gdb: add default description reg types
[fw/openocd] / src / server / gdb_server.c
index e17ccffa9f3eefa65336880be46fed7a325276c5..a9681c79716ea36f6c91d80b8ce0841e6f4c1ab7 100644 (file)
  *   Copyright (C) ST-Ericsson SA 2011                                     *
  *   michel.jaouen@stericsson.com : smp minimum support                    *
  *                                                                         *
+ *   Copyright (C) 2013 Andes Technology                                   *
+ *   Hsiangkai Wang <hkwang@andestech.com>                                 *
+ *                                                                         *
+ *   Copyright (C) 2013 Franck Jullien                                     *
+ *   elec4fun@gmail.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     *
@@ -114,6 +120,14 @@ static int gdb_flash_program = 1;
  */
 static int gdb_report_data_abort;
 
+/* set if we are sending target descriptions to gdb
+ * via qXfer:features:read packet */
+/* disabled by default */
+static int gdb_use_target_description;
+
+/* current processing free-run type, used by file-I/O */
+static char gdb_running_type;
+
 static int gdb_last_signal(struct target *target)
 {
        switch (target->debug_reason) {
@@ -680,6 +694,146 @@ static int gdb_output(struct command_context *context, const char *line)
        return ERROR_OK;
 }
 
+static void gdb_signal_reply(struct target *target, struct connection *connection)
+{
+       struct gdb_connection *gdb_connection = connection->priv;
+       char sig_reply[20];
+       char stop_reason[20];
+       int sig_reply_len;
+       int signal_var;
+
+       if (target->debug_reason == DBG_REASON_EXIT) {
+               sig_reply_len = snprintf(sig_reply, sizeof(sig_reply), "W00");
+       } else {
+               if (gdb_connection->ctrl_c) {
+                       signal_var = 0x2;
+                       gdb_connection->ctrl_c = 0;
+               } else
+                       signal_var = gdb_last_signal(target);
+
+               stop_reason[0] = '\0';
+               if (target->debug_reason == DBG_REASON_WATCHPOINT) {
+                       enum watchpoint_rw hit_wp_type;
+                       uint32_t hit_wp_address;
+
+                       if (watchpoint_hit(target, &hit_wp_type, &hit_wp_address) == ERROR_OK) {
+
+                               switch (hit_wp_type) {
+                                       case WPT_WRITE:
+                                               snprintf(stop_reason, sizeof(stop_reason),
+                                                               "watch:%08x;", hit_wp_address);
+                                               break;
+                                       case WPT_READ:
+                                               snprintf(stop_reason, sizeof(stop_reason),
+                                                               "rwatch:%08x;", hit_wp_address);
+                                               break;
+                                       case WPT_ACCESS:
+                                               snprintf(stop_reason, sizeof(stop_reason),
+                                                               "awatch:%08x;", hit_wp_address);
+                                               break;
+                                       default:
+                                               break;
+                               }
+                       }
+               }
+
+               sig_reply_len = snprintf(sig_reply, sizeof(sig_reply), "T%2.2x%s",
+                               signal_var, stop_reason);
+       }
+
+       gdb_put_packet(connection, sig_reply, sig_reply_len);
+       gdb_connection->frontend_state = TARGET_HALTED;
+       rtos_update_threads(target);
+}
+
+static void gdb_fileio_reply(struct target *target, struct connection *connection)
+{
+       struct gdb_connection *gdb_connection = connection->priv;
+       char fileio_command[256];
+       int command_len;
+       bool program_exited = false;
+
+       if (strcmp(target->fileio_info->identifier, "open") == 0)
+               sprintf(fileio_command, "F%s,%x/%x,%x,%x", target->fileio_info->identifier,
+                               target->fileio_info->param_1,
+                               target->fileio_info->param_2,
+                               target->fileio_info->param_3,
+                               target->fileio_info->param_4);
+       else if (strcmp(target->fileio_info->identifier, "close") == 0)
+               sprintf(fileio_command, "F%s,%x", target->fileio_info->identifier,
+                               target->fileio_info->param_1);
+       else if (strcmp(target->fileio_info->identifier, "read") == 0)
