X-Git-Url: https://review.openocd.org/gitweb?p=openocd.git;a=blobdiff_plain;f=src%2Fhelper%2Fcommand.c;h=3cb36ea27590850c4f18131f10d265604b6af7d4;hp=640568436e30de2a10df9971d284735864677915;hb=17a9dea53a71e9d7e241262725f3dd707b620d37;hpb=50c086ffb94f199c088f4cc52b7887b668dddf00

diff --git a/src/helper/command.c b/src/helper/command.c
index 640568436e..3cb36ea275 100644
--- a/src/helper/command.c
+++ b/src/helper/command.c
@@ -2,7 +2,7 @@
  *   Copyright (C) 2005 by Dominic Rath                                    *
  *   Dominic.Rath@gmx.de                                                   *
  *                                                                         *
- *   Copyright (C) 2007,2008 Øyvind Harboe                                 *
+ *   Copyright (C) 2007,2008 Øyvind Harboe                                 *
  *   oyvind.harboe@zylin.com                                               *
  *                                                                         *
  *   Copyright (C) 2008, Duane Ellis                                       *
@@ -44,29 +44,26 @@
 #include "jim-eventloop.h"
 
 
-int fast_and_dangerous = 0;
 Jim_Interp *interp = NULL;
 
-int handle_sleep_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
-int handle_fast_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
+static int run_command(struct command_context *context,
+		struct command *c, const char *words[], unsigned num_words);
 
-int run_command(command_context_t *context, command_t *c, char *words[], int num_words);
-
-static void tcl_output(void *privData, const char *file, int line, const char *function, const char *string)
+static void tcl_output(void *privData, const char *file, unsigned line,
+		const char *function, const char *string)
 {
-	Jim_Obj *tclOutput=(Jim_Obj *)privData;
-
+	Jim_Obj *tclOutput = (Jim_Obj *)privData;
 	Jim_AppendString(interp, tclOutput, string, strlen(string));
 }
 
-extern command_context_t *global_cmd_ctx;
+extern struct command_context *global_cmd_ctx;
 
-void script_debug(Jim_Interp *interp, const char *name, int argc, Jim_Obj *const *argv)
+void script_debug(Jim_Interp *interp, const char *name,
+		unsigned argc, Jim_Obj *const *argv)
 {
-	int i;
-
 	LOG_DEBUG("command - %s", name);
-	for (i = 0; i < argc; i++) {
+	for (unsigned i = 0; i < argc; i++)
+	{
 		int len;
 		const char *w = Jim_GetString(argv[i], &len);
 
@@ -78,15 +75,58 @@ void script_debug(Jim_Interp *interp, const char *name, int argc, Jim_Obj *const
 	}
 }
 
+static void script_command_args_free(const char **words, unsigned nwords)
+{
+	for (unsigned i = 0; i < nwords; i++)
+		free((void *)words[i]);
+	free(words);
+}
+static const char **script_command_args_alloc(
+		unsigned argc, Jim_Obj *const *argv, unsigned *nwords)
+{
+	const char **words = malloc(argc * sizeof(char *));
+	if (NULL == words)
+		return NULL;
+
+	unsigned i;
+	for (i = 0; i < argc; i++)
+	{
+		int len;
+		const char *w = Jim_GetString(argv[i], &len);
+		/* a comment may end the line early */
+		if (*w == '#')
+			break;
+
+		words[i] = strdup(w);
+		if (words[i] == NULL)
+		{
+			script_command_args_free(words, i);
+			return NULL;
+		}
+	}
+	*nwords = i;
+	return words;
+}
+
+static struct command_context *current_command_context(void)
+{
+	/* grab the command context from the associated data */
+	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.
+		 */
+		cmd_ctx = global_cmd_ctx;
+	}
+	return cmd_ctx;
+}
+
 static int script_command(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 {
 	/* the private data is stashed in the interp structure */
-	command_t *c;
-	command_context_t *context;
+	struct command *c;
 	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
@@ -94,9 +134,9 @@ static int script_command(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 	 * to the fn and fish it out manually.
 	 */
 	c = interp->cmdPrivData;
-	if (c==NULL)
+	if (c == NULL)
 	{
-		LOG_ERROR("BUG: interp->cmdPrivData==NULL");
+		LOG_ERROR("BUG: interp->cmdPrivData == NULL");
 		return JIM_ERR;
 	}
 	target_call_timer_callbacks_now();
@@ -104,33 +144,10 @@ static int script_command(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 
 	script_debug(interp, c->name, argc, argv);
 
