Duane Ellis: fix warnings
[fw/openocd] / src / jtag / jtag.c
index fe76a32213067e4510fa215e805e2b8256e77368..d34cec5a257b3187221eadb7b9870408ff3f2d87 100644 (file)
@@ -2,6 +2,9 @@
  *   Copyright (C) 2005 by Dominic Rath                                    *
  *   Dominic.Rath@gmx.de                                                   *
  *                                                                         *
+ *   Copyright (C) 2007,2008 Ã˜yvind Harboe                                      *
+ *   oyvind.harboe@zylin.com                                               *
+ *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU General Public License as published by  *
  *   the Free Software Foundation; either version 2 of the License, or     *
 
 #include "command.h"
 #include "log.h"
-#include "interpreter.h"
 
 #include "stdlib.h"
 #include "string.h"
 #include <unistd.h>
 
-
 /* note that this is not marked as static as it must be available from outside jtag.c for those 
    that implement the jtag_xxx() minidriver layer 
 */
@@ -106,7 +107,7 @@ tap_transition_t tap_transitions[16] =
 
 char* jtag_event_strings[] =
 {
-       "JTAG controller reset(tms or TRST)"
+       "JTAG controller reset (TLR or TRST)"
 };
 
 /* kludge!!!! these are just global variables that the
@@ -142,7 +143,7 @@ int jtag_ntrst_delay = 0; /* default to no nTRST delay */
 jtag_event_callback_t *jtag_event_callbacks;
 
 /* speed in kHz*/
-static int speed1 = 0, speed2 = 0;
+static int speed_khz = 0;
 /* flag if the kHz speed was defined */
 static int hasKHz = 0;
 
@@ -156,7 +157,11 @@ static int hasKHz = 0;
 #if BUILD_PARPORT == 1
        extern jtag_interface_t parport_interface;
 #endif
-
+        
+#if BUILD_DUMMY == 1
+       extern jtag_interface_t dummy_interface;
+#endif
+       
 #if BUILD_FT2232_FTD2XX == 1
        extern jtag_interface_t ft2232_interface;
 #endif
@@ -189,6 +194,10 @@ static int hasKHz = 0;
        extern jtag_interface_t usbprog_interface;
 #endif
 
+#if BUILD_JLINK == 1
+       extern jtag_interface_t jlink_interface;
+#endif
+
 jtag_interface_t *jtag_interfaces[] = {
 #if BUILD_ECOSBOARD == 1
        &eCosBoard_interface,
@@ -196,6 +205,9 @@ jtag_interface_t *jtag_interfaces[] = {
 #if BUILD_PARPORT == 1
        &parport_interface,
 #endif
+#if BUILD_DUMMY == 1
+       &dummy_interface,
+#endif
 #if BUILD_FT2232_FTD2XX == 1
        &ft2232_interface,
 #endif
@@ -219,6 +231,9 @@ jtag_interface_t *jtag_interfaces[] = {
 #endif
 #if BUILD_USBPROG == 1
        &usbprog_interface,
+#endif
+#if BUILD_JLINK == 1
+       &jlink_interface,
 #endif
        NULL,
 };
@@ -228,7 +243,7 @@ jtag_interface_t *jtag = NULL;
 /* configuration */
 jtag_interface_t *jtag_interface = NULL;
 int jtag_speed = 0;
-int jtag_speed_post_reset = 0;
+
 
 
 /* forward declarations */
@@ -254,7 +269,7 @@ int handle_endstate_command(struct command_context_s *cmd_ctx, char *cmd, char *
 int handle_jtag_reset_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
 int handle_runtest_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
 int handle_irscan_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
-int handle_drscan_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
+int Jim_Command_drscan(Jim_Interp *interp, int argc, Jim_Obj *const *argv);
 
 int handle_verify_ircapture_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
 
@@ -386,7 +401,7 @@ void* cmd_queue_alloc(size_t size)
        return t + offset;
 }
 
-void cmd_queue_free()
+void cmd_queue_free(void)
 {
        cmd_queue_page_t *page = cmd_queue_pages;
 
