
339 /* examine instruction type */
341 /* branch instructions */
342 if ((instruction.type >= ARM_B) && (instruction.type <= ARM_BLX))
344 uint32_t target;
346 if (instruction.info.b_bl_bx_blx.reg_operand == -1)
348 target = instruction.info.b_bl_bx_blx.target_address;
350 else
352 target = sim->get_reg_mode(sim, instruction.info.b_bl_bx_blx.reg_operand);
353 if (instruction.info.b_bl_bx_blx.reg_operand == 15)
355 target += 2 * instruction_size;
359 if (dry_run_pc)
361 *dry_run_pc = target;
362 return ERROR_OK;
364 else
366 if (instruction.type == ARM_B)
368 sim->set_reg(sim, 15, target);
370 else if (instruction.type == ARM_BL)
372 uint32_t old_pc = sim->get_reg(sim, 15);
373 sim->set_reg_mode(sim, 14, old_pc + 4);
374 sim->set_reg(sim, 15, target);
376 else if (instruction.type == ARM_BX)
378 if (target & 0x1)
380 sim->set_state(sim, ARMV4_5_STATE_THUMB);
382 else
384 sim->set_state(sim, ARMV4_5_STATE_ARM);
386 sim->set_reg(sim, 15, target & 0xfffffffe);
388 else if (instruction.type == ARM_BLX)
390 uint32_t old_pc = sim->get_reg(sim, 15);
391 sim->set_reg_mode(sim, 14, old_pc + 4);
393 if (target & 0x1)
395 sim->set_state(sim, ARMV4_5_STATE_THUMB);
397 else
399 sim->set_state(sim, ARMV4_5_STATE_ARM);
401 sim->set_reg(sim, 15, target & 0xfffffffe);
404 return ERROR_OK;
407 /* data processing instructions, except compare instructions (CMP, CMN, TST, TEQ) */
408 else if (((instruction.type >= ARM_AND) && (instruction.type <= ARM_RSC))
409 || ((instruction.type >= ARM_ORR) && (instruction.type <= ARM_MVN)))
411 uint32_t Rd, Rn, shifter_operand;
412 uint8_t C = sim->get_cpsr(sim, 29, 1);
413 uint8_t carry_out;
415 Rd = 0x0;
416 /* ARM_MOV and ARM_MVN does not use Rn */
417 if ((instruction.type != ARM_MOV) && (instruction.type != ARM_MVN))
418 Rn = sim->get_reg_mode(sim, instruction.info.data_proc.Rn);
419 else
420 Rn = 0;
422 shifter_operand = arm_shifter_operand(sim, instruction.info.data_proc.variant, instruction.info.data_proc.shifter_operand, &carry_out);
424 /* adjust Rn in case the PC is being read */
425 if (instruction.info.data_proc.Rn == 15)
426 Rn += 2 * instruction_size;
428 if (instruction.type == ARM_AND)
429 Rd = Rn & shifter_operand;
430 else if (instruction.type == ARM_EOR)
431 Rd = Rn ^ shifter_operand;
432 else if (instruction.type == ARM_SUB)
433 Rd = Rn - shifter_operand;
434 else if (instruction.type == ARM_RSB)
435 Rd = shifter_operand - Rn;
436 else if (instruction.type == ARM_ADD)
437 Rd = Rn + shifter_operand;
438 else if (instruction.type == ARM_ADC)
439 Rd = Rn + shifter_operand + (C & 1);
440 else if (instruction.type == ARM_SBC)
441 Rd = Rn - shifter_operand - (C & 1) ? 0 : 1;
442 else if (instruction.type == ARM_RSC)
443 Rd = shifter_operand - Rn - (C & 1) ? 0 : 1;
444 else if (instruction.type == ARM_ORR)
445 Rd = Rn | shifter_operand;
446 else if (instruction.type == ARM_BIC)
447 Rd = Rn & ~(shifter_operand);
448 else if (instruction.type == ARM_MOV)
449 Rd = shifter_operand;
450 else if (instruction.type == ARM_MVN)
451 Rd = ~shifter_operand;
452 else
453 LOG_WARNING("unhandled instruction type");
455 if (dry_run_pc)
457 if (instruction.info.data_proc.Rd == 15)
459 *dry_run_pc = Rd;
460 return ERROR_OK;
462 else
464 *dry_run_pc = current_pc + instruction_size;
467 return ERROR_OK;
469 else
471 sim->set_reg_mode(sim, instruction.info.data_proc.Rd, Rd);
472 LOG_WARNING("no updating of flags yet");
474 if (instruction.info.data_proc.Rd == 15)
475 return ERROR_OK;
478 /* compare instructions (CMP, CMN, TST, TEQ) */
479 else if ((instruction.type >= ARM_TST) && (instruction.type <= ARM_CMN))
481 if (dry_run_pc)
483 *dry_run_pc = current_pc + instruction_size;
484 return ERROR_OK;
486 else
488 LOG_WARNING("no updating of flags yet");
491 /* load register instructions */
492 else if ((instruction.type >= ARM_LDR) && (instruction.type <= ARM_LDRSH))
494 uint32_t load_address = 0, modified_address = 0, load_value;
495 uint32_t Rn = sim->get_reg_mode(sim, instruction.info.load_store.Rn);
