X-Git-Url: https://review.openocd.org/gitweb?p=openocd.git;a=blobdiff_plain;f=src%2Fhelper%2Fcommand.c;h=ea768b2d16bd21d34112dc08a57f7dad214599fd;hp=51b3f9f54d1c96aeaeae61e367e220a15edee283;hb=127f9da4fe0a3e2eaa86c5cd32bb45b6a7083171;hpb=2461855494cd045567c15c502ba215caffb37ce3

diff --git a/src/helper/command.c b/src/helper/command.c
index 51b3f9f54d..ea768b2d16 100644
--- a/src/helper/command.c
+++ b/src/helper/command.c
@@ -36,7 +36,7 @@
 #endif
 
 // @todo the inclusion of target.h here is a layering violation
-#include "target.h"
+#include <target/target.h>
 #include "command.h"
 #include "configuration.h"
 #include "log.h"
@@ -44,24 +44,79 @@
 #include "jim-eventloop.h"
 
 
-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)
 {
-	Jim_Obj *tclOutput = (Jim_Obj *)privData;
-	Jim_AppendString(interp, tclOutput, string, strlen(string));
+	struct log_capture_state *state = (struct log_capture_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;
+}
+
+static void command_log_capture_finish(struct log_capture_state *state)
+{
+	if (NULL == state)
+		return;
+
+	log_remove_callback(tcl_output, state);
+
+	Jim_SetResult(state->interp, state->output);
+	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 : JIM_ERR;
 }
 
 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)
 {
-	LOG_DEBUG("command - %s", name);
+	if (debug_level < LOG_LVL_DEBUG)
+		return;
+
+	char * dbg = alloc_printf("command - %s", name);
 	for (unsigned i = 0; i < argc; i++)
 	{
 		int len;
@@ -71,8 +126,12 @@ void script_debug(Jim_Interp *interp, const char *name,
 		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 void script_command_args_free(const char **words, unsigned nwords)
@@ -108,72 +167,64 @@ static const char **script_command_args_alloc(
 	return words;
 }
 
-static int script_command(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+struct command_context *current_command_context(Jim_Interp *interp)
 {
-	/* the private data is stashed in the interp structure */
-	struct command *c;
-	struct command_context *context;
-	int retval;
-
-	/* 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)
+	/* grab the command context from the associated data */
+	struct command_context *cmd_ctx = Jim_GetAssocData(interp, "context");
+	if (NULL == cmd_ctx)
 	{
-		LOG_ERROR("BUG: interp->cmdPrivData == NULL");
-		return JIM_ERR;
+		/* Tcl can invoke commands directly instead of via command_run_line(). This would
+		 * 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.
+		 */
+		cmd_ctx = global_cmd_ctx;
 	}
+	return cmd_ctx;
+}
+
+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*/
 
-	script_debug(interp, c->name, argc, argv);
-
 	unsigned nwords;
 	const char **words = script_command_args_alloc(argc, argv, &nwords);
 	if (NULL == words)
 		return JIM_ERR;
 
-	/* grab the command context from the associated data */
-	context = Jim_GetAssocData(interp, "context");
-	if (context == NULL)
-	{
-		/* Tcl can invoke commands directly instead of via command_run_line(). This would
-		 * happen when the Jim Tcl interpreter is provided by eCos.
-		 */
-		context = global_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);
+	struct log_capture_state *state = NULL;
+	if (capture)
+		state = command_log_capture_start(interp);
 
-	retval = run_command(context, c, (const char **)words, nwords);
+	struct command_context *cmd_ctx = current_command_context(interp);
+	int retval = run_command(cmd_ctx, c, (const char **)words, nwords);
 
-	log_remove_callback(tcl_output, tclOutput);
-
-	/* We dump output into this local variable */
-	Jim_SetResult(interp, tclOutput);
-	Jim_DecrRefCount(interp, tclOutput);
+	command_log_capture_finish(state);
 
 	script_command_args_free(words, nwords);
+	return command_retval_set(interp, retval);
+}
 
-	int *return_retval = Jim_GetAssocData(interp, "retval");
-	if (return_retval != NULL)
-	{
-		*return_retval = retval;
-	}
+static int script_command(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+{
+	/* the private data is stashed in the interp structure */
 
-	return (retval == ERROR_OK)?JIM_OK:JIM_ERR;
+	struct command *c = interp->cmdPrivData;
+	assert(c);
+	script_debug(interp, c->name, argc, argv);
+	return script_command_run(interp, argc, argv, c, true);
 }
 
