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"
30 #ifdef _DEBUG_JTAG_IO_
31 #define DEBUG_JTAG_IO(expr ...) LOG_DEBUG(expr)
33 #define DEBUG_JTAG_IO(expr ...)
36 #ifndef DEBUG_JTAG_IOZ
37 #define DEBUG_JTAG_IOZ 64
40 /*-----<Macros>--------------------------------------------------*/
43 * When given an array, compute its DIMension; in other words, the
44 * number of elements in the array
46 #define DIM(x) (sizeof(x)/sizeof((x)[0]))
48 /** Calculate the number of bytes required to hold @a n TAP scan bits */
49 #define TAP_SCAN_BYTES(n) CEIL(n, 8)
51 /*-----</Macros>-------------------------------------------------*/
54 * Defines JTAG Test Access Port states.
56 * These definitions were gleaned from the ARM7TDMI-S Technical
57 * Reference Manual and validated against several other ARM core
58 * technical manuals. tap_get_tms_path() is sensitive to this numbering
59 * and ordering of the TAP states; furthermore, some interfaces require
60 * specific numbers be used, as they are handed-off directly to their
61 * hardware implementations.
63 typedef enum tap_state
66 /* These are the old numbers. Leave as-is for now... */
67 TAP_RESET = 0, TAP_IDLE = 8,
68 TAP_DRSELECT = 1, TAP_DRCAPTURE = 2, TAP_DRSHIFT = 3, TAP_DREXIT1 = 4,
69 TAP_DRPAUSE = 5, TAP_DREXIT2 = 6, TAP_DRUPDATE = 7,
70 TAP_IRSELECT = 9, TAP_IRCAPTURE = 10, TAP_IRSHIFT = 11, TAP_IREXIT1 = 12,
71 TAP_IRPAUSE = 13, TAP_IREXIT2 = 14, TAP_IRUPDATE = 15,
73 TAP_NUM_STATES = 16, TAP_INVALID = -1,
75 /* Proper ARM recommended numbers */
93 TAP_NUM_STATES = 0x10,
100 * Function tap_state_name
101 * Returns a string suitable for display representing the JTAG tap_state
103 const char* tap_state_name(tap_state_t state);
105 /// The current TAP state of the pending JTAG command queue.
106 extern tap_state_t cmd_queue_cur_state;
109 * This structure defines a single scan field in the scan. It provides
110 * fields for the field's width and pointers to scan input and output
113 * In addition, this structure includes a value and mask that is used by
114 * jtag_add_dr_scan_check() to validate the value that was scanned out.
116 * The allocated, modified, and intmp fields are internal work space.
118 typedef struct scan_field_s
120 /// A pointer to the tap structure to which this field refers.
123 /// The number of bits this field specifies (up to 32)
125 /// A pointer to value to be scanned into the device
127 /// A pointer to a 32-bit memory location for data scanned out
130 /// The value used to check the data scanned out.
132 /// The mask to go with check_value
135 /// in_value has been allocated for the queue
137 /// Indicates we modified the in_value.
139 /// temporary storage for performing value checks synchronously
143 typedef struct jtag_tap_event_action_s jtag_tap_event_action_t;
145 /* this is really: typedef jtag_tap_t */
146 /* But - the typedef is done in "types.h" */
147 /* due to "forward decloration reasons" */
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 u32 ir_capture_value;
160 u8* expected; /**< Capture-IR expected value */
162 u8* expected_mask; /**< Capture-IR expected mask */
164 /**< device identification code */
166 /// Array of expected identification codes */
168 /// Number of expected identification codes
171 /// current instruction
173 /// Bypass register selected
176 jtag_tap_event_action_t *event_action;
178 jtag_tap_t* next_tap;
181 void jtag_tap_init(jtag_tap_t *tap);
182 void jtag_tap_free(jtag_tap_t *tap);
184 extern jtag_tap_t* jtag_all_taps(void);
185 extern const char *jtag_tap_name(const jtag_tap_t *tap);
186 extern jtag_tap_t* jtag_tap_by_string(const char* dotted_name);
187 extern jtag_tap_t* jtag_tap_by_jim_obj(Jim_Interp* interp, Jim_Obj* obj);
188 extern jtag_tap_t* jtag_tap_by_position(unsigned abs_position);
189 extern jtag_tap_t* jtag_tap_next_enabled(jtag_tap_t* p);
190 extern unsigned jtag_tap_count_enabled(void);
191 extern unsigned jtag_tap_count(void);
195 * There are three cases when JTAG_TRST_ASSERTED callback is invoked. The
196 * event is invoked *after* TRST is asserted(or queued rather). It is illegal
197 * to communicate with the JTAG interface during the callback(as there is
198 * currently a queue being built).
