Add the current command to the command information
[fw/openocd] / src / helper / command.c
index f474756ad692d976af89ad620f01f50d6c59e5d3..e55f9e73e48682fbb331c7fc5514b846416cae86 100644 (file)
@@ -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                                       *
@@ -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"
 #include "jim-eventloop.h"
 
 
-int fast_and_dangerous = 0;
-Jim_Interp *interp = NULL;
+/* nice short description of source file */
+#define __THIS__FILE__ "command.c"
 
-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);
 
-int run_command(command_context_t *context, command_t *c, char *words[], int num_words);
+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)
+{
+       struct log_capture_state *state = (struct log_capture_state *)privData;
+       Jim_AppendString(state->interp, state->output, string, strlen(string));
+}
 
-static void tcl_output(void *privData, const char *file, int line, const char *function, const char *string)
+static struct log_capture_state *command_log_capture_start(Jim_Interp *interp)
 {
-       Jim_Obj *tclOutput=(Jim_Obj *)privData;
+       /* 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);
 
-       Jim_AppendString(interp, tclOutput, string, strlen(string));
+       return state;
 }
 
-extern command_context_t *global_cmd_ctx;
+static void command_log_capture_finish(struct log_capture_state *state)
+{
+       if (NULL == state)
+               return;
+
+       log_remove_callback(tcl_output, state);
 
-void script_debug(Jim_Interp *interp, const char *name, int argc, Jim_Obj *const *argv)
+       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 i;
+       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;
 
+void script_debug(Jim_Interp *interp, const char *name,
+               unsigned argc, Jim_Obj *const *argv)
+{
        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);
 
@@ -78,282 +125,366 @@ void script_debug(Jim_Interp *interp, const char *name, int argc, Jim_Obj *const
        }
 }
 
-static int script_command(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+static void script_command_args_free(const char **words, unsigned nwords)
 {
-       /* the private data is stashed in the interp structure */
-       command_t *c;
-       command_context_t *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*/
-
-       script_debug(interp, c->name, argc, argv);
+       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;
 
-       words = malloc(sizeof(char *) * argc);
+       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 */
+               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)
                {
-                       return JIM_ERR;
+                       script_command_args_free(words, i);
+                       return NULL;
                }
        }
-       nwords = i;
+       *nwords = i;
+       return words;
+}
 
+static 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.
                 */
-               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);
+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*/
 
-       log_add_callback(tcl_output, tclOutput);
+       unsigned nwords;
+       const char **words = script_command_args_alloc(argc, argv, &nwords);
+       if (NULL == words)
+               return JIM_ERR;
 
-       retval = run_command(context, c, words, nwords);
+       struct log_capture_state *state = NULL;
+       if (capture)
+               state = command_log_capture_start(interp);
 
-       log_remove_callback(tcl_output, tclOutput);
+       struct command_context *cmd_ctx = current_command_context(interp);
+       int retval = run_command(cmd_ctx, c, (const char **)words, nwords);
 
-       /* We dump output into this local variable */
-       Jim_SetResult(interp, tclOutput);
-       Jim_DecrRefCount(interp, tclOutput);
+       command_log_capture_finish(state);
 
-       for (i = 0; i < nwords; i++)
-               free(words[i]);
-       free(words);
+       script_command_args_free(words, nwords);
+       return command_retval_set(interp, retval);
+}
 
-       int *return_retval = Jim_GetAssocData(interp, "retval");
-       if (return_retval != NULL)
+static int script_command(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
+{
+       /* the private data is stashed in the interp structure */
+
+       struct command *c = interp->cmdPrivData;
+       assert(c);
+       script_debug(interp, c->name, argc, argv);
+       return script_command_run(interp, argc, argv, c, true);
+}
+
+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.
+ * @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)
+{
+       for (struct command *cc = head; cc; cc = cc->next)
        {
-               *return_retval = retval;
+               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);
+}
 
-       return (retval==ERROR_OK)?JIM_OK:JIM_ERR;
+/**
+ * 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;
+       }
+
+       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;
+       }
 }
 
-/* nice short description of source file */
-#define __THIS__FILE__ "command.c"
+static struct command **command_list_for_parent(
+               struct command_context *cmd_ctx, struct command *parent)
+{
+       return parent ? &parent->children : &cmd_ctx->commands;
+}
 
-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)
+static void command_free(struct command *c)
 {
-       command_t *c, *p;
+       /// @todo if command has a handler, unregister its jim command!
 