-/* nice short description of source file */
-#define __THIS__FILE__ "command.c"
+static struct command *command_root(struct command *c)
+{
+	while (NULL != c->parent)
+		c = c->parent;
+	return c;
+}
 
 /**
  * Find a command by name from a list of commands.
@@ -189,6 +240,16 @@ static struct command *command_find(struct command *head, const char *name)
 	}
 	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 into the linked list, sorted by name.
@@ -223,27 +284,6 @@ static struct command **command_list_for_parent(
 	return parent ? &parent->children : &cmd_ctx->commands;
 }
 
-static struct command *command_new(struct command_context *cmd_ctx,
-		struct command *parent, const char *name,
-		command_handler_t handler, enum command_mode mode,
-		const char *help)
-{
-	assert(name);
-
-	struct command *c = malloc(sizeof(struct command));
-	memset(c, 0, sizeof(struct command));
-
-	c->name = strdup(name);
-	if (help)
-		c->help = strdup(help);
-	c->parent = parent;
-	c->handler = handler;
-	c->mode = mode;
-
-	command_add_child(command_list_for_parent(cmd_ctx, parent), c);
-
-	return c;
-}
 static void command_free(struct command *c)
 {
 	/// @todo if command has a handler, unregister its jim command!
@@ -259,9 +299,75 @@ static void command_free(struct command *c)
 		free(c->name);
 	if (c->help)
 		free((void*)c->help);
+	if (c->usage)
+		free((void*)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);
+
+	struct command *c = calloc(1, sizeof(struct command));
+	if (NULL == c)
+		return NULL;
+
+	c->name = strdup(cr->name);
+	if (cr->help)
+		c->help = strdup(cr->help);
+	if (cr->usage)
+		c->usage = strdup(cr->usage);
+
+	if (!c->name || (cr->help && !c->help) || (cr->usage && !c->usage))
+		goto command_new_error;
+
+	c->parent = parent;
+	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(command_list_for_parent(cmd_ctx, parent), c);
+
+	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;
+	const char *ocd_name = alloc_printf("ocd_%s", c->name);
+	if (NULL == ocd_name)
+		return JIM_ERR;
+
+	LOG_DEBUG("registering '%s'...", ocd_name);
+
+	Jim_CmdProc func = c->handler ? &script_command : &command_unknown;
+	int retval = Jim_CreateCommand(interp, ocd_name, func, c, NULL);
+	free((void *)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} {eval ocd_bouncer %s $args}",
+			c->name, c->name);
+	if (NULL == override_name)
+		return JIM_ERR;
+
+	retval = Jim_Eval_Named(interp, override_name, 0, 0);
+	free((void *)override_name);
+
+	return retval;
+}
+
 struct command* register_command(struct command_context *context,
 		struct command *parent, const struct command_registration *cr)
 {
@@ -273,50 +379,68 @@ struct command* register_command(struct command_context *context,
 	struct command *c = command_find(*head, name);
 	if (NULL != c)
 	{
-		LOG_ERROR("command '%s' is already registered in '%s' context",
+		/* 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;
 	}
 
-	c = command_new(context, parent, name, cr->handler, cr->mode, cr->help);
-	/* if allocation failed or it is a placeholder (no handler), we're done */
-	if (NULL == c || NULL == c->handler)
-		return c;
-
-	const char *full_name = command_name(c, '_');
-
-	const char *ocd_name = alloc_printf("ocd_%s", full_name);
-	Jim_CreateCommand(interp, ocd_name, script_command, c, NULL);
-	free((void *)ocd_name);
-
-	/* 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);
+	c = command_new(context, parent, cr);
+	if (NULL == c)
+		return NULL;
 
-	free((void *)full_name);
+	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));
 
+	if (ERROR_OK != retval)
+	{
+		unregister_command(context, parent, name);
+		c = NULL;
+	}
 	return c;
 }
 
