rtt: Fix writing to down channels

Change-Id: I8d8d458ce687f5112a575c084a9c111c6896707b

src/Makefile.am

@@ -53,7 +53,8 @@ endif
 	%D%/target/libtarget.la \
 	%D%/server/libserver.la \
 	%D%/rtos/librtos.la \
-	%D%/helper/libhelper.la
+	%D%/helper/libhelper.la \
+	%D%/rtt/librtt.la
 
 BIN2C = $(srcdir)/%D%/helper/bin2char.sh
 
@@ -83,3 +84,4 @@ include %D%/rtos/Makefile.am
 include %D%/server/Makefile.am
 include %D%/flash/Makefile.am
 include %D%/pld/Makefile.am
+include %D%/rtt/Makefile.am

src/flash/nor/stellaris.c

@@ -1356,6 +1356,7 @@ COMMAND_HANDLER(stellaris_handle_recover_command)
 {
 	struct flash_bank *bank;
 	int retval;
+	const char *tmp;
 
 	if (CMD_ARGC != 0)
 		return ERROR_COMMAND_SYNTAX_ERROR;
@@ -1370,8 +1371,11 @@ COMMAND_HANDLER(stellaris_handle_recover_command)
 	 * cycle to recover.
 	 */
 
-	Jim_Eval_Named(CMD_CTX->interp, "catch { hla_command \"debug unlock\" }", 0, 0);
-	if (!strcmp(Jim_GetString(Jim_GetResult(CMD_CTX->interp), NULL), "0")) {
+	Jim_Eval_Named(CMD_CTX->interp->interp,
+		"catch { hla_command \"debug unlock\" }", 0, 0);
+	tmp = Jim_GetString(Jim_GetResult(CMD_CTX->interp->interp), NULL);
+
+	if (!strcmp(tmp, "0")) {
 		retval = ERROR_OK;
 		goto user_action;
 	}

src/helper/command.c

@@ -356,7 +356,7 @@ static int command_unknown(Jim_Interp *interp, int argc, Jim_Obj *const *argv);
 static int register_command_handler(struct command_context *cmd_ctx,
 	struct command *c)
 {
-	Jim_Interp *interp = cmd_ctx->interp;
+	Jim_Interp *interp = cmd_ctx->interp->interp;
 	char *ocd_name = alloc_printf("ocd_%s", c->name);
 	if (NULL == ocd_name)
 		return JIM_ERR;
@@ -406,7 +406,7 @@ struct command *register_command(struct command_context *context,
 
 	int retval = ERROR_OK;
 	if (NULL != cr->jim_handler && NULL == parent) {
-		retval = Jim_CreateCommand(context->interp, cr->name,
+		retval = Jim_CreateCommand(context->interp->interp, cr->name,
 				cr->jim_handler, cr->jim_handler_data, NULL);
 	} else if (NULL != cr->handler || NULL != parent)
 		retval = register_command_handler(context, command_root(c));
@@ -643,7 +643,7 @@ int command_run_line(struct command_context *context, char *line)
 	 * happen when the Jim Tcl interpreter is provided by eCos for
 	 * instance.
 	 */
-	Jim_Interp *interp = context->interp;
+	Jim_Interp *interp = context->interp->interp;
 	Jim_DeleteAssocData(interp, "context");
 	retcode = Jim_SetAssocData(interp, "context", NULL, context);
 	if (retcode == JIM_OK) {
@@ -720,8 +720,14 @@ void command_set_output_handler(struct command_context *context,
 
 struct command_context *copy_command_context(struct command_context *context)
 {
-	struct command_context *copy_context = malloc(sizeof(struct command_context));
+	struct command_context *copy_context;
 
+	copy_context = malloc(sizeof(struct command_context));
+
+	if (!copy_context)
+		return NULL;
+
+	context->interp->refcnt++;
 	*copy_context = *context;
 
 	return copy_context;
@@ -729,9 +735,18 @@ struct command_context *copy_command_context(struct command_context *context)
 
 void command_done(struct command_context *cmd_ctx)
 {
-	if (NULL == cmd_ctx)
+	if (cmd_ctx == NULL)
 		return;
 
+	cmd_ctx->interp->refcnt--;
+
+	if (!cmd_ctx->interp->refcnt) {
+		if (cmd_ctx->interp->free)
+			Jim_FreeInterp(cmd_ctx->interp->interp);
+
+		free(cmd_ctx->interp);
+	}
+
 	free(cmd_ctx);
 }
 
@@ -1269,14 +1284,28 @@ static const struct command_registration command_builtin_handlers[] = {
 
 struct command_context *command_init(const char *startup_tcl, Jim_Interp *interp)
 {
-	struct command_context *context = malloc(sizeof(struct command_context));
+	struct command_context *context;
 	const char *HostOs;
 
+	context = malloc(sizeof(struct command_context));
+
+	if (!context) {
+		LOG_ERROR("Failed to allocate command context.");
+		return NULL;
+	}
+
 	context->mode = COMMAND_EXEC;
 	context->commands = NULL;
 	context->current_target = 0;
 	context->output_handler = NULL;
 	context->output_handler_priv = NULL;
+	context->interp = malloc(sizeof(struct command_interpreter));
+
+	if (!context->interp) {
+		LOG_ERROR("Failed to allocate command interpreter.");
+		free(context);
+		return NULL;
+	}
 
 	/* Create a jim interpreter if we were not handed one */
 	if (interp == NULL) {
@@ -1285,9 +1314,13 @@ struct command_context *command_init(const char *startup_tcl, Jim_Interp *interp
 		/* Add all the Jim core commands */
 		Jim_RegisterCoreCommands(interp);
 		Jim_InitStaticExtensions(interp);
+		context->interp->free = true;
+	} else {
+		context->interp->free = false;
 	}
 
-	context->interp = interp;
+	context->interp->interp = interp;
+	context->interp->refcnt = 1;
 
 	/* Stick to lowercase for HostOS strings. */
 #if defined(_MSC_VER)
@@ -1355,7 +1388,7 @@ void process_jim_events(struct command_context *cmd_ctx)
 		return;
 
 	recursion++;
-	Jim_ProcessEvents(cmd_ctx->interp, JIM_ALL_EVENTS | JIM_DONT_WAIT);
+	Jim_ProcessEvents(cmd_ctx->interp->interp, JIM_ALL_EVENTS | JIM_DONT_WAIT);
 	recursion--;
 }
 

src/helper/command.h

@@ -22,8 +22,12 @@
 #ifndef OPENOCD_HELPER_COMMAND_H
 #define OPENOCD_HELPER_COMMAND_H
 
+#include <stdint.h>
+#include <stdbool.h>
 #include <jim-nvp.h>
 
+#include <helper/types.h>
+
 /* To achieve C99 printf compatibility in MinGW, gnu_printf should be
  * used for __attribute__((format( ... ))), with GCC v4.4 or later
  */
@@ -39,6 +43,22 @@ enum command_mode {
 	COMMAND_ANY,
 };
 