-	words = malloc(sizeof(char *) * argc);
-	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)
-		{
-			return JIM_ERR;
-		}
-	}
-	nwords = i;
-
-	/* 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;
-	}
+	unsigned nwords;
+	const char **words = script_command_args_alloc(argc, argv, &nwords);
+	if (NULL == words)
+		return JIM_ERR;
 
 	/* capture log output and return it */
 	Jim_Obj *tclOutput = Jim_NewStringObj(interp, "", 0);
@@ -139,7 +156,8 @@ static int script_command(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 
 	log_add_callback(tcl_output, tclOutput);
 
-	retval = run_command(context, c, words, nwords);
+	struct command_context *cmd_ctx = current_command_context();
+	retval = run_command(cmd_ctx, c, (const char **)words, nwords);
 
 	log_remove_callback(tcl_output, tclOutput);
 
@@ -147,9 +165,7 @@ static int script_command(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 	Jim_SetResult(interp, tclOutput);
 	Jim_DecrRefCount(interp, tclOutput);
 
-	for (i = 0; i < nwords; i++)
-		free(words[i]);
-	free(words);
+	script_command_args_free(words, nwords);
 
 	int *return_retval = Jim_GetAssocData(interp, "retval");
 	if (return_retval != NULL)
@@ -157,203 +173,266 @@ static int script_command(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 		*return_retval = retval;
 	}
 
-	return (retval==ERROR_OK)?JIM_OK:JIM_ERR;
+	return (retval == ERROR_OK)?JIM_OK:JIM_ERR;
 }
 
 /* nice short description of source file */
 #define __THIS__FILE__ "command.c"
 
-command_t* register_command(command_context_t *context, command_t *parent, char *name, int (*handler)(struct command_context_s *context, char* name, char** args, int argc), enum command_mode mode, char *help)
+/**
+ * Find a command by name from a list of commands.
+ * @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)
 {
-	command_t *c, *p;
+	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);
+}
 
-	if (!context || !name)
-		return NULL;
+/**
+ * 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)
+	{
+		*head = c;
+		return;
+	}
 
-	c = malloc(sizeof(command_t));
+	while ((*head)->next && (strcmp(c->name, (*head)->name) > 0))
+		head = &(*head)->next;
 
-	c->name = strdup(name);
+	if (strcmp(c->name, (*head)->name) > 0) {
+		c->next = (*head)->next;
+		(*head)->next = c;
+	} else {
+		c->next = *head;
+		*head = c;
+	}
+}
+
+static struct command **command_list_for_parent(
+		struct command_context *cmd_ctx, struct command *parent)
+{
+	return parent ? &parent->children : &cmd_ctx->commands;
+}
+
+static struct command *command_new(struct command_context *cmd_ctx,
+		struct command *parent, const struct command_registration *cr)
+{
+	assert(cr->name);
+
+	struct command *c = malloc(sizeof(struct command));
+	memset(c, 0, sizeof(struct command));
+
+	c->name = strdup(cr->name);
+	if (cr->help)
+		c->help = strdup(cr->help);
+	if (cr->usage)
+		c->usage = strdup(cr->usage);
 	c->parent = parent;
-	c->children = NULL;
-	c->handler = handler;
-	c->mode = mode;
-	if (!help)
-		help="";
-	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;
 
-	/* place command in tree */
-	if (parent)
-	{
-		if (parent->children)
-		{
-			/* find last child */
-			for (p = parent->children; p && p->next; p = p->next);
-			if (p)
-				p->next = c;
-		}
-		else
-		{
-			parent->children = c;
-		}
-	}
-	else
+	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!
+
+	while (NULL != c->children)
 	{
-		if (context->commands)
-		{
-			/* find last command */
-			for (p = context->commands; p && p->next; p = p->next);
-			if (p)
-				p->next = c;
-		}
-		else
-		{
-			context->commands = c;
-		}
+		struct command *tmp = c->children;
+		c->children = tmp->next;
+		command_free(tmp);
 	}
 
