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.
122 typedef struct scan_field_s
124 /// A pointer to the tap structure to which this field refers.
125 struct jtag_tap* tap;
127 /// The number of bits this field specifies (up to 32)
129 /// A pointer to value to be scanned into the device
131 /// A pointer to a 32-bit memory location for data scanned out
134 /// The value used to check the data scanned out.
135 uint8_t* check_value;
136 /// The mask to go with check_value
139 /// in_value has been allocated for the queue
141 /// Indicates we modified the in_value.
143 /// temporary storage for performing value checks synchronously
147 typedef struct jtag_tap_event_action_s jtag_tap_event_action_t;
152 const char* dotted_name;
153 int abs_chain_position;
154 /// Is this TAP disabled after JTAG reset?
155 bool disabled_after_reset;
156 /// Is this TAP currently enabled?
158 int ir_length; /**< size of instruction register */
159 uint32_t ir_capture_value;
160 uint8_t* expected; /**< Capture-IR expected value */
161 uint32_t ir_capture_mask;
162 uint8_t* expected_mask; /**< Capture-IR expected mask */
163 uint32_t idcode; /**< device identification code */
164 /** not all devices have idcode,
165 * we'll discover this during chain examination */
168 /// Array of expected identification codes */
169 uint32_t* expected_ids;
170 /// Number of expected identification codes
171 uint8_t expected_ids_cnt;
173 /// current instruction
175 /// Bypass register selected
178 jtag_tap_event_action_t *event_action;
180 struct jtag_tap* next_tap;
183 void jtag_tap_init(struct jtag_tap *tap);
184 void jtag_tap_free(struct jtag_tap *tap);
186 struct jtag_tap* jtag_all_taps(void);
187 const char *jtag_tap_name(const struct jtag_tap *tap);
188 struct jtag_tap* jtag_tap_by_string(const char* dotted_name);
189 struct jtag_tap* jtag_tap_by_jim_obj(Jim_Interp* interp, Jim_Obj* obj);
190 struct jtag_tap* jtag_tap_next_enabled(struct jtag_tap* p);
191 unsigned jtag_tap_count_enabled(void);
192 unsigned jtag_tap_count(void);
196 * - TRST_ASSERTED triggers two sets of callbacks, after operations to
197 * reset the scan chain -- via TMS+TCK signaling, or deasserting the
198 * nTRST signal -- are queued:
200 * + Callbacks in C code fire first, patching internal state
201 * + Then post-reset event scripts fire ... activating JTAG circuits
202 * via TCK cycles, exiting SWD mode via TMS sequences, etc
204 * During those callbacks, scan chain contents have not been validated.
205 * JTAG operations that address a specific TAP (primarily DR/IR scans)
206 * must *not* be queued.
208 * - TAP_EVENT_SETUP is reported after TRST_ASSERTED, and after the scan
209 * chain has been validated. JTAG operations including scans that
210 * target specific TAPs may be performed.
212 * - TAP_EVENT_ENABLE and TAP_EVENT_DISABLE implement TAP activation and
213 * deactivation outside the core using scripted code that understands
214 * the specific JTAG router type. They might be triggered indirectly
215 * from EVENT_SETUP operations.
219 JTAG_TAP_EVENT_SETUP,
220 JTAG_TAP_EVENT_ENABLE,
221 JTAG_TAP_EVENT_DISABLE,
224 struct jtag_tap_event_action_s
226 enum jtag_event event;
228 jtag_tap_event_action_t* next;
232 * Defines the function signature requide for JTAG event callback
233 * functions, which are added with jtag_register_event_callback()
234 * and removed jtag_unregister_event_callback().
235 * @param event The event to handle.
236 * @param prive A pointer to data that was passed to
237 * jtag_register_event_callback().
238 * @returns Must return ERROR_OK on success, or an error code on failure.
240 * @todo Change to return void or define a use for its return code.
242 typedef int (*jtag_event_handler_t)(enum jtag_event event, void* priv);
244 int jtag_register_event_callback(jtag_event_handler_t f, void *x);
245 int jtag_unregister_event_callback(jtag_event_handler_t f, void *x);
247 int jtag_call_event_callbacks(enum jtag_event event);
250 /// @returns The current JTAG speed setting.
251 int jtag_get_speed(void);
254 * Given a @a speed setting, use the interface @c speed_div callback to
255 * adjust the setting.