+/**
+ * Helper struct to share a common Jim interpreter among multiple command
+ * contexts.
+ */
+struct command_interpreter {
+	/** Jim interpreter. */
+	Jim_Interp *interp;
+	/** Number of references held on this interpreter. */
+	unsigned int refcnt;
+	/**
+	 * Determines whether the Jim interpreter should be free'd when the last
+	 * reference is released.
+	 */
+	bool free;
+};
+
 struct command_context;
 
 /** The type signature for command context's output handler. */
@@ -46,7 +66,7 @@ typedef int (*command_output_handler_t)(struct command_context *context,
 		const char *line);
 
 struct command_context {
-	Jim_Interp *interp;
+	struct command_interpreter *interp;
 	enum command_mode mode;
 	struct command *commands;
 	int current_target;

src/helper/replacements.h

@@ -25,6 +25,8 @@
 #ifndef OPENOCD_HELPER_REPLACEMENTS_H
 #define OPENOCD_HELPER_REPLACEMENTS_H
 
+#include <stdint.h>
+
 /* MIN,MAX macros */
 #ifndef MIN
 #define MIN(a, b) (((a) < (b)) ? (a) : (b))

src/helper/types.h

@@ -22,7 +22,12 @@
 #ifndef OPENOCD_HELPER_TYPES_H
 #define OPENOCD_HELPER_TYPES_H
 
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
 #include <stddef.h>
+#include <assert.h>
 #ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif

src/jtag/core.c

@@ -1582,7 +1582,10 @@ int jtag_init(struct command_context *cmd_ctx)
 	if (retval != ERROR_OK)
 		return retval;
 
-	if (Jim_Eval_Named(cmd_ctx->interp, "jtag_init", __FILE__, __LINE__) != JIM_OK)
+	retval = Jim_Eval_Named(cmd_ctx->interp->interp, "jtag_init", __FILE__,
+		__LINE__);
+
+	if (retval != JIM_OK)
 		return ERROR_FAIL;
 
 	return ERROR_OK;

src/openocd.c

@@ -37,9 +37,11 @@
 #include <flash/nand/core.h>
 #include <pld/pld.h>
 #include <flash/mflash.h>
+#include <rtt/rtt.h>
 
 #include <server/server.h>
 #include <server/gdb_server.h>
+#include <server/rtt_server.h>
 
 #ifdef HAVE_STRINGS_H
 #include <strings.h>
@@ -170,7 +172,10 @@ COMMAND_HANDLER(handle_init_command)
 	command_context_mode(CMD_CTX, COMMAND_EXEC);
 
 	/* initialize telnet subsystem */
-	gdb_target_add_all(all_targets);
+	retval = gdb_target_add_all(all_targets);
+
+	if (retval != ERROR_OK)
+		return retval;
 
 	target_register_event_callback(log_target_callback_event_handler, CMD_CTX);
 
@@ -245,6 +250,8 @@ struct command_context *setup_command_handler(Jim_Interp *interp)
 		&server_register_commands,
 		&gdb_register_commands,
 		&log_register_commands,
+		&rtt_register_commands,
+		&rtt_server_register_commands,
 		&transport_register_commands,
 		&interface_register_commands,
 		&target_register_commands,
@@ -297,8 +304,10 @@ static int openocd_thread(int argc, char *argv[], struct command_context *cmd_ct
 
 	if (init_at_startup) {
 		ret = command_run_line(cmd_ctx, "init");
-		if (ERROR_OK != ret)
+		if (ERROR_OK != ret) {
+			server_quit();
 			return ERROR_FAIL;
+		}
 	}
 
 	ret = server_loop(cmd_ctx);
@@ -330,6 +339,9 @@ int openocd_main(int argc, char *argv[])
 	if (ioutil_init(cmd_ctx) != ERROR_OK)
 		return EXIT_FAILURE;
 
+	if (rtt_init() != ERROR_OK)
+		return EXIT_FAILURE;
+
 	LOG_OUTPUT("For bug reports, read\n\t"
 		"http://openocd.org/doc/doxygen/bugs.html"
 		"\n");
@@ -347,6 +359,8 @@ int openocd_main(int argc, char *argv[])
 
 	adapter_quit();
 
+	rtt_exit();
+
 	if (ERROR_FAIL == ret)
 		return EXIT_FAILURE;
 	else if (ERROR_OK != ret)

src/rtt/Makefile.am

@@ -0,0 +1,2 @@
+noinst_LTLIBRARIES += %D%/librtt.la
+%C%_librtt_la_SOURCES = %D%/rtt.c %D%/rtt.h

