X-Git-Url: https://review.openocd.org/gitweb?p=openocd.git;a=blobdiff_plain;f=src%2Fhelper%2Fcommand.c;h=1ff4e01a7d1a5d51c4cf1cd26ed8d394bec43eb8;hp=b9d0d087ad4f873ac61a6ce37e08e38f48de05d8;hb=d0eb66f729ff50ffa21a3ea22bcff46167fe627a;hpb=cffc98ad8047b6dc8d38a6422136638f2df992d2

diff --git a/src/helper/command.c b/src/helper/command.c
index b9d0d087ad..1ff4e01a7d 100644
--- a/src/helper/command.c
+++ b/src/helper/command.c
@@ -22,346 +22,484 @@
  *   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.             *
+ *   along with this program.  If not, see <http://www.gnu.org/licenses/>. *
  ***************************************************************************/
+
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
-#if !BUILD_ECOSBOARD
-/* see Embedder-HOWTO.txt in Jim Tcl project hosted on BerliOS*/
+/* see Embedded-HOWTO.txt in Jim Tcl project hosted on BerliOS*/
 #define JIM_EMBEDDED
-#endif
 
-// @todo the inclusion of target.h here is a layering violation
-#include "target.h"
+/* @todo the inclusion of target.h here is a layering violation */
+#include <jtag/jtag.h>
+#include <target/target.h>
 #include "command.h"
 #include "configuration.h"
 #include "log.h"
 #include "time_support.h"
 #include "jim-eventloop.h"
 
-
-int fast_and_dangerous = 0;
-Jim_Interp *interp = NULL;
+/* nice short description of source file */
+#define __THIS__FILE__ "command.c"
 
 static int run_command(struct command_context *context,
 		struct command *c, const char *words[], unsigned num_words);
 
+struct log_capture_state {
+	Jim_Interp *interp;
+	Jim_Obj *output;
+};
+
 static void tcl_output(void *privData, const char *file, unsigned line,
-		const char *function, const char *string)
+	const char *function, const char *string)
 {
-	Jim_Obj *tclOutput = (Jim_Obj *)privData;
-	Jim_AppendString(interp, tclOutput, string, strlen(string));
+	struct log_capture_state *state = privData;
+	Jim_AppendString(state->interp, state->output, string, strlen(string));
+}
+
+static struct log_capture_state *command_log_capture_start(Jim_Interp *interp)
+{
+	/* capture log output and return it. A garbage collect can
+	 * happen, so we need a reference count to this object */
+	Jim_Obj *tclOutput = Jim_NewStringObj(interp, "", 0);
+	if (NULL == tclOutput)
+		return NULL;
+
+	struct log_capture_state *state = malloc(sizeof(*state));
+	if (NULL == state)
+		return NULL;
+
+	state->interp = interp;
+	Jim_IncrRefCount(tclOutput);
+	state->output = tclOutput;
+
+	log_add_callback(tcl_output, state);
+
+	return state;
+}
+
+/* Classic openocd commands provide progress output which we
+ * will capture and return as a Tcl return value.
+ *
+ * However, if a non-openocd command has been invoked, then it
+ * makes sense to return the tcl return value from that command.
+ *
+ * The tcl return value is empty for openocd commands that provide
+ * progress output.
+ *
+ * Therefore we set the tcl return value only if we actually
+ * captured output.
+ */
+static void command_log_capture_finish(struct log_capture_state *state)
+{
+	if (NULL == state)
+		return;
+
+	log_remove_callback(tcl_output, state);
+
+	int length;
+	Jim_GetString(state->output, &length);
+
+	if (length > 0)
+		Jim_SetResult(state->interp, state->output);
+	else {
+		/* No output captured, use tcl return value (which could
+		 * be empty too). */
+	}
+	Jim_DecrRefCount(state->interp, state->output);
+
+	free(state);
+}
+
+static int command_retval_set(Jim_Interp *interp, int retval)
+{
+	int *return_retval = Jim_GetAssocData(interp, "retval");
+	if (return_retval != NULL)
+		*return_retval = retval;
+
+	return (retval == ERROR_OK) ? JIM_OK : retval;
 }
 
 extern struct command_context *global_cmd_ctx;
 
+/* dump a single line to the log for the command.
+ * Do nothing in case we are not at debug level 3 */
 void script_debug(Jim_Interp *interp, const char *name,
-		unsigned argc, Jim_Obj *const *argv)
+	unsigned argc, Jim_Obj * const *argv)
 {
-	LOG_DEBUG("command - %s", name);
-	for (unsigned i = 0; i < argc; i++)
-	{
+	if (debug_level < LOG_LVL_DEBUG)
+		return;
+
+	char *dbg = alloc_printf("command - %s", name);
+	for (unsigned i = 0; i < argc; i++) {
 		int len;
 		const char *w = Jim_GetString(argv[i], &len);
-
-		/* end of line comment? */
-		if (*w == '#')
-			break;
-
-		LOG_DEBUG("%s - argv[%d]=%s", name, i, w);
+		char *t = alloc_printf("%s %s", dbg, w);
+		free(dbg);
+		dbg = t;
 	}
+	LOG_DEBUG("%s", dbg);
+	free(dbg);
 }
 
-static int script_command(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+static void script_command_args_free(char **words, unsigned nwords)
 {
-	/* the private data is stashed in the interp structure */
-	struct command *c;
-	struct command_context *context;
-	int retval;
-	int i;
-	int nwords;
-	char **words;
-
-	/* DANGER!!!! be careful what we invoke here, since interp->cmdPrivData might
-	 * get overwritten by running other Jim commands! Treat it as an
-	 * emphemeral global variable that is used in lieu of an argument
-	 * to the fn and fish it out manually.
-	 */
-	c = interp->cmdPrivData;
-	if (c == NULL)
-	{
-		LOG_ERROR("BUG: interp->cmdPrivData == NULL");
-		return JIM_ERR;
-	}
-	target_call_timer_callbacks_now();
-	LOG_USER_N("%s", ""); /* Keep GDB connection alive*/
+	for (unsigned i = 0; i < nwords; i++)
+		free(words[i]);
+	free(words);
+}
 
-	script_debug(interp, c->name, argc, argv);
+static char **script_command_args_alloc(
+	unsigned argc, Jim_Obj * const *argv, unsigned *nwords)
+{
+	char **words = malloc(argc * sizeof(char *));
+	if (NULL == words)
+		return NULL;
 
-	words = malloc(argc * sizeof(char *));
-	for (i = 0; i < argc; i++)
-	{
+	unsigned i;
+	for (i = 0; i < argc; i++) {
 		int len;
 		const char *w = Jim_GetString(argv[i], &len);
-		if (*w=='#')
-		{
-			/* hit an end of line comment */
-			break;
-		}
 		words[i] = strdup(w);
-		if (words[i] == NULL)
-		{
-			int j;
-			for (j = 0; j < i; j++)
-				free(words[j]);
-			free(words);
-			return JIM_ERR;
+		if (words[i] == NULL) {
+			script_command_args_free(words, i);
+			return NULL;
 		}
 	}
-	nwords = i;
+	*nwords = i;
+	return words;
+}
 
+struct command_context *current_command_context(Jim_Interp *interp)
+{
 	/* grab the command context from the associated data */
-	context = Jim_GetAssocData(interp, "context");
-	if (context == NULL)
-	{
+	struct command_context *cmd_ctx = Jim_GetAssocData(interp, "context");
+	if (NULL == cmd_ctx) {
 		/* Tcl can invoke commands directly instead of via command_run_line(). This would
-		 * happen when the Jim Tcl interpreter is provided by eCos.
+		 * happen when the Jim Tcl interpreter is provided by eCos or if we are running
+		 * commands in a startup script.
+		 *
+		 * A telnet or gdb server would provide a non-default command context to
+		 * handle piping of error output, have a separate current target, etc.
 		 */
-		context = global_cmd_ctx;
+		cmd_ctx = global_cmd_ctx;
 	}
+	return cmd_ctx;
+}
 
-	/* capture log output and return it */
-	Jim_Obj *tclOutput = Jim_NewStringObj(interp, "", 0);
-	/* a garbage collect can happen, so we need a reference count to this object */
-	Jim_IncrRefCount(tclOutput);
-
-	log_add_callback(tcl_output, tclOutput);
+static int script_command_run(Jim_Interp *interp,
+	int argc, Jim_Obj * const *argv, struct command *c, bool capture)
+{
+	target_call_timer_callbacks_now();
+	LOG_USER_N("%s", "");	/* Keep GDB connection alive*/
 
