+/**
+ * Initialize JTAG chain using only a RESET reset. If init fails,
+ * try reset + init.
+ */
+int jtag_init(struct command_context* cmd_ctx);
+
+/// reset, then initialize JTAG chain
+int jtag_init_reset(struct command_context* cmd_ctx);
+int jtag_register_commands(struct command_context* cmd_ctx);
+int jtag_init_inner(struct command_context *cmd_ctx);
+
+/**
+ * @file
+ * The JTAG interface can be implemented with a software or hardware fifo.
+ *
+ * TAP_DRSHIFT and TAP_IRSHIFT are illegal end states; however,
+ * TAP_DRSHIFT/IRSHIFT can be emulated as end states, by using longer
+ * scans.
+ *
+ * Code that is relatively insensitive to the path taken through state
+ * machine (as long as it is JTAG compliant) can use @a endstate for
+ * jtag_add_xxx_scan(). Otherwise, the pause state must be specified as
+ * end state and a subsequent jtag_add_pathmove() must be issued.
+ */
+
+/**
+ * Generate an IR SCAN with a list of scan fields with one entry for
+ * each enabled TAP.
+ *
+ * If the input field list contains an instruction value for a TAP then
+ * that is used otherwise the TAP is set to bypass.
+ *
+ * TAPs for which no fields are passed are marked as bypassed for
+ * subsequent DR SCANs.
+ *
+ */
+void jtag_add_ir_scan(int num_fields,
+ struct scan_field* fields, tap_state_t endstate);
+/**
+ * The same as jtag_add_ir_scan except no verification is performed out
+ * the output values.
+ */
+void jtag_add_ir_scan_noverify(int num_fields,
+ const struct scan_field *fields, tap_state_t state);
+/**
+ * Duplicate the scan fields passed into the function into an IR SCAN
+ * command. This function assumes that the caller handles extra fields
+ * for bypassed TAPs.
+ */
+void jtag_add_plain_ir_scan(int num_fields,
+ const struct scan_field* fields, tap_state_t endstate);
+
+
+/**
+ * Set in_value to point to 32 bits of memory to scan into. This
+ * function is a way to handle the case of synchronous and asynchronous
+ * JTAG queues.
+ *
+ * In the event of an asynchronous queue execution the queue buffer
+ * allocation method is used, for the synchronous case the temporary 32
+ * bits come from the input field itself.
+ */
+void jtag_alloc_in_value32(struct scan_field *field);
+
+/**
+ * Generate a DR SCAN using the fields passed to the function.
+ * For connected TAPs, the function checks in_fields and uses fields
+ * specified there. For bypassed TAPs, the function generates a dummy
+ * 1-bit field. The bypass status of TAPs is set by jtag_add_ir_scan().
+ */
+void jtag_add_dr_scan(int num_fields,
+ const struct scan_field* fields, tap_state_t endstate);
+/// A version of jtag_add_dr_scan() that uses the check_value/mask fields
+void jtag_add_dr_scan_check(int num_fields,
+ struct scan_field* fields, tap_state_t endstate);
+/**
+ * Duplicate the scan fields passed into the function into a DR SCAN
+ * command. Unlike jtag_add_dr_scan(), this function assumes that the
+ * caller handles extra fields for bypassed TAPs.
+ */
+void jtag_add_plain_dr_scan(int num_fields,
+ const struct scan_field* fields, tap_state_t endstate);
+
+/**
+ * Defines the type of data passed to the jtag_callback_t interface.
+ * The underlying type must allow storing an @c int or pointer type.
+ */
+typedef intptr_t jtag_callback_data_t;
+
+/**
+ * Defines a simple JTAG callback that can allow conversions on data
+ * scanned in from an interface.
+ *
+ * This callback should only be used for conversion that cannot fail.
+ * For conversion types or checks that can fail, use the more complete
+ * variant: jtag_callback_t.
+ */
+typedef void (*jtag_callback1_t)(jtag_callback_data_t data0);
+
+/// A simpler version of jtag_add_callback4().
+void jtag_add_callback(jtag_callback1_t, jtag_callback_data_t data0);
+
+
+
+/**
+ * Defines the interface of the JTAG callback mechanism.
