Ejemplo n.º 1
0
static int arm11_assert_reset(struct target *target)
{
	struct arm11_common *arm11 = target_to_arm11(target);

	/* optionally catch reset vector */
	if (target->reset_halt && !(arm11->vcr & 1))
		CHECK_RETVAL(arm11_sc7_set_vcr(arm11, arm11->vcr | 1));

	/* Issue some kind of warm reset. */
	if (target_has_event_action(target, TARGET_EVENT_RESET_ASSERT)) {
		target_handle_event(target, TARGET_EVENT_RESET_ASSERT);
	} else if (jtag_get_reset_config() & RESET_HAS_SRST) {
		/* REVISIT handle "pulls" cases, if there's
		 * hardware that needs them to work.
		 */
		jtag_add_reset(0, 1);
	} else {
		LOG_ERROR("%s: how to reset?", target_name(target));
		return ERROR_FAIL;
	}

	/* registers are now invalid */
	register_cache_invalidate(arm11->arm.core_cache);

	target->state = TARGET_RESET;

	return ERROR_OK;
}
Ejemplo n.º 2
0
static int arm11_deassert_reset(struct target *target)
{
	struct arm11_common *arm11 = target_to_arm11(target);
	int retval;

	/* be certain SRST is off */
	jtag_add_reset(0, 0);

	/* WORKAROUND i.MX31 problems:  SRST goofs the TAP, and resets
	 * at least DSCR.  OMAP24xx doesn't show that problem, though
	 * SRST-only reset seems to be problematic for other reasons.
	 * (Secure boot sequences being one likelihood!)
	 */
	jtag_add_tlr();

	CHECK_RETVAL(arm11_poll(target));

	if (target->reset_halt) {
		if (target->state != TARGET_HALTED) {
			LOG_WARNING("%s: ran after reset and before halt ...",
					target_name(target));
			if ((retval = target_halt(target)) != ERROR_OK)
				return retval;
		}
	}

	/* maybe restore vector catch config */
	if (target->reset_halt && !(arm11->vcr & 1))
		CHECK_RETVAL(arm11_sc7_set_vcr(arm11, arm11->vcr));

	return ERROR_OK;
}
Ejemplo n.º 3
0
/* target break-/watchpoint control
* rw: 0 = write, 1 = read, 2 = access
*/
static int arm11_add_breakpoint(struct target *target,
		struct breakpoint *breakpoint)
{
	struct arm11_common *arm11 = target_to_arm11(target);

#if 0
	if (breakpoint->type == BKPT_SOFT)
	{
		LOG_INFO("sw breakpoint requested, but software breakpoints not enabled");
		return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
	}
#endif

	if (!arm11->free_brps)
	{
		LOG_DEBUG("no breakpoint unit available for hardware breakpoint");
		return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
	}

	if (breakpoint->length != 4)
	{
		LOG_DEBUG("only breakpoints of four bytes length supported");
		return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
	}

	arm11->free_brps--;

	return ERROR_OK;
}
Ejemplo n.º 4
0
/* poll current target status */
static int arm11_poll(struct target *target)
{
	int retval;
	struct arm11_common *arm11 = target_to_arm11(target);

	CHECK_RETVAL(arm11_check_init(arm11));

	if (arm11->dscr & DSCR_CORE_HALTED) {
		if (target->state != TARGET_HALTED) {
			enum target_state old_state = target->state;

			LOG_DEBUG("enter TARGET_HALTED");
			retval = arm11_debug_entry(arm11);
			if (retval != ERROR_OK)
				return retval;

			target_call_event_callbacks(target,
				(old_state == TARGET_DEBUG_RUNNING)
				? TARGET_EVENT_DEBUG_HALTED
				: TARGET_EVENT_HALTED);
		}
	} else {
		if (target->state != TARGET_RUNNING && target->state != TARGET_DEBUG_RUNNING) {
			LOG_DEBUG("enter TARGET_RUNNING");
			target->state                   = TARGET_RUNNING;
			target->debug_reason    = DBG_REASON_NOTHALTED;
		}
	}

	return ERROR_OK;
}
Ejemplo n.º 5
0
/* target execution control */
static int arm11_halt(struct target *target)
{
	struct arm11_common *arm11 = target_to_arm11(target);

