2 * Copyright (c) 2010 by David Brownell
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software Foundation,
16 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 * Infrastructure for specifying and managing the transport protocol
25 * used in a given debug or programming session.
27 * Examples of "debug-capable" transports are JTAG or SWD.
28 * Additionally, JTAG supports boundary scan testing.
30 * Examples of "programming-capable" transports include SPI or UART;
31 * those are used (often mediated by a ROM bootloader) for ISP style
32 * programming, to perform an initial load of code into flash, or
33 * sometimes into SRAM. Target code could use "variant" options to
34 * decide how to use such protocols. For example, Cortex-M3 cores
35 * from TI/Luminary and from NXP use different protocols for for
36 * UART or SPI based firmware loading.
38 * As a rule, there are protocols layered on top of the transport.
39 * For example, different chip families use JTAG in different ways
40 * for debugging. Also, each family that supports programming over
41 * a UART link for initial firmware loading tends to define its own
42 * messaging and error handling.
45 #include <helper/log.h>
47 #include <transport/transport.h>
49 extern struct command_context
*global_cmd_ctx
;
52 /*-----------------------------------------------------------------------*/
55 * Infrastructure internals
58 /** List of transports known to OpenOCD. */
59 static struct transport
*transport_list
;
62 * NULL-terminated Vector of names of transports which the
63 * currently selected debug adapter supports. This is declared
64 * by the time that adapter is fully set up.
66 static const char **allowed_transports
;
68 /** * The transport being used for the current OpenOCD session. */
69 static struct transport
*session
;
71 static int transport_select(struct command_context
*ctx
, const char *name
)
73 /* name may only identify a known transport;
74 * caller guarantees session's transport isn't yet set.*/
75 for (struct transport
*t
= transport_list
; t
; t
= t
->next
) {
76 if (strcmp(t
->name
, name
) == 0) {
77 int retval
= t
->select(ctx
);
78 /* select() registers commands specific to this
79 * transport, and may also reset the link, e.g.
80 * forcing it to JTAG or SWD mode.
82 if (retval
== ERROR_OK
)
85 LOG_ERROR("Error selecting '%s' as "
86 "transport", t
->name
);
91 LOG_ERROR("No transport named '%s' is available.", name
);
96 * Called by debug adapter drivers, or affiliated Tcl config scripts,
97 * to declare the set of transports supported by an adapter. When
98 * there is only one member of that set, it is automatically selected.
100 int allow_transports(struct command_context
*ctx
, const char **vector
)
102 /* NOTE: caller is required to provide only a list
103 * of *valid* transport names
105 * REVISIT should we validate that? and insist there's
106 * at least one non-NULL element in that list?
108 * ... allow removals, e.g. external strapping prevents use
109 * of one transport; C code should be definitive about what
110 * can be used when all goes well.
112 if (allowed_transports
!= NULL
|| session
) {
113 LOG_ERROR("Can't modify the set of allowed transports.");
118 allowed_transports
= vector
;
120 /* autoselect if there's no choice ... */
122 LOG_INFO("only one transport option; autoselect '%s'",
124 return transport_select(ctx
, vector
[0]);
126 /* guard against user config errors */
127 LOG_WARNING("must select a transport.");
129 LOG_DEBUG("allow transport '%s'", *vector
);
138 * Used to verify corrrect adapter driver initialization.
140 * @returns true iff the adapter declared one or more transports.
142 bool transports_are_declared(void)
144 return allowed_transports
!= NULL
;
148 * Registers a transport. There are general purpose transports
149 * (such as JTAG), as well as relatively proprietary ones which are
150 * specific to a given chip (or chip family).
152 * Code implementing a transport needs to register it before it can
153 * be selected and then activated. This is a dynamic process, so
154 * that chips (and families) can define transports as needed (without
155 * nneeding error-prone static tables).
157 * @param new_transport the transport being registered. On a
158 * successful return, this memory is owned by the transport framework.
160 * @returns ERROR_OK on success, else a fault code.