src/rtt/rtt.c

@@ -0,0 +1,516 @@
+/*
+ * Copyright (C) 2016-2017 by Marc Schink
+ * openocd-dev@marcschink.de
+ *
+ * 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
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+
+#include <helper/log.h>
+#include <helper/list.h>
+#include <target/target.h>
+#include <target/rtt.h>
+
+#include "rtt.h"
+
+static struct rtt_source global_source;
+static struct rtt_control global_ctrl;
+static struct target *global_target;
+static target_addr_t global_addr;
+static uint32_t global_length;
+static char global_id[RTT_MAX_CB_ID_LENGTH];
+static size_t global_id_length;
+static bool global_configured;
+static bool global_started;
+static bool global_changed;
+static bool global_found_cb;
+
+static struct rtt_sink_list **global_sink_list;
+static size_t global_sink_list_length;
+
+int rtt_init(void)
+{
+	global_sink_list_length = 1;
+	global_sink_list = calloc(global_sink_list_length,
+		sizeof(struct rtt_sink_list *));
+
+	if (!global_sink_list)
+		return ERROR_FAIL;
+
+	global_sink_list[0] = NULL;
+	global_started = false;
+
+	return ERROR_OK;
+}
+
+int rtt_exit(void)
+{
+	free(global_sink_list);
+
+	return ERROR_OK;
+}
+
+static int read_channel_callback(void *user_data)
+{
+	int ret;
+
+	ret = global_source.read(&global_ctrl, global_sink_list,
+		global_sink_list_length, global_target, NULL);
+
+	if (ret != ERROR_OK) {
+		target_unregister_timer_callback(&read_channel_callback, NULL);
+		global_source.stop(global_target, NULL);
+		return ret;
+	}
+
+	return ERROR_OK;
+}
+
+int rtt_register_source(const struct rtt_source source, struct target *target)
+{
+	global_source = source;
+	global_target = target;
+
+	return ERROR_OK;
+}
+
+int rtt_start(void)
+{
+	int ret;
+	target_addr_t addr = global_addr;
+
+	if (global_started) {
+		LOG_INFO("RTT already started");
+		return ERROR_OK;
+	}
+
+	if (!global_found_cb || global_changed) {
+		global_source.find_cb(&addr, global_length, global_id,
+			global_id_length, &global_found_cb, global_target, NULL);
+
+		global_changed = false;
+
+		if (global_found_cb) {
+			LOG_INFO("RTT control block found at 0x%" TARGET_PRIxADDR, addr);
+			global_ctrl.address = addr;
+		} else {
+			LOG_INFO("No RTT control block found");
+			return ERROR_OK;
+		}
+	}
+
+	ret = global_source.read_cb(global_ctrl.address, &global_ctrl,
+		global_target, NULL);
+
+	if (ret != ERROR_OK)
+		return ret;
+
+	ret = global_source.start(&global_ctrl, global_target, NULL);
+
+	if (ret != ERROR_OK)
+		return ret;
+
+	target_register_timer_callback(&read_channel_callback, 100, 1, NULL);
+	global_started = true;
+
+	return ERROR_OK;
+}
+
+int rtt_stop(void)
+{
+	int ret;
+
+	target_unregister_timer_callback(&read_channel_callback, NULL);
+	global_started = false;
+
+	ret = global_source.stop(global_target, NULL);
+
+	if (ret != ERROR_OK)
+		return ret;
+
+	return ERROR_OK;
+}
+
+static int adjust_sink_list(size_t length)
+{
+	size_t i;
+	struct rtt_sink_list **tmp;
+
+	if (length <= global_sink_list_length)
+		return ERROR_OK;
+
+	tmp = realloc(global_sink_list, sizeof(struct rtt_sink_list *) * length);
+
+	if (!tmp)
+		return ERROR_FAIL;
+
+	for (i = global_sink_list_length; i < length; i++)
+		tmp[i] = NULL;
+
+	global_sink_list = tmp;
+	global_sink_list_length = length;
+
+	return ERROR_OK;
+}
+
+int rtt_register_sink(unsigned int channel, rtt_sink_read read,
+		void *user_data)
+{
+	struct rtt_sink_list *tmp;
+
+	if (channel >= global_sink_list_length) {
+		if (adjust_sink_list(channel + 1) != ERROR_OK)
+			return ERROR_FAIL;
+	}
+
+	LOG_DEBUG("Registering sink for RTT channel %u", channel);
+
+	tmp = malloc(sizeof(struct rtt_sink_list));
+
+	if (!tmp)
+		return ERROR_FAIL;
+
+	tmp->read = read;
+	tmp->user_data = user_data;
+	tmp->next = global_sink_list[channel];
+
+	global_sink_list[channel] = tmp;
+
+	return ERROR_OK;
+}
+
+int rtt_unregister_sink(unsigned int channel, rtt_sink_read read,
+		void *user_data)
+{
+	struct rtt_sink_list *sink;
+	struct rtt_sink_list *prev_sink;
+
+	LOG_DEBUG("Unregistering sink for RTT channel %u", channel);
+
+	if (channel >= global_sink_list_length)
+		return ERROR_FAIL;
+
+	prev_sink = global_sink_list[channel];
+
+	for (sink = global_sink_list[channel]; sink; prev_sink = sink,
+			sink = sink->next) {
+		if (sink->read == read && sink->user_data == user_data) {
+
+			if (sink == global_sink_list[channel])
+				global_sink_list[channel] = sink->next;
+			else
+				prev_sink->next = sink->next;
+
+			free(sink);
+
+			return ERROR_OK;
+		}
+	}
+
+	return ERROR_OK;
+}
+
+int rtt_write_channel(unsigned int channel, const uint8_t *buffer,
+		size_t *length)
+{
+	if (!global_source.write)
+		return ERROR_FAIL;
+
+	if (channel >= global_ctrl.num_up_buffers) {
+		LOG_WARNING("Down-channel %u is not available", channel);
+		return ERROR_OK;
+	}
+
+	return global_source.write(&global_ctrl, channel, buffer, length,
+		global_target, NULL);
+}
+
+COMMAND_HANDLER(handle_rtt_setup_command)
+{
+	target_addr_t addr;
+	uint32_t length;
+	struct rtt_source source;
+
+	if (CMD_ARGC != 3)
+		return ERROR_COMMAND_SYNTAX_ERROR;
+
+	COMMAND_PARSE_NUMBER(target_addr, CMD_ARGV[0], addr);
+	COMMAND_PARSE_NUMBER(u32, CMD_ARGV[1], length);
+
+	global_id_length = strlen(CMD_ARGV[2]);
+
+	if (!global_id_length || global_id_length > RTT_MAX_CB_ID_LENGTH) {
+		LOG_ERROR("Invalid RTT control block ID");
+		return ERROR_COMMAND_ARGUMENT_INVALID;
+	}
+
+	source.find_cb = &target_rtt_find_control_block;
+	source.read_cb = &target_rtt_read_control_block;
+	source.start = &target_rtt_start;
+	source.stop = &target_rtt_stop;
+	source.read = &target_rtt_read_callback;
+	source.write = &target_rtt_write_callback;
+	source.read_buffer_info = &target_rtt_read_buffer_info;
+
+	rtt_register_source(source, get_current_target(CMD_CTX));
+
+	global_addr = addr;
+	global_length = length;
+	memcpy(global_id, CMD_ARGV[2], global_id_length);
+	global_changed = true;
+	global_configured = true;
+
+	return ERROR_OK;
+}
+
+COMMAND_HANDLER(handle_rtt_start_command)
+{
+	int ret;
+
+	if (CMD_ARGC > 0)
+		return ERROR_COMMAND_SYNTAX_ERROR;
+
+	if (global_started) {
+		LOG_INFO("RTT already started");
+		return ERROR_OK;
+	}
+
+	if (!global_configured) {
+		LOG_ERROR("RTT is not configured");
+		return ERROR_FAIL;
+	}
+
+	ret = rtt_start();
+
+	if (ret != ERROR_OK)
+		return ret;
+
+	return ERROR_OK;
+}
+
+COMMAND_HANDLER(handle_rtt_stop_command)
+{
+	int ret;
+
+	if (CMD_ARGC > 0)
+		return ERROR_COMMAND_SYNTAX_ERROR;
+
+	ret = rtt_stop();
+
+	if (ret != ERROR_OK)
+		return ret;
+
+	return ERROR_OK;
+}
+
+COMMAND_HANDLER(handle_rtt_channels_command)
+{
+	int ret;
+	size_t i;
+	char channel_name[32];
+	struct rtt_buffer_info info;
+
+	if (!global_found_cb) {
+		LOG_ERROR("RTT control block not available");
+		return ERROR_FAIL;
+	}
+
+	command_print(CMD_CTX, "Channels: up=%u, down=%u",
+		global_ctrl.num_up_buffers, global_ctrl.num_down_buffers);
+
+	LOG_INFO("Up-channels:");
+
+	info.name = channel_name;
+	info.name_length = sizeof(channel_name);
+
+	for (i = 0; i < global_ctrl.num_up_buffers; i++) {
+		ret = global_source.read_buffer_info(&global_ctrl, i, true, &info,
+			global_target, NULL);
+
+		if (ret != ERROR_OK)
+			return ret;
+
+		if (!info.size)
+			continue;
+
+		LOG_INFO("%zu: %s %u %u", i, info.name, info.size, info.flags);
+	}
+
+	LOG_INFO("Down-channels:");
+
+	for (i = 0; i < global_ctrl.num_down_buffers; i++) {
+		ret = global_source.read_buffer_info(&global_ctrl, i, false, &info,
+			global_target, NULL);
+
+		if (ret != ERROR_OK)
+			return ret;
+
+		if (!info.size)
+			continue;
+
+		LOG_INFO("%zu: %s %u %u", i, info.name, info.size, info.flags);
+	}
+
+	return ERROR_OK;
+}
+
+static int jim_channel_list(Jim_Interp *interp, int argc,
+		Jim_Obj * const *argv)
+{
+	int ret;
+	size_t i;
+	Jim_Obj *list;
+	Jim_Obj *channel_list;
+	char channel_name[128];
+	struct rtt_buffer_info info;
+
+	if (!global_found_cb) {
+		LOG_ERROR("RTT control block not available");
+		return ERROR_FAIL;
+	}
+
+	info.name = channel_name;
+	info.name_length = sizeof(channel_name);
+
+	list = Jim_NewListObj(interp, NULL, 0);
+
+	channel_list = Jim_NewListObj(interp, NULL, 0);
+
+	for (i = 0; i < global_ctrl.num_up_buffers; i++) {
+		ret = global_source.read_buffer_info(&global_ctrl, i, true, &info,
+			global_target, NULL);
+
+		if (ret != ERROR_OK)
+			return ret;
+
+		if (!info.size)
+			continue;
+
+		Jim_Obj *tmp = Jim_NewListObj(interp, NULL, 0);
+
+		Jim_ListAppendElement(interp, tmp, Jim_NewStringObj(interp,
+			"name", -1));
+		Jim_ListAppendElement(interp, tmp, Jim_NewStringObj(interp,
+			info.name, -1));
+
+		Jim_ListAppendElement(interp, tmp, Jim_NewStringObj(interp,
+			"size", -1));
+		Jim_ListAppendElement(interp, tmp, Jim_NewIntObj(interp,
+			info.size));
+
+		Jim_ListAppendElement(interp, tmp, Jim_NewStringObj(interp,
+			"flags", -1));
+		Jim_ListAppendElement(interp, tmp, Jim_NewIntObj(interp,
+			info.flags));
+
+		Jim_ListAppendElement(interp, channel_list, tmp);
+	}
+
+	Jim_ListAppendElement(interp, list, channel_list);
+
+	channel_list = Jim_NewListObj(interp, NULL, 0);
+
+	for (i = 0; i < global_ctrl.num_down_buffers; i++) {
+		ret = global_source.read_buffer_info(&global_ctrl, i, false, &info,
+			global_target, NULL);
+
+		if (ret != ERROR_OK)
+			return ret;
+
+		if (!info.size)
+			continue;
+
+		Jim_Obj *tmp = Jim_NewListObj(interp, NULL, 0);
+
+		Jim_ListAppendElement(interp, tmp, Jim_NewStringObj(interp,
+			"name", -1));
+		Jim_ListAppendElement(interp, tmp, Jim_NewStringObj(interp,
+			info.name, -1));
+
+		Jim_ListAppendElement(interp, tmp, Jim_NewStringObj(interp,
+			"size", -1));
+		Jim_ListAppendElement(interp, tmp, Jim_NewIntObj(interp,
+			info.size));
+
+		Jim_ListAppendElement(interp, tmp, Jim_NewStringObj(interp,
+			"flags", -1));
+		Jim_ListAppendElement(interp, tmp, Jim_NewIntObj(interp,
+			info.flags));
+
+		Jim_ListAppendElement(interp, channel_list, tmp);
+	}
+
+	Jim_ListAppendElement(interp, list, channel_list);
+	Jim_SetResult(interp, list);
+
+	return JIM_OK;
+}
+
+static const struct command_registration rtt_subcommand_handlers[] = {
+	{
+		.name = "setup",
+		.handler = handle_rtt_setup_command,
+		.mode = COMMAND_ANY,
+		.help = "setup RTT",
+		.usage = "<address> <length> <ID>"
+	},
+	{
+		.name = "start",
+		.handler = handle_rtt_start_command,
+		.mode = COMMAND_EXEC,
+		.help = "start RTT",
+		.usage = ""
+	},
+	{
+		.name = "stop",
+		.handler = handle_rtt_stop_command,
+		.mode = COMMAND_EXEC,
+		.help = "stop RTT",
+		.usage = ""
+	},
+	{
+		.name = "channels",
+		.handler = handle_rtt_channels_command,
+		.mode = COMMAND_EXEC,
+		.help = "list available channels",
+		.usage = ""
+	},
+	{
+		.name = "channellist",
+		.jim_handler = jim_channel_list,
+		.mode = COMMAND_EXEC,
+		.help = "list available channels",
+		.usage = ""
+	},
+	COMMAND_REGISTRATION_DONE
+};
+
+static const struct command_registration rtt_command_handlers[] = {
+	{
+		.name = "rtt",
+		.mode = COMMAND_EXEC,
+		.help = "RTT commands",
+		.usage = "",
+		.chain = rtt_subcommand_handlers
+	},
+	COMMAND_REGISTRATION_DONE
+};
+
+int rtt_register_commands(struct command_context *ctx)
+{
+	return register_commands(ctx, NULL, rtt_command_handlers);
+}