 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; i++)
+	for (i = 0; cmds[i].name || cmds[i].chain; i++)
 	{
-		struct command *c = register_command(cmd_ctx, parent, cmds + i);
-		if (NULL != c)
-			continue;
+		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 ERROR_FAIL;
 	}
-	return ERROR_OK;
+	return retval;
 }
 
 int unregister_all_commands(struct command_context *context,
@@ -361,6 +485,14 @@ int unregister_command(struct command_context *context,
 	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) {
@@ -439,18 +571,32 @@ 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)
 {
-	if (!((context->mode == COMMAND_CONFIG) || (c->mode == COMMAND_ANY) || (c->mode == context->mode)))
+	if (!command_can_run(context, c))
 	{
-		/* Config commands can not run after the config stage */
-		LOG_ERROR("Command '%s' only runs during configuration stage", c->name);
+		/* 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,
+			.current = c,
 			.name = c->name,
 			.argc = num_words - 1,
 			.argv = words + 1,
@@ -461,7 +607,7 @@ static int run_command(struct command_context *context,
 		/* 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;
@@ -495,6 +641,7 @@ int command_run_line(struct command_context *context, char *line)
 	 * happen when the Jim Tcl interpreter is provided by eCos for
 	 * instance.
 	 */
+	Jim_Interp *interp = context->interp;
 	Jim_DeleteAssocData(interp, "context");
 	retcode = Jim_SetAssocData(interp, "context", NULL, context);
 	if (retcode == JIM_OK)
@@ -504,7 +651,7 @@ int command_run_line(struct command_context *context, char *line)
 		retcode = Jim_SetAssocData(interp, "retval", NULL, &retval);
 		if (retcode == JIM_OK)
 		{
-			retcode = Jim_Eval_Named(interp, line, __THIS__FILE__, __LINE__);
+			retcode = Jim_Eval_Named(interp, line, 0, 0);
 
 			Jim_DeleteAssocData(interp, "retval");
 		}
@@ -582,12 +729,12 @@ struct command_context* copy_command_context(struct command_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 */
@@ -702,23 +849,13 @@ static int jim_capture(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 {
 	if (argc != 2)
 		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);
-
-	log_add_callback(tcl_output, tclOutput);
 
-	retcode = Jim_Eval_Named(interp, str, __THIS__FILE__, __LINE__);
+	struct log_capture_state *state = command_log_capture_start(interp);
 
-	log_remove_callback(tcl_output, tclOutput);
+	const char *str = Jim_GetString(argv[1], NULL);
+	int retcode = Jim_Eval_Named(interp, str, __THIS__FILE__, __LINE__);
 
-	/* We dump output into this local variable */
-	Jim_SetResult(interp, tclOutput);
-	Jim_DecrRefCount(interp, tclOutput);
+	command_log_capture_finish(state);
 
 	return retcode;
 }
@@ -729,6 +866,8 @@ static COMMAND_HELPER(command_help_find, struct command *head,
 	if (0 == CMD_ARGC)
 		return ERROR_INVALID_ARGUMENTS;
 	*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_INVALID_ARGUMENTS;
 	if (--CMD_ARGC == 0)
@@ -737,41 +876,287 @@ static COMMAND_HELPER(command_help_find, struct command *head,
 	return CALL_COMMAND_HANDLER(command_help_find, (*out)->children, out);
 }
 
-static COMMAND_HELPER(command_help_show, struct command *c, unsigned n);
+static COMMAND_HELPER(command_help_show, struct command *c, unsigned n,
+		bool show_help, const char *match);
 
-static COMMAND_HELPER(command_help_show_list, struct command *head, unsigned n)
+static COMMAND_HELPER(command_help_show_list, struct command *head, unsigned n,
+		bool show_help, const char *match)
 {
 	for (struct command *c = head; NULL != c; c = c->next)
-		CALL_COMMAND_HANDLER(command_help_show, c, n);
+		CALL_COMMAND_HANDLER(command_help_show, c, n, show_help, match);
 	return ERROR_OK;
 }
-static COMMAND_HELPER(command_help_show, struct command *c, unsigned n)
+
+#define HELP_LINE_WIDTH(_n) (int)(76 - (2 * _n))
+
+static void command_help_show_indent(unsigned n)
 {
-	command_run_linef(CMD_CTX, "cmd_help {%s} {%s} %d", command_name(c, ' '),
-			c->help ? : "no help available", 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_N("%.*s", (int)(cp - last), last);
+		LOG_USER_N("\n");
+		last = cp + 1;
+		n = n2;
+	}
+}
+static COMMAND_HELPER(command_help_show, struct command *c, unsigned n,
+		bool show_help, const char *match)
+{
+	if (!command_can_run(CMD_CTX, c))
+		return ERROR_OK;
+
+	char *cmd_name = command_name(c, ' ');
+	if (NULL == cmd_name)
+		return -ENOMEM;
+
+	/* If the match string occurs anywhere, we print out
+	 * stuff for this command. */
+	bool is_match = (strstr(cmd_name, match) != NULL) ||
+	((c->usage != NULL) && (strstr(c->usage, match) != NULL)) ||
+	((c->help != NULL) && (strstr(c->help, match) != NULL));
+
+	if (is_match)
+	{
+		command_help_show_indent(n);
+		LOG_USER_N("%s", cmd_name);
+	}
+	free(cmd_name);
+
+	if (is_match)
+	{
+		if (c->usage) {
+			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 >= 2)
 		return ERROR_OK;
 