+               sprintf(fileio_command, "F%s,%x,%x,%x", target->fileio_info->identifier,
+                               target->fileio_info->param_1,
+                               target->fileio_info->param_2,
+                               target->fileio_info->param_3);
+       else if (strcmp(target->fileio_info->identifier, "write") == 0)
+               sprintf(fileio_command, "F%s,%x,%x,%x", target->fileio_info->identifier,
+                               target->fileio_info->param_1,
+                               target->fileio_info->param_2,
+                               target->fileio_info->param_3);
+       else if (strcmp(target->fileio_info->identifier, "lseek") == 0)
+               sprintf(fileio_command, "F%s,%x,%x,%x", target->fileio_info->identifier,
+                               target->fileio_info->param_1,
+                               target->fileio_info->param_2,
+                               target->fileio_info->param_3);
+       else if (strcmp(target->fileio_info->identifier, "rename") == 0)
+               sprintf(fileio_command, "F%s,%x/%x,%x/%x", target->fileio_info->identifier,
+                               target->fileio_info->param_1,
+                               target->fileio_info->param_2,
+                               target->fileio_info->param_3,
+                               target->fileio_info->param_4);
+       else if (strcmp(target->fileio_info->identifier, "unlink") == 0)
+               sprintf(fileio_command, "F%s,%x/%x", target->fileio_info->identifier,
+                               target->fileio_info->param_1,
+                               target->fileio_info->param_2);
+       else if (strcmp(target->fileio_info->identifier, "stat") == 0)
+               sprintf(fileio_command, "F%s,%x/%x,%x", target->fileio_info->identifier,
+                               target->fileio_info->param_1,
+                               target->fileio_info->param_2,
+                               target->fileio_info->param_3);
+       else if (strcmp(target->fileio_info->identifier, "fstat") == 0)
+               sprintf(fileio_command, "F%s,%x,%x", target->fileio_info->identifier,
+                               target->fileio_info->param_1,
+                               target->fileio_info->param_2);
+       else if (strcmp(target->fileio_info->identifier, "gettimeofday") == 0)
+               sprintf(fileio_command, "F%s,%x,%x", target->fileio_info->identifier,
+                               target->fileio_info->param_1,
+                               target->fileio_info->param_2);
+       else if (strcmp(target->fileio_info->identifier, "isatty") == 0)
+               sprintf(fileio_command, "F%s,%x", target->fileio_info->identifier,
+                               target->fileio_info->param_1);
+       else if (strcmp(target->fileio_info->identifier, "system") == 0)
+               sprintf(fileio_command, "F%s,%x/%x", target->fileio_info->identifier,
+                               target->fileio_info->param_1,
+                               target->fileio_info->param_2);
+       else if (strcmp(target->fileio_info->identifier, "exit") == 0) {
+               /* If target hits exit syscall, report to GDB the program is terminated.
+                * In addition, let target run its own exit syscall handler. */
+               program_exited = true;
+               sprintf(fileio_command, "W%02x", target->fileio_info->param_1);
+       } else {
+               LOG_DEBUG("Unknown syscall: %s", target->fileio_info->identifier);
+
+               /* encounter unknown syscall, continue */
+               gdb_connection->frontend_state = TARGET_RUNNING;
+               target_resume(target, 1, 0x0, 0, 0);
+               return;
+       }
+
+       command_len = strlen(fileio_command);
+       gdb_put_packet(connection, fileio_command, command_len);
+
+       if (program_exited) {
+               /* Use target_resume() to let target run its own exit syscall handler. */
+               gdb_connection->frontend_state = TARGET_RUNNING;
+               target_resume(target, 1, 0x0, 0, 0);
+       } else {
+               gdb_connection->frontend_state = TARGET_HALTED;
+               rtos_update_threads(target);
+       }
+}
+
 static void gdb_frontend_halted(struct target *target, struct connection *connection)
 {
        struct gdb_connection *gdb_connection = connection->priv;
@@ -694,22 +848,14 @@ static void gdb_frontend_halted(struct target *target, struct connection *connec
         * that are to be ignored.
         */
        if (gdb_connection->frontend_state == TARGET_RUNNING) {
-               char sig_reply[4];
-               int signal_var;
-
                /* stop forwarding log packets! */
                log_remove_callback(gdb_log_callback, connection);
 