src/rtt/rtt.h

@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2016-2017 by Marc Schink
+ * openocd-dev@marcschink.de
+ *
+ * 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
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef OPENOCD_RTT_RTT_H
+#define OPENOCD_RTT_RTT_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <helper/command.h>
+#include <target/target.h>
+
+#define RTT_MAX_CB_ID_LENGTH	16
+#define RTT_MIN_BUFFER_SIZE	2
+#define RTT_CB_LENGTH		(RTT_MAX_CB_ID_LENGTH + 4 + 4)
+#define RTT_BUFFER_LENGTH	24
+
+struct rtt_control {
+	target_addr_t address;
+	char id[RTT_MAX_CB_ID_LENGTH + 1];
+	uint32_t num_up_buffers;
+	uint32_t num_down_buffers;
+};
+
+struct rtt_buffer {
+	target_addr_t address;
+	target_addr_t name_addr;
+	target_addr_t buffer_addr;
+	uint32_t size;
+	uint32_t write_offset;
+	uint32_t read_offset;
+	uint32_t flags;
+};
+
+struct rtt_buffer_info {
+	char *name;
+	size_t name_length;
+	uint32_t size;
+	uint32_t flags;
+};
+
+typedef int (*rtt_sink_read)(unsigned int channel, const uint8_t *buffer,
+		size_t length, void *user_data);
+
+struct rtt_sink_list {
+	rtt_sink_read read;
+	void *user_data;
+
+	struct rtt_sink_list *next;
+};
+
+enum rtt_channel_type {
+	RTT_CHANNEL_TYPE_UP,
+	RTT_CHANNEL_TYPE_DOWN
+};
+
+typedef int (*rtt_source_find_ctrl_block)(target_addr_t *address,
+		size_t length, const char *id, size_t id_length, bool *found,
+		struct target *target, void *user_data);
+typedef int (*rtt_source_read_ctrl_block)(target_addr_t address,
+		struct rtt_control *ctrl_block, struct target *target,
+		void *user_data);
+typedef int (*rtt_source_read_buffer_info)(const struct rtt_control *ctrl,
+		unsigned int channel, enum rtt_channel_type type,
+		struct rtt_buffer_info *info, struct target *target, void *user_data);
+typedef int (*rtt_source_start)(const struct rtt_control *ctrl,
+		struct target *target, void *user_data);
+typedef int (*rtt_source_stop)(struct target *target, void *user_data);
+typedef int (*rtt_source_read)(const struct rtt_control *ctrl,
+		struct rtt_sink_list **sinks, size_t num_channels,
+		struct target *target, void *user_data);
+typedef int (*rtt_source_write)(struct rtt_control *ctrl,
+		unsigned int channel, const uint8_t *buffer, size_t *length,
+		struct target *target, void *user_data);
+
+struct rtt_source {
+	rtt_source_find_ctrl_block find_cb;
+	rtt_source_read_ctrl_block read_cb;
+	rtt_source_read_buffer_info read_buffer_info;
+	rtt_source_start start;
+	rtt_source_stop stop;
+	rtt_source_read read;
+	rtt_source_write write;
+};
+
+int rtt_init(void);
+int rtt_exit(void);
+
+int rtt_register_source(const struct rtt_source source, struct target *target);
+
+int rtt_start(void);
+int rtt_stop(void);
+
+int rtt_register_sink(unsigned int channel, rtt_sink_read read,
+		void *user_data);
+int rtt_unregister_sink(unsigned int channel, rtt_sink_read read,
+		void *user_data);
+
+int rtt_write_channel(unsigned int channel, const uint8_t *buffer,
+		size_t *length);
+
+int rtt_register_commands(struct command_context *ctx);
+
+#endif /* OPENOCD_RTT_RTT_H */