-       if (!context || !name)
+       while (NULL != c->children)
+       {
+               struct command *tmp = c->children;
+               c->children = tmp->next;
+               command_free(tmp);
+       }
+
+       if (c->name)
+               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 = malloc(sizeof(command_t));
+       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->name = strdup(name);
        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
-       {
-               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;
-               }
-       }
+       command_add_child(command_list_for_parent(cmd_ctx, parent), c);
 
-       /* just a placeholder, no handler */
-       if (c->handler==NULL)
-               return c;
+       return 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);
+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%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} {eval ocd_bouncer %s $args}",
+                       c->name, c->name);
+       if (NULL == override_name)
+               return JIM_ERR;
+
+       retval = Jim_Eval_Named(interp, override_name, __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);
+       return retval;
+}
+
+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)
+       {
+               LOG_ERROR("command '%s' is already registered in '%s' context",
+                               name, parent ? parent->name : "<global>");
+               return c;
+       }
 
-       Jim_Obj *cmd_list=Jim_NewListObj(interp, NULL, 0);
+       c = command_new(context, parent, cr);
+       if (NULL == c)
+               return NULL;
 
-       /* maximum of two levels :-) */
-       if (c->parent != NULL)
+       int retval = ERROR_OK;
+       if (NULL != cr->jim_handler && NULL == parent)
        {
-               Jim_ListAppendElement(interp, cmd_list, Jim_NewStringObj(interp, c->parent->name, -1));
+               retval = Jim_CreateCommand(context->interp, cr->name,
+                               cr->jim_handler, cr->jim_handler_data, NULL);
        }
-       Jim_ListAppendElement(interp, cmd_list, Jim_NewStringObj(interp, c->name, -1));
+       else if (NULL != cr->handler || NULL != parent)
+               retval = register_command_handler(context, command_root(c));
 
-       Jim_ListAppendElement(interp, cmd_entry, cmd_list);
-       Jim_ListAppendElement(interp, cmd_entry, Jim_NewStringObj(interp, help, -1));
-       Jim_ListAppendElement(interp, helptext, cmd_entry);
+       if (ERROR_OK != retval)
+       {
+               unregister_command(context, parent, name);
+               c = 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;
-                       }
-
-                       /* unregister children */
-                       while (NULL != c->children)
-                       {
-                               c2 = c->children;
-                               c->children = c->children->next;
-                               free(c2->name);
-                               c2->name = NULL;
-                               free(c2);
-                               c2 = NULL;
-                       }
+               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_output_text(command_context_t *context, const char *data)
+void command_set_handler_data(struct command *c, void *p)
 {
-       if ( context && context->output_handler && data  ){
-               context->output_handler( context, data );
+       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) {
+               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 +508,7 @@ 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 +533,68 @@ 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)
+{
+       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 bool command_can_run(struct command_context *cmd_ctx, struct command *c)
 {
-       int start_word=0;
-       if (!((context->mode == COMMAND_CONFIG) || (c->mode == COMMAND_ANY) || (c->mode == context->mode) ))
+       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 (!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;
        }
 
-       int retval = c->handler(context, c->name, words + start_word + 1, num_words - start_word - 1);
+       struct command_invocation cmd = {
+                       .ctx = context,
+                       .current = c,
+                       .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, "usage %s", full_name);
+                       free(full_name);
+               } else
+                       retval = -ENOMEM;
        }
        else if (retval == ERROR_COMMAND_CLOSE_CONNECTION)
        {
@@ -443,20 +611,21 @@ 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
         * 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)
@@ -466,7 +635,7 @@ 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");
                }
@@ -478,7 +647,7 @@ int command_run_line(command_context_t *context, char *line)
                        /* 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;
@@ -492,63 +661,64 @@ 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)
        {
-               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)
+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 */
@@ -599,7 +769,7 @@ 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;
@@ -663,31 +833,463 @@ static int jim_capture(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 {
        if (argc != 2)
                return JIM_ERR;
-       int retcode;
+
+       struct log_capture_state *state = command_log_capture_start(interp);
+
        const char *str = Jim_GetString(argv[1], NULL);
+       int retcode = Jim_Eval_Named(interp, str, __THIS__FILE__, __LINE__);
 