	LOG_DEBUG("target->state: %s",
		target_state_name(target));

	if (target->state == TARGET_UNKNOWN)
	{
		arm11->simulate_reset_on_next_halt = true;
	}

	if (target->state == TARGET_HALTED)
	{
		LOG_DEBUG("target was already halted");
		return ERROR_OK;
	}

	arm11_add_IR(arm11, ARM11_HALT, TAP_IDLE);

	CHECK_RETVAL(jtag_execute_queue());

	int i = 0;

	while (1)
	{
		CHECK_RETVAL(arm11_read_DSCR(arm11));

		if (arm11->dscr & DSCR_CORE_HALTED)
			break;


		long long then = 0;
		if (i == 1000)
		{
			then = timeval_ms();
		}
		if (i >= 1000)
		{
			if ((timeval_ms()-then) > 1000)
			{
				LOG_WARNING("Timeout (1000ms) waiting for instructions to complete");
				return ERROR_FAIL;
			}
		}
		i++;
	}

	enum target_state old_state	= target->state;

	CHECK_RETVAL(arm11_debug_entry(arm11));

	CHECK_RETVAL(
		target_call_event_callbacks(target,
			old_state == TARGET_DEBUG_RUNNING ? TARGET_EVENT_DEBUG_HALTED : TARGET_EVENT_HALTED));

	return ERROR_OK;
}
Ejemplo n.º 6
0
static int arm11_remove_breakpoint(struct target *target,
		struct breakpoint *breakpoint)
{
	struct arm11_common *arm11 = target_to_arm11(target);

	arm11->free_brps++;

	return ERROR_OK;
}
Ejemplo n.º 7
0
/* architecture specific status reply */
static int arm11_arch_state(struct target *target)
{
	struct arm11_common *arm11 = target_to_arm11(target);
	int retval;

	retval = arm_arch_state(target);

	/* REVISIT also display ARM11-specific MMU and cache status ... */

	if (target->debug_reason == DBG_REASON_WATCHPOINT)
		LOG_USER("Watchpoint triggered at PC %#08x",
				(unsigned) arm11->dpm.wp_pc);

	return retval;
}
Ejemplo n.º 8
0
static int arm11_assert_reset(struct target *target)
{
	struct arm11_common *arm11 = target_to_arm11(target);

	if (!(target_was_examined(target))) {
		if (jtag_get_reset_config() & RESET_HAS_SRST)
			jtag_add_reset(0, 1);
		else {
			LOG_WARNING("Reset is not asserted because the target is not examined.");
			LOG_WARNING("Use a reset button or power cycle the target.");
			return ERROR_TARGET_NOT_EXAMINED;
		}
	} else {

		/* optionally catch reset vector */
		if (target->reset_halt && !(arm11->vcr & 1))
			CHECK_RETVAL(arm11_sc7_set_vcr(arm11, arm11->vcr | 1));

		/* Issue some kind of warm reset. */
		if (target_has_event_action(target, TARGET_EVENT_RESET_ASSERT))
			target_handle_event(target, TARGET_EVENT_RESET_ASSERT);
		else if (jtag_get_reset_config() & RESET_HAS_SRST) {
			/* REVISIT handle "pulls" cases, if there's
			 * hardware that needs them to work.
			 */
			jtag_add_reset(0, 1);
		} else {
			LOG_ERROR("%s: how to reset?", target_name(target));
			return ERROR_FAIL;
		}
	}

	/* registers are now invalid */
	register_cache_invalidate(arm11->arm.core_cache);

	target->state = TARGET_RESET;

	return ERROR_OK;
}
Ejemplo n.º 9
0
/*
* no_increment - in the future we may want to be able
* to read/write a range of data to a "port". a "port" is an action on
* read memory address for some peripheral.
*/
static int arm11_write_memory_inner(struct target *target,
		uint32_t address, uint32_t size,
		uint32_t count, const uint8_t *buffer,
		bool no_increment)
{
	int retval;

	if (target->state != TARGET_HALTED)
	{
		LOG_WARNING("target was not halted");
		return ERROR_TARGET_NOT_HALTED;
	}