src/server/Makefile.am

@@ -8,7 +8,9 @@ noinst_LTLIBRARIES += %D%/libserver.la
 	%D%/gdb_server.h \
 	%D%/server_stubs.c \
 	%D%/tcl_server.c \
-	%D%/tcl_server.h
+	%D%/tcl_server.h \
+	%D%/rtt_server.c \
+	%D%/rtt_server.h
 
 %C%_libserver_la_CFLAGS = $(AM_CFLAGS)
 if IS_MINGW

src/server/rtt_server.c

@@ -0,0 +1,182 @@
+/*
+ * Copyright (C) 2016-2017 by Marc Schink
+ * openocd-dev@marcschink.de
+ *
+ * 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
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdint.h>
+#include <rtt/rtt.h>
+
+#include "server.h"
+#include "rtt_server.h"
+
+/**
+ * @file
+ *
+ * RTT server.
+ *
+ * This server allows access to Real Time Transfer (RTT) channels via TCP
+ * connections.
+ */
+
+struct rtt_service {
+	unsigned int channel;
+};
+
+static int read_callback(unsigned int channel, const uint8_t *buffer,
+		size_t length, void *user_data)
+{
+	int ret;
+	struct connection *connection;
+	size_t offset;
+
+	connection = (struct connection *)user_data;
+	offset = 0;
+
+	while (offset < length) {
+		ret = connection_write(connection, buffer + offset, length - offset);
+
+		if (ret < 0) {
+			LOG_ERROR("Failed to write data to socket.");
+			return ERROR_FAIL;
+		}
+
+		offset += ret;
+	}
+
+	return ERROR_OK;
+}
+
+static int rtt_new_connection(struct connection *connection)
+{
+	int ret;
+	struct rtt_service *service;
+
+	service = connection->service->priv;
+
+	LOG_DEBUG("New connection for RTT channel %u", service->channel);
+
+	ret = rtt_register_sink(service->channel, &read_callback, connection);
+
+	if (ret != ERROR_OK)
+		return ret;
+
+	return ERROR_OK;
+}
+
+static int rtt_connection_closed(struct connection *connection)
+{
+	struct rtt_service *service;
+
+	service = (struct rtt_service *)connection->service->priv;
+	rtt_unregister_sink(service->channel, &read_callback, connection);
+
+	LOG_DEBUG("Connection for RTT channel %u closed", service->channel);
+
+	return ERROR_OK;
+}
+
+static int rtt_input(struct connection *connection)
+{
+	int bytes_read;
+	unsigned char buffer[1024];
+	struct rtt_service *service;
+	size_t length;
+
+	service = (struct rtt_service *)connection->service->priv;
+	bytes_read = connection_read(connection, buffer, sizeof(buffer));
+
+	if (!bytes_read)
+		return ERROR_SERVER_REMOTE_CLOSED;
+	else if (bytes_read < 0) {
+		LOG_ERROR("error during read: %s", strerror(errno));
+		return ERROR_SERVER_REMOTE_CLOSED;
+	}
+
+	length = bytes_read;
+	rtt_write_channel(service->channel, buffer, &length);
+
+	return ERROR_OK;
+}
+
+COMMAND_HANDLER(handle_rtt_start_command)
+{
+	int ret;
+	struct rtt_service *service;
+
+	if (CMD_ARGC != 2)
+		return ERROR_COMMAND_SYNTAX_ERROR;
+
+	service = malloc(sizeof(struct rtt_service));
+
+	if (!service)
+		return ERROR_FAIL;
+
+	COMMAND_PARSE_NUMBER(uint, CMD_ARGV[1], service->channel);
+
+	ret = add_service("RTT", CMD_ARGV[0], CONNECTION_LIMIT_UNLIMITED,
+		rtt_new_connection, rtt_input, rtt_connection_closed, service);
+
+	if (ret != ERROR_OK) {
+		free(service);
+		return ERROR_FAIL;
+	}
+
+	return ERROR_OK;
+}
+
+COMMAND_HANDLER(handle_rtt_stop_command)
+{
+	if (CMD_ARGC != 1)
+		return ERROR_COMMAND_SYNTAX_ERROR;
+
+	remove_service("RTT", CMD_ARGV[0]);
+
+	return ERROR_OK;
+}
+
+static const struct command_registration rtt_subcommand_handlers[] = {
+	{
+		.name = "start",
+		.handler = handle_rtt_start_command,
+		.mode = COMMAND_ANY,
+		.help = "Start a RTT server",
+		.usage = "<port> <channel>"
+	},
+	{
+		.name = "stop",
+		.handler = handle_rtt_stop_command,
+		.mode = COMMAND_ANY,
+		.help = "Stop a RTT server",
+		.usage = "<port>"
+	},
+	COMMAND_REGISTRATION_DONE
+};
+
+static const struct command_registration rtt_command_handlers[] = {
+	{
+		.name = "rttserver",
+		.mode = COMMAND_ANY,
+		.help = "RTT server",
+		.usage = "",
+		.chain = rtt_subcommand_handlers
+	},
+	COMMAND_REGISTRATION_DONE
+};
+
+int rtt_server_register_commands(struct command_context *ctx)
+{
+	return register_commands(ctx, NULL, rtt_command_handlers);
+}

src/server/rtt_server.h

@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2016-2017 by Marc Schink
+ * openocd-dev@marcschink.de
+ *
+ * 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
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef OPENOCD_SERVER_RTT_SERVER_H
+#define OPENOCD_SERVER_RTT_SERVER_H
+
+#include <helper/command.h>
+
+int rtt_server_register_commands(struct command_context *ctx);
+
+#endif /* OPENOCD_SERVER_RTT_SERVER_H */

src/server/server.c

@@ -67,10 +67,23 @@ static int add_connection(struct service *service, struct command_context *cmd_c
 	int flag = 1;
 
 	c = malloc(sizeof(struct connection));
+
+	if (!c) {
+		LOG_ERROR("Failed to allocate connection.");
+		return ERROR_FAIL;
+	}
+
+	c->cmd_ctx = copy_command_context(cmd_ctx);
+
+	if (!c->cmd_ctx) {
+		LOG_ERROR("Failed to copy command context.");
+		free(c);
+		return ERROR_FAIL;
+	}
+
 	c->fd = -1;
 	c->fd_out = -1;
 	memset(&c->sin, 0, sizeof(c->sin));
-	c->cmd_ctx = copy_command_context(cmd_ctx);
 	c->service = service;
 	c->input_pending = 0;
 	c->priv = NULL;
@@ -132,7 +145,9 @@ static int add_connection(struct service *service, struct command_context *cmd_c
 		free(out_file);
 		if (c->fd_out == -1) {
 			LOG_ERROR("could not open %s", service->port);
-			exit(1);
+			command_done(c->cmd_ctx);
+			free(c);
+			return ERROR_FAIL;
 		}
 