-               if (gdb_connection->ctrl_c) {
-                       signal_var = 0x2;
-                       gdb_connection->ctrl_c = 0;
-               } else
-                       signal_var = gdb_last_signal(target);
-
-               snprintf(sig_reply, 4, "T%2.2x", signal_var);
-               gdb_put_packet(connection, sig_reply, 3);
-               gdb_connection->frontend_state = TARGET_HALTED;
-               rtos_update_threads(target);
+               /* check fileio first */
+               if (target_get_gdb_fileio_info(target, target->fileio_info) == ERROR_OK)
+                       gdb_fileio_reply(target, connection);
+               else
+                       gdb_signal_reply(target, connection);
        }
 }
 
@@ -718,6 +864,10 @@ static int gdb_target_callback_event_handler(struct target *target,
 {
        int retval;
        struct connection *connection = priv;
+       struct gdb_service *gdb_service = connection->service->priv;
+
+       if (gdb_service->target != target)
+               return ERROR_OK;
 
        switch (event) {
                case TARGET_EVENT_GDB_HALT:
@@ -756,7 +906,7 @@ static int gdb_new_connection(struct connection *connection)
        gdb_connection->closed = 0;
        gdb_connection->busy = 0;
        gdb_connection->noack_mode = 0;
-       gdb_connection->sync = true;
+       gdb_connection->sync = false;
        gdb_connection->mem_write_error = false;
        gdb_connection->attached = true;
 
@@ -968,7 +1118,8 @@ static int gdb_get_registers_packet(struct connection *connection,
        if ((target->rtos != NULL) && (ERROR_OK == rtos_get_gdb_reg_list(connection)))
                return ERROR_OK;
 
-       retval = target_get_gdb_reg_list(target, &reg_list, &reg_list_size);
+       retval = target_get_gdb_reg_list(target, &reg_list, &reg_list_size,
+                       REG_CLASS_GENERAL);
        if (retval != ERROR_OK)
                return gdb_error(connection, retval);
 
@@ -1027,7 +1178,8 @@ static int gdb_set_registers_packet(struct connection *connection,
                return ERROR_SERVER_REMOTE_CLOSED;
        }
 
-       retval = target_get_gdb_reg_list(target, &reg_list, &reg_list_size);
+       retval = target_get_gdb_reg_list(target, &reg_list, &reg_list_size,
+                       REG_CLASS_GENERAL);
        if (retval != ERROR_OK)
                return gdb_error(connection, retval);
 
@@ -1072,7 +1224,8 @@ static int gdb_get_register_packet(struct connection *connection,
        LOG_DEBUG("-");
 #endif
 
-       retval = target_get_gdb_reg_list(target, &reg_list, &reg_list_size);
+       retval = target_get_gdb_reg_list(target, &reg_list, &reg_list_size,
+                       REG_CLASS_ALL);
        if (retval != ERROR_OK)
                return gdb_error(connection, retval);
 
@@ -1109,7 +1262,8 @@ static int gdb_set_register_packet(struct connection *connection,
 
        LOG_DEBUG("-");
 
-       retval = target_get_gdb_reg_list(target, &reg_list, &reg_list_size);
+       retval = target_get_gdb_reg_list(target, &reg_list, &reg_list_size,
+                       REG_CLASS_ALL);
        if (retval != ERROR_OK)
                return gdb_error(connection, retval);
 
@@ -1346,6 +1500,7 @@ static int gdb_step_continue_packet(struct connection *connection,
        } else
                current = 1;
 
