Merge branch 'dsp5680xx_cherry' of git://repo.or.cz/openocd/dsp568013 into HEAD
[fw/openocd] / src / helper / command.c
index 61a791dc676a8df084b9d2d41cadf0f457878735..b00a231268cb7fb77f47a2c7dc6b7261e0707e31 100644 (file)
@@ -36,7 +36,8 @@
 #endif
 
 // @todo the inclusion of target.h here is a layering violation
-#include "target.h"
+#include <jtag/jtag.h>
+#include <target/target.h>
 #include "command.h"
 #include "configuration.h"
 #include "log.h"
 /* nice short description of source file */
 #define __THIS__FILE__ "command.c"
 
-Jim_Interp *interp = NULL;
 
 static int run_command(struct command_context *context,
                struct command *c, const char *words[], unsigned num_words);
 
+struct log_capture_state {
+       Jim_Interp *interp;
+       Jim_Obj *output;
+};
+
 static void tcl_output(void *privData, const char *file, unsigned line,
                const char *function, const char *string)
 {
-       Jim_Obj *tclOutput = (Jim_Obj *)privData;
-       Jim_AppendString(interp, tclOutput, string, strlen(string));
+       struct log_capture_state *state = (struct log_capture_state *)privData;
+       Jim_AppendString(state->interp, state->output, string, strlen(string));
 }
 
-static Jim_Obj *command_log_capture_start(Jim_Interp *interp)
+static struct log_capture_state *command_log_capture_start(Jim_Interp *interp)
 {
        /* capture log output and return it. A garbage collect can
         * happen, so we need a reference count to this object */
        Jim_Obj *tclOutput = Jim_NewStringObj(interp, "", 0);
        if (NULL == tclOutput)
                return NULL;
+
+       struct log_capture_state *state = malloc(sizeof(*state));
+       if (NULL == state)
+               return NULL;
+
+       state->interp = interp;
        Jim_IncrRefCount(tclOutput);
-       log_add_callback(tcl_output, tclOutput);
-       return tclOutput;
+       state->output = tclOutput;
+
+       log_add_callback(tcl_output, state);
+
+       return state;
 }
 
-static void command_log_capture_finish(Jim_Interp *interp, Jim_Obj *tclOutput)
+/* Classic openocd commands provide progress output which we
+ * will capture and return as a Tcl return value.
+ *
+ * However, if a non-openocd command has been invoked, then it
+ * makes sense to return the tcl return value from that command.
+ *
+ * The tcl return value is empty for openocd commands that provide
+ * progress output.
+ *
+ * Therefore we set the tcl return value only if we actually
+ * captured output.
+ */
+static void command_log_capture_finish(struct log_capture_state *state) 
 {
-       log_remove_callback(tcl_output, tclOutput);
-       Jim_SetResult(interp, tclOutput);
-       Jim_DecrRefCount(interp, tclOutput);
+       if (NULL == state)
+               return;
+
+       log_remove_callback(tcl_output, state);
+
+       int length;
+       Jim_GetString(state->output, &length);
+
+       if (length > 0)
+       {
+               Jim_SetResult(state->interp, state->output);
+       } else
+       {
+               /* No output captured, use tcl return value (which could
+                * be empty too). */
+       }
+       Jim_DecrRefCount(state->interp, state->output);
+
+       free(state);
 }
 
 static int command_retval_set(Jim_Interp *interp, int retval)
@@ -89,21 +131,25 @@ static int command_retval_set(Jim_Interp *interp, int retval)
 
 extern struct command_context *global_cmd_ctx;
 