162 int transport_register(struct transport
*new_transport
)
166 for (t
= transport_list
; t
; t
= t
->next
) {
167 if (strcmp(t
->name
, new_transport
->name
) == 0) {
168 LOG_ERROR("transport name already used");
173 if (!new_transport
->select
|| !new_transport
->init
) {
174 LOG_ERROR("invalid transport %s", new_transport
->name
);
177 /* splice this into the list */
178 new_transport
->next
= transport_list
;
179 transport_list
= new_transport
;
180 LOG_DEBUG("register '%s'", new_transport
->name
);
186 * Returns the transport currently being used by this debug or
187 * programming session.
189 * @returns handle to the read-only transport entity.
191 struct transport
*get_current_transport(void)
194 /* REVISIT -- constify */
199 /*-----------------------------------------------------------------------*/
202 * Infrastructure for Tcl interface to transports.
206 * Makes and stores a copy of a set of transports passed as
207 * parameters to a command.
209 * @param vector where the resulting copy is stored, as an argv-style
210 * NULL-terminated vector.
212 COMMAND_HELPER(transport_list_parse
, char ***vector
)
215 unsigned n
= CMD_ARGC
;
221 return ERROR_COMMAND_SYNTAX_ERROR
;
223 /* our return vector must be NULL terminated */
224 argv
= (char **) calloc(n
+ 1, sizeof(char *));
228 for (unsigned i
= 0; i
< n
; i
++) {
231 for (t
= transport_list
; t
; t
= t
->next
) {
232 if (strcmp(t
->name
, CMD_ARGV
[i
]) != 0)
234 argv
[j
++] = strdup(CMD_ARGV
[i
]);
238 LOG_ERROR("no such transport '%s'", CMD_ARGV
[i
]);
247 for (unsigned i
= 0; i
< n
; i
++)
253 COMMAND_HANDLER(handle_transport_init
)
255 LOG_DEBUG("%s", __func__
);
257 LOG_ERROR("session's transport is not selected.");
261 return session
->init(CMD_CTX
);
264 COMMAND_HANDLER(handle_transport_list
)
267 return ERROR_COMMAND_SYNTAX_ERROR
;
269 command_print(CMD_CTX
, "The following transports are available:");
271 for (struct transport
*t
= transport_list
; t
; t
= t
->next
)
272 command_print(CMD_CTX
, "\t%s", t
->name
);
278 * Implements the Tcl "transport select" command, choosing the
279 * transport to be used in this debug session from among the
280 * set supported by the debug adapter being used. Return value
281 * is scriptable (allowing "if swd then..." etc).
283 static int jim_transport_select(Jim_Interp
*interp
, int argc
, Jim_Obj
*const *argv
)
286 case 1: /* return/display */
288 LOG_ERROR("session's transport is not selected.");
291 Jim_SetResultString(interp
, session
->name
, -1);
297 /* can't change session's transport after-the-fact */
298 LOG_ERROR("session's transport is already selected.");
302 /* Is this transport supported by our debug adapter?
303 * Example, "JTAG-only" means SWD is not supported.
305 * NOTE: requires adapter to have been set up, with
306 * transports declared via C.
308 if (!allowed_transports
) {
309 LOG_ERROR("Debug adapter doesn't support any transports?");
313 for (unsigned i
= 0; allowed_transports
[i
]; i
++) {
315 if (strcmp(allowed_transports
[i
], argv
[1]->bytes
) == 0)
316 return transport_select(global_cmd_ctx
, argv
[1]->bytes
);
319 LOG_ERROR("Debug adapter doesn't support '%s' "
320 "transport", argv
[1]->bytes
);
324 Jim_WrongNumArgs(interp
, 1, argv
, "[too many parameters]");
329 static const struct command_registration transport_commands
[] = {
332 .handler
= handle_transport_init
,
333 /* this would be COMMAND_CONFIG ... except that
334 * it needs to trigger event handlers that may
335 * require COMMAND_EXEC ...
338 .help
= "Initialize this session's transport",
342 .handler
= handle_transport_list
,
344 .help
= "list all built-in transports",
348 .jim_handler
= jim_transport_select
,
350 .help
= "Select this session's transport",
351 .usage
= "[transport_name]",
353 COMMAND_REGISTRATION_DONE
356 static const struct command_registration transport_group
[] = {
360 .help
= "Transport command group",
361 .chain
= transport_commands
,
363 COMMAND_REGISTRATION_DONE
367 int transport_register_commands(struct command_context
*ctx
)
369 return register_commands(ctx
, NULL
, transport_group
);