diff --git a/src/rtos/linux.c b/src/rtos/linux.c
index 0fc763557..80d84d73e 100644
--- a/src/rtos/linux.c
+++ b/src/rtos/linux.c
@@ -226,7 +226,8 @@ static int linux_os_thread_reg_list(struct rtos *rtos,
 		/*LOG_INFO("thread %lx current on core %x",thread_id,
 		 * target->coreid);*/
 		retval =
-			target_get_gdb_reg_list(target, &reg_list, &reg_list_size);
+			target_get_gdb_reg_list(target, &reg_list, &reg_list_size,
+					REG_CLASS_GENERAL);
 
 		if (retval != ERROR_OK)
 			return retval;
@@ -498,7 +499,7 @@ int get_current(struct target *target, int create)
 		int retval;
 
 		if (target_get_gdb_reg_list(head->target, &reg_list,
-				&reg_list_size) != ERROR_OK) {
+				&reg_list_size, REG_CLASS_GENERAL) != ERROR_OK) {
 			free(buffer);
 			return ERROR_TARGET_FAILURE;
 		}
diff --git a/src/server/gdb_server.c b/src/server/gdb_server.c
index e17ccffa9..beeeedcce 100644
--- a/src/server/gdb_server.c
+++ b/src/server/gdb_server.c
@@ -14,6 +14,12 @@
  *   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 +120,11 @@ 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;
+
 static int gdb_last_signal(struct target *target)
 {
 	switch (target->debug_reason) {
@@ -968,7 +979,8 @@ 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 +1039,8 @@ 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 +1085,8 @@ 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 +1123,8 @@ 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);
 
@@ -1670,6 +1685,331 @@ 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_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_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 +2084,10 @@ 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 +2103,6 @@ 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 +2117,12 @@ 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;
@@ -2372,6 +2706,54 @@ 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);
+
+	free(tdesc_filename);
+
+	if (retval != ERROR_OK) {
+		LOG_WARNING("Can't open %s for writing", tdesc_filename);
+		return ERROR_FAIL;
+	}
+
+	retval = fileio_write(&fileio, tdesc_length, tdesc, &size_written);
+
+	fileio_close(&fileio);
+
+	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 +2806,19 @@ 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
 };
 
diff --git a/src/target/arm.h b/src/target/arm.h
index 4a4d928c6..e2d264615 100644
--- a/src/target/arm.h
+++ b/src/target/arm.h
@@ -211,7 +211,8 @@ extern const struct command_registration arm_command_handlers[];
 
 int arm_arch_state(struct target *target);
 int arm_get_gdb_reg_list(struct target *target,
-		struct reg **reg_list[], int *reg_list_size);
+		struct reg **reg_list[], int *reg_list_size,
+		enum target_register_class reg_class);
 
 int arm_init_arch_info(struct target *target, struct arm *arm);
 
diff --git a/src/target/armv4_5.c b/src/target/armv4_5.c
index 91830f57c..a2f055753 100644
--- a/src/target/armv4_5.c
+++ b/src/target/armv4_5.c
@@ -1051,7 +1051,8 @@ const struct command_registration arm_command_handlers[] = {
 };
 
 int arm_get_gdb_reg_list(struct target *target,
-	struct reg **reg_list[], int *reg_list_size)
+	struct reg **reg_list[], int *reg_list_size,
+	enum target_register_class reg_class)
 {
 	struct arm *arm = target_to_arm(target);
 	int i;
diff --git a/src/target/armv7m.c b/src/target/armv7m.c
index 622de490e..d32352a75 100644
--- a/src/target/armv7m.c
+++ b/src/target/armv7m.c
@@ -259,7 +259,8 @@ static int armv7m_write_core_reg(struct target *target, struct reg *r,
  * hardware, so this also fakes a set of long-obsolete FPA registers that
  * are not used in EABI based software stacks.
  */
-int armv7m_get_gdb_reg_list(struct target *target, struct reg **reg_list[], int *reg_list_size)
+int armv7m_get_gdb_reg_list(struct target *target, struct reg **reg_list[],
+		int *reg_list_size, enum target_register_class reg_class)
 {
 	struct armv7m_common *armv7m = target_to_armv7m(target);
 	int i;
diff --git a/src/target/armv7m.h b/src/target/armv7m.h
index bc245fb7f..d028f4efb 100644
--- a/src/target/armv7m.h
+++ b/src/target/armv7m.h
@@ -195,7 +195,8 @@ int armv7m_mode_to_number(enum armv7m_mode mode);
 