-	// turn words[0] into CMD_ARGV[-1] with this cast
-	retval = run_command(context, c, (const char **)words, nwords);
+	unsigned nwords;
+	char **words = script_command_args_alloc(argc, argv, &nwords);
+	if (NULL == words)
+		return JIM_ERR;
 
-	log_remove_callback(tcl_output, tclOutput);
+	struct log_capture_state *state = NULL;
+	if (capture)
+		state = command_log_capture_start(interp);
 
-	/* We dump output into this local variable */
-	Jim_SetResult(interp, tclOutput);
-	Jim_DecrRefCount(interp, tclOutput);
+	struct command_context *cmd_ctx = current_command_context(interp);
+	int retval = run_command(cmd_ctx, c, (const char **)words, nwords);
 
-	for (i = 0; i < nwords; i++)
-		free(words[i]);
-	free(words);
+	command_log_capture_finish(state);
 
-	int *return_retval = Jim_GetAssocData(interp, "retval");
-	if (return_retval != NULL)
-	{
-		*return_retval = retval;
-	}
-
-	return (retval == ERROR_OK)?JIM_OK:JIM_ERR;
+	script_command_args_free(words, nwords);
+	return command_retval_set(interp, retval);
 }
 
-static Jim_Obj *command_name_list(struct command *c)
+static int script_command(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 {
-	Jim_Obj *cmd_list = c->parent ?
-			command_name_list(c->parent) :
-			Jim_NewListObj(interp, NULL, 0);
-	Jim_ListAppendElement(interp, cmd_list,
-			Jim_NewStringObj(interp, c->name, -1));
+	/* the private data is stashed in the interp structure */
 
-	return cmd_list;
+	struct command *c = interp->cmdPrivData;
+	assert(c);
+	script_debug(interp, c->name, argc, argv);
+	return script_command_run(interp, argc, argv, c, true);
 }
 
-static void command_helptext_add(Jim_Obj *cmd_list, const char *help)
+static struct command *command_root(struct command *c)
 {
-	Jim_Obj *cmd_entry = Jim_NewListObj(interp, NULL, 0);
-	Jim_ListAppendElement(interp, cmd_entry, cmd_list);
-	Jim_ListAppendElement(interp, cmd_entry,
-			Jim_NewStringObj(interp, help ? : "", -1));
-
-	/* accumulate help text in Tcl helptext list.  */
-	Jim_Obj *helptext = Jim_GetGlobalVariableStr(interp,
-			"ocd_helptext", JIM_ERRMSG);
-	if (Jim_IsShared(helptext))
-		helptext = Jim_DuplicateObj(interp, helptext);
-	Jim_ListAppendElement(interp, helptext, cmd_entry);
+	while (NULL != c->parent)
+		c = c->parent;
+	return c;
 }
 
-/* nice short description of source file */
-#define __THIS__FILE__ "command.c"
-
 /**
  * Find a command by name from a list of commands.
- * @returns The named command if found, or NULL.
+ * @returns Returns the named command if it exists in the list.
+ * Returns NULL otherwise.
  */
-static struct command *command_find(struct command **head, const char *name)
+static struct command *command_find(struct command *head, const char *name)
 {
-	assert(head);
-	for (struct command *cc = *head; cc; cc = cc->next)
-	{
+	for (struct command *cc = head; cc; cc = cc->next) {
 		if (strcmp(cc->name, name) == 0)
 			return cc;
 	}
 	return NULL;
 }
 
+struct command *command_find_in_context(struct command_context *cmd_ctx,
+	const char *name)
+{
+	return command_find(cmd_ctx->commands, name);
+}
+struct command *command_find_in_parent(struct command *parent,
+	const char *name)
+{
+	return command_find(parent->children, name);
+}
+
 /**
- * Add the command to the end of linked list.
- * @returns Returns false if the named command already exists in the list.
- * Returns true otherwise.
+ * Add the command into the linked list, sorted by name.
+ * @param head Address to head of command list pointer, which may be
+ * updated if @c c gets inserted at the beginning of the list.
+ * @param c The command to add to the list pointed to by @c head.
  */
 static void command_add_child(struct command **head, struct command *c)
 {
 	assert(head);
-	if (NULL == *head)
-	{
+	if (NULL == *head) {
 		*head = c;
 		return;
 	}
-	struct command *cc = *head;
-	while (cc->next) cc = cc->next;
-	cc->next = c;
+
+	while ((*head)->next && (strcmp(c->name, (*head)->name) > 0))
+		head = &(*head)->next;
+
+	if (strcmp(c->name, (*head)->name) > 0) {
+		c->next = (*head)->next;
+		(*head)->next = c;
+	} else {
+		c->next = *head;
+		*head = c;
+	}
 }
 
-struct command* register_command(struct command_context *context,
-		struct command *parent, char *name, command_handler_t handler,
-		enum command_mode mode, char *help)
+static struct command **command_list_for_parent(
+	struct command_context *cmd_ctx, struct command *parent)
 {
-	if (!context || !name)
+	return parent ? &parent->children : &cmd_ctx->commands;
+}
+
+static void command_free(struct command *c)
+{
+	/** @todo if command has a handler, unregister its jim command! */
+
+	while (NULL != c->children) {
+		struct command *tmp = c->children;
+		c->children = tmp->next;
+		command_free(tmp);
+	}
+
+	free(c->name);
+	free(c->help);
+	free(c->usage);
+	free(c);
+}
+
+static struct command *command_new(struct command_context *cmd_ctx,
+	struct command *parent, const struct command_registration *cr)
+{
+	assert(cr->name);
+
+	/*
+	 * If it is a non-jim command with no .usage specified,
+	 * log an error.
+	 *
+	 * strlen(.usage) == 0 means that the command takes no
+	 * arguments.
+	*/
+	if ((cr->jim_handler == NULL) && (cr->usage == NULL)) {
+		LOG_DEBUG("BUG: command '%s%s%s' does not have the "
+			"'.usage' field filled out",
+			parent && parent->name ? parent->name : "",
+			parent && parent->name ? " " : "",
+			cr->name);
+	}
+
+	struct command *c = calloc(1, sizeof(struct command));
+	if (NULL == c)
 		return NULL;
 
-	struct command **head = parent ? &parent->children : &context->commands;
-	struct command *c = command_find(head, name);
-	if (NULL != c)
-		return c;
+	c->name = strdup(cr->name);
+	if (cr->help)
+		c->help = strdup(cr->help);
+	if (cr->usage)
+		c->usage = strdup(cr->usage);
 
-	c = malloc(sizeof(struct command));
+	if (!c->name || (cr->help && !c->help) || (cr->usage && !c->usage))
+		goto command_new_error;
 
-	c->name = strdup(name);
 	c->parent = parent;
-	c->children = NULL;
-	c->handler = handler;
-	c->mode = mode;
-	c->next = NULL;
+	c->handler = cr->handler;
+	c->jim_handler = cr->jim_handler;
+	c->jim_handler_data = cr->jim_handler_data;
+	c->mode = cr->mode;
 
-	command_add_child(head, c);
+	command_add_child(command_list_for_parent(cmd_ctx, parent), c);
 
-	command_helptext_add(command_name_list(c), help);
+	return c;
 
-	/* just a placeholder, no handler */
-	if (c->handler == NULL)
-		return c;
+command_new_error:
+	command_free(c);
+	return NULL;
+}
+
+static int command_unknown(Jim_Interp *interp, int argc, Jim_Obj *const *argv);
+
+static int register_command_handler(struct command_context *cmd_ctx,
+	struct command *c)
+{
+	Jim_Interp *interp = cmd_ctx->interp;
+	char *ocd_name = alloc_printf("ocd_%s", c->name);
+	if (NULL == ocd_name)
+		return JIM_ERR;
 
-	const char *full_name = command_name(c, '_');
+	LOG_DEBUG("registering '%s'...", ocd_name);
 
-	const char *ocd_name = alloc_printf("ocd_%s", full_name);
-	Jim_CreateCommand(interp, ocd_name, script_command, c, NULL);
-	free((void *)ocd_name);
+	Jim_CmdProc *func = c->handler ? &script_command : &command_unknown;
+	int retval = Jim_CreateCommand(interp, ocd_name, func, c, NULL);
+	free(ocd_name);
+	if (JIM_OK != retval)
+		return retval;
 