256 * @param speed The speed setting to convert back to readable KHz.
257 * @returns ERROR_OK if the interface has not been initialized or on success;
258 * otherwise, the error code produced by the @c speed_div callback.
260 int jtag_get_speed_readable(int *speed);
262 /// Attempt to configure the interface for the specified KHz.
263 int jtag_config_khz(unsigned khz);
266 * Attempt to enable RTCK/RCLK. If that fails, fallback to the
267 * specified frequency.
269 int jtag_config_rclk(unsigned fallback_speed_khz);
271 /// Retreives the clock speed of the JTAG interface in KHz.
272 unsigned jtag_get_speed_khz(void);
277 RESET_HAS_TRST = 0x1,
278 RESET_HAS_SRST = 0x2,
279 RESET_TRST_AND_SRST = 0x3,
280 RESET_SRST_PULLS_TRST = 0x4,
281 RESET_TRST_PULLS_SRST = 0x8,
282 RESET_TRST_OPEN_DRAIN = 0x10,
283 RESET_SRST_PUSH_PULL = 0x20,
284 RESET_SRST_NO_GATING = 0x40,
287 enum reset_types jtag_get_reset_config(void);
288 void jtag_set_reset_config(enum reset_types type);
290 void jtag_set_nsrst_delay(unsigned delay);
291 unsigned jtag_get_nsrst_delay(void);
293 void jtag_set_ntrst_delay(unsigned delay);
294 unsigned jtag_get_ntrst_delay(void);
296 void jtag_set_nsrst_assert_width(unsigned delay);
297 unsigned jtag_get_nsrst_assert_width(void);
299 void jtag_set_ntrst_assert_width(unsigned delay);
300 unsigned jtag_get_ntrst_assert_width(void);
302 /// @returns The current state of TRST.
303 int jtag_get_trst(void);
304 /// @returns The current state of SRST.
305 int jtag_get_srst(void);
307 /// Enable or disable data scan verification checking.
308 void jtag_set_verify(bool enable);
309 /// @returns True if data scan verification will be performed.
310 bool jtag_will_verify(void);
312 /// Enable or disable verification of IR scan checking.
313 void jtag_set_verify_capture_ir(bool enable);
314 /// @returns True if IR scan verification will be performed.
315 bool jtag_will_verify_capture_ir(void);
318 * Initialize interface upon startup. Return a successful no-op upon
319 * subsequent invocations.
321 int jtag_interface_init(struct command_context_s* cmd_ctx);
323 /// Shutdown the JTAG interface upon program exit.
324 int jtag_interface_quit(void);
327 * Initialize JTAG chain using only a RESET reset. If init fails,
330 int jtag_init(struct command_context_s* cmd_ctx);
332 /// reset, then initialize JTAG chain
333 int jtag_init_reset(struct command_context_s* cmd_ctx);
334 int jtag_register_commands(struct command_context_s* cmd_ctx);
335 int jtag_init_inner(struct command_context_s *cmd_ctx);
339 * The JTAG interface can be implemented with a software or hardware fifo.
341 * TAP_DRSHIFT and TAP_IRSHIFT are illegal end states; however,
342 * TAP_DRSHIFT/IRSHIFT can be emulated as end states, by using longer
345 * Code that is relatively insensitive to the path taken through state
346 * machine (as long as it is JTAG compliant) can use @a endstate for
347 * jtag_add_xxx_scan(). Otherwise, the pause state must be specified as
348 * end state and a subsequent jtag_add_pathmove() must be issued.
352 * Generate an IR SCAN with a list of scan fields with one entry for
355 * If the input field list contains an instruction value for a TAP then
356 * that is used otherwise the TAP is set to bypass.
358 * TAPs for which no fields are passed are marked as bypassed for
359 * subsequent DR SCANs.
362 void jtag_add_ir_scan(int num_fields,
363 scan_field_t* fields, tap_state_t endstate);
365 * The same as jtag_add_ir_scan except no verification is performed out
368 void jtag_add_ir_scan_noverify(int num_fields,
369 const scan_field_t *fields, tap_state_t state);
371 * Duplicate the scan fields passed into the function into an IR SCAN
372 * command. This function assumes that the caller handles extra fields
375 void jtag_add_plain_ir_scan(int num_fields,
376 const scan_field_t* fields, tap_state_t endstate);
380 * Set in_value to point to 32 bits of memory to scan into. This
381 * function is a way to handle the case of synchronous and asynchronous
384 * In the event of an asynchronous queue execution the queue buffer
385 * allocation method is used, for the synchronous case the temporary 32
386 * bits come from the input field itself.