+/* dump a single line to the log for the command.
+ * Do nothing in case we are not at debug level 3 */
 void script_debug(Jim_Interp *interp, const char *name,
                unsigned argc, Jim_Obj *const *argv)
 {
-       LOG_DEBUG("command - %s", name);
+       if (debug_level < LOG_LVL_DEBUG)
+               return;
+
+       char * dbg = alloc_printf("command - %s", name);
        for (unsigned i = 0; i < argc; i++)
        {
                int len;
                const char *w = Jim_GetString(argv[i], &len);
-
-               /* end of line comment? */
-               if (*w == '#')
-                       break;
-
-               LOG_DEBUG("%s - argv[%d]=%s", name, i, w);
+               char * t = alloc_printf("%s %s", dbg, w);
+               free (dbg);
+               dbg = t;
        }
+       LOG_DEBUG("%s", dbg);
+       free(dbg);
 }
 
 static void script_command_args_free(const char **words, unsigned nwords)
@@ -124,10 +170,6 @@ static const char **script_command_args_alloc(
        {
                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)
                {
@@ -139,14 +181,18 @@ static const char **script_command_args_alloc(
        return words;
 }
 
-static struct command_context *current_command_context(void)
+struct command_context *current_command_context(Jim_Interp *interp)
 {
        /* 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.
+                * happen when the Jim Tcl interpreter is provided by eCos or if we are running
+                * commands in a startup script.
+                *
+                * A telnet or gdb server would provide a non-default command context to
+                * handle piping of error output, have a separate current target, etc.
                 */
                cmd_ctx = global_cmd_ctx;
        }
@@ -164,15 +210,14 @@ static int script_command_run(Jim_Interp *interp,
        if (NULL == words)
                return JIM_ERR;
 
-       Jim_Obj *tclOutput = NULL;
+       struct log_capture_state *state = NULL;
        if (capture)
-               tclOutput = command_log_capture_start(interp);
+               state = command_log_capture_start(interp);
 
-       struct command_context *cmd_ctx = current_command_context();
+       struct command_context *cmd_ctx = current_command_context(interp);
        int retval = run_command(cmd_ctx, c, (const char **)words, nwords);
 
-       if (capture)
-               command_log_capture_finish(interp, tclOutput);
+       command_log_capture_finish(state);
 
        script_command_args_free(words, nwords);
        return command_retval_set(interp, retval);
@@ -253,19 +298,44 @@ static struct command **command_list_for_parent(
        return parent ? &parent->children : &cmd_ctx->commands;
 }
 
+static void command_free(struct command *c)
+{
+       /// @todo if command has a handler, unregister its jim command!
+
+       while (NULL != c->children)
+       {
+               struct command *tmp = c->children;
+               c->children = tmp->next;
+               command_free(tmp);
+       }
+
+       if (c->name)
+               free((void *)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 = malloc(sizeof(struct command));
-       memset(c, 0, sizeof(struct command));
+       struct command *c = calloc(1, sizeof(struct command));
+       if (NULL == c)
+               return NULL;
 
        c->name = strdup(cr->name);
        if (cr->help)
                c->help = strdup(cr->help);
        if (cr->usage)
                c->usage = strdup(cr->usage);
+
+       if (!c->name || (cr->help && !c->help) || (cr->usage && !c->usage))
+               goto command_new_error;
+
        c->parent = parent;
        c->handler = cr->handler;
        c->jim_handler = cr->jim_handler;
@@ -275,31 +345,18 @@ static struct command *command_new(struct command_context *cmd_ctx,
        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)
-       {
-               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);
+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 *c)
+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;
@@ -319,7 +376,7 @@ static int register_command_handler(struct command *c)
        if (NULL == override_name)
                return JIM_ERR;
 