@@ -401,7 +416,7 @@ void cmd_queue_free()
        cmd_queue_pages = NULL;
 }
 
-static void jtag_prelude1()
+static void jtag_prelude1(void)
 {
        if (jtag_trst == 1)
        {
@@ -588,6 +603,11 @@ int MINIDRIVER(interface_jtag_add_dr_scan)(int num_fields, scan_field_t *fields,
                        bypass_devices++;
                device = device->next;
        }
+       if (bypass_devices >= jtag_num_devices)
+       {
+               LOG_ERROR("all devices in bypass");
+               return ERROR_JTAG_DEVICE_ERROR;
+       }
        
        /* allocate memory for a new list member */
        *last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
@@ -660,8 +680,8 @@ int MINIDRIVER(interface_jtag_add_dr_scan)(int num_fields, scan_field_t *fields,
 
 void MINIDRIVER(interface_jtag_add_dr_out)(int device_num, 
                int num_fields,
-               int *num_bits,
-               u32 *value,
+               const int *num_bits,
+               const u32 *value,
                enum tap_state end_state)
 {
        int i;
@@ -744,9 +764,6 @@ void MINIDRIVER(interface_jtag_add_dr_out)(int device_num,
        }
 }
 
-
-
-
 void jtag_add_plain_dr_scan(int num_fields, scan_field_t *fields, enum tap_state state)
 {
        int retval;
@@ -837,6 +854,11 @@ void jtag_add_pathmove(int num_states, enum tap_state *path)
 
        for (i=0; i<num_states; i++)
        {
+               if (path[i] == TAP_TLR)
+               {
+                       LOG_ERROR("BUG: TAP_TLR is not a valid state for pathmove sequences");
+                       exit(-1);
+               }
                if ((tap_transitions[cur_state].low != path[i])&&
                                (tap_transitions[cur_state].high != path[i]))
                {
@@ -848,14 +870,13 @@ void jtag_add_pathmove(int num_states, enum tap_state *path)
        
        jtag_prelude1();
        
-       cmd_queue_cur_state = path[num_states - 1];
 
        retval=interface_jtag_add_pathmove(num_states, path);
+       cmd_queue_cur_state = path[num_states - 1];
        if (retval!=ERROR_OK)
                jtag_error=retval;
 }
 
-
 int MINIDRIVER(interface_jtag_add_pathmove)(int num_states, enum tap_state *path)
 {
        jtag_command_t **last_cmd = jtag_get_last_command_p();
@@ -913,18 +934,18 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
        
        /* FIX!!! there are *many* different cases here. A better
         * approach is needed for legal combinations of transitions...
-       */
+        */
        if ((jtag_reset_config & RESET_HAS_SRST)&&
                        (jtag_reset_config & RESET_HAS_TRST)&& 
-                       ((jtag_reset_config & RESET_SRST_PULLS_TRST)==0)&&
-                       ((jtag_reset_config & RESET_TRST_PULLS_SRST)==0))
+                       ((jtag_reset_config & RESET_SRST_PULLS_TRST)==0))
        {
                if (((req_tlr_or_trst&&!jtag_trst)||
                                (!req_tlr_or_trst&&jtag_trst))&&
                                ((req_srst&&!jtag_srst)||
                                                (!req_srst&&jtag_srst)))
                {
-                       LOG_ERROR("BUG: transition of req_tlr_or_trst and req_srst in the same jtag_add_reset() call is undefined");
+                       /* FIX!!! srst_pulls_trst allows 1,1 => 0,0 transition.... */
+                       //LOG_ERROR("BUG: transition of req_tlr_or_trst and req_srst in the same jtag_add_reset() call is undefined");
                }
        }
        
@@ -986,7 +1007,7 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
        
        if (trst_with_tlr)
        {
-               LOG_DEBUG("JTAG reset with tms instead of TRST");
+               LOG_DEBUG("JTAG reset with TLR instead of TRST");
                jtag_add_end_state(TAP_TLR);
                jtag_add_tlr();
                jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
@@ -1023,14 +1044,13 @@ int MINIDRIVER(interface_jtag_add_reset)(int req_trst, int req_srst)
        (*last_cmd)->cmd.reset->trst = req_trst;
        (*last_cmd)->cmd.reset->srst = req_srst;
 