388 void jtag_alloc_in_value32(scan_field_t *field);
391 * Generate a DR SCAN using the fields passed to the function.
392 * For connected TAPs, the function checks in_fields and uses fields
393 * specified there. For bypassed TAPs, the function generates a dummy
394 * 1-bit field. The bypass status of TAPs is set by jtag_add_ir_scan().
396 void jtag_add_dr_scan(int num_fields,
397 const scan_field_t* fields, tap_state_t endstate);
398 /// A version of jtag_add_dr_scan() that uses the check_value/mask fields
399 void jtag_add_dr_scan_check(int num_fields,
400 scan_field_t* fields, tap_state_t endstate);
402 * Duplicate the scan fields passed into the function into a DR SCAN
403 * command. Unlike jtag_add_dr_scan(), this function assumes that the
404 * caller handles extra fields for bypassed TAPs.
406 void jtag_add_plain_dr_scan(int num_fields,
407 const scan_field_t* fields, tap_state_t endstate);
410 * Defines the type of data passed to the jtag_callback_t interface.
411 * The underlying type must allow storing an @c int or pointer type.
413 typedef intptr_t jtag_callback_data_t;
416 * Defines a simple JTAG callback that can allow conversions on data
417 * scanned in from an interface.
419 * This callback should only be used for conversion that cannot fail.
420 * For conversion types or checks that can fail, use the more complete
421 * variant: jtag_callback_t.
423 typedef void (*jtag_callback1_t)(jtag_callback_data_t data0);
425 /// A simpler version of jtag_add_callback4().
426 void jtag_add_callback(jtag_callback1_t, jtag_callback_data_t data0);
431 * Defines the interface of the JTAG callback mechanism.
433 * @param in the pointer to the data clocked in
434 * @param data1 An integer big enough to use as an @c int or a pointer.
435 * @param data2 An integer big enough to use as an @c int or a pointer.
436 * @param data3 An integer big enough to use as an @c int or a pointer.
437 * @returns an error code
439 typedef int (*jtag_callback_t)(jtag_callback_data_t data0,
440 jtag_callback_data_t data1,
441 jtag_callback_data_t data2,
442 jtag_callback_data_t data3);
446 * This callback can be executed immediately the queue has been flushed.
448 * The JTAG queue can be executed synchronously or asynchronously.
449 * Typically for USB, the queue is executed asynchronously. For
450 * low-latency interfaces, the queue may be executed synchronously.
452 * The callback mechanism is very general and does not make many
453 * assumptions about what the callback does or what its arguments are.
454 * These callbacks are typically executed *after* the *entire* JTAG
455 * queue has been executed for e.g. USB interfaces, and they are
456 * guaranteeed to be invoked in the order that they were queued.
458 * If the execution of the queue fails before the callbacks, then --
459 * depending on driver implementation -- the callbacks may or may not be
460 * invoked. @todo Can we make this behavior consistent?
462 * The strange name is due to C's lack of overloading using function
465 * @param f The callback function to add.
466 * @param data0 Typically used to point to the data to operate on.
467 * Frequently this will be the data clocked in during a shift operation.
468 * @param data1 An integer big enough to use as an @c int or a pointer.
469 * @param data2 An integer big enough to use as an @c int or a pointer.
470 * @param data3 An integer big enough to use as an @c int or a pointer.
473 void jtag_add_callback4(jtag_callback_t f, jtag_callback_data_t data0,
474 jtag_callback_data_t data1, jtag_callback_data_t data2,
475 jtag_callback_data_t data3);
479 * Run a TAP_RESET reset where the end state is TAP_RESET,
480 * regardless of the start state.
482 void jtag_add_tlr(void);
485 * Application code *must* assume that interfaces will
486 * implement transitions between states with different
487 * paths and path lengths through the state diagram. The
488 * path will vary across interface and also across versions
489 * of the same interface over time. Even if the OpenOCD code
490 * is unchanged, the actual path taken may vary over time
491 * and versions of interface firmware or PCB revisions.