-	/* just a placeholder, no handler */
-	if (c->handler==NULL)
-		return c;
+	if (c->name)
+		free(c->name);
+	if (c->help)
+		free((void*)c->help);
+	if (c->usage)
+		free((void*)c->usage);
+	free(c);
+}
 
-	/* If this is a two level command, e.g. "flash banks", then the
-	 * "unknown" proc in startup.tcl must redirect to  this command.
-	 *
-	 * "flash banks" is translated by "unknown" to "flash_banks"
-	 * if such a proc exists
-	 */
-	/* Print help for command */
-	const char *t1="";
-	const char *t2="";
-	const char *t3="";
-	/* maximum of two levels :-) */
-	if (c->parent!=NULL)
-	{
-		t1=c->parent->name;
-		t2="_";
-	}
-	t3=c->name;
-	const char *full_name=alloc_printf("ocd_%s%s%s", t1, t2, t3);
-	Jim_CreateCommand(interp, full_name, script_command, c, NULL);
-	free((void *)full_name);
+static int register_command_handler(struct command *c)
+{
+	int retval = -ENOMEM;
+	const char *full_name = command_name(c, '_');
+	if (NULL == full_name)
+		return retval;
+
+	const char *ocd_name = alloc_printf("ocd_%s", full_name);
+	if (NULL == full_name)
+		goto free_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%s%s {args} {if {[catch {eval ocd_%s%s%s $args}]==0} {return \"\"} else { return -code error }", t1, t2, t3, t1, t2, t3);
-	Jim_Eval_Named(interp, override_name, __THIS__FILE__, __LINE__ );
+	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);
+	if (NULL == full_name)
+		goto free_full_name;
+
+	Jim_Eval_Named(interp, override_name, __THIS__FILE__, __LINE__);
 	free((void *)override_name);
 
-	/* 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_Obj *cmd_entry=Jim_NewListObj(interp, NULL, 0);
+	retval = ERROR_OK;
 
-	Jim_Obj *cmd_list=Jim_NewListObj(interp, NULL, 0);
+free_full_name:
+	free((void *)full_name);
+	return retval;
+}
 
-	/* maximum of two levels :-) */
-	if (c->parent!=NULL)
+struct command* register_command(struct command_context *context,
+		struct command *parent, const struct command_registration *cr)
+{
+	if (!context || !cr->name)
+		return NULL;
+
+	const char *name = cr->name;
+	struct command **head = command_list_for_parent(context, parent);
+	struct command *c = command_find(*head, name);
+	if (NULL != c)
 	{
-		Jim_ListAppendElement(interp, cmd_list, Jim_NewStringObj(interp, c->parent->name, -1));
+		LOG_ERROR("command '%s' is already registered in '%s' context",
+				name, parent ? parent->name : "<global>");
+		return c;
 	}
-	Jim_ListAppendElement(interp, cmd_list, Jim_NewStringObj(interp, c->name, -1));
 
-	Jim_ListAppendElement(interp, cmd_entry, cmd_list);
-	Jim_ListAppendElement(interp, cmd_entry, Jim_NewStringObj(interp, help, -1));
-	Jim_ListAppendElement(interp, helptext, cmd_entry);
+	c = command_new(context, parent, cr);
+	if (NULL == c)
+		return NULL;
+
+	if (NULL != c->handler)
+	{
+		int retval = register_command_handler(c);
+		if (ERROR_OK != retval)
+		{
+			unregister_command(context, parent, name);
+			return NULL;
+		}
+	}
+
+	if (NULL != cr->jim_handler && NULL == parent)
+		Jim_CreateCommand(interp, cr->name, cr->jim_handler, cr->jim_handler_data, NULL);
+
 	return c;
 }
 
-int unregister_all_commands(command_context_t *context)
+int register_commands(struct command_context *cmd_ctx, struct command *parent,
+		const struct command_registration *cmds)
 {
-	command_t *c, *c2;
-
-	if (context == NULL)
-		return ERROR_OK;
-
-	while (NULL != context->commands)
+	int retval = ERROR_OK;
+	unsigned i;
+	for (i = 0; cmds[i].name || cmds[i].chain; i++)
 	{
-		c = context->commands;
+		const struct command_registration *cr = cmds + i;
 