-       
        return ERROR_OK;
 }
 
 void jtag_add_end_state(enum tap_state state)
 {
        cmd_queue_end_state = state;
-       if ((cmd_queue_end_state == TAP_SD)||(cmd_queue_end_state == TAP_SD))
+       if ((cmd_queue_end_state == TAP_SD)||(cmd_queue_end_state == TAP_SI))
        {
                LOG_ERROR("BUG: TAP_SD/SI can't be end state. Calling code should use a larger scan field");
        }
@@ -1054,6 +1074,7 @@ int MINIDRIVER(interface_jtag_add_sleep)(u32 us)
 
 void jtag_add_sleep(u32 us)
 {
+       keep_alive(); /* we might be running on a very slow JTAG clk */
        int retval=interface_jtag_add_sleep(us);
        if (retval!=ERROR_OK)
                jtag_error=retval;
@@ -1102,7 +1123,6 @@ int jtag_build_buffer(scan_command_t *cmd, u8 **buffer)
        }
 
        return bit_count;
-
 }
 
 int jtag_read_buffer(u8 *buffer, scan_command_t *cmd)
@@ -1222,7 +1242,7 @@ void jtag_set_check_value(scan_field_t *field, u8 *value, u8 *mask, error_handle
                field->in_handler = jtag_check_value;
        else
                field->in_handler = NULL;       /* No check, e.g. embeddedice uses value==NULL to indicate no check */
-       field->in_handler_priv = NULL;  /* this will be filled in at the invocation site to point to the field duplicate */ 
+       field->in_handler_priv = NULL;
        field->in_check_value = value;
        field->in_check_mask = mask;
 }
@@ -1246,7 +1266,13 @@ enum scan_type jtag_scan_type(scan_command_t *cmd)
 int MINIDRIVER(interface_jtag_execute_queue)(void)
 {
        int retval;
-
+       
+       if (jtag==NULL)
+       {
+               LOG_ERROR("No JTAG interface configured yet. Issue 'init' command in startup scripts before communicating with targets.");
+               return ERROR_FAIL;
+       }
+       
        retval = jtag->execute_queue();
        
        cmd_queue_free();
@@ -1340,6 +1366,8 @@ int jtag_examine_chain()
                        /* LSB must not be 0, this indicates a device in bypass */
                        device_count++;
                        
+                       LOG_WARNING("Device was in bypass after TRST/TMS reset");
+                       
                        bit_count += 1;
                }
                else
@@ -1350,7 +1378,28 @@ int jtag_examine_chain()
                        
                        if (idcode == 0x000000FF)
                        {
-                               /* End of chain (invalid manufacturer ID) */
+                               int unexpected=0;
+                               /* End of chain (invalid manufacturer ID) 
+                                * 
+                                * The JTAG examine is the very first thing that happens
+                                * 
+                                * A single JTAG device requires only 64 bits to be read back correctly.
+                                * 
+                                * The code below adds a check that the rest of the data scanned (640 bits)
+                                * are all as expected. This helps diagnose/catch problems with the JTAG chain
+                                * 
+                                * earlier and gives more helpful/explicit error messages.
+                                */
+                               for (bit_count += 32; bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31;bit_count += 32) 
+                               {
+                                       idcode = buf_get_u32(idcode_buffer, bit_count, 32);
+                                       if (unexpected||(idcode != 0x000000FF))
+                                       {
+                                               LOG_WARNING("Unexpected idcode after end of chain! %d 0x%08x", bit_count, idcode);
+                                               unexpected = 1;
+                                       }
+                               }
+                               
                                break;
                        }
                        
@@ -1384,7 +1433,7 @@ int jtag_examine_chain()
        return ERROR_OK;
 }
 
-int jtag_validate_chain()
+int jtag_validate_chain(void)
 {
        jtag_device_t *device = jtag_devices;
        int total_ir_length = 0;
@@ -1449,7 +1498,7 @@ int jtag_register_commands(struct command_context_s *cmd_ctx)
        register_command(cmd_ctx, NULL, "interface", handle_interface_command,
                COMMAND_CONFIG, NULL);
        register_command(cmd_ctx, NULL, "jtag_speed", handle_jtag_speed_command,
-               COMMAND_ANY, "set jtag speed (if supported) <reset speed> [<post reset speed, default value is reset speed>]");
+               COMMAND_ANY, "set jtag speed (if supported)");
        register_command(cmd_ctx, NULL, "jtag_khz", handle_jtag_khz_command,
                COMMAND_ANY, "same as jtag_speed, except it takes maximum khz as arguments. 0 KHz = RTCK.");
        register_command(cmd_ctx, NULL, "jtag_device", handle_jtag_device_command,
@@ -1472,8 +1521,7 @@ int jtag_register_commands(struct command_context_s *cmd_ctx)
                COMMAND_EXEC, "move to Run-Test/Idle, and execute <num_cycles>");
        register_command(cmd_ctx, NULL, "irscan", handle_irscan_command,
                COMMAND_EXEC, "execute IR scan <device> <instr> [dev2] [instr2] ...");
-       register_command(cmd_ctx, NULL, "drscan", handle_drscan_command,
-               COMMAND_EXEC, "execute DR scan <device> <var> [dev2] [var2] ...");
+       register_jim(cmd_ctx, "drscan", Jim_Command_drscan, "execute DR scan <device> <num_bits> <value> <num_bits1> <value2> ...");
 