209 enum jtag_tap_event {
210 JTAG_TAP_EVENT_ENABLE,
211 JTAG_TAP_EVENT_DISABLE
214 struct jtag_tap_event_action_s
216 enum jtag_tap_event event;
218 jtag_tap_event_action_t* next;
222 * Defines the function signature requide for JTAG event callback
223 * functions, which are added with jtag_register_event_callback()
224 * and removed jtag_unregister_event_callback().
225 * @param event The event to handle.
226 * @param prive A pointer to data that was passed to
227 * jtag_register_event_callback().
228 * @returns Must return ERROR_OK on success, or an error code on failure.
230 * @todo Change to return void or define a use for its return code.
232 typedef int (*jtag_event_handler_t)(enum jtag_event event, void* priv);
234 extern int jtag_register_event_callback(jtag_event_handler_t f, void *x);
235 extern int jtag_unregister_event_callback(jtag_event_handler_t f, void *x);
237 extern int jtag_call_event_callbacks(enum jtag_event event);
240 /// @returns The current JTAG speed setting.
241 int jtag_get_speed(void);
243 * Given a @a speed setting, use the interface @c speed_div callback to
244 * adjust the setting.
245 * @param speed The speed setting to convert back to readable KHz.
246 * @returns ERROR_OK if the interface has not been initialized or on success;
247 * otherwise, the error code produced by the @c speed_div callback.
249 int jtag_get_speed_readable(int *speed);
251 * Set the JTAG speed. This routine will call the underlying
252 * interface @c speed callback, if the interface has been initialized.
253 * @param speed The new speed setting.
254 * @returns ERROR_OK during configuration or on success, or an error
255 * code returned from the interface @c speed callback.
257 int jtag_set_speed(int speed);
260 /// Attempt to configure the interface for the specified KHz.
261 int jtag_config_khz(unsigned khz);
262 /// Set the clock speed of the JTAG interface in KHz.
263 void jtag_set_speed_khz(unsigned speed);
264 /// Retreives the clock speed of the JTAG interface in KHz.
265 unsigned jtag_get_speed_khz(void);
270 RESET_HAS_TRST = 0x1,
271 RESET_HAS_SRST = 0x2,
272 RESET_TRST_AND_SRST = 0x3,
273 RESET_SRST_PULLS_TRST = 0x4,
274 RESET_TRST_PULLS_SRST = 0x8,
275 RESET_TRST_OPEN_DRAIN = 0x10,
276 RESET_SRST_PUSH_PULL = 0x20,
279 enum reset_types jtag_get_reset_config(void);
280 void jtag_set_reset_config(enum reset_types type);
282 void jtag_set_nsrst_delay(unsigned delay);
283 unsigned jtag_get_nsrst_delay(void);
285 void jtag_set_ntrst_delay(unsigned delay);
286 unsigned jtag_get_ntrst_delay(void);
288 /// @returns The current state of TRST.
289 int jtag_get_trst(void);
290 /// @returns The current state of SRST.
291 int jtag_get_srst(void);
293 /// Enable or disable data scan verification checking.
294 void jtag_set_verify(bool enable);
295 /// @returns True if data scan verification will be performed.