 		LOG_INFO("accepting '%s' connection from pipe %s", service->name, service->port);
@@ -191,7 +206,13 @@ static int remove_connection(struct service *service, struct connection *connect
 	return ERROR_OK;
 }
 
-/* FIX! make service return error instead of invoking exit() */
+static void free_service(struct service *c)
+{
+	free(c->name);
+	free(c->port);
+	free(c);
+}
+
 int add_service(char *name,
 	const char *port,
 	int max_connections,
@@ -235,7 +256,8 @@ int add_service(char *name,
 		c->fd = socket(AF_INET, SOCK_STREAM, 0);
 		if (c->fd == -1) {
 			LOG_ERROR("error creating socket: %s", strerror(errno));
-			exit(-1);
+			free_service(c);
+			return ERROR_FAIL;
 		}
 
 		setsockopt(c->fd,
@@ -255,7 +277,9 @@ int add_service(char *name,
 			hp = gethostbyname(bindto_name);
 			if (hp == NULL) {
 				LOG_ERROR("couldn't resolve bindto address: %s", bindto_name);
-				exit(-1);
+				close_socket(c->fd);
+				free_service(c);
+				return ERROR_FAIL;
 			}
 			memcpy(&c->sin.sin_addr, hp->h_addr_list[0], hp->h_length);
 		}
@@ -263,7 +287,9 @@ int add_service(char *name,
 
 		if (bind(c->fd, (struct sockaddr *)&c->sin, sizeof(c->sin)) == -1) {
 			LOG_ERROR("couldn't bind %s to socket: %s", name, strerror(errno));
-			exit(-1);
+			close_socket(c->fd);
+			free_service(c);
+			return ERROR_FAIL;
 		}
 
 #ifndef _WIN32
@@ -281,7 +307,9 @@ int add_service(char *name,
 
 		if (listen(c->fd, 1) == -1) {
 			LOG_ERROR("couldn't listen on socket: %s", strerror(errno));
-			exit(-1);
+			close_socket(c->fd);
+			free_service(c);
+			return ERROR_FAIL;
 		}
 	} else if (c->type == CONNECTION_STDINOUT) {
 		c->fd = fileno(stdin);
@@ -302,13 +330,15 @@ int add_service(char *name,
 		/* we currenty do not support named pipes under win32
 		 * so exit openocd for now */
 		LOG_ERROR("Named pipes currently not supported under this os");
-		exit(1);
+		free_service(c);
+		return ERROR_FAIL;
 #else
 		/* Pipe we're reading from */
 		c->fd = open(c->port, O_RDONLY | O_NONBLOCK);
 		if (c->fd == -1) {
 			LOG_ERROR("could not open %s", c->port);
-			exit(1);
+			free_service(c);
+			return ERROR_FAIL;
 		}
 #endif
 	}
@@ -321,6 +351,50 @@ int add_service(char *name,
 	return ERROR_OK;
 }
 
+static void remove_connections(struct service *service)
+{
+	struct connection *connection;
+
+	connection = service->connections;
+
+	while (connection) {
+		struct connection *tmp;
+
+		tmp = connection->next;
+		remove_connection(service, connection);
+		connection = tmp;
+	}
+}
+
+int remove_service(const char *name, const char *port)
+{
+	struct service *tmp;
+	struct service *prev;
+
+	prev = services;
+
+	for (tmp = services; tmp; prev = tmp, tmp = tmp->next) {
+		if (!strcmp(tmp->name, name) && !strcmp(tmp->port, port)) {
+			remove_connections(tmp);
+
+			if (tmp == services)
+				services = tmp->next;
+			else
+				prev->next = tmp->next;
+
+			if (tmp->type != CONNECTION_STDINOUT)
+				close_socket(tmp->fd);
+
+			free(tmp->priv);
+			free_service(tmp);
+
+			return ERROR_OK;
+		}
+	}
+
+	return ERROR_OK;
+}
+
 static int remove_services(void)
 {
 	struct service *c = services;
@@ -329,6 +403,8 @@ static int remove_services(void)
 	while (c) {
 		struct service *next = c->next;
 
+		remove_connections(c);
+
 		if (c->name)
 			free(c->name);
 
@@ -425,7 +501,7 @@ int server_loop(struct command_context *command_context)
 				FD_ZERO(&read_fds);
 			else {
 				LOG_ERROR("error during select: %s", strerror(errno));
-				exit(-1);
+				return ERROR_FAIL;
 			}
 #else
 
@@ -433,7 +509,7 @@ int server_loop(struct command_context *command_context)
 				FD_ZERO(&read_fds);
 			else {
 				LOG_ERROR("error during select: %s", strerror(errno));
-				exit(-1);
+				return ERROR_FAIL;
 			}
 #endif
 		}
@@ -463,11 +539,15 @@ int server_loop(struct command_context *command_context)
 
 		for (service = services; service; service = service->next) {
 			/* handle new connections on listeners */
-			if ((service->fd != -1)
-			    && (FD_ISSET(service->fd, &read_fds))) {
-				if (service->max_connections != 0)
-					add_connection(service, command_context);
-				else {
+			if ((service->fd != -1) && (FD_ISSET(service->fd, &read_fds))) {
+				if (service->max_connections != 0) {
+					retval = add_connection(service, command_context);
+
+					if (retval != ERROR_OK) {
+						LOG_ERROR("%i", retval);
+						return ERROR_FAIL;
+					}
+				} else {
 					if (service->type == CONNECTION_TCP) {
 						struct sockaddr_in sin;
 						socklen_t address_size = sizeof(sin);
@@ -552,7 +632,7 @@ int server_preinit(void)
 
 	if (WSAStartup(wVersionRequested, &wsaData) != 0) {
 		LOG_ERROR("Failed to Open Winsock");
-		exit(-1);
+		return ERROR_FAIL;
 	}
 
 	/* register ctrl-c handler */
@@ -569,11 +649,21 @@ int server_preinit(void)
 
 int server_init(struct command_context *cmd_ctx)
 {
-	int ret = tcl_init();
-	if (ERROR_OK != ret)
+	int ret;
+
+	ret  = tcl_init();
+
+	if (ret != ERROR_OK)
+		return ret;
+
+	ret = telnet_init("Open On-Chip Debugger");
+
+	if (ret != ERROR_OK) {
+		remove_services();
 		return ret;
+	}
 
