1 /***************************************************************************
2 * Copyright (C) 2005 by Dominic Rath *
3 * Dominic.Rath@gmx.de *
5 * Copyright (C) 2007,2008 Øyvind Harboe *
6 * oyvind.harboe@zylin.com *
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. *
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. *
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 ***************************************************************************/
26 #include "binarybuffer.h"
29 #ifdef _DEBUG_JTAG_IO_
30 #define DEBUG_JTAG_IO(expr ...) \
31 do { if (1) LOG_DEBUG(expr); } while (0)
33 #define DEBUG_JTAG_IO(expr ...) \
34 do { if (0) LOG_DEBUG(expr); } while (0)
37 #ifndef DEBUG_JTAG_IOZ
38 #define DEBUG_JTAG_IOZ 64
41 /*-----<Macros>--------------------------------------------------*/
44 * When given an array, compute its DIMension; in other words, the
45 * number of elements in the array
47 #define DIM(x) (sizeof(x)/sizeof((x)[0]))
49 /** Calculate the number of bytes required to hold @a n TAP scan bits */
50 #define TAP_SCAN_BYTES(n) CEIL(n, 8)
52 /*-----</Macros>-------------------------------------------------*/
55 * Defines JTAG Test Access Port states.
57 * These definitions were gleaned from the ARM7TDMI-S Technical
58 * Reference Manual and validated against several other ARM core
61 * FIXME some interfaces require specific numbers be used, as they
62 * are handed-off directly to their hardware implementations.
63 * Fix those drivers to map as appropriate ... then pick some
64 * sane set of numbers here (where 0/uninitialized == INVALID).
66 typedef enum tap_state
71 /* These are the old numbers. Leave as-is for now... */
72 TAP_RESET = 0, TAP_IDLE = 8,
73 TAP_DRSELECT = 1, TAP_DRCAPTURE = 2, TAP_DRSHIFT = 3, TAP_DREXIT1 = 4,
74 TAP_DRPAUSE = 5, TAP_DREXIT2 = 6, TAP_DRUPDATE = 7,
75 TAP_IRSELECT = 9, TAP_IRCAPTURE = 10, TAP_IRSHIFT = 11, TAP_IREXIT1 = 12,
76 TAP_IRPAUSE = 13, TAP_IREXIT2 = 14, TAP_IRUPDATE = 15,
79 /* Proper ARM recommended numbers */
101 * Function tap_state_name
102 * Returns a string suitable for display representing the JTAG tap_state
104 const char *tap_state_name(tap_state_t state);
106 /// Provides user-friendly name lookup of TAP states.
107 tap_state_t tap_state_by_name(const char *name);
109 /// The current TAP state of the pending JTAG command queue.
110 extern tap_state_t cmd_queue_cur_state;
113 * This structure defines a single scan field in the scan. It provides
114 * fields for the field's width and pointers to scan input and output
117 * In addition, this structure includes a value and mask that is used by
118 * jtag_add_dr_scan_check() to validate the value that was scanned out.
120 * The allocated, modified, and intmp fields are internal work space.
123 /// A pointer to the tap structure to which this field refers.
124 struct jtag_tap* tap;
126 /// The number of bits this field specifies (up to 32)
128 /// A pointer to value to be scanned into the device
130 /// A pointer to a 32-bit memory location for data scanned out
133 /// The value used to check the data scanned out.
134 uint8_t* check_value;
135 /// The mask to go with check_value
138 /// in_value has been allocated for the queue
140 /// Indicates we modified the in_value.
142 /// temporary storage for performing value checks synchronously
146 typedef struct jtag_tap_event_action_s jtag_tap_event_action_t;
151 const char* dotted_name;
152 int abs_chain_position;
153 /// Is this TAP disabled after JTAG reset?
154 bool disabled_after_reset;
155 /// Is this TAP currently enabled?