-       retval = Jim_Eval_Named(interp, override_name, __FILE__, __LINE__);
+       retval = Jim_Eval_Named(interp, override_name, 0, 0);
        free((void *)override_name);
 
        return retval;
@@ -336,7 +393,10 @@ struct command* register_command(struct command_context *context,
        struct command *c = command_find(*head, name);
        if (NULL != c)
        {
-               LOG_ERROR("command '%s' is already registered in '%s' context",
+               /* TODO: originally we treated attempting to register a cmd twice as an error
+                * Sometimes we need this behaviour, such as with flash banks.
+                * http://www.mail-archive.com/openocd-development@lists.berlios.de/msg11152.html */
+               LOG_DEBUG("command '%s' is already registered in '%s' context",
                                name, parent ? parent->name : "<global>");
                return c;
        }
@@ -348,11 +408,11 @@ struct command* register_command(struct command_context *context,
        int retval = ERROR_OK;
        if (NULL != cr->jim_handler && NULL == parent)
        {
-               retval = Jim_CreateCommand(interp, cr->name,
+               retval = Jim_CreateCommand(context->interp, cr->name,
                                cr->jim_handler, cr->jim_handler_data, NULL);
        }
        else if (NULL != cr->handler || NULL != parent)
-               retval = register_command_handler(command_root(c));
+               retval = register_command_handler(context, command_root(c));
 
        if (ERROR_OK != retval)
        {
@@ -439,6 +499,14 @@ int unregister_command(struct command_context *context,
        return ERROR_OK;
 }
 
+void command_set_handler_data(struct command *c, void *p)
+{
+       if (NULL != c->handler || NULL != c->jim_handler)
+               c->jim_handler_data = p;
+       for (struct command *cc = c->children; NULL != cc; cc = cc->next)
+               command_set_handler_data(cc, p);
+}
+
 void command_output_text(struct command_context *context, const char *data)
 {
        if (context && context->output_handler && data) {
@@ -517,18 +585,32 @@ char *command_name(struct command *c, char delim)
        return __command_name(c, delim, 0);
 }
 
+static bool command_can_run(struct command_context *cmd_ctx, struct command *c)
+{
+       return c->mode == COMMAND_ANY || c->mode == cmd_ctx->mode;
+}
+
 static int run_command(struct command_context *context,
                struct command *c, const char *words[], unsigned num_words)
 {
-       if (!((context->mode == COMMAND_CONFIG) || (c->mode == COMMAND_ANY) || (c->mode == context->mode)))
+       if (!command_can_run(context, c))
        {
-               /* Config commands can not run after the config stage */
-               LOG_ERROR("Command '%s' only runs during configuration stage", c->name);
+               /* Many commands may be run only before/after 'init' */
+               const char *when;
+               switch (c->mode) {
+               case COMMAND_CONFIG: when = "before"; break;
+               case COMMAND_EXEC: when = "after"; break;
+               // handle the impossible with humor; it guarantees a bug report!
+               default: when = "if Cthulhu is summoned by"; break;
+               }
+               LOG_ERROR("The '%s' command must be used %s 'init'.",
+                               c->name, when);
                return ERROR_FAIL;
        }
 
        struct command_invocation cmd = {
                        .ctx = context,
+                       .current = c,
                        .name = c->name,
                        .argc = num_words - 1,
                        .argv = words + 1,
@@ -539,7 +621,7 @@ static int run_command(struct command_context *context,
                /* Print help for command */
                char *full_name = command_name(c, ' ');
                if (NULL != full_name) {
-                       command_run_linef(context, "help %s", full_name);
+                       command_run_linef(context, "usage %s", full_name);
                        free(full_name);
                } else
                        retval = -ENOMEM;
@@ -573,6 +655,7 @@ int command_run_line(struct command_context *context, char *line)
         * happen when the Jim Tcl interpreter is provided by eCos for
         * instance.
         */
+       Jim_Interp *interp = context->interp;
        Jim_DeleteAssocData(interp, "context");
        retcode = Jim_SetAssocData(interp, "context", NULL, context);
        if (retcode == JIM_OK)
@@ -582,7 +665,7 @@ int command_run_line(struct command_context *context, char *line)
                retcode = Jim_SetAssocData(interp, "retval", NULL, &retval);
                if (retcode == JIM_OK)
                {
-                       retcode = Jim_Eval_Named(interp, line, __THIS__FILE__, __LINE__);
+                       retcode = Jim_Eval_Named(interp, line, 0, 0);
 