+       gdb_running_type = packet[0];
        if (packet[0] == 'c') {
                LOG_DEBUG("continue");
                /* resume at current address, don't handle breakpoints, not debugging */
@@ -1670,6 +1825,335 @@ static int gdb_memory_map(struct connection *connection,
        return ERROR_OK;
 }
 
+static const char *gdb_get_reg_type_name(enum reg_type type)
+{
+       switch (type) {
+               case REG_TYPE_INT:
+                       return "int";
+               case REG_TYPE_INT8:
+                       return "int8";
+               case REG_TYPE_INT16:
+                       return "int16";
+               case REG_TYPE_INT32:
+                       return "int32";
+               case REG_TYPE_INT64:
+                       return "int64";
+               case REG_TYPE_INT128:
+                       return "int128";
+               case REG_TYPE_UINT8:
+                       return "uint8";
+               case REG_TYPE_UINT16:
+                       return "uint16";
+               case REG_TYPE_UINT32:
+                       return "uint32";
+               case REG_TYPE_UINT64:
+                       return "uint64";
+               case REG_TYPE_UINT128:
+                       return "uint128";
+               case REG_TYPE_CODE_PTR:
+                       return "code_ptr";
+               case REG_TYPE_DATA_PTR:
+                       return "data_ptr";
+               case REG_TYPE_FLOAT:
+                       return "float";
+               case REG_TYPE_IEEE_SINGLE:
+                       return "ieee_single";
+               case REG_TYPE_IEEE_DOUBLE:
+                       return "ieee_double";
+               case REG_TYPE_ARCH_DEFINED:
+                       return "int"; /* return arbitrary string to avoid compile warning. */
+       }
+
+       return "int"; /* "int" as default value */
+}
+
+static int gdb_generate_reg_type_description(struct target *target,
+               char **tdesc, int *pos, int *size, struct reg_data_type *type)
+{
+       int retval = ERROR_OK;
+
+       if (type->type_class == REG_TYPE_CLASS_VECTOR) {
+               /* <vector id="id" type="type" count="count"/> */
+               xml_printf(&retval, tdesc, pos, size,
+                               "<vector id=\"%s\" type=\"%s\" count=\"%d\"/>\n",
+                               type->id, type->reg_type_vector->type->id,
+                               type->reg_type_vector->count);
+
+       } else if (type->type_class == REG_TYPE_CLASS_UNION) {
+               /* <union id="id">
+                *  <field name="name" type="type"/> ...
+                * </union> */
+               xml_printf(&retval, tdesc, pos, size,
+                               "<union id=\"%s\">\n",
+                               type->id);
+
+               struct reg_data_type_union_field *field;
+               field = type->reg_type_union->fields;
+               while (field != NULL) {
+                       xml_printf(&retval, tdesc, pos, size,
+                                       "<field name=\"%s\" type=\"%s\"/>\n",
+                                       field->name, field->type->id);
+
+                       field = field->next;
+               }
+
+               xml_printf(&retval, tdesc, pos, size,
+                               "</union>\n");
+
+       } else if (type->type_class == REG_TYPE_CLASS_STRUCT) {
+               struct reg_data_type_struct_field *field;
+               field = type->reg_type_struct->fields;
+
+               if (field->use_bitfields) {
+                       /* <struct id="id" size="size">
+                        *  <field name="name" start="start" end="end"/> ...
+                        * </struct> */
+                       xml_printf(&retval, tdesc, pos, size,
+                                       "<struct id=\"%s\" size=\"%d\">\n",
+                                       type->id, type->reg_type_struct->size);
+                       while (field != NULL) {
+                               xml_printf(&retval, tdesc, pos, size,
+                                               "<field name=\"%s\" start=\"%d\" end=\"%d\"/>\n",
+                                               field->name, field->bitfield->start,
+                                               field->bitfield->end);
+
+                               field = field->next;
+                       }
+               } else {
+                       /* <struct id="id">
+                        *  <field name="name" type="type"/> ...
+                        * </struct> */
+                       xml_printf(&retval, tdesc, pos, size,
+                                       "<struct id=\"%s\">\n",
+                                       type->id);
+                       while (field != NULL) {
+                               xml_printf(&retval, tdesc, pos, size,
+                                               "<field name=\"%s\" type=\"%s\"/>\n",