493 * Use jtag_add_pathmove() when specific transition sequences
496 * Do not use jtag_add_pathmove() unless you need to, but do use it
499 * DANGER! If the target is dependent upon a particular sequence
500 * of transitions for things to work correctly(e.g. as a workaround
501 * for an errata that contradicts the JTAG standard), then pathmove
502 * must be used, even if some jtag interfaces happen to use the
503 * desired path. Worse, the jtag interface used for testing a
504 * particular implementation, could happen to use the "desired"
505 * path when transitioning to/from end
508 * A list of unambigious single clock state transitions, not
509 * all drivers can support this, but it is required for e.g.
510 * XScale and Xilinx support
512 * Note! TAP_RESET must not be used in the path!
514 * Note that the first on the list must be reachable
515 * via a single transition from the current state.
517 * All drivers are required to implement jtag_add_pathmove().
518 * However, if the pathmove sequence can not be precisely
519 * executed, an interface_jtag_add_pathmove() or jtag_execute_queue()
520 * must return an error. It is legal, but not recommended, that
521 * a driver returns an error in all cases for a pathmove if it
522 * can only implement a few transitions and therefore
523 * a partial implementation of pathmove would have little practical
526 * If an error occurs, jtag_error will contain one of these error codes:
527 * - ERROR_JTAG_NOT_STABLE_STATE -- The final state was not stable.
528 * - ERROR_JTAG_STATE_INVALID -- The path passed through TAP_RESET.
529 * - ERROR_JTAG_TRANSITION_INVALID -- The path includes invalid
532 void jtag_add_pathmove(int num_states, const tap_state_t* path);
535 * jtag_add_statemove() moves from the current state to @a goal_state.
537 * @param goal_state The final TAP state.
538 * @return ERROR_OK on success, or an error code on failure.
540 * Moves from the current state to the goal \a state.
541 * Both states must be stable.
543 int jtag_add_statemove(tap_state_t goal_state);
546 * Goes to TAP_IDLE (if we're not already there), cycle
547 * precisely num_cycles in the TAP_IDLE state, after which move
548 * to @a endstate (unless it is also TAP_IDLE).
550 * @param num_cycles Number of cycles in TAP_IDLE state. This argument
551 * may be 0, in which case this routine will navigate to @a endstate
553 * @param endstate The final state.
555 void jtag_add_runtest(int num_cycles, tap_state_t endstate);
558 * A reset of the TAP state machine can be requested.
560 * Whether tms or trst reset is used depends on the capabilities of
561 * the target and jtag interface(reset_config command configures this).
563 * srst can driver a reset of the TAP state machine and vice
566 * Application code may need to examine value of jtag_reset_config
567 * to determine the proper codepath
569 * DANGER! Even though srst drives trst, trst might not be connected to
570 * the interface, and it might actually be *harmful* to assert trst in this case.
572 * This is why combinations such as "reset_config srst_only srst_pulls_trst"
575 * only req_tlr_or_trst and srst can have a transition for a
576 * call as the effects of transitioning both at the "same time"
577 * are undefined, but when srst_pulls_trst or vice versa,
578 * then trst & srst *must* be asserted together.
580 void jtag_add_reset(int req_tlr_or_trst, int srst);
584 * Function jtag_set_end_state
586 * Set a global variable to \a state if \a state != TAP_INVALID.
588 * Return the value of the global variable.
591 tap_state_t jtag_set_end_state(tap_state_t state);
593 * Function jtag_get_end_state
595 * Return the value of the global variable for end state
598 tap_state_t jtag_get_end_state(void);
599 void jtag_add_sleep(uint32_t us);
603 * Function jtag_add_stable_clocks
604 * first checks that the state in which the clocks are to be issued is
605 * stable, then queues up clock_count clocks for transmission.
607 void jtag_add_clocks(int num_cycles);
611 * For software FIFO implementations, the queued commands can be executed
612 * during this call or earlier. A sw queue might decide to push out
613 * some of the jtag_add_xxx() operations once the queue is "big enough".
615 * This fn will return an error code if any of the prior jtag_add_xxx()
616 * calls caused a failure, e.g. check failure. Note that it does not
617 * matter if the operation was executed *before* jtag_execute_queue(),
618 * jtag_execute_queue() will still return an error code.