	LOG_DEBUG("ADDR %08" PRIx32 "  SIZE %08" PRIx32 "  COUNT %08" PRIx32 "", address, size, count);

	struct arm11_common *arm11 = target_to_arm11(target);

	retval = arm11_run_instr_data_prepare(arm11);
	if (retval != ERROR_OK)
		return retval;

	/* load r0 with buffer address */
	/* MRC p14,0,r0,c0,c5,0 */
	retval = arm11_run_instr_data_to_core1(arm11, 0xee100e15, address);
	if (retval != ERROR_OK)
		return retval;

	/* burst writes are not used for single words as those may well be
	 * reset init script writes.
	 *
	 * The other advantage is that as burst writes are default, we'll
	 * now exercise both burst and non-burst code paths with the
	 * default settings, increasing code coverage.
	 */
	bool burst = arm11->memwrite_burst && (count > 1);

	switch (size)
	{
	case 1:
		{
			arm11->arm.core_cache->reg_list[1].dirty = true;

			for (size_t i = 0; i < count; i++)
			{
				/* load r1 from DCC with byte data */
				/* MRC p14,0,r1,c0,c5,0 */
				retval = arm11_run_instr_data_to_core1(arm11, 0xee101e15, *buffer++);
				if (retval != ERROR_OK)
					return retval;

				/* write r1 to memory */
				/* strb    r1, [r0], #1 */
				/* strb    r1, [r0] */
				retval = arm11_run_instr_no_data1(arm11,
					!no_increment
						? 0xe4c01001
						: 0xe5c01000);
				if (retval != ERROR_OK)
					return retval;
			}

			break;
		}

	case 2:
		{
			arm11->arm.core_cache->reg_list[1].dirty = true;

			for (size_t i = 0; i < count; i++)
			{
				uint16_t value;
				memcpy(&value, buffer + i * sizeof(uint16_t), sizeof(uint16_t));

				/* load r1 from DCC with halfword data */
				/* MRC p14,0,r1,c0,c5,0 */
				retval = arm11_run_instr_data_to_core1(arm11, 0xee101e15, value);
				if (retval != ERROR_OK)
					return retval;

				/* write r1 to memory */
				/* strh    r1, [r0], #2 */
				/* strh    r1, [r0] */
				retval = arm11_run_instr_no_data1(arm11,
					!no_increment
						? 0xe0c010b2
						: 0xe1c010b0);
				if (retval != ERROR_OK)
					return retval;
			}

			break;
		}

	case 4: {
		/* stream word data through DCC directly to memory */
		/* increment:		STC p14,c5,[R0],#4 */
		/* no increment:	STC p14,c5,[R0]*/
		uint32_t instr = !no_increment ? 0xeca05e01 : 0xed805e00;

		/** \todo TODO: buffer cast to uint32_t* causes alignment warnings */
		uint32_t *words = (uint32_t*)(void *)buffer;

		/* "burst" here just means trusting each instruction executes
		 * fully before we run the next one:  per-word roundtrips, to
		 * check the Ready flag, are not used.
		 */
		if (!burst)
			retval = arm11_run_instr_data_to_core(arm11,
					instr, words, count);
		else
			retval = arm11_run_instr_data_to_core_noack(arm11,
					instr, words, count);
		if (retval != ERROR_OK)
			return retval;

		break;
	}
	}

	/* r0 verification */
	if (!no_increment)
	{
		uint32_t r0;