                        Jim_DeleteAssocData(interp, "retval");
                }
@@ -592,7 +675,8 @@ int command_run_line(struct command_context *context, char *line)
                if (retval != ERROR_COMMAND_CLOSE_CONNECTION)
                {
                        /* We do not print the connection closed error message */
-                       Jim_PrintErrorMessage(interp);
+                       Jim_MakeErrorMessage(interp);
+                       LOG_USER("%s", Jim_GetString(Jim_GetResult(interp), NULL));
                }
                if (retval == ERROR_OK)
                {
@@ -622,7 +706,7 @@ int command_run_line(struct command_context *context, char *line)
                                buff[chunk] = 0;
                                LOG_USER_N("%s", buff);
                        }
-                       LOG_USER_N("%s", "\n");
+                       LOG_USER_N("\n");
                }
                retval = ERROR_OK;
        }
@@ -639,6 +723,7 @@ int command_run_linef(struct command_context *context, const char *format, ...)
        if (string != NULL)
        {
                retval = command_run_line(context, string);
+               free(string);
        }
        va_end(ap);
        return retval;
@@ -660,12 +745,12 @@ struct command_context* copy_command_context(struct command_context* context)
        return copy_context;
 }
 
-int command_done(struct command_context *context)
+void command_done(struct command_context *cmd_ctx)
 {
-       free(context);
-       context = NULL;
+       if (NULL == cmd_ctx)
+               return;
 
-       return ERROR_OK;
+       free(cmd_ctx);
 }
 
 /* find full path to file */
@@ -684,109 +769,45 @@ static int jim_find(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
        return JIM_OK;
 }
 
-static int jim_echo(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
-{
-       if (argc != 2)
-               return JIM_ERR;
-       const char *str = Jim_GetString(argv[1], NULL);
-       LOG_USER("%s", str);
-       return JIM_OK;
-}
-
-static size_t openocd_jim_fwrite(const void *_ptr, size_t size, size_t n, void *cookie)
+COMMAND_HANDLER(jim_echo)
 {
-       size_t nbytes;
-       const char *ptr;
-       Jim_Interp *interp;
-
-       /* make it a char easier to read code */
-       ptr = _ptr;
-       interp = cookie;
-       nbytes = size * n;
-       if (ptr == NULL || interp == NULL || nbytes == 0) {
-               return 0;
-       }
-
-       /* do we have to chunk it? */
-       if (ptr[nbytes] == 0)
+       if (CMD_ARGC == 2 && !strcmp(CMD_ARGV[0], "-n"))
        {
-               /* no it is a C style string */
-               LOG_USER_N("%s", ptr);
-               return strlen(ptr);
-       }
-       /* GRR we must chunk - not null terminated */
-       while (nbytes) {
-               char chunk[128 + 1];
-               int x;
-
-               x = nbytes;
-               if (x > 128) {
-                       x = 128;
-               }
-               /* copy it */
-               memcpy(chunk, ptr, x);
-               /* terminate it */
-               chunk[n] = 0;
-               /* output it */
-               LOG_USER_N("%s", chunk);
-               ptr += x;
-               nbytes -= x;
-       }
-
-       return n;
-}
-
-static size_t openocd_jim_fread(void *ptr, size_t size, size_t n, void *cookie)
-{
-       /* TCL wants to read... tell him no */
-       return 0;
-}
-
-static int openocd_jim_vfprintf(void *cookie, const char *fmt, va_list ap)
-{
-       char *cp;
-       int n;
-       Jim_Interp *interp;
-
-       n = -1;
-       interp = cookie;
-       if (interp == NULL)
-               return n;
-
-       cp = alloc_vprintf(fmt, ap);
-       if (cp)
-       {
-               LOG_USER_N("%s", cp);
-               n = strlen(cp);
-               free(cp);
+               LOG_USER_N("%s", CMD_ARGV[1]);
+               return JIM_OK;
        }
-       return n;
-}
-
-static int openocd_jim_fflush(void *cookie)
-{
-       /* nothing to flush */
-       return 0;
-}
-
-static char* openocd_jim_fgets(char *s, int size, void *cookie)
-{
-       /* not supported */
-       errno = ENOTSUP;
-       return NULL;
+       if (CMD_ARGC != 1)
+               return JIM_ERR;
+       LOG_USER("%s", CMD_ARGV[0]);
+       return JIM_OK;
 }
 