157 int ir_length; /**< size of instruction register */
158 uint32_t ir_capture_value;
159 uint8_t* expected; /**< Capture-IR expected value */
160 uint32_t ir_capture_mask;
161 uint8_t* expected_mask; /**< Capture-IR expected mask */
162 uint32_t idcode; /**< device identification code */
163 /** not all devices have idcode,
164 * we'll discover this during chain examination */
167 /// Array of expected identification codes */
168 uint32_t* expected_ids;
169 /// Number of expected identification codes
170 uint8_t expected_ids_cnt;
172 /// current instruction
174 /// Bypass register selected
177 jtag_tap_event_action_t *event_action;
179 struct jtag_tap* next_tap;
182 void jtag_tap_init(struct jtag_tap *tap);
183 void jtag_tap_free(struct jtag_tap *tap);
185 struct jtag_tap* jtag_all_taps(void);
186 const char *jtag_tap_name(const struct jtag_tap *tap);
187 struct jtag_tap* jtag_tap_by_string(const char* dotted_name);
188 struct jtag_tap* jtag_tap_by_jim_obj(Jim_Interp* interp, Jim_Obj* obj);
189 struct jtag_tap* jtag_tap_next_enabled(struct jtag_tap* p);
190 unsigned jtag_tap_count_enabled(void);
191 unsigned jtag_tap_count(void);
195 * - TRST_ASSERTED triggers two sets of callbacks, after operations to
196 * reset the scan chain -- via TMS+TCK signaling, or deasserting the
197 * nTRST signal -- are queued:
199 * + Callbacks in C code fire first, patching internal state
200 * + Then post-reset event scripts fire ... activating JTAG circuits
201 * via TCK cycles, exiting SWD mode via TMS sequences, etc
203 * During those callbacks, scan chain contents have not been validated.
204 * JTAG operations that address a specific TAP (primarily DR/IR scans)
205 * must *not* be queued.
207 * - TAP_EVENT_SETUP is reported after TRST_ASSERTED, and after the scan
208 * chain has been validated. JTAG operations including scans that
209 * target specific TAPs may be performed.
211 * - TAP_EVENT_ENABLE and TAP_EVENT_DISABLE implement TAP activation and
212 * deactivation outside the core using scripted code that understands
213 * the specific JTAG router type. They might be triggered indirectly
214 * from EVENT_SETUP operations.
218 JTAG_TAP_EVENT_SETUP,
219 JTAG_TAP_EVENT_ENABLE,
220 JTAG_TAP_EVENT_DISABLE,
223 struct jtag_tap_event_action_s
225 enum jtag_event event;
227 jtag_tap_event_action_t* next;
231 * Defines the function signature requide for JTAG event callback
232 * functions, which are added with jtag_register_event_callback()
233 * and removed jtag_unregister_event_callback().
234 * @param event The event to handle.
235 * @param prive A pointer to data that was passed to
236 * jtag_register_event_callback().
237 * @returns Must return ERROR_OK on success, or an error code on failure.
239 * @todo Change to return void or define a use for its return code.
241 typedef int (*jtag_event_handler_t)(enum jtag_event event, void* priv);
243 int jtag_register_event_callback(jtag_event_handler_t f, void *x);
244 int jtag_unregister_event_callback(jtag_event_handler_t f, void *x);
246 int jtag_call_event_callbacks(enum jtag_event event);
249 /// @returns The current JTAG speed setting.
250 int jtag_get_speed(void);
253 * Given a @a speed setting, use the interface @c speed_div callback to
254 * adjust the setting.
255 * @param speed The speed setting to convert back to readable KHz.
256 * @returns ERROR_OK if the interface has not been initialized or on success;
257 * otherwise, the error code produced by the @c speed_div callback.
259 int jtag_get_speed_readable(int *speed);
261 /// Attempt to configure the interface for the specified KHz.
262 int jtag_config_khz(unsigned khz);
265 * Attempt to enable RTCK/RCLK. If that fails, fallback to the
266 * specified frequency.
268 int jtag_config_rclk(unsigned fallback_speed_khz);
270 /// Retreives the clock speed of the JTAG interface in KHz.