+ *
+ * @param in the pointer to the data clocked in
+ * @param data1 An integer big enough to use as an @c int or a pointer.
+ * @param data2 An integer big enough to use as an @c int or a pointer.
+ * @param data3 An integer big enough to use as an @c int or a pointer.
+ * @returns an error code
+ */
+typedef int (*jtag_callback_t)(jtag_callback_data_t data0,
+ jtag_callback_data_t data1,
+ jtag_callback_data_t data2,
+ jtag_callback_data_t data3);
+
+
+/**
+ * This callback can be executed immediately the queue has been flushed.
+ *
+ * The JTAG queue can be executed synchronously or asynchronously.
+ * Typically for USB, the queue is executed asynchronously. For
+ * low-latency interfaces, the queue may be executed synchronously.
+ *
+ * The callback mechanism is very general and does not make many
+ * assumptions about what the callback does or what its arguments are.
+ * These callbacks are typically executed *after* the *entire* JTAG
+ * queue has been executed for e.g. USB interfaces, and they are
+ * guaranteeed to be invoked in the order that they were queued.
+ *
+ * If the execution of the queue fails before the callbacks, then --
+ * depending on driver implementation -- the callbacks may or may not be
+ * invoked. @todo Can we make this behavior consistent?
+ *
+ * The strange name is due to C's lack of overloading using function
+ * arguments.
+ *
+ * @param f The callback function to add.
+ * @param data0 Typically used to point to the data to operate on.
+ * Frequently this will be the data clocked in during a shift operation.
+ * @param data1 An integer big enough to use as an @c int or a pointer.
+ * @param data2 An integer big enough to use as an @c int or a pointer.
+ * @param data3 An integer big enough to use as an @c int or a pointer.
+ *
+ */
+
+/**
+ * Run a TAP_RESET reset where the end state is TAP_RESET,
+ * regardless of the start state.
+ */
+void jtag_add_tlr(void);
+
+/**
+ * Application code *must* assume that interfaces will
+ * implement transitions between states with different
+ * paths and path lengths through the state diagram. The
+ * path will vary across interface and also across versions
+ * of the same interface over time. Even if the OpenOCD code
+ * is unchanged, the actual path taken may vary over time
+ * and versions of interface firmware or PCB revisions.
+ *
+ * Use jtag_add_pathmove() when specific transition sequences
+ * are required.
+ *
+ * Do not use jtag_add_pathmove() unless you need to, but do use it
+ * if you have to.
+ *
+ * DANGER! If the target is dependent upon a particular sequence
+ * of transitions for things to work correctly(e.g. as a workaround
+ * for an errata that contradicts the JTAG standard), then pathmove
+ * must be used, even if some jtag interfaces happen to use the
+ * desired path. Worse, the jtag interface used for testing a
+ * particular implementation, could happen to use the "desired"
+ * path when transitioning to/from end
+ * state.
+ *
+ * A list of unambigious single clock state transitions, not
+ * all drivers can support this, but it is required for e.g.
+ * XScale and Xilinx support
+ *
+ * Note! TAP_RESET must not be used in the path!
+ *
+ * Note that the first on the list must be reachable
+ * via a single transition from the current state.
+ *
+ * All drivers are required to implement jtag_add_pathmove().
+ * However, if the pathmove sequence can not be precisely
+ * executed, an interface_jtag_add_pathmove() or jtag_execute_queue()
+ * must return an error. It is legal, but not recommended, that
+ * a driver returns an error in all cases for a pathmove if it
+ * can only implement a few transitions and therefore
+ * a partial implementation of pathmove would have little practical
+ * application.
+ *
+ * If an error occurs, jtag_error will contain one of these error codes:
+ * - ERROR_JTAG_NOT_STABLE_STATE -- The final state was not stable.
+ * - ERROR_JTAG_STATE_INVALID -- The path passed through TAP_RESET.
+ * - ERROR_JTAG_TRANSITION_INVALID -- The path includes invalid
+ * state transitions.