-	return CALL_COMMAND_HANDLER(command_help_show_list, c->children, n);
+	return CALL_COMMAND_HANDLER(command_help_show_list,
+			c->children, n, show_help, match);
 }
 COMMAND_HANDLER(handle_help_command)
 {
+	bool full = strcmp(CMD_NAME, "help") == 0;
+	int retval;
 	struct command *c = CMD_CTX->commands;
+	char *match = NULL;
+
+	if (CMD_ARGC == 0)
+		match = "";
+	else if (CMD_ARGC >= 1) {
+		unsigned i;
+
+		for (i = 0; i < CMD_ARGC; ++i) {
+			if (NULL != match) {
+				char *prev = match;
+
+				match = alloc_printf("%s %s", match,
+						CMD_ARGV[i]);
+				free(prev);
+				if (NULL == match) {
+					LOG_ERROR("unable to build "
+							"search string");
+					return -ENOMEM;
+				}
+			} else {
+				match = alloc_printf("%s", CMD_ARGV[i]);
+				if (NULL == match) {
+					LOG_ERROR("unable to build "
+							"search string");
+					return -ENOMEM;
+				}
+			}
+		}
+	} else
+		return ERROR_COMMAND_SYNTAX_ERROR;
 
-	if (0 == CMD_ARGC)
-		return CALL_COMMAND_HANDLER(command_help_show_list, c, 0);
+	retval = CALL_COMMAND_HANDLER(command_help_show_list,
+			c, 0, full, match);
 
-	int retval = CALL_COMMAND_HANDLER(command_help_find, c, &c);
-	if (ERROR_OK != retval)
-		return retval;
+	if (CMD_ARGC >= 1)
+		free(match);
+	return retval;
+}
 
-	return CALL_COMMAND_HANDLER(command_help_show, c, 0);
+static int command_unknown_find(unsigned argc, Jim_Obj *const *argv,
+		struct command *head, struct command **out, bool top_level)
+{
+	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);
 }
 
 
+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;
+	}
+
+	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 script_command_run(interp, count, start, c, found);
+}
+
+static int jim_command_mode(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+{
+	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_command_type(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+{
+	if (1 == argc)
+		return JIM_ERR;
+
+	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;
+	}
+
+	if (c->jim_handler)
+		Jim_SetResultString(interp, "native", -1);
+	else if (c->handler)
+		Jim_SetResultString(interp, "simple", -1);
+	else
+		Jim_SetResultString(interp, "group", -1);
+
+	return JIM_OK;
+}
+
 int help_add_command(struct command_context *cmd_ctx, struct command *parent,
-		const char *cmd_name, const char *help_text)
+		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);
@@ -782,6 +1167,7 @@ int help_add_command(struct command_context *cmd_ctx, struct command *parent,
 				.name = cmd_name,
 				.mode = COMMAND_ANY,
 				.help = help_text,
+				.usage = usage,
 			};
 		nc = register_command(cmd_ctx, parent, &cr);
 		if (NULL == nc)
@@ -790,8 +1176,9 @@ int help_add_command(struct command_context *cmd_ctx, struct command *parent,
 			return ERROR_FAIL;
 		}
 		LOG_DEBUG("added '%s' help text", cmd_name);
+		return ERROR_OK;
 	}
-	else
+	if (help_text)
 	{
 		bool replaced = false;
 		if (nc->help)
@@ -800,12 +1187,25 @@ int help_add_command(struct command_context *cmd_ctx, struct command *parent,
 			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((void *)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;
 }
 
@@ -818,7 +1218,14 @@ COMMAND_HANDLER(handle_help_add_command)
 	}
 
 	// save help text and remove it from argument list
-	const char *help_text = CMD_ARGV[--CMD_ARGC];
+	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_INVALID_ARGUMENTS;
+	}
 	// likewise for the leaf command name
 	const char *cmd_name = CMD_ARGV[--CMD_ARGC];
 