-	return telnet_init("Open On-Chip Debugger");
+	return ERROR_OK;
 }
 
 int server_quit(void)

src/server/server.h

@@ -25,6 +25,10 @@
 #ifndef OPENOCD_SERVER_SERVER_H
 #define OPENOCD_SERVER_SERVER_H
 
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
 #include <helper/log.h>
 
 #ifdef HAVE_NETINET_IN_H
@@ -74,6 +78,7 @@ int add_service(char *name, const char *port,
 		int max_connections, new_connection_handler_t new_connection_handler,
 		input_handler_t in_handler, connection_closed_handler_t close_handler,
 		void *priv);
+int remove_service(const char *name, const char *port);
 
 int server_preinit(void);
 int server_init(struct command_context *cmd_ctx);

src/server/tcl_server.c

@@ -173,7 +173,7 @@ static int tcl_new_connection(struct connection *connection)
 
 static int tcl_input(struct connection *connection)
 {
-	Jim_Interp *interp = (Jim_Interp *)connection->cmd_ctx->interp;
+	Jim_Interp *interp;
 	int retval;
 	int i;
 	ssize_t rlen;
@@ -184,6 +184,8 @@ static int tcl_input(struct connection *connection)
 	char *tc_line_new;
 	int tc_line_size_new;
 
+	interp = connection->cmd_ctx->interp->interp;
+
 	rlen = connection_read(connection, &in, sizeof(in));
 	if (rlen <= 0) {
 		if (rlen < 0)

src/server/telnet_server.c

@@ -619,13 +619,14 @@ static int telnet_connection_closed(struct connection *connection)
 
 int telnet_init(char *banner)
 {
+	int ret;
+	struct telnet_service *telnet_service;
+
 	if (strcmp(telnet_port, "disabled") == 0) {
 		LOG_INFO("telnet server disabled");
 		return ERROR_OK;
 	}
 
-	struct telnet_service *telnet_service;
-
 	telnet_service = malloc(sizeof(struct telnet_service));
 
 	if (!telnet_service) {
@@ -635,13 +636,16 @@ int telnet_init(char *banner)
 
 	telnet_service->banner = banner;
 
-	return add_service("telnet",
-		telnet_port,
-		CONNECTION_LIMIT_UNLIMITED,
-		telnet_new_connection,
-		telnet_input,
-		telnet_connection_closed,
+	ret = add_service("telnet", telnet_port, CONNECTION_LIMIT_UNLIMITED,
+		telnet_new_connection, telnet_input, telnet_connection_closed,
 		telnet_service);
+
+	if (ret != ERROR_OK) {
+		free(telnet_service);
+		return ret;
+	}
+
+	return ERROR_OK;
 }
 
 /* daemon configuration command telnet_port */

src/target/Makefile.am

@@ -38,7 +38,8 @@ TARGET_CORE_SRC = \
 	%D%/target.c \
 	%D%/target_request.c \
 	%D%/testee.c \
-	%D%/smp.c
+	%D%/smp.c \
+	%D%/rtt.c
 
 ARMV4_5_SRC = \
 	%D%/armv4_5.c \
@@ -207,6 +208,7 @@ INTEL_IA32_SRC = \
 	%D%/nds32_aice.h \
 	%D%/lakemont.h \
 	%D%/x86_32_common.h \
-	%D%/arm_cti.h
+	%D%/arm_cti.h \
+	%D%/rtt.h
 
 include %D%/openrisc/Makefile.am

src/target/dsp563xx.c

@@ -1470,7 +1470,7 @@ static int dsp563xx_get_default_memory(void)
 	if (!global_cmd_ctx)
 		return MEM_P;
 
-	interp = global_cmd_ctx->interp;
+	interp = global_cmd_ctx->interp->interp;
 
 	if (!interp)
 		return MEM_P;