 	/* we now need to add an overrideable proc */
-	const char *override_name = alloc_printf("proc %s {args} {"
-			"if {[catch {eval ocd_%s $args}] == 0} "
-			"{return \"\"} else {return -code error}}",
-			full_name, full_name);
-	Jim_Eval_Named(interp, override_name, __THIS__FILE__, __LINE__);
-	free((void *)override_name);
+	char *override_name = alloc_printf(
+			"proc %s {args} {eval ocd_bouncer %s $args}",
+			c->name, c->name);
+	if (NULL == override_name)
+		return JIM_ERR;
 
-	free((void *)full_name);
+	retval = Jim_Eval_Named(interp, override_name, 0, 0);
+	free(override_name);
 
-	return c;
+	return retval;
 }
 
-int unregister_all_commands(struct command_context *context)
+struct command *register_command(struct command_context *context,
+	struct command *parent, const struct command_registration *cr)
 {
-	struct command *c, *c2;
+	if (!context || !cr->name)
+		return NULL;
 
-	if (context == NULL)
-		return ERROR_OK;
+	const char *name = cr->name;
+	struct command **head = command_list_for_parent(context, parent);
+	struct command *c = command_find(*head, name);
+	if (NULL != c) {
+		/* TODO: originally we treated attempting to register a cmd twice as an error
+		 * Sometimes we need this behaviour, such as with flash banks.
+		 * http://www.mail-archive.com/openocd-development@lists.berlios.de/msg11152.html */
+		LOG_DEBUG("command '%s' is already registered in '%s' context",
+			name, parent ? parent->name : "<global>");
+		return c;
+	}
 
-	while (NULL != context->commands)
-	{
-		c = context->commands;
-
-		while (NULL != c->children)
-		{
-			c2 = c->children;
-			c->children = c->children->next;
-			free(c2->name);
-			c2->name = NULL;
-			free(c2);
-			c2 = NULL;
-		}
+	c = command_new(context, parent, cr);
+	if (NULL == c)
+		return NULL;
 
-		context->commands = context->commands->next;
+	int retval = ERROR_OK;
+	if (NULL != cr->jim_handler && NULL == parent) {
+		retval = Jim_CreateCommand(context->interp, cr->name,
+				cr->jim_handler, cr->jim_handler_data, NULL);
+	} else if (NULL != cr->handler || NULL != parent)
+		retval = register_command_handler(context, command_root(c));
 
-		free(c->name);
-		c->name = NULL;
-		free(c);
+	if (ERROR_OK != retval) {
+		unregister_command(context, parent, name);
 		c = NULL;
 	}
+	return c;
+}
 
-	return ERROR_OK;
+int register_commands(struct command_context *cmd_ctx, struct command *parent,
+	const struct command_registration *cmds)
+{
+	int retval = ERROR_OK;
+	unsigned i;
+	for (i = 0; cmds[i].name || cmds[i].chain; i++) {
+		const struct command_registration *cr = cmds + i;
+
+		struct command *c = NULL;
+		if (NULL != cr->name) {
+			c = register_command(cmd_ctx, parent, cr);
+			if (NULL == c) {
+				retval = ERROR_FAIL;
+				break;
+			}
+		}
+		if (NULL != cr->chain) {
+			struct command *p = c ? : parent;
+			retval = register_commands(cmd_ctx, p, cr->chain);
+			if (ERROR_OK != retval)
+				break;
+		}
+	}
+	if (ERROR_OK != retval) {
+		for (unsigned j = 0; j < i; j++)
+			unregister_command(cmd_ctx, parent, cmds[j].name);
+	}
+	return retval;
 }
 
-int unregister_command(struct command_context *context, char *name)
+int unregister_all_commands(struct command_context *context,
+	struct command *parent)
 {
-	struct command *c, *p = NULL, *c2;
+	if (context == NULL)
+		return ERROR_OK;
 
-	if ((!context) || (!name))
-		return ERROR_INVALID_ARGUMENTS;
+	struct command **head = command_list_for_parent(context, parent);
+	while (NULL != *head) {
+		struct command *tmp = *head;
+		*head = tmp->next;
+		command_free(tmp);
+	}
 
-	/* find command */
-	c = context->commands;
+	return ERROR_OK;
+}
 
-	while (NULL != c)
-	{
-		if (strcmp(name, c->name) == 0)
-		{
-			/* unlink command */
-			if (p)
-			{
-				p->next = c->next;
-			}
-			else
-			{
-				/* first element in command list */
-				context->commands = c->next;
-			}
+int unregister_command(struct command_context *context,
+	struct command *parent, const char *name)
+{
+	if ((!context) || (!name))
+		return ERROR_COMMAND_SYNTAX_ERROR;
 
-			/* unregister children */
-			while (NULL != c->children)
-			{
-				c2 = c->children;
-				c->children = c->children->next;
-				free(c2->name);
-				c2->name = NULL;
-				free(c2);
-				c2 = NULL;
-			}
+	struct command *p = NULL;
+	struct command **head = command_list_for_parent(context, parent);
+	for (struct command *c = *head; NULL != c; p = c, c = c->next) {
+		if (strcmp(name, c->name) != 0)
+			continue;
 
-			/* delete command */
-			free(c->name);
-			c->name = NULL;
-			free(c);
-			c = NULL;
-			return ERROR_OK;
-		}
+		if (p)
+			p->next = c->next;
+		else
+			*head = c->next;
 
-		/* remember the last command for unlinking */
-		p = c;
-		c = c->next;
+		command_free(c);
+		return ERROR_OK;
 	}
 
 	return ERROR_OK;
 }
 
+void command_set_handler_data(struct command *c, void *p)
+{
+	if (NULL != c->handler || NULL != c->jim_handler)
+		c->jim_handler_data = p;
+	for (struct command *cc = c->children; NULL != cc; cc = cc->next)
+		command_set_handler_data(cc, p);
+}
+
 void command_output_text(struct command_context *context, const char *data)
 {
-	if (context && context->output_handler && data) {
+	if (context && context->output_handler && data)
 		context->output_handler(context, data);
-	}
 }
 
 void command_print_sameline(struct command_context *context, const char *format, ...)
@@ -372,16 +510,15 @@ void command_print_sameline(struct command_context *context, const char *format,
 	va_start(ap, format);
 
 	string = alloc_vprintf(format, ap);
-	if (string != NULL)
-	{
+	if (string != NULL) {
 		/* we want this collected in the log + we also want to pick it up as a tcl return
 		 * value.
 		 *
 		 * The latter bit isn't precisely neat, but will do for now.
 		 */
 		LOG_USER_N("%s", string);
-		/* We already printed it above */
-		/* command_output_text(context, string); */
+		/* We already printed it above
+		 * command_output_text(context, string); */
 		free(string);
 	}
 
@@ -396,17 +533,17 @@ void command_print(struct command_context *context, const char *format, ...)
 	va_start(ap, format);
 
 	string = alloc_vprintf(format, ap);
-	if (string != NULL)
-	{
-		strcat(string, "\n"); /* alloc_vprintf guaranteed the buffer to be at least one char longer */
+	if (string != NULL) {
+		strcat(string, "\n");	/* alloc_vprintf guaranteed the buffer to be at least one
+					 *char longer */
 		/* we want this collected in the log + we also want to pick it up as a tcl return
 		 * value.
 		 *
 		 * The latter bit isn't precisely neat, but will do for now.
 		 */
 		LOG_USER_N("%s", string);
-		/* We already printed it above */
-		/* command_output_text(context, string); */
+		/* We already printed it above
+		 * command_output_text(context, string); */
 		free(string);
 	}
 
@@ -418,11 +555,15 @@ static char *__command_name(struct command *c, char delim, unsigned extra)
 	char *name;
 	unsigned len = strlen(c->name);
 	if (NULL == c->parent) {
-		// allocate enough for the name, child names, and '\0'
+		/* allocate enough for the name, child names, and '\0' */
 		name = malloc(len + extra + 1);
+		if (!name) {
+			LOG_ERROR("Out of memory");
+			return NULL;
+		}
 		strcpy(name, c->name);
 	} else {
-		// parent's extra must include both the space and name
+		/* parent's extra must include both the space and name */
 		name = __command_name(c->parent, delim, 1 + len + extra);
 		char dstr[2] = { delim, 0 };
 		strcat(name, dstr);
@@ -430,49 +571,81 @@ static char *__command_name(struct command *c, char delim, unsigned extra)
 	}
 	return name;
 }
+
 char *command_name(struct command *c, char delim)
 {
 	return __command_name(c, delim, 0);
 }
 
