+/*
+ * Copyright (c) 2010 by David Brownell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+/** @file
+ * Infrastructure for specifying and managing the transport protocol
+ * used in a given debug or programming session.
+ *
+ * Examples of "debug-capable" transports are JTAG or SWD.
+ * Additionally, JTAG supports boundary scan testing.
+ *
+ * Examples of "programming-capable" transports include SPI or UART;
+ * those are used (often mediated by a ROM bootloader) for ISP style
+ * programming, to perform an initial load of code into flash, or
+ * sometimes into SRAM. Target code could use "variant" options to
+ * decide how to use such protocols. For example, Cortex-M3 cores
+ * from TI/Luminary and from NXP use different protocols for for
+ * UART or SPI based firmware loading.
+ *
+ * As a rule, there are protocols layered on top of the transport.
+ * For example, different chip families use JTAG in different ways
+ * for debugging. Also, each family that supports programming over
+ * a UART link for initial firmware loading tends to define its own
+ * messaging and error handling.
+ */
+
+#include <helper/log.h>
+
+#include "transport.h"
+
+/*-----------------------------------------------------------------------*/
+
+/*
+ * Infrastructure internals
+ */
+
+/** List of transports known to OpenOCD. */
+static struct transport *transport_list;
+
+/**
+ * NULL-terminated Vector of names of transports which the
+ * currently selected debug adapter supports. This is declared
+ * by the time that adapter is fully set up.
+ */
+static const char **allowed_transports;
+
+/** * The transport being used for the current OpenOCD session. */
+static struct transport *session;
+
+static int transport_select(struct command_context *ctx, const char *name)
+{
+ /* name may only identify a known transport;
+ * caller guarantees session's transport isn't yet set.*/
+ for (struct transport *t = transport_list; t; t = t->next) {
+ if (strcmp(t->name, name) == 0) {
+ int retval = t->select(ctx);
+ /* select() registers commands specific to this
+ * transport, and may also reset the link, e.g.
+ * forcing it to JTAG or SWD mode.
+ */
+ if (retval == ERROR_OK)
+ session = t;
+ else
+ LOG_ERROR("Error %d selecting '%s' as "
+ "transport", retval, t->name);
+ return retval;
+ }
+ }
+
+ LOG_ERROR("No transport named '%s' is available.", name);
+ return ERROR_FAIL;
+}
+
+/**
+ * Called by debug adapter drivers, or affiliated Tcl config scripts,
+ * to declare the set of transports supported by an adapter. When
+ * there is only one member of that set, it is automatically selected.
+ */
+int allow_transports(struct command_context *ctx, const char **vector)
+{
+ /* NOTE: caller is required to provide only a list
+ * of *valid* transport names
+ *
+ * REVISIT should we validate that? and insist there's
+ * at least one non-NULL element in that list?
+ */
+ if (allowed_transports != NULL || session) {
+ LOG_ERROR("Can't modify the set of allowed transports.");
+ return ERROR_FAIL;
+ }
+
+
+ allowed_transports = vector;
+
+ /* autoselect if there's no choice ... */
+ if (!vector[1]) {
+ LOG_INFO("only one transport option; autoselect '%s'",
+ vector[0]);
+ return transport_select(ctx, vector [0]);
+ } else {
+ while (*vector)
+ LOG_DEBUG("allow transport '%s'", *vector++);
+ return ERROR_OK;
+ }
+}
+
+
+/**
+ * Used to verify corrrect adapter driver initialization.
+ *
+ * @returns true iff the adapter declared one or more transports.
+ */
+bool transports_are_declared(void)
+{
+ return allowed_transports != NULL;
+}
+
+/**
+ * Registers a transport. There are general purpose transports
+ * (such as JTAG), as well as relatively proprietary ones which are
+ * specific to a given chip (or chip family).
+ *
+ * Code implementing a transport needs to register it before it can
+ * be selected and then activated. This is a dynamic process, so
+ * that chips (and families) can define transports as needed (without
+ * nneeding error-prone static tables).
+ *
+ * @param new_transport the transport being registered. On a
+ * successful return, this memory is owned by the transport framework.
+ *
+ * @returns ERROR_OK on success, else a fault code.
+ */
+int transport_register(struct transport *new_transport)
+{
+ struct transport *t;
+
+ for (t = transport_list; t; t = t->next) {
+ if (strcmp(t->name, new_transport->name) == 0) {
+ LOG_ERROR("transport name already used");
+ return ERROR_FAIL;
+ }
+ }
+
+ if (!new_transport->select || !new_transport->init) {
+ LOG_ERROR("invalid transport %s", new_transport->name);
+ }
+
+ /* splice this into the list */
+ new_transport->next = transport_list;
+ transport_list = new_transport;
+ LOG_DEBUG("register '%s'", t->name);
+
+ return ERROR_OK;
+}
+
+/**
+ * Returns the transport currently being used by this debug or
+ * programming session.
+ *
+ * @returns handle to the read-only transport entity.
+ */
+struct transport *get_current_transport(void)
+{
+
+ /* REVISIT -- constify */
+ return session;
+}
+
+
+/*-----------------------------------------------------------------------*/
+
+/*
+ * Infrastructure for Tcl interface to transports.
+ */
+
+/**
+ * Makes and stores a copy of a set of transports passed as
+ * parameters to a command.