-		while (NULL != c->children)
+		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)
 		{
-			c2 = c->children;
-			c->children = c->children->next;
-			free(c2->name);
-			c2->name = NULL;
-			free(c2);
-			c2 = NULL;
+			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;
+}
 
-		context->commands = context->commands->next;
+int unregister_all_commands(struct command_context *context,
+		struct command *parent)
+{
+	if (context == NULL)
+		return ERROR_OK;
 
-		free(c->name);
-		c->name = NULL;
-		free(c);
-		c = NULL;
+	struct command **head = command_list_for_parent(context, parent);
+	while (NULL != *head)
+	{
+		struct command *tmp = *head;
+		*head = tmp->next;
+		command_free(tmp);
 	}
 
 	return ERROR_OK;
 }
 
-int unregister_command(command_context_t *context, char *name)
+int unregister_command(struct command_context *context,
+		struct command *parent, const char *name)
 {
-	command_t *c, *p = NULL, *c2;
-
 	if ((!context) || (!name))
 		return ERROR_INVALID_ARGUMENTS;
 
-	/* find command */
-	c = context->commands;
-
-	while (NULL != c)
+	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)
-		{
-			/* unlink command */
-			if (p)
-			{
-				p->next = c->next;
-			}
-			else
-			{
-				/* first element in command list */
-				context->commands = c->next;
-			}
+		if (strcmp(name, c->name) != 0)
+			continue;
 
-			/* unregister children */
-			while (NULL != c->children)
-			{
-				c2 = c->children;
-				c->children = c->children->next;
-				free(c2->name);
-				c2->name = NULL;
-				free(c2);
-				c2 = NULL;
-			}
-
-			/* 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_output_text(command_context_t *context, const char *data)
+void command_output_text(struct command_context *context, const char *data)
 {
-	if ( context && context->output_handler && data  ){
-		context->output_handler( context, data );
+	if (context && context->output_handler && data) {
+		context->output_handler(context, data);
 	}
 }
 
-void command_print_sameline(command_context_t *context, const char *format, ...)
+void command_print_sameline(struct command_context *context, const char *format, ...)
 {
 	char *string;
 
@@ -377,7 +456,7 @@ void command_print_sameline(command_context_t *context, const char *format, ...)
 	va_end(ap);
 }
 
-void command_print(command_context_t *context, const char *format, ...)
+void command_print(struct command_context *context, const char *format, ...)
 {
 	char *string;
 
@@ -402,31 +481,54 @@ void command_print(command_context_t *context, const char *format, ...)
 	va_end(ap);
 }
 
-int run_command(command_context_t *context, command_t *c, char *words[], int num_words)
+static char *__command_name(struct command *c, char delim, unsigned extra)
 {
-	int start_word=0;
-	if (!((context->mode == COMMAND_CONFIG) || (c->mode == COMMAND_ANY) || (c->mode == context->mode) ))
+	char *name;
+	unsigned len = strlen(c->name);
+	if (NULL == c->parent) {
+		// allocate enough for the name, child names, and '\0'
+		name = malloc(len + extra + 1);
+		strcpy(name, c->name);
+	} else {
+		// 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);
+		strcat(name, c->name);
+	}
+	return name;
+}
+char *command_name(struct command *c, char delim)
+{
+	return __command_name(c, delim, 0);
+}
+
+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)))
 	{
 		/* Config commands can not run after the config stage */
 		LOG_ERROR("Command '%s' only runs during configuration stage", c->name);
 		return ERROR_FAIL;
 	}
 
-	int retval = c->handler(context, c->name, words + start_word + 1, num_words - start_word - 1);
+	struct command_invocation cmd = {
+			.ctx = context,
+			.name = c->name,
+			.argc = num_words - 1,
+			.argv = words + 1,
+		};
+	int retval = c->handler(&cmd);
 	if (retval == ERROR_COMMAND_SYNTAX_ERROR)
 	{
 		/* Print help for command */
-		const char *t1="";
-		const char *t2="";
-		const char *t3="";
-		/* maximum of two levels :-) */
-		if (c->parent!=NULL)
-		{
-			t1=c->parent->name;
-			t2=" ";
-		}
-		t3=c->name;
-		command_run_linef(context, "help {%s%s%s}", t1, t2, t3);
+		char *full_name = command_name(c, ' ');
+		if (NULL != full_name) {
+			command_run_linef(context, "help %s", full_name);
+			free(full_name);
+		} else
+			retval = -ENOMEM;
 	}
 	else if (retval == ERROR_COMMAND_CLOSE_CONNECTION)
 	{
@@ -443,14 +545,14 @@ int run_command(command_context_t *context, command_t *c, char *words[], int num
 	return retval;
 }
 