296 bool jtag_will_verify(void);
298 /// Enable or disable verification of IR scan checking.
299 void jtag_set_verify_capture_ir(bool enable);
300 /// @returns True if IR scan verification will be performed.
301 bool jtag_will_verify_capture_ir(void);
304 * Initialize interface upon startup. Return a successful no-op upon
305 * subsequent invocations.
307 extern int jtag_interface_init(struct command_context_s* cmd_ctx);
309 /// Shutdown the JTAG interface upon program exit.
310 extern int jtag_interface_quit(void);
313 * Initialize JTAG chain using only a RESET reset. If init fails,
316 extern int jtag_init(struct command_context_s* cmd_ctx);
318 /// reset, then initialize JTAG chain
319 extern int jtag_init_reset(struct command_context_s* cmd_ctx);
320 extern int jtag_register_commands(struct command_context_s* cmd_ctx);
324 * The JTAG interface can be implemented with a software or hardware fifo.
326 * TAP_DRSHIFT and TAP_IRSHIFT are illegal end states; however,
327 * TAP_DRSHIFT/IRSHIFT can be emulated as end states, by using longer
330 * Code that is relatively insensitive to the path taken through state
331 * machine (as long as it is JTAG compliant) can use @a endstate for
332 * jtag_add_xxx_scan(). Otherwise, the pause state must be specified as
333 * end state and a subsequent jtag_add_pathmove() must be issued.
337 * Generate an IR SCAN with a list of scan fields with one entry for
340 * If the input field list contains an instruction value for a TAP then
341 * that is used otherwise the TAP is set to bypass.
343 * TAPs for which no fields are passed are marked as bypassed for
344 * subsequent DR SCANs.
347 extern void jtag_add_ir_scan(int num_fields, scan_field_t* fields, tap_state_t endstate);
349 * The same as jtag_add_ir_scan except no verification is performed out
352 extern void jtag_add_ir_scan_noverify(int num_fields, const scan_field_t *fields, tap_state_t state);
354 * Duplicate the scan fields passed into the function into an IR SCAN
355 * command. This function assumes that the caller handles extra fields
358 extern void jtag_add_plain_ir_scan(int num_fields, const scan_field_t* fields, tap_state_t endstate);
362 * Set in_value to point to 32 bits of memory to scan into. This
363 * function is a way to handle the case of synchronous and asynchronous
366 * In the event of an asynchronous queue execution the queue buffer
367 * allocation method is used, for the synchronous case the temporary 32
368 * bits come from the input field itself.
370 extern void jtag_alloc_in_value32(scan_field_t *field);
373 * Generate a DR SCAN using the fields passed to the function.
374 * For connected TAPs, the function checks in_fields and uses fields
375 * specified there. For bypassed TAPs, the function generates a dummy
376 * 1-bit field. The bypass status of TAPs is set by jtag_add_ir_scan().
378 extern void jtag_add_dr_scan(int num_fields, const scan_field_t* fields, tap_state_t endstate);
379 /// A version of jtag_add_dr_scan() that uses the check_value/mask fields
380 extern void jtag_add_dr_scan_check(int num_fields, scan_field_t* fields, tap_state_t endstate);
382 * Duplicate the scan fields passed into the function into a DR SCAN
383 * command. Unlike jtag_add_dr_scan(), this function assumes that the
384 * caller handles extra fields for bypassed TAPs.
386 extern void jtag_add_plain_dr_scan(int num_fields, const scan_field_t* fields, tap_state_t endstate);
390 * Defines a simple JTAG callback that can allow conversions on data
391 * scanned in from an interface.
393 * This callback should only be used for conversion that cannot fail.
394 * For conversion types or checks that can fail, use the more complete
395 * variant: jtag_callback_t.
397 typedef void (*jtag_callback1_t)(u8 *in);
399 /// A simpler version of jtag_add_callback4().