        register_command(cmd_ctx, NULL, "verify_ircapture", handle_verify_ircapture_command,
                COMMAND_ANY, "verify value captured during Capture-IR <enable|disable>");
@@ -1493,11 +1541,7 @@ int jtag_interface_init(struct command_context_s *cmd_ctx)
        }
        if(hasKHz)
        {
-               /*stay on "reset speed"*/
-               if (jtag_interface->khz(speed1, &speed1) == ERROR_OK)
-                       jtag_speed = speed1;
-               if (jtag_interface->khz(speed2, &speed2) == ERROR_OK)
-                       jtag_speed_post_reset = speed2;
+               jtag_interface->khz(speed_khz, &jtag_speed);
                hasKHz = 0;
        }
 
@@ -1516,7 +1560,7 @@ static int jtag_init_inner(struct command_context_s *cmd_ctx)
        jtag_device_t *device;
        int retval;
 
-       LOG_DEBUG("-");
+       LOG_DEBUG("Init JTAG chain");
        
        device = jtag_devices;
        jtag_ir_scan_size = 0;
@@ -1529,7 +1573,7 @@ static int jtag_init_inner(struct command_context_s *cmd_ctx)
        }
        
        jtag_add_tlr();
-       if ((retval=jtag_execute_queue())==ERROR_OK)
+       if ((retval=jtag_execute_queue())!=ERROR_OK)
                return retval;
 
        /* examine chain first, as this could discover the real chain layout */
@@ -1560,11 +1604,11 @@ int jtag_init_reset(struct command_context_s *cmd_ctx)
        if ((retval=jtag_interface_init(cmd_ctx)) != ERROR_OK)
                return retval;
 
-       LOG_DEBUG("Trying to bring the JTAG controller to life by asserting TRST / tms");
+       LOG_DEBUG("Trying to bring the JTAG controller to life by asserting TRST / TLR");
 
        /* Reset can happen after a power cycle.
         * 
-        * Ideally we would only assert TRST or run tms before the target reset.
+        * Ideally we would only assert TRST or run TLR before the target reset.
         * 
         * However w/srst_pulls_trst, trst is asserted together with the target
         * reset whether we want it or not.
@@ -1577,7 +1621,7 @@ int jtag_init_reset(struct command_context_s *cmd_ctx)
         * NB! order matters!!!! srst *can* disconnect JTAG circuitry
         * 
         */
-       jtag_add_reset(1, 0); /* TMS or TRST */
+       jtag_add_reset(1, 0); /* TLR or TRST */
        if (jtag_reset_config & RESET_HAS_SRST)
        {
                jtag_add_reset(1, 1);
@@ -1610,13 +1654,17 @@ int jtag_init(struct command_context_s *cmd_ctx)
        return jtag_init_reset(cmd_ctx);
 }
 
-
 static int default_khz(int khz, int *jtag_speed)
 {
        LOG_ERROR("Translation from khz to jtag_speed not implemented");
        return ERROR_FAIL;
 }
 
+static int default_speed_div(int speed, int *khz)
+{
+       return ERROR_FAIL;      
+}
+
 int handle_interface_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 {
        int i;
@@ -1647,6 +1695,10 @@ int handle_interface_command(struct command_context_s *cmd_ctx, char *cmd, char
                        {
                                jtag_interface->khz = default_khz;
                        }
+                       if (jtag_interface->speed_div == NULL)
+                       {
+                               jtag_interface->speed_div = default_speed_div;
+                       }
                        return ERROR_OK;
                }
        }
@@ -1826,66 +1878,68 @@ int handle_jtag_ntrst_delay_command(struct command_context_s *cmd_ctx, char *cmd
 
 int handle_jtag_speed_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 {
-       int cur_speed = 0;
+       int retval=ERROR_OK;
        