+/* Capture progress output and return as tcl return value. If the
+ * progress output was empty, return tcl return value.
+ */
 static int jim_capture(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 {
        if (argc != 2)
                return JIM_ERR;
 
-       Jim_Obj *tclOutput = command_log_capture_start(interp);
+       struct log_capture_state *state = command_log_capture_start(interp);
+
+       /* disable polling during capture. This avoids capturing output
+        * from polling.
+        *
+        * This is necessary in order to avoid accidentially getting a non-empty
+        * string for tcl fn's.
+        */
+       bool save_poll = jtag_poll_get_enabled();
+
+       jtag_poll_set_enabled(false);
 
        const char *str = Jim_GetString(argv[1], NULL);
        int retcode = Jim_Eval_Named(interp, str, __THIS__FILE__, __LINE__);
 
-       command_log_capture_finish(interp, tclOutput);
+       jtag_poll_set_enabled(save_poll);
+
+       command_log_capture_finish(state);
 
        return retcode;
 }
@@ -808,13 +829,13 @@ static COMMAND_HELPER(command_help_find, struct command *head,
 }
 
 static COMMAND_HELPER(command_help_show, struct command *c, unsigned n,
-               bool show_help);
+               bool show_help, const char *match);
 
 static COMMAND_HELPER(command_help_show_list, struct command *head, unsigned n,
-               bool show_help)
+               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);
+               CALL_COMMAND_HANDLER(command_help_show, c, n, show_help, match);
        return ERROR_OK;
 }
 
@@ -840,45 +861,120 @@ static void command_help_show_wrap(const char *str, unsigned n, unsigned n2)
                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");
+               LOG_USER("%.*s", (int)(cp - last), last);
                last = cp + 1;
                n = n2;
        }
 }
 static COMMAND_HELPER(command_help_show, struct command *c, unsigned n,
-               bool show_help)
+               bool show_help, const char *match)
 {
-       command_help_show_indent(n);
-       LOG_USER_N("%s", command_name(c, ' '));
-       if (c->usage) {
-               LOG_USER_N(" ");
-               command_help_show_wrap(c->usage, 0, n + 5);
+       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);
        }
-       else
-               LOG_USER_N("\n");
-       if (show_help && c->help)
-               command_help_show_wrap(c->help, n + 3, n + 3);
+       free(cmd_name);
+
+       if (is_match)
+       {
+               if (c->usage) {
+                       LOG_USER_N(" ");
+                       command_help_show_wrap(c->usage, 0, n + 5);
+               }
+               else
+                       LOG_USER_N("\n");
+       }
+
+       if (is_match && show_help)
+       {
+               char *msg;
+
+               /* Normal commands are runtime-only; highlight exceptions */
+               if (c->mode != COMMAND_EXEC) {
+                       const char *stage_msg = "";
+
+                       switch (c->mode) {
+                       case COMMAND_CONFIG:
+                               stage_msg = " (configuration command)";
+                               break;
+                       case COMMAND_ANY:
+                               stage_msg = " (command valid any time)";
+                               break;
+                       default:
+                               stage_msg = " (?mode error?)";
+                               break;
+                       }
+                       msg = alloc_printf("%s%s", c->help ? : "", stage_msg);
+               } else
+                       msg = alloc_printf("%s", c->help ? : "");
+
+               if (NULL != msg)
+               {
+                       command_help_show_wrap(msg, n + 3, n + 3);
+                       free(msg);
+               } else
+                       return -ENOMEM;
+       }
+
        if (++n >= 2)
                return ERROR_OK;
 