+ */
+void jtag_add_pathmove(int num_states, const tap_state_t* path);
+
+/**
+ * jtag_add_statemove() moves from the current state to @a goal_state.
+ *
+ * @param goal_state The final TAP state.
+ * @return ERROR_OK on success, or an error code on failure.
+ *
+ * Moves from the current state to the goal \a state.
+ * Both states must be stable.
+ */
+int jtag_add_statemove(tap_state_t goal_state);
+
+/**
+ * Goes to TAP_IDLE (if we're not already there), cycle
+ * precisely num_cycles in the TAP_IDLE state, after which move
+ * to @a endstate (unless it is also TAP_IDLE).
+ *
+ * @param num_cycles Number of cycles in TAP_IDLE state. This argument
+ * may be 0, in which case this routine will navigate to @a endstate
+ * via TAP_IDLE.
+ * @param endstate The final state.
+ */
+void jtag_add_runtest(int num_cycles, tap_state_t endstate);
+
+/**
+ * A reset of the TAP state machine can be requested.
+ *
+ * Whether tms or trst reset is used depends on the capabilities of
+ * the target and jtag interface(reset_config command configures this).
+ *
+ * srst can driver a reset of the TAP state machine and vice
+ * versa
+ *
+ * Application code may need to examine value of jtag_reset_config
+ * to determine the proper codepath
+ *
+ * DANGER! Even though srst drives trst, trst might not be connected to
+ * the interface, and it might actually be *harmful* to assert trst in this case.
+ *
+ * This is why combinations such as "reset_config srst_only srst_pulls_trst"
+ * are supported.
+ *
+ * only req_tlr_or_trst and srst can have a transition for a
+ * call as the effects of transitioning both at the "same time"
+ * are undefined, but when srst_pulls_trst or vice versa,
+ * then trst & srst *must* be asserted together.
+ */
+void jtag_add_reset(int req_tlr_or_trst, int srst);
+
+
+/**
+ * Function jtag_set_end_state
+ *
+ * Set a global variable to \a state if \a state != TAP_INVALID.
+ *
+ * Return the value of the global variable.
+ *
+ **/
+tap_state_t jtag_set_end_state(tap_state_t state);
+/**
+ * Function jtag_get_end_state
+ *
+ * Return the value of the global variable for end state
+ *
+ **/
+tap_state_t jtag_get_end_state(void);
+void jtag_add_sleep(uint32_t us);
+
+
+/**
+ * Function jtag_add_stable_clocks
+ * first checks that the state in which the clocks are to be issued is
+ * stable, then queues up clock_count clocks for transmission.
+ */
+void jtag_add_clocks(int num_cycles);
+
+
+/**
+ * For software FIFO implementations, the queued commands can be executed
+ * during this call or earlier. A sw queue might decide to push out
+ * some of the jtag_add_xxx() operations once the queue is "big enough".
+ *
+ * This fn will return an error code if any of the prior jtag_add_xxx()
+ * calls caused a failure, e.g. check failure. Note that it does not
+ * matter if the operation was executed *before* jtag_execute_queue(),
+ * jtag_execute_queue() will still return an error code.
+ *
+ * All jtag_add_xxx() calls that have in_handler != NULL will have been
+ * executed when this fn returns, but if what has been queued only
+ * clocks data out, without reading anything back, then JTAG could
+ * be running *after* jtag_execute_queue() returns. The API does
+ * not define a way to flush a hw FIFO that runs *after*
+ * jtag_execute_queue() returns.
+ *
+ * jtag_add_xxx() commands can either be executed immediately or
+ * at some time between the jtag_add_xxx() fn call and jtag_execute_queue().
+ */
+int jtag_execute_queue(void);
+
+/// same as jtag_execute_queue() but does not clear the error flag
+void jtag_execute_queue_noclear(void);
+
+/// @returns the number of times the scan queue has been flushed
+int jtag_get_flush_queue_count(void);
+
+/// Report Tcl event to all TAPs
+void jtag_notify_event(enum jtag_event);
+
+
+/* can be implemented by hw + sw */
+int jtag_power_dropout(int* dropout);
+int jtag_srst_asserted(int* srst_asserted);