-int command_run_line(command_context_t *context, char *line)
+int command_run_line(struct command_context *context, char *line)
 {
 	/* all the parent commands have been registered with the interpreter
 	 * so, can just evaluate the line as a script and check for
 	 * results
 	 */
 	/* run the line thru a script engine */
-	int retval=ERROR_FAIL;
+	int retval = ERROR_FAIL;
 	int retcode;
 	/* Beware! This code needs to be reentrant. It is also possible
 	 * for OpenOCD commands to be invoked directly from Tcl. This would
@@ -466,19 +568,19 @@ int command_run_line(command_context_t *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, __THIS__FILE__, __LINE__);
 
 			Jim_DeleteAssocData(interp, "retval");
 		}
 		Jim_DeleteAssocData(interp, "context");
 	}
 	if (retcode == JIM_ERR) {
-		if (retval!=ERROR_COMMAND_CLOSE_CONNECTION)
+		if (retval != ERROR_COMMAND_CLOSE_CONNECTION)
 		{
 			/* We do not print the connection closed error message */
 			Jim_PrintErrorMessage(interp);
 		}
-		if (retval==ERROR_OK)
+		if (retval == ERROR_OK)
 		{
 			/* It wasn't a low level OpenOCD command that failed */
 			return ERROR_FAIL;
@@ -492,58 +594,59 @@ int command_run_line(command_context_t *context, char *line)
 		int reslen;
 
 		result = Jim_GetString(Jim_GetResult(interp), &reslen);
-		if (reslen>0)
+		if (reslen > 0)
 		{
 			int i;
-			char buff[256+1];
+			char buff[256 + 1];
 			for (i = 0; i < reslen; i += 256)
 			{
 				int chunk;
 				chunk = reslen - i;
 				if (chunk > 256)
 					chunk = 256;
-				strncpy(buff, result+i, chunk);
+				strncpy(buff, result + i, chunk);
 				buff[chunk] = 0;
 				LOG_USER_N("%s", buff);
 			}
 			LOG_USER_N("%s", "\n");
 		}
-		retval=ERROR_OK;
+		retval = ERROR_OK;
 	}
 	return retval;
 }
 
-int command_run_linef(command_context_t *context, const char *format, ...)
+int command_run_linef(struct command_context *context, const char *format, ...)
 {
-	int retval=ERROR_FAIL;
+	int retval = ERROR_FAIL;
 	char *string;
 	va_list ap;
 	va_start(ap, format);
 	string = alloc_vprintf(format, ap);
-	if (string!=NULL)
+	if (string != NULL)
 	{
-		retval=command_run_line(context, string);
+		retval = command_run_line(context, string);
 	}
 	va_end(ap);
 	return retval;
 }
 
-void command_set_output_handler(command_context_t* context, int (*output_handler)(struct command_context_s *context, const char* line), 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;
 }
 
-command_context_t* copy_command_context(command_context_t* context)
+struct command_context* copy_command_context(struct command_context* context)
 {
-	command_context_t* copy_context = malloc(sizeof(command_context_t));
+	struct command_context* copy_context = malloc(sizeof(struct command_context));
 
 	*copy_context = *context;
 
 	return copy_context;
 }
 
-int command_done(command_context_t *context)
+int command_done(struct command_context *context)
 {
 	free(context);
 	context = NULL;
@@ -599,7 +702,7 @@ static size_t openocd_jim_fwrite(const void *_ptr, size_t size, size_t n, void *
 	}
 	/* GRR we must chunk - not null terminated */
 	while (nbytes) {
-		char chunk[128+1];
+		char chunk[128 + 1];
 		int x;
 
 		x = nbytes;
@@ -673,7 +776,7 @@ static int jim_capture(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 
 	log_add_callback(tcl_output, tclOutput);
 
-	retcode = Jim_Eval_Named(interp, str, __THIS__FILE__, __LINE__ );
+	retcode = Jim_Eval_Named(interp, str, __THIS__FILE__, __LINE__);
 
 	log_remove_callback(tcl_output, tclOutput);
 