+                                               field->name, field->type->id);
+
+                               field = field->next;
+                       }
+               }
+
+               xml_printf(&retval, tdesc, pos, size,
+                               "</struct>\n");
+
+       } else if (type->type_class == REG_TYPE_CLASS_FLAGS) {
+               /* <flags id="id" size="size">
+                *  <field name="name" start="start" end="end"/> ...
+                * </flags> */
+               xml_printf(&retval, tdesc, pos, size,
+                               "<flags id=\"%s\" size=\"%d\">\n",
+                               type->id, type->reg_type_flags->size);
+
+               struct reg_data_type_flags_field *field;
+               field = type->reg_type_flags->fields;
+               while (field != NULL) {
+                       xml_printf(&retval, tdesc, pos, size,
+                                       "<field name=\"%s\" start=\"%d\" end=\"%d\"/>\n",
+                                       field->name, field->bitfield->start, field->bitfield->end);
+
+                       field = field->next;
+               }
+
+               xml_printf(&retval, tdesc, pos, size,
+                               "</flags>\n");
+
+       }
+
+       return ERROR_OK;
+}
+
+/* Get a list of available target registers features. feature_list must
+ * be freed by caller.
+ */
+int get_reg_features_list(struct target *target, char **feature_list[], int *feature_list_size,
+               struct reg **reg_list, int reg_list_size)
+{
+       int tbl_sz = 0;
+
+       /* Start with only one element */
+       *feature_list = calloc(1, sizeof(char *));
+
+       for (int i = 0; i < reg_list_size; i++) {
+               if (reg_list[i]->exist == false)
+                       continue;
+
+               if ((reg_list[i]->feature->name != NULL)
+                       && (strcmp(reg_list[i]->feature->name, ""))) {
+                       /* We found a feature, check if the feature is already in the
+                        * table. If not, allocate a new entry for the table and
+                        * put the new feature in it.
+                        */
+                       for (int j = 0; j < (tbl_sz + 1); j++) {
+                               if (!((*feature_list)[j])) {
+                                       (*feature_list)[tbl_sz++] = strdup(reg_list[i]->feature->name);
+                                       *feature_list = realloc(*feature_list, sizeof(char *) * (tbl_sz + 1));
+                                       (*feature_list)[tbl_sz] = NULL;
+                                       break;
+                               } else {
+                                       if (!strcmp((*feature_list)[j], reg_list[i]->feature->name))
+                                               break;
+                               }
+                       }
+               }
+       }
+
+       if (feature_list_size)
+               *feature_list_size = tbl_sz;
+
+       return ERROR_OK;
+}
+
+static int gdb_generate_target_description(struct target *target, char **tdesc)
+{
+       int retval = ERROR_OK;
+       struct reg **reg_list;
+       int reg_list_size;
+       int pos = 0;
+       int size = 0;
+
+       xml_printf(&retval, tdesc, &pos, &size,
+                       "<?xml version=\"1.0\"?>\n"
+                       "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">\n"
+                       "<target version=\"1.0\">\n");
+
+       retval = target_get_gdb_reg_list(target, &reg_list,
+                       &reg_list_size, REG_CLASS_ALL);
+
+       if (retval != ERROR_OK) {
+               LOG_ERROR("get register list failed");
+               return ERROR_FAIL;
+       }
+
+       if (reg_list_size <= 0)
+               return ERROR_FAIL;
+
+       char **features = NULL;
+       /* Get a list of available target registers features */
+       retval = get_reg_features_list(target, &features, NULL, reg_list, reg_list_size);
+       if (retval != ERROR_OK) {
+               LOG_ERROR("Can't get the registers feature list");
+               return ERROR_FAIL;
+       }
+
+       /* If we found some features associated with registers, create sections */
+       int current_feature = 0;
+
+       /* generate target description according to register list */
+       if (features != NULL) {
+               while (features[current_feature]) {
+
+                       xml_printf(&retval, tdesc, &pos, &size,
+                                       "<feature name=\"%s\">\n",
+                                       features[current_feature]);
+
+                       int i;
+                       for (i = 0; i < reg_list_size; i++) {
+
+                               if (reg_list[i]->exist == false)
+                                       continue;
+
+                               if (strcmp(reg_list[i]->feature->name, features[current_feature]))
+                                       continue;
+