 int armv7m_arch_state(struct target *target);
 int armv7m_get_gdb_reg_list(struct target *target,
-		struct reg **reg_list[], int *reg_list_size);
+		struct reg **reg_list[], int *reg_list_size,
+		enum target_register_class reg_class);
 
 int armv7m_init_arch_info(struct target *target, struct armv7m_common *armv7m);
 
diff --git a/src/target/avr32_ap7k.c b/src/target/avr32_ap7k.c
index cc9ab5afa..7c97234df 100644
--- a/src/target/avr32_ap7k.c
+++ b/src/target/avr32_ap7k.c
@@ -576,7 +576,8 @@ int avr32_ap7k_arch_state(struct target *target)
 	return ERROR_OK;
 }
 
-int avr32_ap7k_get_gdb_reg_list(struct target *target, struct reg **reg_list[], int *reg_list_size)
+int avr32_ap7k_get_gdb_reg_list(struct target *target, struct reg **reg_list[],
+		int *reg_list_size, enum target_register_class reg_class)
 {
 #if 0
 	/* get pointers to arch-specific information */
diff --git a/src/target/dsp563xx.c b/src/target/dsp563xx.c
index 1211ac562..8c4701686 100644
--- a/src/target/dsp563xx.c
+++ b/src/target/dsp563xx.c
@@ -354,7 +354,8 @@ static uint8_t gdb_reg_list_idx[] = {
 
 static int dsp563xx_get_gdb_reg_list(struct target *target,
 	struct reg **reg_list[],
-	int *reg_list_size)
+	int *reg_list_size,
+	enum target_register_class reg_class)
 {
 	int i;
 	struct dsp563xx_common *dsp563xx = target_to_dsp563xx(target);
diff --git a/src/target/mips32.c b/src/target/mips32.c
index 1067f7b63..c9cbf86e4 100644
--- a/src/target/mips32.c
+++ b/src/target/mips32.c
@@ -173,7 +173,8 @@ static int mips32_write_core_reg(struct target *target, int num)
 	return ERROR_OK;
 }
 
-int mips32_get_gdb_reg_list(struct target *target, struct reg **reg_list[], int *reg_list_size)
+int mips32_get_gdb_reg_list(struct target *target, struct reg **reg_list[],
+		int *reg_list_size, enum target_register_class reg_class)
 {
 	/* get pointers to arch-specific information */
 	struct mips32_common *mips32 = target_to_mips32(target);
diff --git a/src/target/mips32.h b/src/target/mips32.h
index 97fb5d037..951b2ed72 100644
--- a/src/target/mips32.h
+++ b/src/target/mips32.h
@@ -243,7 +243,8 @@ int mips32_examine(struct target *target);
 int mips32_register_commands(struct command_context *cmd_ctx);
 
 int mips32_get_gdb_reg_list(struct target *target,
-		struct reg **reg_list[], int *reg_list_size);
+		struct reg **reg_list[], int *reg_list_size,
+		enum target_register_class reg_class);
 int mips32_checksum_memory(struct target *target, uint32_t address,
 		uint32_t count, uint32_t *checksum);
 int mips32_blank_check_memory(struct target *target,
diff --git a/src/target/nds32.c b/src/target/nds32.c
index 2d4770977..95a249d05 100644
--- a/src/target/nds32.c
+++ b/src/target/nds32.c
@@ -91,21 +91,23 @@ static int nds32_get_core_reg(struct reg *reg)
 		return ERROR_OK;
 	}
 