271 unsigned jtag_get_speed_khz(void);
276 RESET_HAS_TRST = 0x1,
277 RESET_HAS_SRST = 0x2,
278 RESET_TRST_AND_SRST = 0x3,
279 RESET_SRST_PULLS_TRST = 0x4,
280 RESET_TRST_PULLS_SRST = 0x8,
281 RESET_TRST_OPEN_DRAIN = 0x10,
282 RESET_SRST_PUSH_PULL = 0x20,
283 RESET_SRST_NO_GATING = 0x40,
286 enum reset_types jtag_get_reset_config(void);
287 void jtag_set_reset_config(enum reset_types type);
289 void jtag_set_nsrst_delay(unsigned delay);
290 unsigned jtag_get_nsrst_delay(void);
292 void jtag_set_ntrst_delay(unsigned delay);
293 unsigned jtag_get_ntrst_delay(void);
295 void jtag_set_nsrst_assert_width(unsigned delay);
296 unsigned jtag_get_nsrst_assert_width(void);
298 void jtag_set_ntrst_assert_width(unsigned delay);
299 unsigned jtag_get_ntrst_assert_width(void);
301 /// @returns The current state of TRST.
302 int jtag_get_trst(void);
303 /// @returns The current state of SRST.
304 int jtag_get_srst(void);
306 /// Enable or disable data scan verification checking.
307 void jtag_set_verify(bool enable);
308 /// @returns True if data scan verification will be performed.
309 bool jtag_will_verify(void);
311 /// Enable or disable verification of IR scan checking.
312 void jtag_set_verify_capture_ir(bool enable);
313 /// @returns True if IR scan verification will be performed.
314 bool jtag_will_verify_capture_ir(void);
317 * Initialize interface upon startup. Return a successful no-op upon
318 * subsequent invocations.
320 int jtag_interface_init(struct command_context_s* cmd_ctx);
322 /// Shutdown the JTAG interface upon program exit.
323 int jtag_interface_quit(void);
326 * Initialize JTAG chain using only a RESET reset. If init fails,
329 int jtag_init(struct command_context_s* cmd_ctx);
331 /// reset, then initialize JTAG chain
332 int jtag_init_reset(struct command_context_s* cmd_ctx);
333 int jtag_register_commands(struct command_context_s* cmd_ctx);
334 int jtag_init_inner(struct command_context_s *cmd_ctx);
338 * The JTAG interface can be implemented with a software or hardware fifo.
340 * TAP_DRSHIFT and TAP_IRSHIFT are illegal end states; however,
341 * TAP_DRSHIFT/IRSHIFT can be emulated as end states, by using longer
344 * Code that is relatively insensitive to the path taken through state
345 * machine (as long as it is JTAG compliant) can use @a endstate for
346 * jtag_add_xxx_scan(). Otherwise, the pause state must be specified as
347 * end state and a subsequent jtag_add_pathmove() must be issued.
351 * Generate an IR SCAN with a list of scan fields with one entry for
354 * If the input field list contains an instruction value for a TAP then
355 * that is used otherwise the TAP is set to bypass.
357 * TAPs for which no fields are passed are marked as bypassed for
358 * subsequent DR SCANs.
361 void jtag_add_ir_scan(int num_fields,
362 struct scan_field* fields, tap_state_t endstate);
364 * The same as jtag_add_ir_scan except no verification is performed out
367 void jtag_add_ir_scan_noverify(int num_fields,
368 const struct scan_field *fields, tap_state_t state);
370 * Duplicate the scan fields passed into the function into an IR SCAN
371 * command. This function assumes that the caller handles extra fields
374 void jtag_add_plain_ir_scan(int num_fields,
375 const struct scan_field* fields, tap_state_t endstate);
379 * Set in_value to point to 32 bits of memory to scan into. This
380 * function is a way to handle the case of synchronous and asynchronous
383 * In the event of an asynchronous queue execution the queue buffer
384 * allocation method is used, for the synchronous case the temporary 32
385 * bits come from the input field itself.
387 void jtag_alloc_in_value32(struct scan_field *field);
390 * Generate a DR SCAN using the fields passed to the function.
391 * For connected TAPs, the function checks in_fields and uses fields
392 * specified there. For bypassed TAPs, the function generates a dummy
393 * 1-bit field. The bypass status of TAPs is set by jtag_add_ir_scan().