+                               const char *type_str;
+                               if (reg_list[i]->reg_data_type != NULL) {
+                                       if (reg_list[i]->reg_data_type->type == REG_TYPE_ARCH_DEFINED) {
+                                               /* generate <type... first, if there are architecture-defined types. */
+                                               gdb_generate_reg_type_description(target, tdesc, &pos, &size,
+                                                               reg_list[i]->reg_data_type);
+
+                                               type_str = reg_list[i]->reg_data_type->id;
+                                       } else {
+                                               /* predefined type */
+                                               type_str = gdb_get_reg_type_name(
+                                                               reg_list[i]->reg_data_type->type);
+                                       }
+                               } else {
+                                       /* Default type is "int" */
+                                       type_str = "int";
+                               }
+
+                               xml_printf(&retval, tdesc, &pos, &size,
+                                               "<reg name=\"%s\"", reg_list[i]->name);
+                               xml_printf(&retval, tdesc, &pos, &size,
+                                               " bitsize=\"%d\"", reg_list[i]->size);
+                               xml_printf(&retval, tdesc, &pos, &size,
+                                               " regnum=\"%d\"", reg_list[i]->number);
+                               if (reg_list[i]->caller_save)
+                                       xml_printf(&retval, tdesc, &pos, &size,
+                                                       " save-restore=\"yes\"");
+                               else
+                                       xml_printf(&retval, tdesc, &pos, &size,
+                                                       " save-restore=\"no\"");
+
+                               xml_printf(&retval, tdesc, &pos, &size,
+                                               " type=\"%s\"", type_str);
+
+                               if (reg_list[i]->group != NULL)
+                                       xml_printf(&retval, tdesc, &pos, &size,
+                                                       " group=\"%s\"", reg_list[i]->group);
+
+                               xml_printf(&retval, tdesc, &pos, &size,
+                                               "/>\n");
+                       }
+
+                       xml_printf(&retval, tdesc, &pos, &size,
+                                       "</feature>\n");
+
+                       current_feature++;
+               }
+       }
+
+       xml_printf(&retval, tdesc, &pos, &size,
+                       "</target>\n");
+
+       if (reg_list != NULL)
+               free(reg_list);
+
+       if (features != NULL)
+               free(features);
+
+       return ERROR_OK;
+}
+
+static int gdb_get_target_description_chunk(struct target *target, char **chunk,
+               int32_t offset, uint32_t length)
+{
+       static char *tdesc;
+       static uint32_t tdesc_length;
+
+       if (tdesc == NULL) {
+               gdb_generate_target_description(target, &tdesc);
+               tdesc_length = strlen(tdesc);
+       }
+
+       char transfer_type;
+
+       if (length < (tdesc_length - offset))
+               transfer_type = 'm';
+       else
+               transfer_type = 'l';
+
+       *chunk = malloc(length + 2);
+       (*chunk)[0] = transfer_type;
+       if (transfer_type == 'm') {
+               strncpy((*chunk) + 1, tdesc + offset, length);
+               (*chunk)[1 + length] = '\0';
+       } else {
+               strncpy((*chunk) + 1, tdesc + offset, tdesc_length - offset);
+               (*chunk)[1 + (tdesc_length - offset)] = '\0';
+
+               /* After gdb-server sends out last chunk, invalidate tdesc. */
+               free(tdesc);
+               tdesc = NULL;
+               tdesc_length = 0;
+       }
+
+       return ERROR_OK;
+}
+
 static int gdb_query_packet(struct connection *connection,
                char *packet, int packet_size)
 {
@@ -1744,9 +2228,10 @@ static int gdb_query_packet(struct connection *connection,
                        &buffer,
                        &pos,
                        &size,
-                       "PacketSize=%x;qXfer:memory-map:read%c;qXfer:features:read-;QStartNoAckMode+",
+                       "PacketSize=%x;qXfer:memory-map:read%c;qXfer:features:read%c;QStartNoAckMode+",
                        (GDB_BUFFER_SIZE - 1),
-                       ((gdb_use_memory_map == 1) && (flash_get_bank_count() > 0)) ? '+' : '-');
+                       ((gdb_use_memory_map == 1) && (flash_get_bank_count() > 0)) ? '+' : '-',
+                       (gdb_use_target_description == 1) ? '+' : '-');
 