		/* MCR p14,0,R0,c0,c5,0 */
		retval = arm11_run_instr_data_from_core(arm11, 0xEE000E15, &r0, 1);
		if (retval != ERROR_OK)
			return retval;

		if (address + size * count != r0)
		{
			LOG_ERROR("Data transfer failed. Expected end "
					"address 0x%08x, got 0x%08x",
					(unsigned) (address + size * count),
					(unsigned) r0);

			if (burst)
				LOG_ERROR("use 'arm11 memwrite burst disable' to disable fast burst mode");

			if (arm11->memwrite_error_fatal)
				return ERROR_FAIL;
		}
	}

	return arm11_run_instr_data_finish(arm11);
}
Ejemplo n.º 10
0
/* target memory access
 * size: 1 = byte (8bit), 2 = half-word (16bit), 4 = word (32bit)
 * count: number of items of <size>
 *
 * arm11_config_memrw_no_increment - in the future we may want to be able
 * to read/write a range of data to a "port". a "port" is an action on
 * read memory address for some peripheral.
 */
static int arm11_read_memory_inner(struct target *target,
		uint32_t address, uint32_t size, uint32_t count, uint8_t *buffer,
		bool arm11_config_memrw_no_increment)
{
	/** \todo TODO: check if buffer cast to uint32_t* and uint16_t* might cause alignment problems */
	int retval;

	if (target->state != TARGET_HALTED)
	{
		LOG_WARNING("target was not halted");
		return ERROR_TARGET_NOT_HALTED;
	}

	LOG_DEBUG("ADDR %08" PRIx32 "  SIZE %08" PRIx32 "  COUNT %08" PRIx32 "", address, size, count);

	struct arm11_common *arm11 = target_to_arm11(target);

	retval = arm11_run_instr_data_prepare(arm11);
	if (retval != ERROR_OK)
		return retval;

	/* MRC p14,0,r0,c0,c5,0 */
	retval = arm11_run_instr_data_to_core1(arm11, 0xee100e15, address);
	if (retval != ERROR_OK)
		return retval;

	switch (size)
	{
	case 1:
		arm11->arm.core_cache->reg_list[1].dirty = true;

		for (size_t i = 0; i < count; i++)
		{
			/* ldrb    r1, [r0], #1 */
			/* ldrb    r1, [r0] */
			CHECK_RETVAL(arm11_run_instr_no_data1(arm11,
					!arm11_config_memrw_no_increment ? 0xe4d01001 : 0xe5d01000));

			uint32_t res;
			/* MCR p14,0,R1,c0,c5,0 */
			CHECK_RETVAL(arm11_run_instr_data_from_core(arm11, 0xEE001E15, &res, 1));

			*buffer++ = res;
		}

		break;

	case 2:
		{
			arm11->arm.core_cache->reg_list[1].dirty = true;

			for (size_t i = 0; i < count; i++)
			{
				/* ldrh    r1, [r0], #2 */
				CHECK_RETVAL(arm11_run_instr_no_data1(arm11,
					!arm11_config_memrw_no_increment ? 0xe0d010b2 : 0xe1d010b0));

				uint32_t res;

				/* MCR p14,0,R1,c0,c5,0 */
				CHECK_RETVAL(arm11_run_instr_data_from_core(arm11, 0xEE001E15, &res, 1));

				uint16_t svalue = res;
				memcpy(buffer + i * sizeof(uint16_t), &svalue, sizeof(uint16_t));
			}

			break;
		}

	case 4:
		{
		uint32_t instr = !arm11_config_memrw_no_increment ? 0xecb05e01 : 0xed905e00;
		/** \todo TODO: buffer cast to uint32_t* causes alignment warnings */
		uint32_t *words = (uint32_t *)(void *)buffer;

		/* LDC p14,c5,[R0],#4 */
		/* LDC p14,c5,[R0] */
		CHECK_RETVAL(arm11_run_instr_data_from_core(arm11, instr, words, count));
		break;
		}
	}

	return arm11_run_instr_data_finish(arm11);
}
Ejemplo n.º 11
0
static int arm11_step(struct target *target, int current,
		uint32_t address, int handle_breakpoints)
{
	LOG_DEBUG("target->state: %s",
		target_state_name(target));

	if (target->state != TARGET_HALTED)
	{
		LOG_WARNING("target was not halted");
		return ERROR_TARGET_NOT_HALTED;
	}

	struct arm11_common *arm11 = target_to_arm11(target);

	address = arm11_nextpc(arm11, current, address);