-       if (argc != 0)
+       if (argc == 1)
        {
-               if ((argc<1) || (argc>2))
-                       return ERROR_COMMAND_SYNTAX_ERROR;
-               
                LOG_DEBUG("handle jtag speed");
-               
-               if (argc >= 1)
-                       cur_speed = jtag_speed = jtag_speed_post_reset = strtoul(args[0], NULL, 0);
-               if (argc == 2)
-                       cur_speed = jtag_speed_post_reset = strtoul(args[1], NULL, 0);
+
+               int cur_speed = 0;
+               cur_speed = jtag_speed = strtoul(args[0], NULL, 0);
                        
                /* this command can be called during CONFIG, 
                 * in which case jtag isn't initialized */
                if (jtag)
-                       jtag->speed(cur_speed);
-       }               
-       command_print(cmd_ctx, "jtag_speed: %d, %d", jtag_speed, jtag_speed_post_reset);
+               {
+                       retval=jtag->speed(cur_speed);
+               }
+       } else if (argc == 0)
+       {
+       } else
+       {
+               retval=ERROR_COMMAND_SYNTAX_ERROR;
+       }
+       command_print(cmd_ctx, "jtag_speed: %d", jtag_speed);
        
-       return ERROR_OK;
+       return retval;
 }
 
 int handle_jtag_khz_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 {
+       int retval=ERROR_OK;
        LOG_DEBUG("handle jtag khz");
        
-       if ((argc<1) || (argc>2))
-               return ERROR_COMMAND_SYNTAX_ERROR;
-
-       if (argc >= 1)
-               speed1 = speed2 = strtoul(args[0], NULL, 0);
-       if (argc == 2)
-               speed2 = strtoul(args[1], NULL, 0);
-
-       if (jtag != NULL)
+       if(argc == 1)
+       {
+               speed_khz = strtoul(args[0], NULL, 0);
+               if (jtag != NULL)
+               {
+                       int cur_speed = 0;
+                       LOG_DEBUG("have interface set up");
+                       int speed_div1;
+                       if ((retval=jtag->khz(speed_khz, &speed_div1))!=ERROR_OK)
+                       {
+                               speed_khz = 0;
+                               return retval;
+                       }
+       
+                       cur_speed = jtag_speed = speed_div1;
+       
+                       retval=jtag->speed(cur_speed);
+               } else
+               {
+                       hasKHz = 1;
+               }
+       } else if (argc==0)
        {
-               int cur_speed = 0;
-               LOG_DEBUG("have interface set up");
-               int speed_div1, speed_div2;
-               if (jtag->khz(speed1, &speed_div1)!=ERROR_OK)
-                       return ERROR_OK;
-               if (jtag->khz(speed2, &speed_div2)!=ERROR_OK)
-                       return ERROR_OK;
-
-               if (argc >= 1)
-                       cur_speed = jtag_speed = jtag_speed_post_reset = speed_div1;
-               if (argc == 2)
-                       cur_speed = jtag_speed_post_reset = speed_div2;
-
-               jtag->speed(cur_speed);
        } else
        {
-               hasKHz = 1;
+               retval=ERROR_COMMAND_SYNTAX_ERROR;
        }
-       
-       return ERROR_OK;
-}
+       command_print(cmd_ctx, "jtag_khz: %d", speed_khz);
+       return retval;
 
+}
 
 int handle_endstate_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 {
@@ -1962,7 +2016,6 @@ int handle_runtest_command(struct command_context_s *cmd_ctx, char *cmd, char **
 
 }
 
-
 int handle_irscan_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 {
        int i;
@@ -2000,63 +2053,92 @@ int handle_irscan_command(struct command_context_s *cmd_ctx, char *cmd, char **a
        return ERROR_OK;
 }
 