+static bool command_can_run(struct command_context *cmd_ctx, struct command *c)
+{
+	return c->mode == COMMAND_ANY || c->mode == cmd_ctx->mode;
+}
+
 static int run_command(struct command_context *context,
-		struct command *c, const char *words[], unsigned num_words)
+	struct command *c, const char *words[], unsigned num_words)
 {
-	int start_word = 0;
-	if (!((context->mode == COMMAND_CONFIG) || (c->mode == COMMAND_ANY) || (c->mode == context->mode)))
-	{
-		/* Config commands can not run after the config stage */
-		LOG_ERROR("Command '%s' only runs during configuration stage", c->name);
+	if (!command_can_run(context, c)) {
+		/* Many commands may be run only before/after 'init' */
+		const char *when;
+		switch (c->mode) {
+			case COMMAND_CONFIG:
+				when = "before";
+				break;
+			case COMMAND_EXEC:
+				when = "after";
+				break;
+			/* handle the impossible with humor; it guarantees a bug report! */
+			default:
+				when = "if Cthulhu is summoned by";
+				break;
+		}
+		LOG_ERROR("The '%s' command must be used %s 'init'.",
+			c->name, when);
 		return ERROR_FAIL;
 	}
 
 	struct command_invocation cmd = {
-			.ctx = context,
-			.name = c->name,
-			.argc = num_words - start_word - 1,
-			.argv = words + start_word + 1,
-		};
+		.ctx = context,
+		.current = c,
+		.name = c->name,
+		.argc = num_words - 1,
+		.argv = words + 1,
+	};
+	/* Black magic of overridden current target:
+	 * If the command we are going to handle has a target prefix,
+	 * override the current target temporarily for the time
+	 * of processing the command.
+	 * current_target_override is used also for event handlers
+	 * therefore we prevent touching it if command has no prefix.
+	 * Previous override is saved and restored back to ensure
+	 * correct work when run_command() is re-entered. */
+	struct target *saved_target_override = context->current_target_override;
+	if (c->jim_handler_data)
+		context->current_target_override = c->jim_handler_data;
+
 	int retval = c->handler(&cmd);
-	if (retval == ERROR_COMMAND_SYNTAX_ERROR)
-	{
+
+	if (c->jim_handler_data)
+		context->current_target_override = saved_target_override;
+
+	if (retval == ERROR_COMMAND_SYNTAX_ERROR) {
 		/* Print help for command */
 		char *full_name = command_name(c, ' ');
 		if (NULL != full_name) {
-			command_run_linef(context, "help %s", full_name);
+			command_run_linef(context, "usage %s", full_name);
 			free(full_name);
-		} else
-			retval = -ENOMEM;
-	}
-	else if (retval == ERROR_COMMAND_CLOSE_CONNECTION)
-	{
+		}
+	} else if (retval == ERROR_COMMAND_CLOSE_CONNECTION) {
 		/* just fall through for a shutdown request */
-	}
-	else if (retval != ERROR_OK)
-	{
+	} else if (retval != ERROR_OK) {
 		/* we do not print out an error message because the command *should*
 		 * have printed out an error
 		 */
-		LOG_DEBUG("Command failed with error code %d", retval);
+		char *full_name = command_name(c, ' ');
+		LOG_DEBUG("Command '%s' failed with error code %d",
+					full_name ? full_name : c->name, retval);
+		free(full_name);
 	}
 
 	return retval;
@@ -492,47 +665,31 @@ int command_run_line(struct command_context *context, char *line)
 	 * happen when the Jim Tcl interpreter is provided by eCos for
 	 * instance.
 	 */
+	context->current_target_override = NULL;
+
+	Jim_Interp *interp = context->interp;
 	Jim_DeleteAssocData(interp, "context");
 	retcode = Jim_SetAssocData(interp, "context", NULL, context);
-	if (retcode == JIM_OK)
-	{
+	if (retcode == JIM_OK) {
 		/* associated the return value */
 		Jim_DeleteAssocData(interp, "retval");
 		retcode = Jim_SetAssocData(interp, "retval", NULL, &retval);
-		if (retcode == JIM_OK)
-		{
-			retcode = Jim_Eval_Named(interp, line, __THIS__FILE__, __LINE__);
+		if (retcode == JIM_OK) {
+			retcode = Jim_Eval_Named(interp, line, 0, 0);
 
 			Jim_DeleteAssocData(interp, "retval");
 		}
 		Jim_DeleteAssocData(interp, "context");
 	}
-	if (retcode == JIM_ERR) {
-		if (retval != ERROR_COMMAND_CLOSE_CONNECTION)
-		{
-			/* We do not print the connection closed error message */
-			Jim_PrintErrorMessage(interp);
-		}
-		if (retval == ERROR_OK)
-		{
-			/* It wasn't a low level OpenOCD command that failed */
-			return ERROR_FAIL;
-		}
-		return retval;
-	} else if (retcode == JIM_EXIT) {
-		/* ignore. */
-		/* exit(Jim_GetExitCode(interp)); */
-	} else {
+	if (retcode == JIM_OK) {
 		const char *result;
 		int reslen;
 
 		result = Jim_GetString(Jim_GetResult(interp), &reslen);
-		if (reslen > 0)
-		{
+		if (reslen > 0) {
 			int i;
 			char buff[256 + 1];
-			for (i = 0; i < reslen; i += 256)
-			{
+			for (i = 0; i < reslen; i += 256) {
 				int chunk;
 				chunk = reslen - i;
 				if (chunk > 256)
@@ -541,10 +698,25 @@ int command_run_line(struct command_context *context, char *line)
 				buff[chunk] = 0;
 				LOG_USER_N("%s", buff);
 			}
-			LOG_USER_N("%s", "\n");
+			LOG_USER_N("\n");
 		}
 		retval = ERROR_OK;
+	} else if (retcode == JIM_EXIT) {
+		/* ignore.
+		 * exit(Jim_GetExitCode(interp)); */
+	} else if (retcode == ERROR_COMMAND_CLOSE_CONNECTION) {
+		return retcode;
+	} else {
+		Jim_MakeErrorMessage(interp);
+		LOG_USER("%s", Jim_GetString(Jim_GetResult(interp), NULL));
+
+		if (retval == ERROR_OK) {
+			/* It wasn't a low level OpenOCD command that failed */
+			return ERROR_FAIL;
+		}
+		return retval;
 	}
+
 	return retval;
 }
 
@@ -555,36 +727,36 @@ int command_run_linef(struct command_context *context, const char *format, ...)
 	va_list ap;
 	va_start(ap, format);
 	string = alloc_vprintf(format, ap);
-	if (string != NULL)
-	{
+	if (string != NULL) {
 		retval = command_run_line(context, string);
+		free(string);
 	}
 	va_end(ap);
 	return retval;
 }
 
-void command_set_output_handler(struct command_context* context,
-		command_output_handler_t output_handler, void *priv)
+void command_set_output_handler(struct command_context *context,
+	command_output_handler_t output_handler, void *priv)
 {
 	context->output_handler = output_handler;
 	context->output_handler_priv = priv;
 }
 
-struct command_context* copy_command_context(struct command_context* context)
+struct command_context *copy_command_context(struct command_context *context)
 {
-	struct command_context* copy_context = malloc(sizeof(struct command_context));
+	struct command_context *copy_context = malloc(sizeof(struct command_context));
 
 	*copy_context = *context;
 
 	return copy_context;
 }
 
-int command_done(struct command_context *context)
+void command_done(struct command_context *cmd_ctx)
 {
-	free(context);
-	context = NULL;
+	if (NULL == cmd_ctx)
+		return;
 
-	return ERROR_OK;
+	free(cmd_ctx);
 }
 
 /* find full path to file */
@@ -603,137 +775,420 @@ static int jim_find(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 	return JIM_OK;
 }
 
-static int jim_echo(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+COMMAND_HANDLER(jim_echo)
+{
+	if (CMD_ARGC == 2 && !strcmp(CMD_ARGV[0], "-n")) {
+		LOG_USER_N("%s", CMD_ARGV[1]);
+		return JIM_OK;
+	}
+	if (CMD_ARGC != 1)
+		return JIM_ERR;
+	LOG_USER("%s", CMD_ARGV[0]);
+	return JIM_OK;
+}
+
+/* Capture progress output and return as tcl return value. If the
+ * progress output was empty, return tcl return value.
+ */
+static int jim_capture(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 {
 	if (argc != 2)
 		return JIM_ERR;
+
+	struct log_capture_state *state = command_log_capture_start(interp);
+
+	/* disable polling during capture. This avoids capturing output
+	 * from polling.
+	 *
+	 * This is necessary in order to avoid accidentally getting a non-empty
+	 * string for tcl fn's.
+	 */
+	bool save_poll = jtag_poll_get_enabled();
+
+	jtag_poll_set_enabled(false);
+
 	const char *str = Jim_GetString(argv[1], NULL);
-	LOG_USER("%s", str);
-	return JIM_OK;
+	int retcode = Jim_Eval_Named(interp, str, __THIS__FILE__, __LINE__);
+
+	jtag_poll_set_enabled(save_poll);
+
+	command_log_capture_finish(state);
+
+	return retcode;
 }
 