620 * All jtag_add_xxx() calls that have in_handler != NULL will have been
621 * executed when this fn returns, but if what has been queued only
622 * clocks data out, without reading anything back, then JTAG could
623 * be running *after* jtag_execute_queue() returns. The API does
624 * not define a way to flush a hw FIFO that runs *after*
625 * jtag_execute_queue() returns.
627 * jtag_add_xxx() commands can either be executed immediately or
628 * at some time between the jtag_add_xxx() fn call and jtag_execute_queue().
630 int jtag_execute_queue(void);
632 /// same as jtag_execute_queue() but does not clear the error flag
633 void jtag_execute_queue_noclear(void);
635 /// @returns the number of times the scan queue has been flushed
636 int jtag_get_flush_queue_count(void);
638 /// Report Tcl event to all TAPs
639 void jtag_notify_event(enum jtag_event);
642 /* can be implemented by hw + sw */
643 int jtag_power_dropout(int* dropout);
644 int jtag_srst_asserted(int* srst_asserted);
646 /* JTAG support functions */
649 * Execute jtag queue and check value with an optional mask.
650 * @param field Pointer to scan field.
651 * @param value Pointer to scan value.
652 * @param mask Pointer to scan mask; may be NULL.
653 * @returns Nothing, but calls jtag_set_error() on any error.
655 void jtag_check_value_mask(scan_field_t *field, uint8_t *value, uint8_t *mask);
657 void jtag_sleep(uint32_t us);
660 * The JTAG subsystem defines a number of error codes,
661 * using codes between -100 and -199.
663 #define ERROR_JTAG_INIT_FAILED (-100)
664 #define ERROR_JTAG_INVALID_INTERFACE (-101)
665 #define ERROR_JTAG_NOT_IMPLEMENTED (-102)
666 #define ERROR_JTAG_TRST_ASSERTED (-103)
667 #define ERROR_JTAG_QUEUE_FAILED (-104)
668 #define ERROR_JTAG_NOT_STABLE_STATE (-105)
669 #define ERROR_JTAG_DEVICE_ERROR (-107)
670 #define ERROR_JTAG_STATE_INVALID (-108)
671 #define ERROR_JTAG_TRANSITION_INVALID (-109)
672 #define ERROR_JTAG_INIT_SOFT_FAIL (-110)
675 * jtag_add_dr_out() is a version of jtag_add_dr_scan() which
676 * only scans data out. It operates on 32 bit integers instead
677 * of 8 bit, which makes it a better impedance match with
678 * the calling code which often operate on 32 bit integers.
680 * Current or end_state can not be TAP_RESET. end_state can be TAP_INVALID
682 * num_bits[i] is the number of bits to clock out from value[i] LSB first.
684 * If the device is in bypass, then that is an error condition in
685 * the caller code that is not detected by this fn, whereas
686 * jtag_add_dr_scan() does detect it. Similarly if the device is not in
687 * bypass, data must be passed to it.
689 * If anything fails, then jtag_error will be set and jtag_execute() will
690 * return an error. There is no way to determine if there was a failure
691 * during this function call.
693 * This is an inline fn to speed up embedded hosts. Also note that
694 * interface_jtag_add_dr_out() can be a *small* inline function for
697 * There is no jtag_add_dr_outin() version of this fn that also allows
698 * clocking data back in. Patches gladly accepted!
700 void jtag_add_dr_out(struct jtag_tap* tap,
701 int num_fields, const int* num_bits, const uint32_t* value,
702 tap_state_t end_state);
706 * Set the current JTAG core execution error, unless one was set
707 * by a previous call previously. Driver or application code must
708 * use jtag_error_clear to reset jtag_error once this routine has been
709 * called with a non-zero error code.
711 void jtag_set_error(int error);
712 /// @returns The current value of jtag_error
713 int jtag_get_error(void);
715 * Resets jtag_error to ERROR_OK, returning its previous value.
716 * @returns The previous value of @c jtag_error.
718 int jtag_error_clear(void);
721 * Return true if it's safe for a background polling task to access the
722 * JTAG scan chain. Polling may be explicitly disallowed, and is also
723 * unsafe while nTRST is active or the JTAG clock is gated off.,
725 bool is_jtag_poll_safe(void);
728 * Return flag reporting whether JTAG polling is disallowed.
730 bool jtag_poll_get_enabled(void);
733 * Assign flag reporting whether JTAG polling is disallowed.
735 void jtag_poll_set_enabled(bool value);