497 /* adjust Rn in case the PC is being read */
498 if (instruction.info.load_store.Rn == 15)
499 Rn += 2 * instruction_size;
501 if (instruction.info.load_store.offset_mode == 0)
503 if (instruction.info.load_store.U)
504 modified_address = Rn + instruction.info.load_store.offset.offset;
505 else
506 modified_address = Rn - instruction.info.load_store.offset.offset;
508 else if (instruction.info.load_store.offset_mode == 1)
510 uint32_t offset;
511 uint32_t Rm = sim->get_reg_mode(sim, instruction.info.load_store.offset.reg.Rm);
512 uint8_t shift = instruction.info.load_store.offset.reg.shift;
513 uint8_t shift_imm = instruction.info.load_store.offset.reg.shift_imm;
514 uint8_t carry = sim->get_cpsr(sim, 29, 1);
516 offset = arm_shift(shift, Rm, shift_imm, &carry);
518 if (instruction.info.load_store.U)
519 modified_address = Rn + offset;
520 else
521 modified_address = Rn - offset;
523 else
525 LOG_ERROR("BUG: offset_mode neither 0 (offset) nor 1 (scaled register)");
528 if (instruction.info.load_store.index_mode == 0)
530 /* offset mode
531 * we load from the modified address, but don't change the base address register */
532 load_address = modified_address;
533 modified_address = Rn;
535 else if (instruction.info.load_store.index_mode == 1)
537 /* pre-indexed mode
538 * we load from the modified address, and write it back to the base address register */
539 load_address = modified_address;
541 else if (instruction.info.load_store.index_mode == 2)
543 /* post-indexed mode
544 * we load from the unmodified address, and write the modified address back */
545 load_address = Rn;
548 if ((!dry_run_pc) || (instruction.info.load_store.Rd == 15))
550 if ((retval = target_read_u32(target, load_address, &load_value)) != ERROR_OK)
552 return retval;
556 if (dry_run_pc)
558 if (instruction.info.load_store.Rd == 15)
560 *dry_run_pc = load_value;
561 return ERROR_OK;
563 else
565 *dry_run_pc = current_pc + instruction_size;
568 return ERROR_OK;
570 else
572 if ((instruction.info.load_store.index_mode == 1) ||
573 (instruction.info.load_store.index_mode == 2))
575 sim->set_reg_mode(sim, instruction.info.load_store.Rn, modified_address);
577 sim->set_reg_mode(sim, instruction.info.load_store.Rd, load_value);
579 if (instruction.info.load_store.Rd == 15)
580 return ERROR_OK;
583 /* load multiple instruction */
584 else if (instruction.type == ARM_LDM)
586 int i;
587 uint32_t Rn = sim->get_reg_mode(sim, instruction.info.load_store_multiple.Rn);
588 uint32_t load_values[16];
589 int bits_set = 0;
591 for (i = 0; i < 16; i++)
593 if (instruction.info.load_store_multiple.register_list & (1 << i))
594 bits_set++;
597 switch (instruction.info.load_store_multiple.addressing_mode)
599 case 0: /* Increment after */
600 Rn = Rn;
601 break;
602 case 1: /* Increment before */
603 Rn = Rn + 4;
604 break;
605 case 2: /* Decrement after */
606 Rn = Rn - (bits_set * 4) + 4;
607 break;
608 case 3: /* Decrement before */
609 Rn = Rn - (bits_set * 4);
610 break;
613 for (i = 0; i < 16; i++)
615 if (instruction.info.load_store_multiple.register_list & (1 << i))
617 if ((!dry_run_pc) || (i == 15))
619 target_read_u32(target, Rn, &load_values[i]);
621 Rn += 4;
625 if (dry_run_pc)
627 if (instruction.info.load_store_multiple.register_list & 0x8000)
629 *dry_run_pc = load_values[15];
630 return ERROR_OK;
633 else
635 enum armv4_5_mode mode = sim->get_mode(sim);
636 int update_cpsr = 0;
638 if (instruction.info.load_store_multiple.S)
640 if (instruction.info.load_store_multiple.register_list & 0x8000)
641 update_cpsr = 1;
642 else
643 mode = ARMV4_5_MODE_USR;
646 for (i = 0; i < 16; i++)
648 if (instruction.info.load_store_multiple.register_list & (1 << i))
650 sim->set_reg_mode(sim, i, load_values[i]);
654 if (update_cpsr)
656 uint32_t spsr = sim->get_reg_mode(sim, 16);
657 sim->set_reg(sim, ARMV4_5_CPSR, spsr);
660 /* base register writeback */
661 if (instruction.info.load_store_multiple.W)
662 sim->set_reg_mode(sim, instruction.info.load_store_multiple.Rn, Rn);