-static size_t openocd_jim_fwrite(const void *_ptr, size_t size, size_t n, void *cookie)
+static COMMAND_HELPER(command_help_find, struct command *head,
+	struct command **out)
 {
-	size_t nbytes;
-	const char *ptr;
-	Jim_Interp *interp;
+	if (0 == CMD_ARGC)
+		return ERROR_COMMAND_SYNTAX_ERROR;
+	*out = command_find(head, CMD_ARGV[0]);
+	if (NULL == *out && strncmp(CMD_ARGV[0], "ocd_", 4) == 0)
+		*out = command_find(head, CMD_ARGV[0] + 4);
+	if (NULL == *out)
+		return ERROR_COMMAND_SYNTAX_ERROR;
+	if (--CMD_ARGC == 0)
+		return ERROR_OK;
+	CMD_ARGV++;
+	return CALL_COMMAND_HANDLER(command_help_find, (*out)->children, out);
+}
+
+static COMMAND_HELPER(command_help_show, struct command *c, unsigned n,
+	bool show_help, const char *cmd_match);
 
-	/* make it a char easier to read code */
-	ptr = _ptr;
-	interp = cookie;
-	nbytes = size * n;
-	if (ptr == NULL || interp == NULL || nbytes == 0) {
-		return 0;
+static COMMAND_HELPER(command_help_show_list, struct command *head, unsigned n,
+	bool show_help, const char *cmd_match)
+{
+	for (struct command *c = head; NULL != c; c = c->next)
+		CALL_COMMAND_HANDLER(command_help_show, c, n, show_help, cmd_match);
+	return ERROR_OK;
+}
+
+#define HELP_LINE_WIDTH(_n) (int)(76 - (2 * _n))
+
+static void command_help_show_indent(unsigned n)
+{
+	for (unsigned i = 0; i < n; i++)
+		LOG_USER_N("  ");
+}
+static void command_help_show_wrap(const char *str, unsigned n, unsigned n2)
+{
+	const char *cp = str, *last = str;
+	while (*cp) {
+		const char *next = last;
+		do {
+			cp = next;
+			do {
+				next++;
+			} while (*next != ' ' && *next != '\t' && *next != '\0');
+		} while ((next - last < HELP_LINE_WIDTH(n)) && *next != '\0');
+		if (next - last < HELP_LINE_WIDTH(n))
+			cp = next;
+		command_help_show_indent(n);
+		LOG_USER("%.*s", (int)(cp - last), last);
+		last = cp + 1;
+		n = n2;
 	}
+}
 
-	/* do we have to chunk it? */
-	if (ptr[nbytes] == 0)
-	{
-		/* no it is a C style string */
-		LOG_USER_N("%s", ptr);
-		return strlen(ptr);
-	}
-	/* GRR we must chunk - not null terminated */
-	while (nbytes) {
-		char chunk[128 + 1];
-		int x;
-
-		x = nbytes;
-		if (x > 128) {
-			x = 128;
-		}
-		/* copy it */
-		memcpy(chunk, ptr, x);
-		/* terminate it */
-		chunk[n] = 0;
-		/* output it */
-		LOG_USER_N("%s", chunk);
-		ptr += x;
-		nbytes -= x;
+static COMMAND_HELPER(command_help_show, struct command *c, unsigned n,
+	bool show_help, const char *cmd_match)
+{
+	char *cmd_name = command_name(c, ' ');
+	if (NULL == cmd_name)
+		return ERROR_FAIL;
+
+	/* If the match string occurs anywhere, we print out
+	 * stuff for this command. */
+	bool is_match = (strstr(cmd_name, cmd_match) != NULL) ||
+		((c->usage != NULL) && (strstr(c->usage, cmd_match) != NULL)) ||
+		((c->help != NULL) && (strstr(c->help, cmd_match) != NULL));
+
+	if (is_match) {
+		command_help_show_indent(n);
+		LOG_USER_N("%s", cmd_name);
 	}
+	free(cmd_name);
 
-	return n;
+	if (is_match) {
+		if (c->usage && strlen(c->usage) > 0) {
+			LOG_USER_N(" ");
+			command_help_show_wrap(c->usage, 0, n + 5);
+		} else
+			LOG_USER_N("\n");
+	}
+
+	if (is_match && show_help) {
+		char *msg;
+
+		/* Normal commands are runtime-only; highlight exceptions */
+		if (c->mode != COMMAND_EXEC) {
+			const char *stage_msg = "";
+
+			switch (c->mode) {
+				case COMMAND_CONFIG:
+					stage_msg = " (configuration command)";
+					break;
+				case COMMAND_ANY:
+					stage_msg = " (command valid any time)";
+					break;
+				default:
+					stage_msg = " (?mode error?)";
+					break;
+			}
+			msg = alloc_printf("%s%s", c->help ? : "", stage_msg);
+		} else
+			msg = alloc_printf("%s", c->help ? : "");
+
+		if (NULL != msg) {
+			command_help_show_wrap(msg, n + 3, n + 3);
+			free(msg);
+		} else
+			return -ENOMEM;
+	}
+
+	if (++n > 5) {
+		LOG_ERROR("command recursion exceeded");
+		return ERROR_FAIL;
+	}
+
+	return CALL_COMMAND_HANDLER(command_help_show_list,
+		c->children, n, show_help, cmd_match);
 }
 
-static size_t openocd_jim_fread(void *ptr, size_t size, size_t n, void *cookie)
+COMMAND_HANDLER(handle_help_command)
 {
-	/* TCL wants to read... tell him no */
-	return 0;
+	bool full = strcmp(CMD_NAME, "help") == 0;
+	int retval;
+	struct command *c = CMD_CTX->commands;
+	char *cmd_match = NULL;
+
+	if (CMD_ARGC == 0)
+		cmd_match = "";
+	else if (CMD_ARGC >= 1) {
+		unsigned i;
+
+		for (i = 0; i < CMD_ARGC; ++i) {
+			if (NULL != cmd_match) {
+				char *prev = cmd_match;
+
+				cmd_match = alloc_printf("%s %s", cmd_match, CMD_ARGV[i]);
+				free(prev);
+				if (NULL == cmd_match) {
+					LOG_ERROR("unable to build search string");
+					return -ENOMEM;
+				}
+			} else {
+				cmd_match = alloc_printf("%s", CMD_ARGV[i]);
+				if (NULL == cmd_match) {
+					LOG_ERROR("unable to build search string");
+					return -ENOMEM;
+				}
+			}
+		}
+	} else
+		return ERROR_COMMAND_SYNTAX_ERROR;
+
+	retval = CALL_COMMAND_HANDLER(command_help_show_list,
+			c, 0, full, cmd_match);
+
+	if (CMD_ARGC >= 1)
+		free(cmd_match);
+	return retval;
 }
 
-static int openocd_jim_vfprintf(void *cookie, const char *fmt, va_list ap)
+static int command_unknown_find(unsigned argc, Jim_Obj *const *argv,
+	struct command *head, struct command **out, bool top_level)
 {
-	char *cp;
-	int n;
-	Jim_Interp *interp;
+	if (0 == argc)
+		return argc;
+	const char *cmd_name = Jim_GetString(argv[0], NULL);
+	struct command *c = command_find(head, cmd_name);
+	if (NULL == c && top_level && strncmp(cmd_name, "ocd_", 4) == 0)
+		c = command_find(head, cmd_name + 4);
+	if (NULL == c)
+		return argc;
+	*out = c;
+	return command_unknown_find(--argc, ++argv, (*out)->children, out, false);
+}
 
-	n = -1;
-	interp = cookie;
-	if (interp == NULL)
-		return n;
+static int command_unknown(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+{
+	const char *cmd_name = Jim_GetString(argv[0], NULL);
+	if (strcmp(cmd_name, "unknown") == 0) {
+		if (argc == 1)
+			return JIM_OK;
+		argc--;
+		argv++;
+	}
+	script_debug(interp, cmd_name, argc, argv);
+
+	struct command_context *cmd_ctx = current_command_context(interp);
+	struct command *c = cmd_ctx->commands;
+	int remaining = command_unknown_find(argc, argv, c, &c, true);
+	/* if nothing could be consumed, then it's really an unknown command */
+	if (remaining == argc) {
+		const char *cmd = Jim_GetString(argv[0], NULL);
+		LOG_ERROR("Unknown command:\n  %s", cmd);
+		return JIM_OK;
+	}
 