400 extern void jtag_add_callback(jtag_callback1_t, u8 *in);
404 * Defines the type of data passed to the jtag_callback_t interface.
405 * The underlying type must allow storing an @c int or pointer type.
407 typedef intptr_t jtag_callback_data_t;
410 * Defines the interface of the JTAG callback mechanism.
412 * @param in the pointer to the data clocked in
413 * @param data1 An integer big enough to use as an @c int or a pointer.
414 * @param data2 An integer big enough to use as an @c int or a pointer.
415 * @param data3 An integer big enough to use as an @c int or a pointer.
416 * @returns an error code
418 typedef int (*jtag_callback_t)(u8 *in, jtag_callback_data_t data1, jtag_callback_data_t data2, jtag_callback_data_t data3);
422 * This callback can be executed immediately the queue has been flushed.
424 * The JTAG queue can be executed synchronously or asynchronously.
425 * Typically for USB, the queue is executed asynchronously. For
426 * low-latency interfaces, the queue may be executed synchronously.
428 * The callback mechanism is very general and does not make many
429 * assumptions about what the callback does or what its arguments are.
430 * These callbacks are typically executed *after* the *entire* JTAG
431 * queue has been executed for e.g. USB interfaces, and they are
432 * guaranteeed to be invoked in the order that they were queued.
434 * If the execution of the queue fails before the callbacks, then --
435 * depending on driver implementation -- the callbacks may or may not be
436 * invoked. @todo Can we make this behavior consistent?
438 * The strange name is due to C's lack of overloading using function
441 * @param f The callback function to add.
442 * @param in Typically used to point to the data to operate on.
443 * Frequently this will be the data clocked in during a shift operation.
444 * @param data1 An integer big enough to use as an @c int or a pointer.
445 * @param data2 An integer big enough to use as an @c int or a pointer.
446 * @param data3 An integer big enough to use as an @c int or a pointer.
449 extern void jtag_add_callback4(jtag_callback_t f, u8 *in,
450 jtag_callback_data_t data1, jtag_callback_data_t data2,
451 jtag_callback_data_t data3);
455 * Run a TAP_RESET reset where the end state is TAP_RESET,
456 * regardless of the start state.
458 extern void jtag_add_tlr(void);
461 * Application code *must* assume that interfaces will
462 * implement transitions between states with different
463 * paths and path lengths through the state diagram. The
464 * path will vary across interface and also across versions
465 * of the same interface over time. Even if the OpenOCD code
466 * is unchanged, the actual path taken may vary over time
467 * and versions of interface firmware or PCB revisions.
469 * Use jtag_add_pathmove() when specific transition sequences
472 * Do not use jtag_add_pathmove() unless you need to, but do use it
475 * DANGER! If the target is dependent upon a particular sequence
476 * of transitions for things to work correctly(e.g. as a workaround
477 * for an errata that contradicts the JTAG standard), then pathmove
478 * must be used, even if some jtag interfaces happen to use the
479 * desired path. Worse, the jtag interface used for testing a
480 * particular implementation, could happen to use the "desired"
481 * path when transitioning to/from end
484 * A list of unambigious single clock state transitions, not
485 * all drivers can support this, but it is required for e.g.
486 * XScale and Xilinx support
488 * Note! TAP_RESET must not be used in the path!
490 * Note that the first on the list must be reachable
491 * via a single transition from the current state.
493 * All drivers are required to implement jtag_add_pathmove().
494 * However, if the pathmove sequence can not be precisely
495 * executed, an interface_jtag_add_pathmove() or jtag_execute_queue()
496 * must return an error. It is legal, but not recommended, that
497 * a driver returns an error in all cases for a pathmove if it
498 * can only implement a few transitions and therefore
499 * a partial implementation of pathmove would have little practical
502 * If an error occurs, jtag_error will contain one of these error codes:
503 * - ERROR_JTAG_NOT_STABLE_STATE -- The final state was not stable.