                if (retval != ERROR_OK) {
                        gdb_send_error(connection, 01);
@@ -1762,8 +2247,6 @@ static int gdb_query_packet(struct connection *connection,
                return gdb_memory_map(connection, packet, packet_size);
        else if (strncmp(packet, "qXfer:features:read:", 20) == 0) {
                char *xml = NULL;
-               int size = 0;
-               int pos = 0;
                int retval = ERROR_OK;
 
                int offset;
@@ -1778,17 +2261,12 @@ static int gdb_query_packet(struct connection *connection,
                        return ERROR_OK;
                }
 
-               if (strcmp(annex, "target.xml") != 0) {
-                       gdb_send_error(connection, 01);
-                       return ERROR_OK;
-               }
-
-               xml_printf(&retval,
-                       &xml,
-                       &pos,
-                       &size, \
-                       "l < target version=\"1.0\">\n < architecture > arm</architecture>\n</target>\n");
-
+               /* Target should prepare correct target description for annex.
+                * The first character of returned xml is 'm' or 'l'. 'm' for
+                * there are *more* chunks to transfer. 'l' for it is the *last*
+                * chunk of target description.
+                */
+               retval = gdb_get_target_description_chunk(target, &xml, offset, length);
                if (retval != ERROR_OK) {
                        gdb_error(connection, retval);
                        return retval;
@@ -1951,6 +2429,54 @@ static int gdb_detach(struct connection *connection)
        return gdb_put_packet(connection, "OK", 2);
 }
 
+/* The format of 'F' response packet is
+ * Fretcode,errno,Ctrl-C flag;call-specific attachment
+ */
+static int gdb_fileio_response_packet(struct connection *connection,
+               char *packet, int packet_size)
+{
+       struct target *target = get_target_from_connection(connection);
+       char *separator;
+       char *parsing_point;
+       int fileio_retcode = strtoul(packet + 1, &separator, 16);
+       int fileio_errno = 0;
+       bool fileio_ctrl_c = false;
+       int retval;
+
+       LOG_DEBUG("-");
+
+       if (*separator == ',') {
+               parsing_point = separator + 1;
+               fileio_errno = strtoul(parsing_point, &separator, 16);
+               if (*separator == ',') {
+                       if (*(separator + 1) == 'C') {
+                               /* TODO: process ctrl-c */
+                               fileio_ctrl_c = true;
+                       }
+               }
+       }
+
+       LOG_DEBUG("File-I/O response, retcode: 0x%x, errno: 0x%x, ctrl-c: %s",
+                       fileio_retcode, fileio_errno, fileio_ctrl_c ? "true" : "false");
+
+       retval = target_gdb_fileio_end(target, fileio_retcode, fileio_errno, fileio_ctrl_c);
+       if (retval != ERROR_OK)
+               return ERROR_FAIL;
+
+       /* After File-I/O ends, keep continue or step */
+       if (gdb_running_type == 'c')
+               retval = target_resume(target, 1, 0x0, 0, 0);
+       else if (gdb_running_type == 's')
+               retval = target_step(target, 1, 0x0, 0);
+       else
+               retval = ERROR_FAIL;
+
+       if (retval != ERROR_OK)
+               return ERROR_FAIL;
+
+       return ERROR_OK;
+}
+
 static void gdb_log_callback(void *priv, const char *file, unsigned line,
                const char *function, const char *string)
 {
@@ -2177,6 +2703,19 @@ static int gdb_input_inner(struct connection *connection)
                                        gdb_write_smp_packet(connection, packet, packet_size);
                                        break;
 