395 void jtag_add_dr_scan(int num_fields,
396 const struct scan_field* fields, tap_state_t endstate);
397 /// A version of jtag_add_dr_scan() that uses the check_value/mask fields
398 void jtag_add_dr_scan_check(int num_fields,
399 struct scan_field* fields, tap_state_t endstate);
401 * Duplicate the scan fields passed into the function into a DR SCAN
402 * command. Unlike jtag_add_dr_scan(), this function assumes that the
403 * caller handles extra fields for bypassed TAPs.
405 void jtag_add_plain_dr_scan(int num_fields,
406 const struct scan_field* fields, tap_state_t endstate);
409 * Defines the type of data passed to the jtag_callback_t interface.
410 * The underlying type must allow storing an @c int or pointer type.
412 typedef intptr_t jtag_callback_data_t;
415 * Defines a simple JTAG callback that can allow conversions on data
416 * scanned in from an interface.
418 * This callback should only be used for conversion that cannot fail.
419 * For conversion types or checks that can fail, use the more complete
420 * variant: jtag_callback_t.
422 typedef void (*jtag_callback1_t)(jtag_callback_data_t data0);
424 /// A simpler version of jtag_add_callback4().
425 void jtag_add_callback(jtag_callback1_t, jtag_callback_data_t data0);
430 * Defines the interface of the JTAG callback mechanism.
432 * @param in the pointer to the data clocked in
433 * @param data1 An integer big enough to use as an @c int or a pointer.
434 * @param data2 An integer big enough to use as an @c int or a pointer.
435 * @param data3 An integer big enough to use as an @c int or a pointer.
436 * @returns an error code
438 typedef int (*jtag_callback_t)(jtag_callback_data_t data0,
439 jtag_callback_data_t data1,
440 jtag_callback_data_t data2,
441 jtag_callback_data_t data3);
445 * This callback can be executed immediately the queue has been flushed.
447 * The JTAG queue can be executed synchronously or asynchronously.
448 * Typically for USB, the queue is executed asynchronously. For
449 * low-latency interfaces, the queue may be executed synchronously.
451 * The callback mechanism is very general and does not make many
452 * assumptions about what the callback does or what its arguments are.
453 * These callbacks are typically executed *after* the *entire* JTAG
454 * queue has been executed for e.g. USB interfaces, and they are
455 * guaranteeed to be invoked in the order that they were queued.
457 * If the execution of the queue fails before the callbacks, then --
458 * depending on driver implementation -- the callbacks may or may not be
459 * invoked. @todo Can we make this behavior consistent?
461 * The strange name is due to C's lack of overloading using function
464 * @param f The callback function to add.
465 * @param data0 Typically used to point to the data to operate on.
466 * Frequently this will be the data clocked in during a shift operation.
467 * @param data1 An integer big enough to use as an @c int or a pointer.
468 * @param data2 An integer big enough to use as an @c int or a pointer.
469 * @param data3 An integer big enough to use as an @c int or a pointer.
472 void jtag_add_callback4(jtag_callback_t f, jtag_callback_data_t data0,
473 jtag_callback_data_t data1, jtag_callback_data_t data2,
474 jtag_callback_data_t data3);
478 * Run a TAP_RESET reset where the end state is TAP_RESET,
479 * regardless of the start state.
481 void jtag_add_tlr(void);
484 * Application code *must* assume that interfaces will
485 * implement transitions between states with different
486 * paths and path lengths through the state diagram. The
487 * path will vary across interface and also across versions
488 * of the same interface over time. Even if the OpenOCD code
489 * is unchanged, the actual path taken may vary over time
490 * and versions of interface firmware or PCB revisions.
492 * Use jtag_add_pathmove() when specific transition sequences
495 * Do not use jtag_add_pathmove() unless you need to, but do use it
498 * DANGER! If the target is dependent upon a particular sequence
499 * of transitions for things to work correctly(e.g. as a workaround
500 * for an errata that contradicts the JTAG standard), then pathmove
501 * must be used, even if some jtag interfaces happen to use the
502 * desired path. Worse, the jtag interface used for testing a
503 * particular implementation, could happen to use the "desired"
504 * path when transitioning to/from end
507 * A list of unambigious single clock state transitions, not
508 * all drivers can support this, but it is required for e.g.