+	int mapped_regnum = nds32->register_map(nds32, reg_arch_info->num);
+
 	if (reg_arch_info->enable == false) {
 		reg_arch_info->value = NDS32_REGISTER_DISABLE;
 		retval = ERROR_FAIL;
 	} else {
 		if ((nds32->fpu_enable == false) &&
-			(NDS32_REG_TYPE_FPU == nds32_reg_type(reg_arch_info->num))) {
+			(NDS32_REG_TYPE_FPU == nds32_reg_type(mapped_regnum))) {
 			reg_arch_info->value = 0;
 			retval = ERROR_OK;
 		} else if ((nds32->audio_enable == false) &&
-			(NDS32_REG_TYPE_AUMR == nds32_reg_type(reg_arch_info->num))) {
+			(NDS32_REG_TYPE_AUMR == nds32_reg_type(mapped_regnum))) {
 			reg_arch_info->value = 0;
 			retval = ERROR_OK;
 		} else {
 			retval = aice_read_register(aice,
-					reg_arch_info->num, &(reg_arch_info->value));
+					mapped_regnum, &(reg_arch_info->value));
 		}
 
 		LOG_DEBUG("reading register %i(%s), value: 0x%8.8" PRIx32,
@@ -301,44 +303,46 @@ static int nds32_set_core_reg(struct reg *reg, uint8_t *buf)
 		return ERROR_TARGET_NOT_HALTED;
 	}
 
+	int mapped_regnum = nds32->register_map(nds32, reg_arch_info->num);
+
 	/* ignore values that will generate exception */
-	if (nds32_reg_exception(reg_arch_info->num, value))
+	if (nds32_reg_exception(mapped_regnum, value))
 		return ERROR_OK;
 
 	LOG_DEBUG("writing register %i(%s) with value 0x%8.8" PRIx32,
 			reg_arch_info->num, reg->name, value);
 
 	if ((nds32->fpu_enable == false) &&
-		(NDS32_REG_TYPE_FPU == nds32_reg_type(reg_arch_info->num))) {
+		(NDS32_REG_TYPE_FPU == nds32_reg_type(mapped_regnum))) {
 
 		buf_set_u32(reg->value, 0, 32, 0);
 	} else if ((nds32->audio_enable == false) &&
-		(NDS32_REG_TYPE_AUMR == nds32_reg_type(reg_arch_info->num))) {
+		(NDS32_REG_TYPE_AUMR == nds32_reg_type(mapped_regnum))) {
 
 		buf_set_u32(reg->value, 0, 32, 0);
 	} else {
 		buf_set_u32(reg->value, 0, 32, value);
-		aice_write_register(aice, reg_arch_info->num, reg_arch_info->value);
+		aice_write_register(aice, mapped_regnum, reg_arch_info->value);
 
 		/* After set value to registers, read the value from target
 		 * to avoid W1C inconsistency. */
-		aice_read_register(aice, reg_arch_info->num, &(reg_arch_info->value));
+		aice_read_register(aice, mapped_regnum, &(reg_arch_info->value));
 	}
 
 	reg->valid = true;
 	reg->dirty = false;
 
 	/* update registers to take effect right now */
-	if (IR0 == reg_arch_info->num) {
+	if (IR0 == mapped_regnum) {
 		nds32_update_psw(nds32);
-	} else if (MR0 == reg_arch_info->num) {
+	} else if (MR0 == mapped_regnum) {
 		nds32_update_mmu_info(nds32);
-	} else if ((MR6 == reg_arch_info->num) || (MR7 == reg_arch_info->num)) {
+	} else if ((MR6 == mapped_regnum) || (MR7 == mapped_regnum)) {
 		/* update lm information */
 		nds32_update_lm_info(nds32);
-	} else if (MR8 == reg_arch_info->num) {
+	} else if (MR8 == mapped_regnum) {
 		nds32_update_cache_info(nds32);
-	} else if (FUCPR == reg_arch_info->num) {
+	} else if (FUCPR == mapped_regnum) {
 		/* update audio/fpu setting */
 		nds32_check_extension(nds32);
 	}
@@ -415,17 +419,62 @@ static struct reg_cache *nds32_build_reg_cache(struct target *target,
 		reg_arch_info[i].enable = false;
 
 		reg_list[i].name = nds32_reg_simple_name(i);
+		reg_list[i].number = reg_arch_info[i].num;
 		reg_list[i].size = nds32_reg_size(i);
 		reg_list[i].arch_info = &reg_arch_info[i];
 