+                               case 'F':
+                                       /* File-I/O extension */
+                                       /* After gdb uses host-side syscall to complete target file
+                                        * I/O, gdb sends host-side syscall return value to target
+                                        * by 'F' packet.
+                                        * The format of 'F' response packet is
+                                        * Fretcode,errno,Ctrl-C flag;call-specific attachment
+                                        */
+                                       gdb_con->frontend_state = TARGET_RUNNING;
+                                       log_add_callback(gdb_log_callback, connection);
+                                       gdb_fileio_response_packet(connection, packet, packet_size);
+                                       break;
+
                                default:
                                        /* ignore unknown packets */
                                        LOG_DEBUG("ignoring 0x%2.2x packet", packet[0]);
@@ -2372,6 +2911,54 @@ COMMAND_HANDLER(handle_gdb_breakpoint_override_command)
        return ERROR_OK;
 }
 
+COMMAND_HANDLER(handle_gdb_target_description_command)
+{
+       if (CMD_ARGC != 1)
+               return ERROR_COMMAND_SYNTAX_ERROR;
+
+       COMMAND_PARSE_ENABLE(CMD_ARGV[0], gdb_use_target_description);
+       return ERROR_OK;
+}
+
+COMMAND_HANDLER(handle_gdb_save_tdesc_command)
+{
+       static char *tdesc;
+       static uint32_t tdesc_length;
+       struct target *target = get_current_target(CMD_CTX);
+       char *tdesc_filename;
+
+       if (tdesc == NULL) {
+               gdb_generate_target_description(target, &tdesc);
+               tdesc_length = strlen(tdesc);
+       }
+
+       struct fileio fileio;
+       size_t size_written;
+
+       tdesc_filename = malloc(strlen(target_type_name(target)) + 5);
+       sprintf(tdesc_filename, "%s.xml", target_type_name(target));
+
+       int retval = fileio_open(&fileio, tdesc_filename, FILEIO_WRITE, FILEIO_TEXT);
+
+       if (retval != ERROR_OK) {
+               LOG_WARNING("Can't open %s for writing", tdesc_filename);
+               free(tdesc_filename);
+               return ERROR_FAIL;
+       }
+
+       retval = fileio_write(&fileio, tdesc_length, tdesc, &size_written);
+
+       fileio_close(&fileio);
+       free(tdesc_filename);
+
+       if (retval != ERROR_OK) {
+               LOG_WARNING("Error while writing the tdesc file");
+               return ERROR_FAIL;
+       }
+
+       return ERROR_OK;
+}
+
 static const struct command_registration gdb_command_handlers[] = {
        {
                .name = "gdb_sync",
@@ -2424,6 +3011,19 @@ static const struct command_registration gdb_command_handlers[] = {
                        "to be used by gdb 'break' commands.",
                .usage = "('hard'|'soft'|'disable')"
        },
+       {
+               .name = "gdb_target_description",
+               .handler = handle_gdb_target_description_command,
+               .mode = COMMAND_CONFIG,
+               .help = "enable or disable target description",
+               .usage = "('enable'|'disable')"
+       },
+       {
+               .name = "gdb_save_tdesc",
+               .handler = handle_gdb_save_tdesc_command,
+               .mode = COMMAND_EXEC,
+               .help = "Save the target description file",
+       },
        COMMAND_REGISTRATION_DONE
 };