509 * XScale and Xilinx support
511 * Note! TAP_RESET must not be used in the path!
513 * Note that the first on the list must be reachable
514 * via a single transition from the current state.
516 * All drivers are required to implement jtag_add_pathmove().
517 * However, if the pathmove sequence can not be precisely
518 * executed, an interface_jtag_add_pathmove() or jtag_execute_queue()
519 * must return an error. It is legal, but not recommended, that
520 * a driver returns an error in all cases for a pathmove if it
521 * can only implement a few transitions and therefore
522 * a partial implementation of pathmove would have little practical
525 * If an error occurs, jtag_error will contain one of these error codes:
526 * - ERROR_JTAG_NOT_STABLE_STATE -- The final state was not stable.
527 * - ERROR_JTAG_STATE_INVALID -- The path passed through TAP_RESET.
528 * - ERROR_JTAG_TRANSITION_INVALID -- The path includes invalid
531 void jtag_add_pathmove(int num_states, const tap_state_t* path);
534 * jtag_add_statemove() moves from the current state to @a goal_state.
536 * @param goal_state The final TAP state.
537 * @return ERROR_OK on success, or an error code on failure.
539 * Moves from the current state to the goal \a state.
540 * Both states must be stable.
542 int jtag_add_statemove(tap_state_t goal_state);
545 * Goes to TAP_IDLE (if we're not already there), cycle
546 * precisely num_cycles in the TAP_IDLE state, after which move
547 * to @a endstate (unless it is also TAP_IDLE).
549 * @param num_cycles Number of cycles in TAP_IDLE state. This argument
550 * may be 0, in which case this routine will navigate to @a endstate
552 * @param endstate The final state.
554 void jtag_add_runtest(int num_cycles, tap_state_t endstate);
557 * A reset of the TAP state machine can be requested.
559 * Whether tms or trst reset is used depends on the capabilities of
560 * the target and jtag interface(reset_config command configures this).
562 * srst can driver a reset of the TAP state machine and vice
565 * Application code may need to examine value of jtag_reset_config
566 * to determine the proper codepath
568 * DANGER! Even though srst drives trst, trst might not be connected to
569 * the interface, and it might actually be *harmful* to assert trst in this case.
571 * This is why combinations such as "reset_config srst_only srst_pulls_trst"
574 * only req_tlr_or_trst and srst can have a transition for a
575 * call as the effects of transitioning both at the "same time"
576 * are undefined, but when srst_pulls_trst or vice versa,
577 * then trst & srst *must* be asserted together.
579 void jtag_add_reset(int req_tlr_or_trst, int srst);
583 * Function jtag_set_end_state
585 * Set a global variable to \a state if \a state != TAP_INVALID.
587 * Return the value of the global variable.
590 tap_state_t jtag_set_end_state(tap_state_t state);
592 * Function jtag_get_end_state
594 * Return the value of the global variable for end state
597 tap_state_t jtag_get_end_state(void);
598 void jtag_add_sleep(uint32_t us);
602 * Function jtag_add_stable_clocks
603 * first checks that the state in which the clocks are to be issued is
604 * stable, then queues up clock_count clocks for transmission.
606 void jtag_add_clocks(int num_cycles);
610 * For software FIFO implementations, the queued commands can be executed
611 * during this call or earlier. A sw queue might decide to push out
612 * some of the jtag_add_xxx() operations once the queue is "big enough".
614 * This fn will return an error code if any of the prior jtag_add_xxx()
615 * calls caused a failure, e.g. check failure. Note that it does not
616 * matter if the operation was executed *before* jtag_execute_queue(),
617 * jtag_execute_queue() will still return an error code.
619 * All jtag_add_xxx() calls that have in_handler != NULL will have been
620 * executed when this fn returns, but if what has been queued only
621 * clocks data out, without reading anything back, then JTAG could
622 * be running *after* jtag_execute_queue() returns. The API does
623 * not define a way to flush a hw FIFO that runs *after*
624 * jtag_execute_queue() returns.