-int handle_drscan_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
+int Jim_Command_drscan(Jim_Interp *interp, int argc, Jim_Obj *const *args)
 {
+       int retval;
        scan_field_t *fields;
-       int num_fields = 0;
+       int num_fields;
        int field_count = 0;
-       var_t *var;
-       int i, j;
-       
-       if ((argc < 2) || (argc % 2))
+       int i, e;
+       long device;
+
+       /* args[1] = device
+        * args[2] = num_bits
+        * args[3] = hex string
+        * ... repeat num bits and hex string ...
+        */
+       if ((argc < 4) || ((argc % 2)!=0))
        {
-               return ERROR_COMMAND_SYNTAX_ERROR;
+               Jim_WrongNumArgs(interp, 1, args, "wrong arguments");
+               return JIM_ERR;
        }
 
-       for (i = 0; i < argc; i+=2)
+       for (i = 2; i < argc; i+=2)
        {
-               var = get_var_by_namenum(args[i+1]);
-               if (var)
-               {
-                       num_fields += var->num_fields;
-               }
-               else
-               {
-                       command_print(cmd_ctx, "variable %s doesn't exist", args[i+1]);
-                       return ERROR_OK;
-               }
+               long bits;
+
+               e = Jim_GetLong(interp, args[i], &bits);
+               if (e != JIM_OK)
+                       return e;
        }
 
-       fields = malloc(sizeof(scan_field_t) * num_fields);
+       e = Jim_GetLong(interp, args[1], &device);
+       if (e != JIM_OK)
+               return e;
 
-       for (i = 0; i < argc; i+=2)
+       num_fields=(argc-2)/2;
+       fields = malloc(sizeof(scan_field_t) * num_fields);
+       for (i = 2; i < argc; i+=2)
        {
-               var = get_var_by_namenum(args[i+1]);
-       
-               for (j = 0; j < var->num_fields; j++)
-               {
-                       fields[field_count].device = strtol(args[i], NULL, 0);
-                       fields[field_count].num_bits = var->fields[j].num_bits;
-                       fields[field_count].out_value = malloc(CEIL(var->fields[j].num_bits, 8));
-                       buf_set_u32(fields[field_count].out_value, 0, var->fields[j].num_bits, var->fields[j].value);
-                       fields[field_count].out_mask = NULL;
-                       fields[field_count].in_value = fields[field_count].out_value;
-                       fields[field_count].in_check_mask = NULL;
-                       fields[field_count].in_check_value = NULL;
-                       fields[field_count].in_handler = field_le_to_host;
-                       fields[field_count++].in_handler_priv = &(var->fields[j]);
-               }
+               long bits;
+               int len;
+               const char *str;
+
+               Jim_GetLong(interp, args[i], &bits);
+               str = Jim_GetString(args[i+1], &len);
+               
+               fields[field_count].device = device;
+               fields[field_count].num_bits = bits;
+               fields[field_count].out_value = malloc(CEIL(bits, 8));
+               str_to_buf(str, len, fields[field_count].out_value, bits, 0);
+               fields[field_count].out_mask = NULL;
+               fields[field_count].in_value = fields[field_count].out_value;
+               fields[field_count].in_check_mask = NULL;
+               fields[field_count].in_check_value = NULL;
+               fields[field_count].in_handler = NULL;
+               fields[field_count++].in_handler_priv = NULL;
        }
 
        jtag_add_dr_scan(num_fields, fields, -1);
-       jtag_execute_queue();
-       
-       for (i = 0; i < argc / 2; i++)
-               free(fields[i].out_value);
+       retval = jtag_execute_queue();
+       if (retval != ERROR_OK)
+       {
+               Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
+               Jim_AppendStrings(interp, Jim_GetResult(interp), "drscan: jtag execute failed", NULL);
+               return JIM_ERR;
+       }
 
+       field_count=0;
+       Jim_Obj *list = Jim_NewListObj(interp, NULL, 0);
+       for (i = 2; i < argc; i+=2)
+       {
+               long bits;
+               char *str;
+
+               Jim_GetLong(interp, args[i], &bits);
+               str = buf_to_str(fields[field_count].in_value, bits, 16);
+               free(fields[field_count].out_value);
+
+               Jim_ListAppendElement(interp, list, Jim_NewStringObj(interp, str, strlen(str)));
+               free(str);
+               field_count++;
+       }
+
+       Jim_SetResult(interp, list);
+       
        free(fields);
 
-       return ERROR_OK;
+       return JIM_OK;
 }
 
 int handle_verify_ircapture_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)