-	cp = alloc_vprintf(fmt, ap);
-	if (cp)
-	{
-		LOG_USER_N("%s", cp);
-		n = strlen(cp);
-		free(cp);
+	bool found = true;
+	Jim_Obj *const *start;
+	unsigned count;
+	if (c->handler || c->jim_handler) {
+		/* include the command name in the list */
+		count = remaining + 1;
+		start = argv + (argc - remaining - 1);
+	} else {
+		c = command_find(cmd_ctx->commands, "usage");
+		if (NULL == c) {
+			LOG_ERROR("unknown command, but usage is missing too");
+			return JIM_ERR;
+		}
+		count = argc - remaining;
+		start = argv;
+		found = false;
+	}
+	/* pass the command through to the intended handler */
+	if (c->jim_handler) {
+		interp->cmdPrivData = c->jim_handler_data;
+		return (*c->jim_handler)(interp, count, start);
 	}
-	return n;
-}
 
-static int openocd_jim_fflush(void *cookie)
-{
-	/* nothing to flush */
-	return 0;
+	return script_command_run(interp, count, start, c, found);
 }
 
-static char* openocd_jim_fgets(char *s, int size, void *cookie)
+static int jim_command_mode(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 {
-	/* not supported */
-	errno = ENOTSUP;
-	return NULL;
+	struct command_context *cmd_ctx = current_command_context(interp);
+	enum command_mode mode;
+
+	if (argc > 1) {
+		struct command *c = cmd_ctx->commands;
+		int remaining = command_unknown_find(argc - 1, argv + 1, c, &c, true);
+		/* if nothing could be consumed, then it's an unknown command */
+		if (remaining == argc - 1) {
+			Jim_SetResultString(interp, "unknown", -1);
+			return JIM_OK;
+		}
+		mode = c->mode;
+	} else
+		mode = cmd_ctx->mode;
+
+	const char *mode_str;
+	switch (mode) {
+		case COMMAND_ANY:
+			mode_str = "any";
+			break;
+		case COMMAND_CONFIG:
+			mode_str = "config";
+			break;
+		case COMMAND_EXEC:
+			mode_str = "exec";
+			break;
+		default:
+			mode_str = "unknown";
+			break;
+	}
+	Jim_SetResultString(interp, mode_str, -1);
+	return JIM_OK;
 }
 
-static int jim_capture(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+static int jim_command_type(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 {
-	if (argc != 2)
+	if (1 == argc)
 		return JIM_ERR;
-	int retcode;
-	const char *str = Jim_GetString(argv[1], NULL);
 
-	/* capture log output and return it */
-	Jim_Obj *tclOutput = Jim_NewStringObj(interp, "", 0);
-	/* a garbage collect can happen, so we need a reference count to this object */
-	Jim_IncrRefCount(tclOutput);
+	struct command_context *cmd_ctx = current_command_context(interp);
+	struct command *c = cmd_ctx->commands;
+	int remaining = command_unknown_find(argc - 1, argv + 1, c, &c, true);
+	/* if nothing could be consumed, then it's an unknown command */
+	if (remaining == argc - 1) {
+		Jim_SetResultString(interp, "unknown", -1);
+		return JIM_OK;
+	}
 
-	log_add_callback(tcl_output, tclOutput);
+	if (c->jim_handler)
+		Jim_SetResultString(interp, "native", -1);
+	else if (c->handler)
+		Jim_SetResultString(interp, "simple", -1);
+	else if (remaining == 0)
+		Jim_SetResultString(interp, "group", -1);
+	else
+		Jim_SetResultString(interp, "unknown", -1);
 
-	retcode = Jim_Eval_Named(interp, str, __THIS__FILE__, __LINE__);
+	return JIM_OK;
+}
 
-	log_remove_callback(tcl_output, tclOutput);
+int help_add_command(struct command_context *cmd_ctx, struct command *parent,
+	const char *cmd_name, const char *help_text, const char *usage)
+{
+	struct command **head = command_list_for_parent(cmd_ctx, parent);
+	struct command *nc = command_find(*head, cmd_name);
+	if (NULL == nc) {
+		/* add a new command with help text */
+		struct command_registration cr = {
+			.name = cmd_name,
+			.mode = COMMAND_ANY,
+			.help = help_text,
+			.usage = usage,
+		};
+		nc = register_command(cmd_ctx, parent, &cr);
+		if (NULL == nc) {
+			LOG_ERROR("failed to add '%s' help text", cmd_name);
+			return ERROR_FAIL;
+		}
+		LOG_DEBUG("added '%s' help text", cmd_name);
+		return ERROR_OK;
+	}
+	if (help_text) {
+		bool replaced = false;
+		if (nc->help) {
+			free(nc->help);
+			replaced = true;
+		}
+		nc->help = strdup(help_text);
+		if (replaced)
+			LOG_INFO("replaced existing '%s' help", cmd_name);
+		else
+			LOG_DEBUG("added '%s' help text", cmd_name);
+	}
+	if (usage) {
+		bool replaced = false;
+		if (nc->usage) {
+			free(nc->usage);
+			replaced = true;
+		}
+		nc->usage = strdup(usage);
+		if (replaced)
+			LOG_INFO("replaced existing '%s' usage", cmd_name);
+		else
+			LOG_DEBUG("added '%s' usage text", cmd_name);
+	}
+	return ERROR_OK;
+}
 
-	/* We dump output into this local variable */
-	Jim_SetResult(interp, tclOutput);
-	Jim_DecrRefCount(interp, tclOutput);
+COMMAND_HANDLER(handle_help_add_command)
+{
+	if (CMD_ARGC < 2) {
+		LOG_ERROR("%s: insufficient arguments", CMD_NAME);
+		return ERROR_COMMAND_SYNTAX_ERROR;
+	}
 
-	return retcode;
+	/* save help text and remove it from argument list */
+	const char *str = CMD_ARGV[--CMD_ARGC];
+	const char *help = !strcmp(CMD_NAME, "add_help_text") ? str : NULL;
+	const char *usage = !strcmp(CMD_NAME, "add_usage_text") ? str : NULL;
+	if (!help && !usage) {
+		LOG_ERROR("command name '%s' is unknown", CMD_NAME);
+		return ERROR_COMMAND_SYNTAX_ERROR;
+	}
+	/* likewise for the leaf command name */
+	const char *cmd_name = CMD_ARGV[--CMD_ARGC];
+
+	struct command *c = NULL;
+	if (CMD_ARGC > 0) {
+		c = CMD_CTX->commands;
+		int retval = CALL_COMMAND_HANDLER(command_help_find, c, &c);
+		if (ERROR_OK != retval)
+			return retval;
+	}
+	return help_add_command(CMD_CTX, c, cmd_name, help, usage);
 }
 
-/* sleep command sleeps for <n> miliseconds
+/* sleep command sleeps for <n> milliseconds
  * this is useful in target startup scripts
  */
 COMMAND_HANDLER(handle_sleep_command)
 {
 	bool busy = false;
-	if (CMD_ARGC == 2)
-	{
+	if (CMD_ARGC == 2) {
 		if (strcmp(CMD_ARGV[1], "busy") == 0)
 			busy = true;
 		else
 			return ERROR_COMMAND_SYNTAX_ERROR;
-	}
-	else if (CMD_ARGC < 1 || CMD_ARGC > 2)
+	} else if (CMD_ARGC < 1 || CMD_ARGC > 2)
 		return ERROR_COMMAND_SYNTAX_ERROR;
 
 	unsigned long duration = 0;
@@ -741,52 +1196,120 @@ COMMAND_HANDLER(handle_sleep_command)
 	if (ERROR_OK != retval)
 		return retval;
 