626 * jtag_add_xxx() commands can either be executed immediately or
627 * at some time between the jtag_add_xxx() fn call and jtag_execute_queue().
629 int jtag_execute_queue(void);
631 /// same as jtag_execute_queue() but does not clear the error flag
632 void jtag_execute_queue_noclear(void);
634 /// @returns the number of times the scan queue has been flushed
635 int jtag_get_flush_queue_count(void);
637 /// Report Tcl event to all TAPs
638 void jtag_notify_event(enum jtag_event);
641 /* can be implemented by hw + sw */
642 int jtag_power_dropout(int* dropout);
643 int jtag_srst_asserted(int* srst_asserted);
645 /* JTAG support functions */
648 * Execute jtag queue and check value with an optional mask.
649 * @param field Pointer to scan field.
650 * @param value Pointer to scan value.
651 * @param mask Pointer to scan mask; may be NULL.
652 * @returns Nothing, but calls jtag_set_error() on any error.
654 void jtag_check_value_mask(struct scan_field *field, uint8_t *value, uint8_t *mask);
656 void jtag_sleep(uint32_t us);
659 * The JTAG subsystem defines a number of error codes,
660 * using codes between -100 and -199.
662 #define ERROR_JTAG_INIT_FAILED (-100)
663 #define ERROR_JTAG_INVALID_INTERFACE (-101)
664 #define ERROR_JTAG_NOT_IMPLEMENTED (-102)
665 #define ERROR_JTAG_TRST_ASSERTED (-103)
666 #define ERROR_JTAG_QUEUE_FAILED (-104)
667 #define ERROR_JTAG_NOT_STABLE_STATE (-105)
668 #define ERROR_JTAG_DEVICE_ERROR (-107)
669 #define ERROR_JTAG_STATE_INVALID (-108)
670 #define ERROR_JTAG_TRANSITION_INVALID (-109)
671 #define ERROR_JTAG_INIT_SOFT_FAIL (-110)
674 * jtag_add_dr_out() is a version of jtag_add_dr_scan() which
675 * only scans data out. It operates on 32 bit integers instead
676 * of 8 bit, which makes it a better impedance match with
677 * the calling code which often operate on 32 bit integers.
679 * Current or end_state can not be TAP_RESET. end_state can be TAP_INVALID
681 * num_bits[i] is the number of bits to clock out from value[i] LSB first.
683 * If the device is in bypass, then that is an error condition in
684 * the caller code that is not detected by this fn, whereas
685 * jtag_add_dr_scan() does detect it. Similarly if the device is not in
686 * bypass, data must be passed to it.
688 * If anything fails, then jtag_error will be set and jtag_execute() will
689 * return an error. There is no way to determine if there was a failure
690 * during this function call.
692 * This is an inline fn to speed up embedded hosts. Also note that
693 * interface_jtag_add_dr_out() can be a *small* inline function for
696 * There is no jtag_add_dr_outin() version of this fn that also allows
697 * clocking data back in. Patches gladly accepted!
699 void jtag_add_dr_out(struct jtag_tap* tap,
700 int num_fields, const int* num_bits, const uint32_t* value,
701 tap_state_t end_state);
705 * Set the current JTAG core execution error, unless one was set
706 * by a previous call previously. Driver or application code must
707 * use jtag_error_clear to reset jtag_error once this routine has been
708 * called with a non-zero error code.
710 void jtag_set_error(int error);
711 /// @returns The current value of jtag_error
712 int jtag_get_error(void);
714 * Resets jtag_error to ERROR_OK, returning its previous value.
715 * @returns The previous value of @c jtag_error.
717 int jtag_error_clear(void);
720 * Return true if it's safe for a background polling task to access the
721 * JTAG scan chain. Polling may be explicitly disallowed, and is also
722 * unsafe while nTRST is active or the JTAG clock is gated off.,
724 bool is_jtag_poll_safe(void);
727 * Return flag reporting whether JTAG polling is disallowed.
729 bool jtag_poll_get_enabled(void);
732 * Assign flag reporting whether JTAG polling is disallowed.
734 void jtag_poll_set_enabled(bool value);