@@ -684,10 +787,285 @@ static int jim_capture(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 	return retcode;
 }
 
-command_context_t* command_init()
+static COMMAND_HELPER(command_help_find, struct command *head,
+		struct command **out)
+{
+	if (0 == CMD_ARGC)
+		return ERROR_INVALID_ARGUMENTS;
+	*out = command_find(head, CMD_ARGV[0]);
+	if (NULL == *out)
+		return ERROR_INVALID_ARGUMENTS;
+	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);
+
+static COMMAND_HELPER(command_help_show_list, struct command *head, unsigned n,
+		bool show_help)
+{
+	for (struct command *c = head; NULL != c; c = c->next)
+		CALL_COMMAND_HANDLER(command_help_show, c, n, show_help);
+	return ERROR_OK;
+}
+static COMMAND_HELPER(command_help_show, struct command *c, unsigned n,
+		bool show_help)
+{
+	const char *usage = c->usage ? : "";
+	const char *help = "";
+	const char *sep = "";
+	if (show_help && c->help)
+	{
+		help = c->help ? : "";
+		sep = c->usage ? " | " : "";
+	}
+	command_run_linef(CMD_CTX, "cmd_help {%s} {%s%s%s} %d",
+			command_name(c, ' '), usage, sep, help, n);
+
+	if (++n >= 2)
+		return ERROR_OK;
+
+	return CALL_COMMAND_HANDLER(command_help_show_list,
+			c->children, n, show_help);
+}
+COMMAND_HANDLER(handle_help_command)
 {
-	command_context_t* context = malloc(sizeof(command_context_t));
-	extern const char startup_tcl[];
+	struct command *c = CMD_CTX->commands;
+
+	if (0 == CMD_ARGC)
+		return CALL_COMMAND_HANDLER(command_help_show_list, c, 0, true);
+
+	int retval = CALL_COMMAND_HANDLER(command_help_find, c, &c);
+	if (ERROR_OK != retval)
+		return retval;
+
+	return CALL_COMMAND_HANDLER(command_help_show, c, 0, true);
+}
+
+COMMAND_HANDLER(handle_usage_command)
+{
+	struct command *c = CMD_CTX->commands;
+
+	if (0 == CMD_ARGC)
+		return CALL_COMMAND_HANDLER(command_help_show_list, c, 0, false);
+
+	int retval = CALL_COMMAND_HANDLER(command_help_find, c, &c);
+	if (ERROR_OK != retval)
+		return retval;
+
+	return CALL_COMMAND_HANDLER(command_help_show, c, 0, false);
+}
+
+static int command_unknown_find(unsigned argc, Jim_Obj *const *argv,
+		struct command *head, struct command **out)
+{
+	if (0 == argc)
+		return argc;
+	struct command *c = command_find(head, Jim_GetString(argv[0], NULL));
+	if (NULL == c)
+		return argc;
+	*out = c;
+	return command_unknown_find(--argc, ++argv, (*out)->children, out);
+}
+
+static int command_unknown(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+{
+	const char *cmd_name = Jim_GetString(argv[0], NULL);
+	script_debug(interp, cmd_name, argc - 1, argv + 1);
+
+	struct command_context *cmd_ctx = current_command_context();
+	struct command *c = cmd_ctx->commands;
+	int remaining = command_unknown_find(argc - 1, argv + 1, c, &c);
+	// if nothing could be consumed, then it's really an unknown command
+	if (remaining == argc - 1)
+	{
+		const char *cmd = Jim_GetString(argv[1], 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, "help");
+		if (NULL == c)
+		{
+			LOG_ERROR("unknown command, but help 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);
+	}
+
+	unsigned nwords;
+	const char **words = script_command_args_alloc(count, start, &nwords);
+	if (NULL == words)
+		return JIM_ERR;
+
+	int retval = run_command(cmd_ctx, c, words, nwords);
+
+	script_command_args_free(words, nwords);
+
+	if (!found && ERROR_OK == retval)
+		retval = ERROR_FAIL;
+
+	return retval;
+}
+
+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);
+	}
+	else
+	{
+		bool replaced = false;
+		if (nc->help)
+		{
+			free((void *)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);
+	}
+	return ERROR_OK;
+}
+
+COMMAND_HANDLER(handle_help_add_command)
+{
+	if (CMD_ARGC < 2)
+	{
+		LOG_ERROR("%s: insufficient arguments", CMD_NAME);
+		return ERROR_INVALID_ARGUMENTS;
+	}
+
+	// save help text and remove it from argument list
+	const char *help_text = CMD_ARGV[--CMD_ARGC];
+	// 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_text, NULL);
+}
+
+/* sleep command sleeps for <n> miliseconds
+ * this is useful in target startup scripts
+ */
+COMMAND_HANDLER(handle_sleep_command)
+{
+	bool busy = false;
+	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)
+		return ERROR_COMMAND_SYNTAX_ERROR;
+
+	unsigned long duration = 0;
+	int retval = parse_ulong(CMD_ARGV[0], &duration);
+	if (ERROR_OK != retval)
+		return retval;
+
+	if (!busy)
+	{
+		long long then = timeval_ms();
+		while (timeval_ms() - then < (long long)duration)
+		{
+			target_call_timer_callbacks_now();
+			usleep(1000);
+		}
+	}
+	else
+		busy_sleep(duration);
+
+	return ERROR_OK;
+}
+
+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",
+		.usage = "<command> [...] <help_text>]",
+	},
+	{
+		.name = "sleep",
+		.handler = &handle_sleep_command,
+		.mode = COMMAND_ANY,
+		.help = "sleep for n milliseconds.  "
+			"\"busy\" will busy wait",
+		.usage = "<n> [busy]",
+	},
+	{
+		.name = "help",
+		.handler = &handle_help_command,
+		.mode = COMMAND_ANY,
+		.help = "show built-in command help",
+		.usage = "[<command_name> ...]",
+	},
+	{
+		.name = "usage",
+		.handler = &handle_usage_command,
+		.mode = COMMAND_ANY,
+		.help = "show command usage",
+		.usage = "[<command_name> ...]",
+	},
+	COMMAND_REGISTRATION_DONE
+};
+
+struct command_context* command_init(const char *startup_tcl)
+{
+	struct command_context* context = malloc(sizeof(struct command_context));
 	const char *HostOs;
 