+		reg_list[i].reg_data_type = malloc(sizeof(struct reg_data_type));
+
 		if (FD0 <= reg_arch_info[i].num && reg_arch_info[i].num <= FD31) {
 			reg_list[i].value = &(reg_arch_info[i].value_64);
 			reg_list[i].type = &nds32_reg_access_type_64;
+
+			reg_list[i].reg_data_type->type = REG_TYPE_IEEE_DOUBLE;
+			reg_list[i].reg_data_type->id = "ieee_double";
+			reg_list[i].group = "float";
 		} else {
 			reg_list[i].value = &(reg_arch_info[i].value);
 			reg_list[i].type = &nds32_reg_access_type;
+			reg_list[i].group = "general";
+
+			if ((FS0 <= reg_arch_info[i].num) && (reg_arch_info[i].num <= FS31)) {
+				reg_list[i].reg_data_type->type = REG_TYPE_IEEE_SINGLE;
+				reg_list[i].reg_data_type->id = "ieee_single";
+				reg_list[i].group = "float";
+			} else if ((reg_arch_info[i].num == FPCSR) ||
+				   (reg_arch_info[i].num == FPCFG)) {
+				reg_list[i].group = "float";
+			} else if ((reg_arch_info[i].num == R28) ||
+				   (reg_arch_info[i].num == R29) ||
+				   (reg_arch_info[i].num == R31)) {
+				reg_list[i].reg_data_type->type = REG_TYPE_DATA_PTR;
+				reg_list[i].reg_data_type->id = "data_ptr";
+			} else if ((reg_arch_info[i].num == R30) ||
+				   (reg_arch_info[i].num == PC)) {
+				reg_list[i].reg_data_type->type = REG_TYPE_CODE_PTR;
+				reg_list[i].reg_data_type->id = "code_ptr";
+			} else {
+				reg_list[i].reg_data_type->type = REG_TYPE_UINT32;
+				reg_list[i].reg_data_type->id = "uint32";
+			}
 		}
 
+		if (R16 <= reg_arch_info[i].num && reg_arch_info[i].num <= R25)
+			reg_list[i].caller_save = true;
+		else
+			reg_list[i].caller_save = false;
+
+		reg_list[i].feature = malloc(sizeof(struct reg_feature));
+
+		if (R0 <= reg_arch_info[i].num && reg_arch_info[i].num <= IFC_LP)
+			reg_list[i].feature->name = "org.gnu.gdb.nds32.core";
+		else if (CR0 <= reg_arch_info[i].num && reg_arch_info[i].num <= SECUR0)
+			reg_list[i].feature->name = "org.gnu.gdb.nds32.system";
+		else if (D0L24 <= reg_arch_info[i].num && reg_arch_info[i].num <= CBE3)
+			reg_list[i].feature->name = "org.gnu.gdb.nds32.audio";
+		else if (FPCSR <= reg_arch_info[i].num && reg_arch_info[i].num <= FD31)
+			reg_list[i].feature->name = "org.gnu.gdb.nds32.fpu";
+
 		cache->num_regs++;
 	}
 
@@ -451,9 +500,7 @@ static struct reg *nds32_reg_current(struct nds32 *nds32, unsigned regnum)
 {
 	struct reg *r;
 
-	/* Register mapping, pass user-view registers to gdb */
-	int mapped_regnum = nds32->register_map(nds32, regnum);
-	r = nds32->core_cache->reg_list + mapped_regnum;
+	r = nds32->core_cache->reg_list + regnum;
 
 	return r;
 }
@@ -512,12 +559,36 @@ int nds32_set_mapped_reg(struct nds32 *nds32, unsigned regnum, uint32_t value)
 	return r->type->set(r, set_value);
 }
 
-/** get all register list */
-int nds32_get_gdb_reg_list(struct target *target,
+/** get general register list */
+static int nds32_get_general_reg_list(struct nds32 *nds32,
+		struct reg **reg_list[], int *reg_list_size)
+{
+	struct reg *reg_current;
+	int i;
+	int current_idx;
+
+	/** freed in gdb_server.c */
+	*reg_list = malloc(sizeof(struct reg *) * (IFC_LP - R0 + 1));
+	current_idx = 0;
+
+	for (i = R0; i < IFC_LP + 1; i++) {
+		reg_current = nds32_reg_current(nds32, i);
+		if (((struct nds32_reg *)reg_current->arch_info)->enable) {
+			(*reg_list)[current_idx] = reg_current;
+			current_idx++;
+		}
+	}
+	*reg_list_size = current_idx;
+
+	return ERROR_OK;
+}
+
+/** get all register list */
+static int nds32_get_all_reg_list(struct nds32 *nds32,
 		struct reg **reg_list[], int *reg_list_size)
 {
-	struct nds32 *nds32 = target_to_nds32(target);
 	struct reg_cache *reg_cache = nds32->core_cache;
+	struct reg *reg_current;
 	unsigned int i;
 