	LOG_DEBUG("STEP PC %08" PRIx32 "%s", address, !current ? "!" : "");


	/** \todo TODO: Thumb not supported here */

	uint32_t	next_instruction;

	CHECK_RETVAL(arm11_read_memory_word(arm11, address, &next_instruction));

	/* skip over BKPT */
	if ((next_instruction & 0xFFF00070) == 0xe1200070)
	{
		address = arm11_nextpc(arm11, 0, address + 4);
		LOG_DEBUG("Skipping BKPT");
	}
	/* skip over Wait for interrupt / Standby */
	/* mcr	15, 0, r?, cr7, cr0, {4} */
	else if ((next_instruction & 0xFFFF0FFF) == 0xee070f90)
	{
		address = arm11_nextpc(arm11, 0, address + 4);
		LOG_DEBUG("Skipping WFI");
	}
	/* ignore B to self */
	else if ((next_instruction & 0xFEFFFFFF) == 0xeafffffe)
	{
		LOG_DEBUG("Not stepping jump to self");
	}
	else
	{
		/** \todo TODO: check if break-/watchpoints make any sense at all in combination
		* with this. */

		/** \todo TODO: check if disabling IRQs might be a good idea here. Alternatively
		* the VCR might be something worth looking into. */


		/* Set up breakpoint for stepping */

		struct arm11_sc7_action	brp[2];

		brp[0].write	= 1;
		brp[0].address	= ARM11_SC7_BVR0;
		brp[1].write	= 1;
		brp[1].address	= ARM11_SC7_BCR0;

		if (arm11->hardware_step)
		{
			/* Hardware single stepping ("instruction address
			 * mismatch") is used if enabled.  It's not quite
			 * exactly "run one instruction"; "branch to here"
			 * loops won't break, neither will some other cases,
			 * but it's probably the best default.
			 *
			 * Hardware single stepping isn't supported on v6
			 * debug modules.  ARM1176 and v7 can support it...
			 *
			 * FIXME Thumb stepping likely needs to use 0x03
			 * or 0xc0 byte masks, not 0x0f.
			 */
			 brp[0].value	= address;
			 brp[1].value	= 0x1 | (3 << 1) | (0x0F << 5)
					| (0 << 14) | (0 << 16) | (0 << 20)
					| (2 << 21);
		} else
		{
			/* Sets a breakpoint on the next PC, as calculated
			 * by instruction set simulation.
			 *
			 * REVISIT stepping Thumb on ARM1156 requires Thumb2
			 * support from the simulator.
			 */
			uint32_t next_pc;
			int retval;

			retval = arm_simulate_step(target, &next_pc);
			if (retval != ERROR_OK)
				return retval;

			brp[0].value	= next_pc;
			brp[1].value	= 0x1 | (3 << 1) | (0x0F << 5)
					| (0 << 14) | (0 << 16) | (0 << 20)
					| (0 << 21);
		}

		CHECK_RETVAL(arm11_sc7_run(arm11, brp, ARRAY_SIZE(brp)));

		/* resume */


		if (arm11->step_irq_enable)
			/* this disable should be redundant ... */
			arm11->dscr &= ~DSCR_INT_DIS;
		else
			arm11->dscr |= DSCR_INT_DIS;


		CHECK_RETVAL(arm11_leave_debug_state(arm11, handle_breakpoints));

		arm11_add_IR(arm11, ARM11_RESTART, TAP_IDLE);

		CHECK_RETVAL(jtag_execute_queue());

		/* wait for halt */
		int i = 0;

		while (1)
		{
			const uint32_t mask = DSCR_CORE_RESTARTED
					| DSCR_CORE_HALTED;

			CHECK_RETVAL(arm11_read_DSCR(arm11));
			LOG_DEBUG("DSCR %08x e", (unsigned) arm11->dscr);

			if ((arm11->dscr & mask) == mask)
				break;

			long long then = 0;
			if (i == 1000)
			{
				then = timeval_ms();
			}
			if (i >= 1000)
			{
				if ((timeval_ms()-then) > 1000)
				{
					LOG_WARNING("Timeout (1000ms) waiting for instructions to complete");
					return ERROR_FAIL;
				}
			}
			i++;
		}