        return CALL_COMMAND_HANDLER(command_help_show_list,
-                       c->children, n, show_help);
+                       c->children, n, show_help, match);
 }
 COMMAND_HANDLER(handle_help_command)
 {
        bool full = strcmp(CMD_NAME, "help") == 0;
-
+       int retval;
        struct command *c = CMD_CTX->commands;
+       char *match = NULL;
+
+       if (CMD_ARGC == 0)
+               match = "";
+       else if (CMD_ARGC >= 1) {
+               unsigned i;
+
+               for (i = 0; i < CMD_ARGC; ++i) {
+                       if (NULL != match) {
+                               char *prev = match;
+
+                               match = alloc_printf("%s %s", match,
+                                               CMD_ARGV[i]);
+                               free(prev);
+                               if (NULL == match) {
+                                       LOG_ERROR("unable to build "
+                                                       "search string");
+                                       return -ENOMEM;
+                               }
+                       } else {
+                               match = alloc_printf("%s", CMD_ARGV[i]);
+                               if (NULL == match) {
+                                       LOG_ERROR("unable to build "
+                                                       "search string");
+                                       return -ENOMEM;
+                               }
+                       }
+               }
+       } else
+               return ERROR_COMMAND_SYNTAX_ERROR;
 
-       if (0 == CMD_ARGC)
-               return CALL_COMMAND_HANDLER(command_help_show_list, c, 0, full);
-
-       int retval = CALL_COMMAND_HANDLER(command_help_find, c, &c);
-       if (ERROR_OK != retval)
-               return retval;
+       retval = CALL_COMMAND_HANDLER(command_help_show_list,
+                       c, 0, full, match);
 
-       return CALL_COMMAND_HANDLER(command_help_show, c, 0, full);
+       if (CMD_ARGC >= 1)
+               free(match);
+       return retval;
 }
 
 static int command_unknown_find(unsigned argc, Jim_Obj *const *argv,
@@ -896,6 +992,7 @@ static int command_unknown_find(unsigned argc, Jim_Obj *const *argv,
        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);
@@ -908,7 +1005,7 @@ static int command_unknown(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
        }
        script_debug(interp, cmd_name, argc, argv);
 
-       struct command_context *cmd_ctx = current_command_context();
+       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
@@ -930,10 +1027,10 @@ static int command_unknown(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
        }
        else
        {
-               c = command_find(cmd_ctx->commands, "help");
+               c = command_find(cmd_ctx->commands, "usage");
                if (NULL == c)
                {
-                       LOG_ERROR("unknown command, but help is missing too");
+                       LOG_ERROR("unknown command, but usage is missing too");
                        return JIM_ERR;
                }
                count = argc - remaining;
@@ -952,8 +1049,9 @@ static int command_unknown(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 
 static int jim_command_mode(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 {
-       struct command_context *cmd_ctx = current_command_context();
+       struct command_context *cmd_ctx = current_command_context(interp);
        enum command_mode mode;
+
        if (argc > 1)
        {
                struct command *c = cmd_ctx->commands;
@@ -985,7 +1083,7 @@ 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();
+       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
@@ -1090,7 +1188,7 @@ COMMAND_HANDLER(handle_help_add_command)
        return help_add_command(CMD_CTX, c, cmd_name, help, usage);
 }
 