504 * - ERROR_JTAG_STATE_INVALID -- The path passed through TAP_RESET.
505 * - ERROR_JTAG_TRANSITION_INVALID -- The path includes invalid
508 extern void jtag_add_pathmove(int num_states, const tap_state_t* path);
511 * jtag_add_statemove() moves from the current state to @a goal_state.
513 * @param goal_state The final TAP state.
514 * @return ERROR_OK on success, or an error code on failure.
516 * Moves from the current state to the goal \a state.
518 * This needs to be handled according to the xsvf spec, see the XSTATE
519 * command description. From the XSVF spec, pertaining to XSTATE:
521 * For special states known as stable states (Test-Logic-Reset,
522 * Run-Test/Idle, Pause-DR, Pause- IR), an XSVF interpreter follows
523 * predefined TAP state paths when the starting state is a stable state
524 * and when the XSTATE specifies a new stable state. See the STATE
525 * command in the [Ref 5] for the TAP state paths between stable
528 * For non-stable states, XSTATE should specify a state that is only one
529 * TAP state transition distance from the current TAP state to avoid
530 * undefined TAP state paths. A sequence of multiple XSTATE commands can
531 * be issued to transition the TAP through a specific state path.
533 * @note Unless @c tms_bits holds a path that agrees with [Ref 5] in the
534 * above spec, then this code is not fully conformant to the xsvf spec.
535 * This puts a burden on tap_get_tms_path() function from the xsvf spec.
536 * If in doubt, you should confirm that that burden is being met.
538 * Otherwise, @a goal_state must be immediately reachable in one clock
539 * cycle, and does not need to be a stable state.
541 extern int jtag_add_statemove(tap_state_t goal_state);
544 * Goes to TAP_IDLE (if we're not already there), cycle
545 * precisely num_cycles in the TAP_IDLE state, after which move
546 * to @a endstate (unless it is also TAP_IDLE).
548 * @param num_cycles Number of cycles in TAP_IDLE state. This argument
549 * may be 0, in which case this routine will navigate to @a endstate
551 * @param endstate The final state.
553 extern void jtag_add_runtest(int num_cycles, tap_state_t endstate);
556 * A reset of the TAP state machine can be requested.
558 * Whether tms or trst reset is used depends on the capabilities of
559 * the target and jtag interface(reset_config command configures this).
561 * srst can driver a reset of the TAP state machine and vice
564 * Application code may need to examine value of jtag_reset_config
565 * to determine the proper codepath
567 * DANGER! Even though srst drives trst, trst might not be connected to
568 * the interface, and it might actually be *harmful* to assert trst in this case.
570 * This is why combinations such as "reset_config srst_only srst_pulls_trst"
573 * only req_tlr_or_trst and srst can have a transition for a
574 * call as the effects of transitioning both at the "same time"
575 * are undefined, but when srst_pulls_trst or vice versa,
576 * then trst & srst *must* be asserted together.
578 extern void jtag_add_reset(int req_tlr_or_trst, int srst);
582 * Function jtag_set_end_state
584 * Set a global variable to \a state if \a state != TAP_INVALID.
586 * Return the value of the global variable.
589 extern tap_state_t jtag_set_end_state(tap_state_t state);
591 * Function jtag_get_end_state
593 * Return the value of the global variable for end state
596 extern tap_state_t jtag_get_end_state(void);
597 extern void jtag_add_sleep(u32 us);
601 * Function jtag_add_stable_clocks
602 * first checks that the state in which the clocks are to be issued is
603 * stable, then queues up clock_count clocks for transmission.
605 void jtag_add_clocks(int num_cycles);
609 * For software FIFO implementations, the queued commands can be executed
610 * during this call or earlier. A sw queue might decide to push out
611 * some of the jtag_add_xxx() operations once the queue is "big enough".
613 * This fn will return an error code if any of the prior jtag_add_xxx()
614 * calls caused a failure, e.g. check failure. Note that it does not
615 * matter if the operation was executed *before* jtag_execute_queue(),
616 * jtag_execute_queue() will still return an error code.