		/* clear breakpoint */
		CHECK_RETVAL(arm11_sc7_clear_vbw(arm11));

		/* save state */
		CHECK_RETVAL(arm11_debug_entry(arm11));

		/* restore default state */
		arm11->dscr &= ~DSCR_INT_DIS;

	}

	target->debug_reason = DBG_REASON_SINGLESTEP;

	CHECK_RETVAL(target_call_event_callbacks(target, TARGET_EVENT_HALTED));

	return ERROR_OK;
}
Ejemplo n.º 12
0
static int arm11_resume(struct target *target, int current,
		uint32_t address, int handle_breakpoints, int debug_execution)
{
	//	  LOG_DEBUG("current %d  address %08x  handle_breakpoints %d  debug_execution %d",
	//	current, address, handle_breakpoints, debug_execution);

	struct arm11_common *arm11 = target_to_arm11(target);

	LOG_DEBUG("target->state: %s",
		target_state_name(target));


	if (target->state != TARGET_HALTED)
	{
		LOG_ERROR("Target not halted");
		return ERROR_TARGET_NOT_HALTED;
	}

	address = arm11_nextpc(arm11, current, address);

	LOG_DEBUG("RESUME PC %08" PRIx32 "%s", address, !current ? "!" : "");

	/* clear breakpoints/watchpoints and VCR*/
	CHECK_RETVAL(arm11_sc7_clear_vbw(arm11));

	if (!debug_execution)
		target_free_all_working_areas(target);

	/* Should we skip over breakpoints matching the PC? */
	if (handle_breakpoints) {
		struct breakpoint *bp;

		for (bp = target->breakpoints; bp; bp = bp->next)
		{
			if (bp->address == address)
			{
				LOG_DEBUG("must step over %08" PRIx32 "", bp->address);
				arm11_step(target, 1, 0, 0);
				break;
			}
		}
	}

	/* activate all breakpoints */
	if (true) {
		struct breakpoint *bp;
		unsigned brp_num = 0;

		for (bp = target->breakpoints; bp; bp = bp->next)
		{
			struct arm11_sc7_action	brp[2];

			brp[0].write	= 1;
			brp[0].address	= ARM11_SC7_BVR0 + brp_num;
			brp[0].value	= bp->address;
			brp[1].write	= 1;
			brp[1].address	= ARM11_SC7_BCR0 + brp_num;
			brp[1].value	= 0x1 | (3 << 1) | (0x0F << 5) | (0 << 14) | (0 << 16) | (0 << 20) | (0 << 21);

			CHECK_RETVAL(arm11_sc7_run(arm11, brp, ARRAY_SIZE(brp)));

			LOG_DEBUG("Add BP %d at %08" PRIx32, brp_num,
					bp->address);

			brp_num++;
		}

		if (arm11->vcr)
			CHECK_RETVAL(arm11_sc7_set_vcr(arm11, arm11->vcr));
	}

	/* activate all watchpoints and breakpoints */
	CHECK_RETVAL(arm11_leave_debug_state(arm11, true));

	arm11_add_IR(arm11, ARM11_RESTART, TAP_IDLE);

	CHECK_RETVAL(jtag_execute_queue());

	int i = 0;
	while (1)
	{
		CHECK_RETVAL(arm11_read_DSCR(arm11));