-/* sleep command sleeps for <n> miliseconds
+/* sleep command sleeps for <n> milliseconds
  * this is useful in target startup scripts
  */
 COMMAND_HANDLER(handle_sleep_command)
@@ -1130,59 +1228,75 @@ static const struct command_registration command_subcommand_handlers[] = {
        {
                .name = "mode",
                .mode = COMMAND_ANY,
-               .jim_handler = &jim_command_mode,
-               .usage = "[<name> ...]",
+               .jim_handler = jim_command_mode,
+               .usage = "[command_name ...]",
                .help = "Returns the command modes allowed by a  command:"
                        "'any', 'config', or 'exec'.  If no command is"
-                       "specified, returns the current command mode.",
+                       "specified, returns the current command mode.  "
+                       "Returns 'unknown' if an unknown command is given. "
+                       "Command can be multiple tokens.",
        },
        {
                .name = "type",
                .mode = COMMAND_ANY,
-               .jim_handler = &jim_command_type,
-               .usage = "<name> ...",
+               .jim_handler = jim_command_type,
+               .usage = "command_name [...]",
                .help = "Returns the type of built-in command:"
-                       "'native', 'simple', 'group', or 'unknown'",
+                       "'native', 'simple', 'group', or 'unknown'. "
+                       "Command can be multiple tokens.",
        },
        COMMAND_REGISTRATION_DONE
 };
 
 static const struct command_registration command_builtin_handlers[] = {
+       {
+               .name = "echo",
+               .handler = jim_echo,
+               .mode = COMMAND_ANY,
+               .help = "Logs a message at \"user\" priority. "
+                       "Output message to stdout. "
+                       "Option \"-n\" suppresses trailing newline",
+               .usage = "[-n] string",
+       },
        {
                .name = "add_help_text",
-               .handler = &handle_help_add_command,
+               .handler = handle_help_add_command,
                .mode = COMMAND_ANY,
-               .help = "add new command help text",
-               .usage = "<command> [...] <help_text>]",
+               .help = "Add new command help text; "
+                       "Command can be multiple tokens.",
+               .usage = "command_name helptext_string",
        },
        {
                .name = "add_usage_text",
-               .handler = &handle_help_add_command,
+               .handler = handle_help_add_command,
                .mode = COMMAND_ANY,
-               .help = "add new command usage text",
-               .usage = "<command> [...] <usage_text>]",
+               .help = "Add new command usage text; "
+                       "command can be multiple tokens.",
+               .usage = "command_name usage_string",
        },
        {
                .name = "sleep",
-               .handler = &handle_sleep_command,
+               .handler = handle_sleep_command,
                .mode = COMMAND_ANY,
-               .help = "sleep for n milliseconds.  "
-                       "\"busy\" will busy wait",
-               .usage = "<n> [busy]",
+               .help = "Sleep for specified number of milliseconds.  "
+                       "\"busy\" will busy wait instead (avoid this).",
+               .usage = "milliseconds ['busy']",
        },
        {
                .name = "help",
-               .handler = &handle_help_command,
+               .handler = handle_help_command,
                .mode = COMMAND_ANY,
-               .help = "show full command help",
-               .usage = "[<command> ...]",
+               .help = "Show full command help; "
+                       "command can be multiple tokens.",
+               .usage = "[command_name]",
        },
        {
                .name = "usage",
-               .handler = &handle_help_command,
+               .handler = handle_help_command,
                .mode = COMMAND_ANY,
-               .help = "show basic command usage",
-               .usage = "[<command> ...]",
+               .help = "Show basic command usage; "
+                       "command can be multiple tokens.",
+               .usage = "[command_name]",
        },
        {
                .name = "command",
@@ -1193,7 +1307,7 @@ static const struct command_registration command_builtin_handlers[] = {
        COMMAND_REGISTRATION_DONE
 };
 
-struct command_context* command_init(const char *startup_tcl)
+struct command_context* command_init(const char *startup_tcl, Jim_Interp *interp)
 {
        struct command_context* context = malloc(sizeof(struct command_context));
        const char *HostOs;
@@ -1205,13 +1319,19 @@ struct command_context* command_init(const char *startup_tcl)
        context->output_handler_priv = NULL;
 