618 * All jtag_add_xxx() calls that have in_handler!=NULL will have been
619 * executed when this fn returns, but if what has been queued only
620 * clocks data out, without reading anything back, then JTAG could
621 * be running *after* jtag_execute_queue() returns. The API does
622 * not define a way to flush a hw FIFO that runs *after*
623 * jtag_execute_queue() returns.
625 * jtag_add_xxx() commands can either be executed immediately or
626 * at some time between the jtag_add_xxx() fn call and jtag_execute_queue().
628 extern int jtag_execute_queue(void);
630 /// same as jtag_execute_queue() but does not clear the error flag
631 extern void jtag_execute_queue_noclear(void);
633 /// @returns the number of times the scan queue has been flushed
634 int jtag_get_flush_queue_count(void);
637 /* can be implemented by hw+sw */
638 extern int jtag_power_dropout(int* dropout);
639 extern int jtag_srst_asserted(int* srst_asserted);
641 /* JTAG support functions */
644 * Execute jtag queue and check value with an optional mask.
645 * @param field Pointer to scan field.
646 * @param value Pointer to scan value.
647 * @param mask Pointer to scan mask; may be NULL.
648 * @returns Nothing, but calls jtag_set_error() on any error.
650 extern void jtag_check_value_mask(scan_field_t *field, u8 *value, u8 *mask);
652 extern void jtag_sleep(u32 us);
655 * The JTAG subsystem defines a number of error codes,
656 * using codes between -100 and -199.
658 #define ERROR_JTAG_INIT_FAILED (-100)
659 #define ERROR_JTAG_INVALID_INTERFACE (-101)
660 #define ERROR_JTAG_NOT_IMPLEMENTED (-102)
661 #define ERROR_JTAG_TRST_ASSERTED (-103)
662 #define ERROR_JTAG_QUEUE_FAILED (-104)
663 #define ERROR_JTAG_NOT_STABLE_STATE (-105)
664 #define ERROR_JTAG_DEVICE_ERROR (-107)
665 #define ERROR_JTAG_STATE_INVALID (-108)
666 #define ERROR_JTAG_TRANSITION_INVALID (-109)
669 * jtag_add_dr_out() is a version of jtag_add_dr_scan() which
670 * only scans data out. It operates on 32 bit integers instead
671 * of 8 bit, which makes it a better impedance match with
672 * the calling code which often operate on 32 bit integers.
674 * Current or end_state can not be TAP_RESET. end_state can be TAP_INVALID
676 * num_bits[i] is the number of bits to clock out from value[i] LSB first.
678 * If the device is in bypass, then that is an error condition in
679 * the caller code that is not detected by this fn, whereas
680 * jtag_add_dr_scan() does detect it. Similarly if the device is not in
681 * bypass, data must be passed to it.
683 * If anything fails, then jtag_error will be set and jtag_execute() will
684 * return an error. There is no way to determine if there was a failure
685 * during this function call.
687 * This is an inline fn to speed up embedded hosts. Also note that
688 * interface_jtag_add_dr_out() can be a *small* inline function for
691 * There is no jtag_add_dr_outin() version of this fn that also allows
692 * clocking data back in. Patches gladly accepted!
694 extern void jtag_add_dr_out(jtag_tap_t* tap,
695 int num_fields, const int* num_bits, const u32* value,
696 tap_state_t end_state);
700 * Set the current JTAG core execution error, unless one was set
701 * by a previous call previously. Driver or application code must
702 * use jtag_error_clear to reset jtag_error once this routine has been
703 * called with a non-zero error code.
705 void jtag_set_error(int error);
706 /// @returns The current value of jtag_error
707 int jtag_get_error(void);
709 * Resets jtag_error to ERROR_OK, returning its previous value.
710 * @returns The previous value of @c jtag_error.
712 int jtag_error_clear(void);