		LOG_DEBUG("DSCR %08x", (unsigned) arm11->dscr);

		if (arm11->dscr & DSCR_CORE_RESTARTED)
			break;


		long long then = 0;
		if (i == 1000)
		{
			then = timeval_ms();
		}
		if (i >= 1000)
		{
			if ((timeval_ms()-then) > 1000)
			{
				LOG_WARNING("Timeout (1000ms) waiting for instructions to complete");
				return ERROR_FAIL;
			}
		}
		i++;
	}

	target->debug_reason = DBG_REASON_NOTHALTED;
	if (!debug_execution)
		target->state = TARGET_RUNNING;
	else
		target->state = TARGET_DEBUG_RUNNING;
	CHECK_RETVAL(target_call_event_callbacks(target, TARGET_EVENT_RESUMED));

	return ERROR_OK;
}
Ejemplo n.º 13
0
/* talk to the target and set things up */
static int arm11_examine(struct target *target)
{
	int retval;
	char *type;
	struct arm11_common *arm11 = target_to_arm11(target);
	uint32_t didr, device_id;
	uint8_t implementor;

	/* FIXME split into do-first-time and do-every-time logic ... */

	/* check IDCODE */

	arm11_add_IR(arm11, ARM11_IDCODE, ARM11_TAP_DEFAULT);

	struct scan_field		idcode_field;

	arm11_setup_field(arm11, 32, NULL, &device_id, &idcode_field);

	arm11_add_dr_scan_vc(arm11->arm.target->tap, 1, &idcode_field, TAP_DRPAUSE);

	/* check DIDR */

	arm11_add_debug_SCAN_N(arm11, 0x00, ARM11_TAP_DEFAULT);

	arm11_add_IR(arm11, ARM11_INTEST, ARM11_TAP_DEFAULT);

	struct scan_field		chain0_fields[2];

	arm11_setup_field(arm11, 32, NULL, &didr, chain0_fields + 0);
	arm11_setup_field(arm11,  8, NULL, &implementor, chain0_fields + 1);

	arm11_add_dr_scan_vc(arm11->arm.target->tap, ARRAY_SIZE(chain0_fields), chain0_fields, TAP_IDLE);

	CHECK_RETVAL(jtag_execute_queue());

	/* assume the manufacturer id is ok; check the part # */
	switch ((device_id >> 12) & 0xFFFF)
	{
	case 0x7B36:
		type = "ARM1136";
		break;
	case 0x7B37:
		type = "ARM11 MPCore";
		break;
	case 0x7B56:
		type = "ARM1156";
		break;
	case 0x7B76:
		arm11->arm.core_type = ARM_MODE_MON;
		/* NOTE: could default arm11->hardware_step to true */
		type = "ARM1176";
		break;
	default:
		LOG_ERROR("unexpected ARM11 ID code");
		return ERROR_FAIL;
	}
	LOG_INFO("found %s", type);

	/* unlikely this could ever fail, but ... */
	switch ((didr >> 16) & 0x0F) {
	case ARM11_DEBUG_V6:
	case ARM11_DEBUG_V61:		/* supports security extensions */
		break;
	default:
		LOG_ERROR("Only ARM v6 and v6.1 debug supported.");
		return ERROR_FAIL;
	}

	arm11->brp = ((didr >> 24) & 0x0F) + 1;

	/** \todo TODO: reserve one brp slot if we allow breakpoints during step */
	arm11->free_brps = arm11->brp;

	LOG_DEBUG("IDCODE %08" PRIx32 " IMPLEMENTOR %02x DIDR %08" PRIx32,
			device_id, implementor, didr);

	/* as a side-effect this reads DSCR and thus
	 * clears the ARM11_DSCR_STICKY_PRECISE_DATA_ABORT / Sticky Precise Data Abort Flag
	 * as suggested by the spec.
	 */

	retval = arm11_check_init(arm11);
	if (retval != ERROR_OK)
		return retval;

	/* Build register cache "late", after target_init(), since we
	 * want to know if this core supports Secure Monitor mode.
	 */
	if (!target_was_examined(target))
		CHECK_RETVAL(arm11_dpm_init(arm11, didr));

	/* ETM on ARM11 still uses original scanchain 6 access mode */
	if (arm11->arm.etm && !target_was_examined(target)) {
		*register_get_last_cache_p(&target->reg_cache) =
			etm_build_reg_cache(target, &arm11->jtag_info,
					arm11->arm.etm);
		CHECK_RETVAL(etm_setup(target));
	}

	target_set_examined(target);

	return ERROR_OK;
}