664 if (instruction.info.load_store_multiple.register_list & 0x8000)
665 return ERROR_OK;
668 /* store multiple instruction */
669 else if (instruction.type == ARM_STM)
671 int i;
673 if (dry_run_pc)
675 /* STM wont affect PC (advance by instruction size */
677 else
679 uint32_t Rn = sim->get_reg_mode(sim, instruction.info.load_store_multiple.Rn);
680 int bits_set = 0;
681 enum armv4_5_mode mode = sim->get_mode(sim);
683 for (i = 0; i < 16; i++)
685 if (instruction.info.load_store_multiple.register_list & (1 << i))
686 bits_set++;
689 if (instruction.info.load_store_multiple.S)
691 mode = ARMV4_5_MODE_USR;
694 switch (instruction.info.load_store_multiple.addressing_mode)
696 case 0: /* Increment after */
697 Rn = Rn;
698 break;
699 case 1: /* Increment before */
700 Rn = Rn + 4;
701 break;
702 case 2: /* Decrement after */
703 Rn = Rn - (bits_set * 4) + 4;
704 break;
705 case 3: /* Decrement before */
706 Rn = Rn - (bits_set * 4);
707 break;
710 for (i = 0; i < 16; i++)
712 if (instruction.info.load_store_multiple.register_list & (1 << i))
714 target_write_u32(target, Rn, sim->get_reg_mode(sim, i));
715 Rn += 4;
719 /* base register writeback */
720 if (instruction.info.load_store_multiple.W)
721 sim->set_reg_mode(sim, instruction.info.load_store_multiple.Rn, Rn);
725 else if (!dry_run_pc)
727 /* the instruction wasn't handled, but we're supposed to simulate it
729 LOG_ERROR("Unimplemented instruction, could not simulate it.");
730 return ERROR_FAIL;
733 if (dry_run_pc)
735 *dry_run_pc = current_pc + instruction_size;
736 return ERROR_OK;
738 else
740 sim->set_reg(sim, 15, current_pc + instruction_size);
741 return ERROR_OK;
746 static uint32_t armv4_5_get_reg(struct arm_sim_interface *sim, int reg)
748 armv4_5_common_t *armv4_5 = (armv4_5_common_t *)sim->user_data;
750 return buf_get_u32(armv4_5->core_cache->reg_list[reg].value, 0, 32);
753 static void armv4_5_set_reg(struct arm_sim_interface *sim, int reg, uint32_t value)
755 armv4_5_common_t *armv4_5 = (armv4_5_common_t *)sim->user_data;
757 buf_set_u32(armv4_5->core_cache->reg_list[reg].value, 0, 32, value);
760 static uint32_t armv4_5_get_reg_mode(struct arm_sim_interface *sim, int reg)
762 armv4_5_common_t *armv4_5 = (armv4_5_common_t *)sim->user_data;
764 return buf_get_u32(ARMV4_5_CORE_REG_MODE(armv4_5->core_cache, armv4_5->core_mode, reg).value, 0, 32);
767 static void armv4_5_set_reg_mode(struct arm_sim_interface *sim, int reg, uint32_t value)
769 armv4_5_common_t *armv4_5 = (armv4_5_common_t *)sim->user_data;
771 buf_set_u32(ARMV4_5_CORE_REG_MODE(armv4_5->core_cache, armv4_5->core_mode, reg).value, 0, 32, value);
774 static uint32_t armv4_5_get_cpsr(struct arm_sim_interface *sim, int pos, int bits)
776 armv4_5_common_t *armv4_5 = (armv4_5_common_t *)sim->user_data;
778 return buf_get_u32(armv4_5->core_cache->reg_list[ARMV4_5_CPSR].value, pos, bits);
781 static enum armv4_5_state armv4_5_get_state(struct arm_sim_interface *sim)
783 armv4_5_common_t *armv4_5 = (armv4_5_common_t *)sim->user_data;
785 return armv4_5->core_state;
788 static void armv4_5_set_state(struct arm_sim_interface *sim, enum armv4_5_state mode)
790 armv4_5_common_t *armv4_5 = (armv4_5_common_t *)sim->user_data;
792 armv4_5->core_state = mode;
796 static enum armv4_5_mode armv4_5_get_mode(struct arm_sim_interface *sim)
798 armv4_5_common_t *armv4_5 = (armv4_5_common_t *)sim->user_data;
800 return armv4_5->core_mode;
805 int arm_simulate_step(target_t *target, uint32_t *dry_run_pc)
807 armv4_5_common_t *armv4_5 = target->arch_info;
809 struct arm_sim_interface sim;
811 sim.user_data=armv4_5;
812 sim.get_reg=&armv4_5_get_reg;
813 sim.set_reg=&armv4_5_set_reg;
814 sim.get_reg_mode=&armv4_5_get_reg_mode;
815 sim.set_reg_mode=&armv4_5_set_reg_mode;
816 sim.get_cpsr=&armv4_5_get_cpsr;
817 sim.get_mode=&armv4_5_get_mode;
818 sim.get_state=&armv4_5_get_state;
819 sim.set_state=&armv4_5_set_state;
821 return arm_simulate_step_core(target, dry_run_pc, &sim);