 	context->mode = COMMAND_EXEC;
@@ -704,7 +1082,7 @@ command_context_t* command_init()
 	Jim_RegisterCoreCommands(interp);
 #endif
 
-#if defined( _MSC_VER )
+#if defined(_MSC_VER)
 	/* WinXX - is generic, the forward
 	 * looking problem is this:
 	 *
@@ -713,19 +1091,24 @@ command_context_t* command_init()
 	 * "winxx" is generic.
 	 */
 	HostOs = "winxx";
-#elif defined( __LINUX__)
+#elif defined(__linux__)
 	HostOs = "linux";
-#elif defined( __DARWIN__ )
+#elif defined(__DARWIN__)
 	HostOs = "darwin";
-#elif defined( __CYGWIN__ )
+#elif defined(__CYGWIN__)
 	HostOs = "cygwin";
-#elif defined( __MINGW32__ )
+#elif defined(__MINGW32__)
 	HostOs = "mingw32";
+#elif defined(__ECOS)
+	HostOs = "ecos";
 #else
+#warn unrecognized host OS...
 	HostOs = "other";
 #endif
-	Jim_SetGlobalVariableStr( interp, "ocd_HOSTOS", Jim_NewStringObj( interp, HostOs , strlen(HostOs)) );
+	Jim_SetGlobalVariableStr(interp, "ocd_HOSTOS",
+			Jim_NewStringObj(interp, HostOs , strlen(HostOs)));
 
+	Jim_CreateCommand(interp, "unknown", &command_unknown, NULL, NULL);
 	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);
@@ -740,28 +1123,24 @@ command_context_t* command_init()
 	interp->cb_fflush = openocd_jim_fflush;
 	interp->cb_fgets = openocd_jim_fgets;
 
-	add_default_dirs();
+	register_commands(context, NULL, command_builtin_handlers);
 