-	if (!busy)
-	{
-		long long then = timeval_ms();
-		while (timeval_ms() - then < (long long)duration)
-		{
+	if (!busy) {
+		int64_t then = timeval_ms();
+		while (timeval_ms() - then < (int64_t)duration) {
 			target_call_timer_callbacks_now();
 			usleep(1000);
 		}
-	}
-	else
+	} else
 		busy_sleep(duration);
 
 	return ERROR_OK;
 }
 
-COMMAND_HANDLER(handle_fast_command)
-{
-	if (CMD_ARGC != 1)
-		return ERROR_COMMAND_SYNTAX_ERROR;
-
-	fast_and_dangerous = strcmp("enable", CMD_ARGV[0]) == 0;
-
-	return ERROR_OK;
-}
-
-
-struct command_context* command_init()
+static const struct command_registration command_subcommand_handlers[] = {
+	{
+		.name = "mode",
+		.mode = COMMAND_ANY,
+		.jim_handler = jim_command_mode,
+		.usage = "[command_name ...]",
+		.help = "Returns the command modes allowed by a  command:"
+			"'any', 'config', or 'exec'.  If no command is"
+			"specified, returns the current command mode.  "
+			"Returns 'unknown' if an unknown command is given. "
+			"Command can be multiple tokens.",
+	},
+	{
+		.name = "type",
+		.mode = COMMAND_ANY,
+		.jim_handler = jim_command_type,
+		.usage = "command_name [...]",
+		.help = "Returns the type of built-in command:"
+			"'native', 'simple', 'group', or 'unknown'. "
+			"Command can be multiple tokens.",
+	},
+	COMMAND_REGISTRATION_DONE
+};
+
+static const struct command_registration command_builtin_handlers[] = {
+	{
+		.name = "echo",
+		.handler = jim_echo,
+		.mode = COMMAND_ANY,
+		.help = "Logs a message at \"user\" priority. "
+			"Output message to stdout. "
+			"Option \"-n\" suppresses trailing newline",
+		.usage = "[-n] string",
+	},
+	{
+		.name = "add_help_text",
+		.handler = handle_help_add_command,
+		.mode = COMMAND_ANY,
+		.help = "Add new command help text; "
+			"Command can be multiple tokens.",
+		.usage = "command_name helptext_string",
+	},
+	{
+		.name = "add_usage_text",
+		.handler = handle_help_add_command,
+		.mode = COMMAND_ANY,
+		.help = "Add new command usage text; "
+			"command can be multiple tokens.",
+		.usage = "command_name usage_string",
+	},
+	{
+		.name = "sleep",
+		.handler = handle_sleep_command,
+		.mode = COMMAND_ANY,
+		.help = "Sleep for specified number of milliseconds.  "
+			"\"busy\" will busy wait instead (avoid this).",
+		.usage = "milliseconds ['busy']",
+	},
+	{
+		.name = "help",
+		.handler = handle_help_command,
+		.mode = COMMAND_ANY,
+		.help = "Show full command help; "
+			"command can be multiple tokens.",
+		.usage = "[command_name]",
+	},
+	{
+		.name = "usage",
+		.handler = handle_help_command,
+		.mode = COMMAND_ANY,
+		.help = "Show basic command usage; "
+			"command can be multiple tokens.",
+		.usage = "[command_name]",
+	},
+	{
+		.name = "command",
+		.mode = COMMAND_ANY,
+		.help = "core command group (introspection)",
+		.chain = command_subcommand_handlers,
+	},
+	COMMAND_REGISTRATION_DONE
+};
+
+struct command_context *command_init(const char *startup_tcl, Jim_Interp *interp)
 {
-	struct command_context* context = malloc(sizeof(struct command_context));
-	extern const char startup_tcl[];
+	struct command_context *context = calloc(1, sizeof(struct command_context));
 	const char *HostOs;
 
 	context->mode = COMMAND_EXEC;
-	context->commands = NULL;
-	context->current_target = 0;
-	context->output_handler = NULL;
-	context->output_handler_priv = NULL;
-
-#if !BUILD_ECOSBOARD
-	Jim_InitEmbedded();
-	/* Create an interpreter */
-	interp = Jim_CreateInterp();
-	/* Add all the Jim core commands */
-	Jim_RegisterCoreCommands(interp);
-#endif
 
+	/* Create a jim interpreter if we were not handed one */
+	if (interp == NULL) {
+		/* Create an interpreter */
+		interp = Jim_CreateInterp();
+		/* Add all the Jim core commands */
+		Jim_RegisterCoreCommands(interp);
+		Jim_InitStaticExtensions(interp);
+	}
+
+	context->interp = interp;
+
+	/* Stick to lowercase for HostOS strings. */
 #if defined(_MSC_VER)
 	/* WinXX - is generic, the forward
 	 * looking problem is this:
@@ -798,7 +1321,7 @@ struct command_context* command_init()
 	HostOs = "winxx";
 #elif defined(__linux__)
 	HostOs = "linux";
-#elif defined(__DARWIN__)
+#elif defined(__APPLE__) || defined(__DARWIN__)
 	HostOs = "darwin";
 #elif defined(__CYGWIN__)
 	HostOs = "cygwin";
@@ -806,153 +1329,169 @@ struct command_context* command_init()
 	HostOs = "mingw32";
 #elif defined(__ECOS)
 	HostOs = "ecos";
+#elif defined(__FreeBSD__)
+	HostOs = "freebsd";
+#elif defined(__NetBSD__)
+	HostOs = "netbsd";
+#elif defined(__OpenBSD__)
+	HostOs = "openbsd";
 #else
-#warn unrecognized host OS...
+#warning "Unrecognized host OS..."
 	HostOs = "other";
 #endif
 	Jim_SetGlobalVariableStr(interp, "ocd_HOSTOS",
-			Jim_NewStringObj(interp, HostOs , strlen(HostOs)));
+		Jim_NewStringObj(interp, HostOs, strlen(HostOs)));
 
 	Jim_CreateCommand(interp, "ocd_find", jim_find, NULL, NULL);
-	Jim_CreateCommand(interp, "echo", jim_echo, NULL, NULL);
 	Jim_CreateCommand(interp, "capture", jim_capture, NULL, NULL);
 
-	/* Set Jim's STDIO */
-	interp->cookie_stdin = interp;
-	interp->cookie_stdout = interp;
-	interp->cookie_stderr = interp;
-	interp->cb_fwrite = openocd_jim_fwrite;
-	interp->cb_fread = openocd_jim_fread ;
-	interp->cb_vfprintf = openocd_jim_vfprintf;
-	interp->cb_fflush = openocd_jim_fflush;
-	interp->cb_fgets = openocd_jim_fgets;
-
-#if !BUILD_ECOSBOARD
-	Jim_EventLoopOnLoad(interp);
-#endif
-	if (Jim_Eval_Named(interp, startup_tcl, "embedded:startup.tcl",1) == JIM_ERR)
-	{
+	register_commands(context, NULL, command_builtin_handlers);
+
+	Jim_SetAssocData(interp, "context", NULL, context);
+	if (Jim_Eval_Named(interp, startup_tcl, "embedded:startup.tcl", 1) == JIM_ERR) {
 		LOG_ERROR("Failed to run startup.tcl (embedded into OpenOCD)");
-		Jim_PrintErrorMessage(interp);
+		Jim_MakeErrorMessage(interp);
+		LOG_USER_N("%s", Jim_GetString(Jim_GetResult(interp), NULL));
 		exit(-1);
 	}
-
-	register_command(context, NULL, "sleep",
-			handle_sleep_command, COMMAND_ANY,
-			"<n> [busy] - sleep for n milliseconds. "
-			"\"busy\" means busy wait");
-	register_command(context, NULL, "fast",
-			handle_fast_command, COMMAND_ANY,
-			"fast <enable/disable> - place at beginning of "
-			"config files. Sets defaults to fast and dangerous.");
+	Jim_DeleteAssocData(interp, "context");
 
 	return context;
 }
 
-int command_context_mode(struct command_context *cmd_ctx, enum command_mode mode)
+void command_exit(struct command_context *context)
 {
-	if (!cmd_ctx)
-		return ERROR_INVALID_ARGUMENTS;
+	if (!context)
+		return;
 
-	cmd_ctx->mode = mode;
-	return ERROR_OK;
+	Jim_FreeInterp(context->interp);
+	command_done(context);
 }
 
-void process_jim_events(void)
+int command_context_mode(struct command_context *cmd_ctx, enum command_mode mode)
 {
-#if !BUILD_ECOSBOARD
-	static int recursion = 0;
+	if (!cmd_ctx)
+		return ERROR_COMMAND_SYNTAX_ERROR;
 
-	if (!recursion)
-	{
-		recursion++;
-		Jim_ProcessEvents (interp, JIM_ALL_EVENTS | JIM_DONT_WAIT);
-		recursion--;
-	}
-#endif
+	cmd_ctx->mode = mode;
+	return ERROR_OK;
 }
 