@@ -830,10 +1237,10 @@ COMMAND_HANDLER(handle_help_add_command)
 		if (ERROR_OK != retval)
 			return retval;
 	}
-	return help_add_command(CMD_CTX, c, cmd_name, help_text);
+	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)
@@ -869,7 +1276,81 @@ COMMAND_HANDLER(handle_sleep_command)
 	return ERROR_OK;
 }
 
-struct command_context* command_init(const char *startup_tcl)
+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 = "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));
 	const char *HostOs;
@@ -881,13 +1362,19 @@ struct command_context* command_init(const char *startup_tcl)
 	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);
+	/* Create a jim interpreter if we were not handed one */
+	if (interp == NULL)
+	{
+		Jim_InitEmbedded();
+		/* Create an interpreter */
+		interp = Jim_CreateInterp();
+		/* Add all the Jim core commands */
+		Jim_RegisterCoreCommands(interp);
+	}
 #endif
+	context->interp = interp;
 
+	/* Stick to lowercase for HostOS strings. */
 #if defined(_MSC_VER)
 	/* WinXX - is generic, the forward
 	 * looking problem is this:
@@ -899,7 +1386,7 @@ struct command_context* command_init(const char *startup_tcl)
 	HostOs = "winxx";
 #elif defined(__linux__)
 	HostOs = "linux";
-#elif defined(__DARWIN__)
+#elif defined(__APPLE__) || defined(__DARWIN__)
 	HostOs = "darwin";
 #elif defined(__CYGWIN__)
 	HostOs = "cygwin";
@@ -907,8 +1394,10 @@ struct command_context* command_init(const char *startup_tcl)
 	HostOs = "mingw32";
 #elif defined(__ECOS)
 	HostOs = "ecos";
+#elif defined(__FreeBSD__)
+	HostOs = "freebsd";
 #else
-#warn unrecognized host OS...
+#warning "Unrecognized host OS..."
 	HostOs = "other";
 #endif
 	Jim_SetGlobalVariableStr(interp, "ocd_HOSTOS",
@@ -928,10 +1417,7 @@ struct command_context* command_init(const char *startup_tcl)
 	interp->cb_fflush = openocd_jim_fflush;
 	interp->cb_fgets = openocd_jim_fgets;
 
-	COMMAND_REGISTER(context, NULL, "add_help_text",
-			handle_help_add_command, COMMAND_ANY,
-			"<command> [...] <help_text>] - "
-			"add new command help text");
+	register_commands(context, NULL, command_builtin_handlers);
 
 #if !BUILD_ECOSBOARD
 	Jim_EventLoopOnLoad(interp);
@@ -945,15 +1431,6 @@ struct command_context* command_init(const char *startup_tcl)
 	}
 	Jim_DeleteAssocData(interp, "context");
 
-	COMMAND_REGISTER(context, NULL, "sleep",
-			handle_sleep_command, COMMAND_ANY,
-			"<n> [busy] - sleep for n milliseconds. "
-			"\"busy\" means busy wait");
-
-	COMMAND_REGISTER(context, NULL, "help",
-			&handle_help_command, COMMAND_ANY,
-			"[<command_name> ...] - show built-in command help");
-
 	return context;
 }
 
@@ -966,32 +1443,19 @@ int command_context_mode(struct command_context *cmd_ctx, enum command_mode mode
 	return ERROR_OK;
 }
 
-void process_jim_events(void)
+void process_jim_events(struct command_context *cmd_ctx)
 {
 #if !BUILD_ECOSBOARD
 	static int recursion = 0;
+	if (recursion)
+		return;
 
-	if (!recursion)
-	{
-		recursion++;
-		Jim_ProcessEvents (interp, JIM_ALL_EVENTS | JIM_DONT_WAIT);
-		recursion--;
-	}
+	recursion++;
+	Jim_ProcessEvents(cmd_ctx->interp, JIM_ALL_EVENTS | JIM_DONT_WAIT);
+	recursion--;
 #endif
 }
 
-void register_jim(struct command_context *cmd_ctx, const char *name,
-		Jim_CmdProc cmd, const char *help)
-{
-	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));
-
-	help_add_command(cmd_ctx, NULL, name, help);
-}
-
 #define DEFINE_PARSE_NUM_TYPE(name, type, func, min, max) \
 	int parse##name(const char *str, type *ul) \
 	{ \