 	*reg_list_size = reg_cache->num_regs;
@@ -525,12 +596,35 @@ int nds32_get_gdb_reg_list(struct target *target,
 	/** freed in gdb_server.c */
 	*reg_list = malloc(sizeof(struct reg *) * (*reg_list_size));
 
-	for (i = 0; i < reg_cache->num_regs; i++)
-		(*reg_list)[i] = nds32_reg_current(nds32, i);
+	for (i = 0; i < reg_cache->num_regs; i++) {
+		reg_current = nds32_reg_current(nds32, i);
+		reg_current->exist = ((struct nds32_reg *)
+				reg_current->arch_info)->enable;
+		(*reg_list)[i] = reg_current;
+	}
 
 	return ERROR_OK;
 }
 
+/** get all register list */
+int nds32_get_gdb_reg_list(struct target *target,
+		struct reg **reg_list[], int *reg_list_size,
+		enum target_register_class reg_class)
+{
+	struct nds32 *nds32 = target_to_nds32(target);
+
+	switch (reg_class) {
+		case REG_CLASS_ALL:
+			return nds32_get_all_reg_list(nds32, reg_list, reg_list_size);
+		case REG_CLASS_GENERAL:
+			return nds32_get_general_reg_list(nds32, reg_list, reg_list_size);
+		default:
+			return ERROR_FAIL;
+	}
+
+	return ERROR_FAIL;
+}
+
 static int nds32_select_memory_mode(struct target *target, uint32_t address,
 		uint32_t length, uint32_t *end_address)
 {
diff --git a/src/target/nds32.h b/src/target/nds32.h
index f585c2d30..b7e787cf0 100644
--- a/src/target/nds32.h
+++ b/src/target/nds32.h
@@ -341,7 +341,7 @@ struct nds32 {
 };
 
 struct nds32_reg {
-	uint32_t num;
+	int32_t num;
 	uint32_t value;
 	uint64_t value_64;
 	struct target *target;
@@ -364,7 +364,8 @@ extern int nds32_remove_software_breakpoint(struct target *target,
 		struct breakpoint *breakpoint);
 
 extern int nds32_get_gdb_reg_list(struct target *target,
-		struct reg **reg_list[], int *reg_list_size);
+		struct reg **reg_list[], int *reg_list_size,
+		enum target_register_class reg_class);
 
 extern int nds32_write_buffer(struct target *target, uint32_t address,
 		uint32_t size, const uint8_t *buffer);
diff --git a/src/target/register.h b/src/target/register.h
index 3810d145b..9e0f1ce83 100644
--- a/src/target/register.h
+++ b/src/target/register.h
@@ -26,12 +26,105 @@
 
 struct target;
 