-       /* 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);
+       command_log_capture_finish(state);
 
-       log_add_callback(tcl_output, tclOutput);
+       return retcode;
+}
 
-       retcode = Jim_Eval_Named(interp, str, __THIS__FILE__, __LINE__ );
+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 && 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)
+               return ERROR_OK;
+       CMD_ARGV++;
+       return CALL_COMMAND_HANDLER(command_help_find, (*out)->children, out);
+}
 
-       log_remove_callback(tcl_output, tclOutput);
+static COMMAND_HELPER(command_help_show, struct command *c, unsigned n,
+               bool show_help, const char *match);
 
-       /* We dump output into this local variable */
-       Jim_SetResult(interp, tclOutput);
-       Jim_DecrRefCount(interp, tclOutput);
+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, show_help, match);
+       return ERROR_OK;
+}
 
-       return retcode;
+#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_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)
+       {
+               const char *stage_msg;
+               switch (c->mode) {
+               case COMMAND_CONFIG: stage_msg = "CONFIG"; break;
+               case COMMAND_EXEC: stage_msg = "EXEC"; break;
+               case COMMAND_ANY: stage_msg = "CONFIG or EXEC"; break;
+               default: stage_msg = "***UNKNOWN***"; break;
+               }
+               char *msg = alloc_printf("%s%sValid Modes: %s",
+                       c->help ? : "", c->help ? "  " : "", stage_msg);
+               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, show_help, match);
+}
+COMMAND_HANDLER(handle_help_command)
+{
+       bool full = strcmp(CMD_NAME, "help") == 0;
+
+       struct command *c = CMD_CTX->commands;
+
+       const char *match = "";
+       if (CMD_ARGC == 0)
+               match = "";
+       else if (CMD_ARGC == 1)
+               match = CMD_ARGV[0]; 
+       else
+               return ERROR_COMMAND_SYNTAX_ERROR;
+               
+       return CALL_COMMAND_HANDLER(command_help_show_list, c, 0, full, match);
+}
+
+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 *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((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);
+       }
+       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;
+}
+
+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 *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];
+
+       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
+ * 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;
 }
 
-command_context_t* command_init()
+static const struct command_registration command_subcommand_handlers[] = {
+       {
+               .name = "mode",
+               .mode = COMMAND_ANY,
+               .jim_handler = &jim_command_mode,
+               .usage = "[<name> ...]",
+               .help = "Returns the command modes allowed by a  command:"
+                       "'any', 'config', or 'exec'.  If no command is"
+                       "specified, returns the current command mode.",
+       },
+       {
+               .name = "type",
+               .mode = COMMAND_ANY,
+               .jim_handler = &jim_command_type,
+               .usage = "<name> ...",
+               .help = "Returns the type of built-in command:"
+                       "'native', 'simple', 'group', or 'unknown'",
+       },
+       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",
+               .usage = "<command> [...] <help_text>]",
+       },
+       {
+               .name = "add_usage_text",
+               .handler = &handle_help_add_command,
+               .mode = COMMAND_ANY,
+               .help = "add new command usage text",
+               .usage = "<command> [...] <usage_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 full command help",
+               .usage = "[<command> ...]",
+       },
+       {
+               .name = "usage",
+               .handler = &handle_help_command,
+               .mode = COMMAND_ANY,
+               .help = "show basic command usage",
+               .usage = "[<command> ...]",
+       },
+       {
+               .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)
 {
-       command_context_t* context = malloc(sizeof(command_context_t));
-       extern const char startup_tcl[];
+       struct command_context* context = malloc(sizeof(struct command_context));
        const char *HostOs;
 
        context->mode = COMMAND_EXEC;
@@ -697,14 +1299,19 @@ command_context_t* command_init()
        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;
 
-#if defined( _MSC_VER )
+#if defined(_MSC_VER)
        /* WinXX - is generic, the forward
         * looking problem is this:
         *
@@ -713,18 +1320,22 @@ 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, "ocd_find", jim_find, NULL, NULL);
        Jim_CreateCommand(interp, "echo", jim_echo, NULL, NULL);
@@ -740,28 +1351,24 @@ 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;
@@ -770,112 +1377,44 @@ 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)
+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_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 +1435,7 @@ 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 +1450,51 @@ 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;
+}