 #if !BUILD_ECOSBOARD
-       Jim_InitEmbedded();
-       /* Create an interpreter */
-       interp = Jim_CreateInterp();
-       /* Add all the Jim core commands */
-       Jim_RegisterCoreCommands(interp);
+       /* Create a jim interpreter if we were not handed one */
+       if (interp == NULL)
+       {
+               /* Create an interpreter */
+               interp = Jim_CreateInterp();
+               /* Add all the Jim core commands */
+               Jim_RegisterCoreCommands(interp);
+               Jim_InitStaticExtensions(interp);
+       }
 #endif
+       context->interp = interp;
 
+       /* Stick to lowercase for HostOS strings. */
 #if defined(_MSC_VER)
        /* WinXX - is generic, the forward
         * looking problem is this:
@@ -1223,7 +1343,7 @@ struct command_context* command_init(const char *startup_tcl)
        HostOs = "winxx";
 #elif defined(__linux__)
        HostOs = "linux";
-#elif defined(__DARWIN__)
+#elif defined(__APPLE__) || defined(__DARWIN__)
        HostOs = "darwin";
 #elif defined(__CYGWIN__)
        HostOs = "cygwin";
@@ -1231,37 +1351,26 @@ struct command_context* command_init(const char *startup_tcl)
        HostOs = "mingw32";
 #elif defined(__ECOS)
        HostOs = "ecos";
+#elif defined(__FreeBSD__)
+       HostOs = "freebsd";
 #else
-#warn unrecognized host OS...
+#warning "Unrecognized host OS..."
        HostOs = "other";
 #endif
        Jim_SetGlobalVariableStr(interp, "ocd_HOSTOS",
                        Jim_NewStringObj(interp, HostOs , strlen(HostOs)));
 
        Jim_CreateCommand(interp, "ocd_find", jim_find, NULL, NULL);
-       Jim_CreateCommand(interp, "echo", jim_echo, NULL, NULL);
        Jim_CreateCommand(interp, "capture", jim_capture, NULL, NULL);
 
-       /* Set Jim's STDIO */
-       interp->cookie_stdin = interp;
-       interp->cookie_stdout = interp;
-       interp->cookie_stderr = interp;
-       interp->cb_fwrite = openocd_jim_fwrite;
-       interp->cb_fread = openocd_jim_fread ;
-       interp->cb_vfprintf = openocd_jim_vfprintf;
-       interp->cb_fflush = openocd_jim_fflush;
-       interp->cb_fgets = openocd_jim_fgets;
-
        register_commands(context, NULL, command_builtin_handlers);
 
-#if !BUILD_ECOSBOARD
-       Jim_EventLoopOnLoad(interp);
-#endif
        Jim_SetAssocData(interp, "context", NULL, context);
        if (Jim_Eval_Named(interp, startup_tcl, "embedded:startup.tcl",1) == JIM_ERR)
        {
                LOG_ERROR("Failed to run startup.tcl (embedded into OpenOCD)");
-               Jim_PrintErrorMessage(interp);
+               Jim_MakeErrorMessage(interp);
+               LOG_USER_N("%s", Jim_GetString(Jim_GetResult(interp), NULL));
                exit(-1);
        }
        Jim_DeleteAssocData(interp, "context");
@@ -1278,17 +1387,16 @@ int command_context_mode(struct command_context *cmd_ctx, enum command_mode mode
        return ERROR_OK;
 }
 
-void process_jim_events(void)
+void process_jim_events(struct command_context *cmd_ctx)
 {
 #if !BUILD_ECOSBOARD
        static int recursion = 0;
+       if (recursion)
+               return;
 
-       if (!recursion)
-       {
-               recursion++;
-               Jim_ProcessEvents (interp, JIM_ALL_EVENTS | JIM_DONT_WAIT);
-               recursion--;
-       }
+       recursion++;
+       Jim_ProcessEvents(cmd_ctx->interp, JIM_ALL_EVENTS | JIM_DONT_WAIT);
+       recursion--;
 #endif
 }