+enum reg_type {
+	REG_TYPE_INT8,
+	REG_TYPE_INT16,
+	REG_TYPE_INT32,
+	REG_TYPE_INT64,
+	REG_TYPE_INT128,
+	REG_TYPE_UINT8,
+	REG_TYPE_UINT16,
+	REG_TYPE_UINT32,
+	REG_TYPE_UINT64,
+	REG_TYPE_UINT128,
+	REG_TYPE_CODE_PTR,
+	REG_TYPE_DATA_PTR,
+	REG_TYPE_IEEE_SINGLE,
+	REG_TYPE_IEEE_DOUBLE,
+	REG_TYPE_ARCH_DEFINED,
+};
+
+struct reg_feature {
+	const char *name;
+};
+
+struct reg_data_type_vector {
+	struct reg_data_type *type;
+	uint32_t count;
+};
+
+struct reg_data_type_union_field {
+	const char *name;
+	struct reg_data_type *type;
+	struct reg_data_type_union_field *next;
+};
+
+struct reg_data_type_union {
+	struct reg_data_type_union_field *fields;
+};
+
+struct reg_data_type_bitfield {
+	uint32_t start;
+	uint32_t end;
+};
+
+struct reg_data_type_struct_field {
+	const char *name;
+	bool use_bitfields;
+	union {
+		struct reg_data_type_bitfield *bitfield;
+		struct reg_data_type *type;
+	};
+	struct reg_data_type_struct_field *next;
+};
+
+struct reg_data_type_struct {
+	uint32_t size;
+	struct reg_data_type_struct_field *fields;
+};
+
+struct reg_data_type_flags_field {
+	const char *name;
+	struct reg_data_type_bitfield *bitfield;
+	struct reg_data_type_flags_field *next;
+};
+
+struct reg_data_type_flags {
+	uint32_t size;
+	struct reg_data_type_flags_field *fields;
+};
+
+enum reg_data_type_class {
+	REG_TYPE_CLASS_VECTOR,
+	REG_TYPE_CLASS_UNION,
+	REG_TYPE_CLASS_STRUCT,
+	REG_TYPE_CLASS_FLAGS,
+};
+
+struct reg_data_type {
+	enum reg_type type;
+	const char *id;
+	enum reg_data_type_class type_class;
+	union {
+		struct reg_data_type_vector *reg_type_vector;
+		struct reg_data_type_union *reg_type_union;
+		struct reg_data_type_struct *reg_type_struct;
+		struct reg_data_type_flags *reg_type_flags;
+	};
+};
+
 struct reg {
 	const char *name;
+	uint32_t number;
+	struct reg_feature *feature;
+	bool caller_save;
 	void *value;
 	bool dirty;
 	bool valid;
+	bool exist;
 	uint32_t size;
+	struct reg_data_type *reg_data_type;
+	const char *group;
 	void *arch_info;
 	const struct reg_arch_type *type;
 };
diff --git a/src/target/target.c b/src/target/target.c
index 1f517ac06..c5b80d647 100644
--- a/src/target/target.c
+++ b/src/target/target.c
@@ -1037,9 +1037,10 @@ int target_remove_watchpoint(struct target *target,
 }
 
 int target_get_gdb_reg_list(struct target *target,
-		struct reg **reg_list[], int *reg_list_size)
+		struct reg **reg_list[], int *reg_list_size,
+		enum target_register_class reg_class)
 {
-	return target->type->get_gdb_reg_list(target, reg_list, reg_list_size);
+	return target->type->get_gdb_reg_list(target, reg_list, reg_list_size, reg_class);
 }
 int target_step(struct target *target,
 		int current, uint32_t address, int handle_breakpoints)
diff --git a/src/target/target.h b/src/target/target.h
index 38bb8753c..42414c692 100644
--- a/src/target/target.h
+++ b/src/target/target.h
@@ -114,6 +114,12 @@ struct backoff_timer {
 	int count;
 };
 
+/* split target registers into multiple class */
+enum target_register_class {
+	REG_CLASS_ALL,
+	REG_CLASS_GENERAL,
+};
+
 /* target_type.h contains the full definition of struct target_type */
 struct target {
 	struct target_type *type;			/* target type definition (name, access functions) */
@@ -399,7 +405,8 @@ int target_remove_watchpoint(struct target *target,
  * This routine is a wrapper for target->type->get_gdb_reg_list.
  */
 int target_get_gdb_reg_list(struct target *target,
-		struct reg **reg_list[], int *reg_list_size);
+		struct reg **reg_list[], int *reg_list_size,
+		enum target_register_class reg_class);
 
 /**
  * Step the target.
diff --git a/src/target/target_type.h b/src/target/target_type.h
index 3a3de7a26..4d9a33f99 100644
--- a/src/target/target_type.h
+++ b/src/target/target_type.h
@@ -101,7 +101,8 @@ struct target_type {
 	 * list, however it is after GDB is connected that monitor commands can
 	 * be run to properly initialize the target
 	 */
-	int (*get_gdb_reg_list)(struct target *target, struct reg **reg_list[], int *reg_list_size);
+	int (*get_gdb_reg_list)(struct target *target, struct reg **reg_list[],
+			int *reg_list_size, enum target_register_class reg_class);
 
 	/* target memory access
 	* size: 1 = byte (8bit), 2 = half-word (16bit), 4 = word (32bit)