+ *
+ * @param vector where the resulting copy is stored, as an argv-style
+ * NULL-terminated vector.
+ */
+COMMAND_HELPER(transport_list_parse, char ***vector)
+{
+ char **argv;
+ unsigned n = CMD_ARGC;
+ unsigned j = 0;
+
+ *vector = NULL;
+
+ if (n < 1)
+ return ERROR_COMMAND_SYNTAX_ERROR;
+
+ /* our return vector must be NULL terminated */
+ argv = (char **) calloc(n + 1, sizeof(char *));
+ if (argv == NULL)
+ return ERROR_FAIL;
+
+ for (unsigned i = 0; i < n; i++) {
+ struct transport *t;
+
+ for (t = transport_list; t; t = t->next) {
+ if (strcmp(t->name, CMD_ARGV[i]) != 0)
+ continue;
+ argv[j++] = strdup(CMD_ARGV[i]);
+ break;
+ }
+ if (!t) {
+ LOG_ERROR("no such transport '%s'", CMD_ARGV[i]);
+ goto fail;
+ }
+ }
+
+ *vector = argv;
+ return ERROR_OK;
+
+fail:
+ for (unsigned i = 0; i < n; i++)
+ free(argv[i]);
+ free(argv);
+ return ERROR_FAIL;
+}
+
+COMMAND_HANDLER(handle_transport_init)
+{
+ LOG_DEBUG("%s", __func__);
+ if (!session) {
+ LOG_ERROR("session's transport is not selected.");
+ return ERROR_FAIL;
+ }
+
+ return session->init(CMD_CTX);
+}
+
+COMMAND_HANDLER(handle_transport_list)
+{
+ if (CMD_ARGC != 0)
+ return ERROR_COMMAND_SYNTAX_ERROR;
+
+ command_print(CMD_CTX, "The following transports are available:");
+
+ for (struct transport *t = transport_list; t; t = t->next)
+ command_print(CMD_CTX, "\t%s", t->name);
+
+ return ERROR_OK;
+}
+
+/**
+ * Implements the Tcl "transport select" command, choosing the
+ * transport to be used in this debug session from among the
+ * set supported by the debug adapter being used.
+ */
+COMMAND_HANDLER(handle_transport_select)
+{
+ int retval = ERROR_OK;;
+
+ switch (CMD_ARGC) {
+ case 0: /* "select" */
+ if (session) {
+ goto show;
+ }
+ LOG_ERROR("session's transport is not selected.");
+ return ERROR_FAIL;
+
+ case 1: /* "select FOO" */
+ if(strcmp(session->name, CMD_ARGV[0]) == 0) {
+ /* NOP */
+ LOG_DEBUG("transport '%s' is already selected",
+ CMD_ARGV[0]);
+ return ERROR_OK;
+ } else {
+
+ /* we can't change this session's transport after-the-fact */
+ if (session) {
+ LOG_ERROR("session's transport is already selected.");
+ return ERROR_FAIL;
+ }
+ }
+ break;
+
+ default: /* select FOO BAR */
+ /* we only select *one* transport per session */
+ LOG_ERROR("may only select one transport!");
+ return ERROR_COMMAND_SYNTAX_ERROR;
+ }
+
+ /* Is this transport supported by our debug adapter?
+ * Example, "JTAG-only" means SWD is not supported.
+ *
+ * NOTE: requires adapter to have been set up, including
+ * declaring transport via C code or Tcl script.
+ */
+ if (!allowed_transports) {
+ LOG_ERROR("Debug adapter doesn't support any transports?");
+ return ERROR_FAIL;
+ }
+ for (unsigned i = 0; allowed_transports[i]; i++) {
+
+ if (strcmp(allowed_transports[i], CMD_ARGV[0]) == 0)
+ return transport_select(CMD_CTX, CMD_ARGV[0]);
+ }
+
+ LOG_ERROR("Debug adapter doesn't support '%s' "
+ "transport?", CMD_ARGV[0]);
+ return ERROR_FAIL;
+
+
+show:
+ /* report the current transport selection */
+ command_print(CMD_CTX, "%s", session->name);
+ return retval;
+}
+
+static const struct command_registration transport_commands[] = {
+ {
+ .name = "init",
+ .handler = handle_transport_init,
+ /* this would be COMMAND_CONFIG ... except that
+ * it needs to trigger event handlers that may
+ * require COMMAND_EXEC ...
+ */
+ .mode = COMMAND_ANY,
+ .help = "Initialize this session's transport",
+ },
+ {
+ .name = "list",
+ .handler = handle_transport_list,
+ .mode = COMMAND_ANY,
+ .help = "list all built-in transports",
+ },
+ {
+ .name = "select",
+ .handler = handle_transport_select,
+ .mode = COMMAND_ANY,
+ .help = "Select this session's transport",
+ .usage = "[transport_name]",
+ },
+ COMMAND_REGISTRATION_DONE
+};
+
+static const struct command_registration transport_group[] = {
+ {
+ .name = "transport",
+ .mode = COMMAND_ANY,
+ .help = "Transport command group",
+ .chain = transport_commands,
+ },
+ COMMAND_REGISTRATION_DONE
+};
+
+
+int transport_register_commands(struct command_context *ctx)
+{
+ return register_commands(ctx, NULL, transport_group);
+}
Code Review / openocd.git / commitdiff