-void register_jim(struct command_context *cmd_ctx, const char *name,
-		Jim_CmdProc cmd, const char *help)
+void process_jim_events(struct command_context *cmd_ctx)
 {
-	Jim_CreateCommand(interp, name, cmd, NULL, NULL);
-
-	Jim_Obj *cmd_list = Jim_NewListObj(interp, NULL, 0);
-	Jim_ListAppendElement(interp, cmd_list,
-			Jim_NewStringObj(interp, name, -1));
-
-	command_helptext_add(cmd_list, help);
-}
+	static int recursion;
+	if (recursion)
+		return;
 
-/* return global variable long value or 0 upon failure */
-long jim_global_long(const char *variable)
-{
-	Jim_Obj *objPtr = Jim_GetGlobalVariableStr(interp, variable, JIM_ERRMSG);
-	long t;
-	if (Jim_GetLong(interp, objPtr, &t) == JIM_OK)
-	{
-		return t;
-	}
-	return 0;
+	recursion++;
+	Jim_ProcessEvents(cmd_ctx->interp, JIM_ALL_EVENTS | JIM_DONT_WAIT);
+	recursion--;
 }
 
 #define DEFINE_PARSE_NUM_TYPE(name, type, func, min, max) \
-	int parse##name(const char *str, type *ul) \
+	int parse ## name(const char *str, type * ul) \
 	{ \
-		if (!*str) \
-		{ \
+		if (!*str) { \
 			LOG_ERROR("Invalid command argument"); \
 			return ERROR_COMMAND_ARGUMENT_INVALID; \
 		} \
 		char *end; \
 		*ul = func(str, &end, 0); \
-		if (*end) \
-		{ \
+		if (*end) { \
 			LOG_ERROR("Invalid command argument"); \
 			return ERROR_COMMAND_ARGUMENT_INVALID; \
 		} \
-		if ((max == *ul) && (ERANGE == errno)) \
-		{ \
-			LOG_ERROR("Argument overflow"); \
-			return ERROR_COMMAND_ARGUMENT_OVERFLOW; \
+		if ((max == *ul) && (ERANGE == errno)) { \
+			LOG_ERROR("Argument overflow");	\
+			return ERROR_COMMAND_ARGUMENT_OVERFLOW;	\
 		} \
-		if (min && (min == *ul) && (ERANGE == errno)) \
-		{ \
+		if (min && (min == *ul) && (ERANGE == errno)) { \
 			LOG_ERROR("Argument underflow"); \
 			return ERROR_COMMAND_ARGUMENT_UNDERFLOW; \
 		} \
 		return ERROR_OK; \
 	}
-DEFINE_PARSE_NUM_TYPE(_ulong, unsigned long , strtoul, 0, ULONG_MAX)
+DEFINE_PARSE_NUM_TYPE(_ulong, unsigned long, strtoul, 0, ULONG_MAX)
 DEFINE_PARSE_NUM_TYPE(_ullong, unsigned long long, strtoull, 0, ULLONG_MAX)
-DEFINE_PARSE_NUM_TYPE(_long, long , strtol, LONG_MIN, LONG_MAX)
+DEFINE_PARSE_NUM_TYPE(_long, long, strtol, LONG_MIN, LONG_MAX)
 DEFINE_PARSE_NUM_TYPE(_llong, long long, strtoll, LLONG_MIN, LLONG_MAX)
 
 #define DEFINE_PARSE_WRAPPER(name, type, min, max, functype, funcname) \
-	int parse##name(const char *str, type *ul) \
+	int parse ## name(const char *str, type * ul) \
 	{ \
 		functype n; \
-		int retval = parse##funcname(str, &n); \
-		if (ERROR_OK != retval) \
+		int retval = parse ## funcname(str, &n); \
+		if (ERROR_OK != retval)	\
 			return retval; \
 		if (n > max) \
-			return ERROR_COMMAND_ARGUMENT_OVERFLOW; \
+			return ERROR_COMMAND_ARGUMENT_OVERFLOW;	\
 		if (min) \
 			return ERROR_COMMAND_ARGUMENT_UNDERFLOW; \
 		*ul = n; \
 		return ERROR_OK; \
 	}
 
-#define DEFINE_PARSE_ULONG(name, type, min, max) \
-	DEFINE_PARSE_WRAPPER(name, type, min, max, unsigned long, _ulong)
-DEFINE_PARSE_ULONG(_uint, unsigned, 0, UINT_MAX)
-DEFINE_PARSE_ULONG(_u32, uint32_t, 0, UINT32_MAX)
-DEFINE_PARSE_ULONG(_u16, uint16_t, 0, UINT16_MAX)
-DEFINE_PARSE_ULONG(_u8, uint8_t, 0, UINT8_MAX)
+#define DEFINE_PARSE_ULONGLONG(name, type, min, max) \
+	DEFINE_PARSE_WRAPPER(name, type, min, max, unsigned long long, _ullong)
+DEFINE_PARSE_ULONGLONG(_uint, unsigned, 0, UINT_MAX)
+DEFINE_PARSE_ULONGLONG(_u64,  uint64_t, 0, UINT64_MAX)
+DEFINE_PARSE_ULONGLONG(_u32,  uint32_t, 0, UINT32_MAX)
+DEFINE_PARSE_ULONGLONG(_u16,  uint16_t, 0, UINT16_MAX)
+DEFINE_PARSE_ULONGLONG(_u8,   uint8_t,  0, UINT8_MAX)
+
+DEFINE_PARSE_ULONGLONG(_target_addr, target_addr_t, 0, TARGET_ADDR_MAX)
+
+#define DEFINE_PARSE_LONGLONG(name, type, min, max) \
+	DEFINE_PARSE_WRAPPER(name, type, min, max, long long, _llong)
+DEFINE_PARSE_LONGLONG(_int, int,     n < INT_MIN,   INT_MAX)
+DEFINE_PARSE_LONGLONG(_s64, int64_t, n < INT64_MIN, INT64_MAX)
+DEFINE_PARSE_LONGLONG(_s32, int32_t, n < INT32_MIN, INT32_MAX)
+DEFINE_PARSE_LONGLONG(_s16, int16_t, n < INT16_MIN, INT16_MAX)
+DEFINE_PARSE_LONGLONG(_s8,  int8_t,  n < INT8_MIN,  INT8_MAX)
+
+static int command_parse_bool(const char *in, bool *out,
+	const char *on, const char *off)
+{
+	if (strcasecmp(in, on) == 0)
+		*out = true;
+	else if (strcasecmp(in, off) == 0)
+		*out = false;
+	else
+		return ERROR_COMMAND_SYNTAX_ERROR;
+	return ERROR_OK;
+}
+
+int command_parse_bool_arg(const char *in, bool *out)
+{
+	if (command_parse_bool(in, out, "on", "off") == ERROR_OK)
+		return ERROR_OK;
+	if (command_parse_bool(in, out, "enable", "disable") == ERROR_OK)
+		return ERROR_OK;
+	if (command_parse_bool(in, out, "true", "false") == ERROR_OK)
+		return ERROR_OK;
+	if (command_parse_bool(in, out, "yes", "no") == ERROR_OK)
+		return ERROR_OK;
+	if (command_parse_bool(in, out, "1", "0") == ERROR_OK)
+		return ERROR_OK;
+	return ERROR_COMMAND_SYNTAX_ERROR;
+}
 
-#define DEFINE_PARSE_LONG(name, type, min, max) \
-	DEFINE_PARSE_WRAPPER(name, type, min, max, long, _long)
-DEFINE_PARSE_LONG(_int, int, n < INT_MIN, INT_MAX)
-DEFINE_PARSE_LONG(_s32, int32_t, n < INT32_MIN, INT32_MAX)
-DEFINE_PARSE_LONG(_s16, int16_t, n < INT16_MIN, INT16_MAX)
-DEFINE_PARSE_LONG(_s8, int8_t, n < INT8_MIN, INT8_MAX)
+COMMAND_HELPER(handle_command_parse_bool, bool *out, const char *label)
+{
+	switch (CMD_ARGC) {
+		case 1: {
+			const char *in = CMD_ARGV[0];
+			if (command_parse_bool_arg(in, out) != ERROR_OK) {
+				LOG_ERROR("%s: argument '%s' is not valid", CMD_NAME, in);
+				return ERROR_COMMAND_SYNTAX_ERROR;
+			}
+		}
+			/* fallthrough */
+		case 0:
+			LOG_INFO("%s is %s", label, *out ? "enabled" : "disabled");
+			break;
+		default:
+			return ERROR_COMMAND_SYNTAX_ERROR;
+	}
+	return ERROR_OK;
+}