 #if !BUILD_ECOSBOARD
 	Jim_EventLoopOnLoad(interp);
 #endif
-	if (Jim_Eval_Named(interp, startup_tcl, "embedded:startup.tcl",1)==JIM_ERR)
+	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 compile time)");
+		LOG_ERROR("Failed to run startup.tcl (embedded into OpenOCD)");
 		Jim_PrintErrorMessage(interp);
 		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(command_context_t *cmd_ctx, enum command_mode mode)
+int command_context_mode(struct command_context *cmd_ctx, enum command_mode mode)
 {
 	if (!cmd_ctx)
 		return ERROR_INVALID_ARGUMENTS;
@@ -770,53 +1149,6 @@ int command_context_mode(command_context_t *cmd_ctx, enum command_mode mode)
 	return ERROR_OK;
 }
 
-/* sleep command sleeps for <n> miliseconds
- * this is useful in target startup scripts
- */
-int handle_sleep_command(struct command_context_s *cmd_ctx,
-		char *cmd, char **args, int argc)
-{
-	bool busy = false;
-	if (argc == 2)
-	{
-		if (strcmp(args[1], "busy") == 0)
-			busy = true;
-		else
-			return ERROR_COMMAND_SYNTAX_ERROR;
-	}
-	else if (argc < 1 || argc > 2)
-		return ERROR_COMMAND_SYNTAX_ERROR;
-
-	unsigned long duration = 0;
-	int retval = parse_ulong(args[0], &duration);
-	if (ERROR_OK != retval)
-		return retval;
-
-	if (!busy)
-	{
-		long long then = timeval_ms();
-		while (timeval_ms() - then < (long long)duration)
-		{
-			target_call_timer_callbacks_now();
-			usleep(1000);
-		}
-	}
-	else
-		busy_sleep(duration);
-
-	return ERROR_OK;
-}
-
-int handle_fast_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
-{
-	if (argc!=1)
-		return ERROR_COMMAND_SYNTAX_ERROR;
-
-	fast_and_dangerous = strcmp("enable", args[0])==0;
-
-	return ERROR_OK;
-}
-
 void process_jim_events(void)
 {
 #if !BUILD_ECOSBOARD
@@ -825,57 +1157,37 @@ void process_jim_events(void)
 	if (!recursion)
 	{
 		recursion++;
-		Jim_ProcessEvents (interp, JIM_ALL_EVENTS|JIM_DONT_WAIT);
+		Jim_ProcessEvents (interp, JIM_ALL_EVENTS | JIM_DONT_WAIT);
 		recursion--;
 	}
 #endif
 }
 
-void register_jim(struct command_context_s *cmd_ctx, const char *name, int (*cmd)(Jim_Interp *interp, int argc, Jim_Obj *const *argv), const char *help)
-{
-	Jim_CreateCommand(interp, name, cmd, NULL, NULL);
-
-	/* FIX!!! it would be prettier to invoke add_help_text...
-	 * 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_Obj *cmd_entry=Jim_NewListObj(interp, NULL, 0);
-
-	Jim_Obj *cmd_list=Jim_NewListObj(interp, NULL, 0);
-	Jim_ListAppendElement(interp, cmd_list, Jim_NewStringObj(interp, name, -1));
-
-	Jim_ListAppendElement(interp, cmd_entry, cmd_list);
-	Jim_ListAppendElement(interp, cmd_entry, Jim_NewStringObj(interp, help, -1));
-	Jim_ListAppendElement(interp, helptext, cmd_entry);
-}
-
-/* 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;
-}
-
 #define DEFINE_PARSE_NUM_TYPE(name, type, func, min, max) \
 	int parse##name(const char *str, type *ul) \
 	{ \
 		if (!*str) \
+		{ \
+			LOG_ERROR("Invalid command argument"); \
 			return ERROR_COMMAND_ARGUMENT_INVALID; \
+		} \
 		char *end; \
 		*ul = func(str, &end, 0); \
 		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 (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)
@@ -896,7 +1208,7 @@ DEFINE_PARSE_NUM_TYPE(_llong, long long, strtoll, LLONG_MIN, LLONG_MAX)
 			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)
@@ -911,3 +1223,51 @@ 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)
+
+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_INVALID_ARGUMENTS;
+}
+
+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_INVALID_ARGUMENTS;
+		}
+		// fall through
+	}
+	case 0:
+		LOG_INFO("%s is %s", label, *out ? "enabled" : "disabled");
+		break;
+	default:
+		return ERROR_INVALID_ARGUMENTS;
+	}
+	return ERROR_OK;
+}