src/target/rtt.c

@@ -0,0 +1,412 @@
+/*
+ * Copyright (C) 2016-2017 by Marc Schink
+ * openocd-dev@marcschink.de
+ *
+ * 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
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stddef.h>
+#include <stdint.h>
+#include <helper/log.h>
+#include <helper/binarybuffer.h>
+#include <helper/command.h>
+#include <rtt/rtt.h>
+
+#include "target.h"
+
+static uint8_t rtt_buffer[1024];
+
+static int read_rtt_buffer(struct target *target,
+		const struct rtt_control *ctrl, unsigned int channel,
+		enum rtt_channel_type type, struct rtt_buffer *buffer)
+{
+	int ret;
+	uint8_t buf[RTT_BUFFER_LENGTH];
+	target_addr_t address;
+
+	address = ctrl->address + RTT_CB_LENGTH + (channel * RTT_BUFFER_LENGTH);
+
+	if (type == RTT_CHANNEL_TYPE_DOWN)
+		address += ctrl->num_up_buffers * RTT_BUFFER_LENGTH;
+
+	ret = target_read_buffer(target, address, RTT_BUFFER_LENGTH, buf);
+
+	if (ret != ERROR_OK)
+		return ret;
+
+	buffer->address = address;
+	buffer->name_addr = buf_get_u32(buf, 0, 32);
+	buffer->buffer_addr = buf_get_u32(buf + 4, 0, 32);
+	buffer->size = buf_get_u32(buf + 8, 0, 32);
+	buffer->write_offset = buf_get_u32(buf + 12, 0, 32);
+	buffer->read_offset = buf_get_u32(buf + 16, 0, 32);
+	buffer->flags = buf_get_u32(buf + 20, 0, 32);
+
+	return ERROR_OK;
+}
+
+int target_rtt_start(const struct rtt_control *ctrl, struct target *target,
+		void *user_data)
+{
+	return ERROR_OK;
+}
+
+int target_rtt_stop(struct target *target, void *user_data)
+{
+	return ERROR_OK;
+}
+
+static int read_buffer_name(struct target *target, target_addr_t address,
+		char *name, size_t length)
+{
+	size_t offset;
+
+	offset = 0;
+
+	while (offset < length) {
+		int ret;
+		size_t tmp;
+
+		tmp = MIN(32, length - offset);
+		ret = target_read_buffer(target, address + offset, tmp,
+			(uint8_t *)name + offset);
+
+		if (ret != ERROR_OK)
+			return ret;
+
+		if (memchr(name + offset, '\0', tmp))
+			return ERROR_OK;
+
+		offset += tmp;
+	}
+
+	name[length - 1] = '\0';
+
+	return ERROR_OK;
+}
+
+static int write_to_channel(struct target *target,
+		const struct rtt_buffer *rttbuf, const uint8_t *buffer, size_t *length)
+{
+	int ret;
+	uint32_t len;
+
+	if (!*length)
+		return ERROR_OK;
+
+	if (rttbuf->write_offset == rttbuf->read_offset) {
+		uint32_t first_length;
+
+		len = MIN(*length, rttbuf->size - 1);
+		first_length = MIN(len, rttbuf->size - rttbuf->write_offset);
+
+		ret = target_write_buffer(target,
+			rttbuf->buffer_addr + rttbuf->write_offset, first_length, buffer);
+
+		if (ret != ERROR_OK)
+			return ret;
+
+		ret = target_write_buffer(target, rttbuf->buffer_addr,
+			len - first_length, buffer + first_length);
+
+		if (ret != ERROR_OK)
+			return ret;
+	} else if (rttbuf->write_offset < rttbuf->read_offset) {
+		len = MIN(*length, rttbuf->read_offset - rttbuf->write_offset - 1);
+
+		if (!len) {
+			*length = 0;
+			return ERROR_OK;
+		}
+
+		ret = target_write_buffer(target,
+			rttbuf->buffer_addr + rttbuf->write_offset, len, buffer);
+
+		if (ret != ERROR_OK)
+			return ret;
+	} else {
+		uint32_t first_length;
+
+		len = MIN(*length,
+			rttbuf->size - rttbuf->write_offset + rttbuf->read_offset - 1);
+
+		if (!len) {
+			*length = 0;
+			return ERROR_OK;
+		}
+
+		first_length = MIN(len, rttbuf->size - rttbuf->write_offset);
+
+		ret = target_write_buffer(target,
+			rttbuf->buffer_addr + rttbuf->write_offset, first_length, buffer);
+
+		if (ret != ERROR_OK)
+			return ret;
+
+		buffer = buffer + first_length;
+
+		ret = target_write_buffer(target, rttbuf->buffer_addr,
+			len - first_length, buffer);
+
+		if (ret != ERROR_OK)
+			return ret;
+	}
+
+	ret = target_write_u32(target, rttbuf->address + 12,
+		(rttbuf->write_offset + len) % rttbuf->size);
+
+	if (ret != ERROR_OK)
+		return ret;
+
+	*length = len;
+
+	return ERROR_OK;
+}
+
+static bool buffer_is_active(const struct rtt_buffer *buf)
+{
+	if (!buf)
+		return false;
+
+	if (!buf->size)
+		return false;
+
+	return true;
+}
+
+int target_rtt_write_callback(struct rtt_control *ctrl,
+		unsigned int channel, const uint8_t *buffer, size_t *length,
+		struct target *target, void *user_data)
+{
+	int ret;
+	struct rtt_buffer rttbuf;
+
+	ret = read_rtt_buffer(target, ctrl, channel, RTT_CHANNEL_TYPE_DOWN, &rttbuf);
+
+	if (ret != ERROR_OK) {
+		LOG_ERROR("Failed to read RTT buffer of down-channel %u", channel);
+		return ret;
+	}
+
+	if (!buffer_is_active(&rttbuf)) {
+		LOG_WARNING("Down-channel %u is not active", channel);
+		return ERROR_OK;
+	}
+
+	if (rttbuf.size < RTT_MIN_BUFFER_SIZE) {
+		LOG_WARNING("Down-channel %u is not large enough", channel);
+		return ERROR_OK;
+	}
+
+	ret = write_to_channel(target, &rttbuf, buffer,	length);
+
+	if (ret != ERROR_OK)
+		return ret;
+
+	LOG_DEBUG("Wrote %zu bytes into RTT down-channel %u", *length, channel);
+
+	return ERROR_OK;
+}
+
+int target_rtt_read_control_block(target_addr_t address,
+		struct rtt_control *ctrl, struct target *target, void *user_data)
+{
+	int ret;
+	uint8_t buf[RTT_CB_LENGTH];
+
+	ret = target_read_buffer(target, address, RTT_CB_LENGTH, buf);
+
+	if (ret != ERROR_OK)
+		return ret;
+
+	memcpy(ctrl->id, buf, RTT_MAX_CB_ID_LENGTH);
+	ctrl->id[RTT_MAX_CB_ID_LENGTH] = '\0';
+	ctrl->num_up_buffers = buf_get_u32(buf + RTT_MAX_CB_ID_LENGTH, 0, 32);
+	ctrl->num_down_buffers = buf_get_u32(buf + RTT_MAX_CB_ID_LENGTH + 4, 0,
+		32);
+
+	return ERROR_OK;
+}
+
+int target_rtt_find_control_block(target_addr_t *address, size_t length,
+		const char *id, size_t id_length, bool *found, struct target *target,
+		void *user_data)
+{
+	target_addr_t addr;
+	uint8_t buf[1024];
+	size_t j;
+	size_t start;
+
+	*found = false;
+
+	j = 0;
+	start = 0;
+
+	LOG_INFO("Searching for RTT control block '%s'", id);
+
+	for (addr = 0; addr < length; addr = addr + sizeof(buf)) {
+		int ret;
+		size_t i;
+
+		ret = target_read_buffer(target, *address + addr, sizeof(buf), buf);
+
+		if (ret != ERROR_OK)
+			return ret;
+
+		for (i = 0; i < sizeof(buf); i++) {
+			if (buf[i] == id[j]) {
+				j++;
+			} else {
+				j = 0;
+				start = addr + i + 1;
+			}
+
+			if (j == id_length) {
+				*address = *address + start;
+				*found = true;
+				return ERROR_OK;
+			}
+		}
+	}
+
+	return ERROR_OK;
+}
+
+int target_rtt_read_buffer_info(const struct rtt_control *ctrl,
+		unsigned int channel, enum rtt_channel_type type,
+		struct rtt_buffer_info *info, struct target *target, void *user_data)
+{
+	int ret;
+	struct rtt_buffer rttbuf;
+
+	ret = read_rtt_buffer(target, ctrl, channel, type, &rttbuf);
+
+	if (ret != ERROR_OK) {
+		LOG_ERROR("Failed to read RTT buffer of channel %u", channel);
+		return ret;
+	}
+
+	ret = read_buffer_name(target, rttbuf.name_addr, info->name,
+		info->name_length);
+
+	if (ret != ERROR_OK)
+		return ret;
+
+	info->size = rttbuf.size;
+	info->flags = rttbuf.flags;
+
+	return ERROR_OK;
+}
+
+static int read_from_channel(struct target *target,
+		const struct rtt_buffer *rttbuf, uint8_t *buffer, size_t *length)
+{
+	int ret;
+	uint32_t len;
+
+	if (!*length)
+		return ERROR_OK;
+
+	if (rttbuf->read_offset == rttbuf->write_offset) {
+		len = 0;
+	} else if (rttbuf->read_offset < rttbuf->write_offset) {
+		len = MIN(*length, rttbuf->write_offset - rttbuf->read_offset);
+
+		ret = target_read_buffer(target,
+			rttbuf->buffer_addr + rttbuf->read_offset, len, buffer);
+
+		if (ret != ERROR_OK)
+			return ret;
+	} else {
+		uint32_t first_length;
+
+		len = MIN(*length,
+			rttbuf->size - rttbuf->read_offset + rttbuf->write_offset);
+		first_length = MIN(len, rttbuf->size - rttbuf->read_offset);
+
+		ret = target_read_buffer(target,
+			rttbuf->buffer_addr + rttbuf->read_offset, first_length, buffer);
+
+		if (ret != ERROR_OK)
+			return ret;
+
+		ret = target_read_buffer(target, rttbuf->buffer_addr,
+			len - first_length, buffer + first_length);
+
+		if (ret != ERROR_OK)
+			return ret;
+	}
+
+	if (len > 0) {
+		ret = target_write_u32(target, rttbuf->address + 16,
+			(rttbuf->read_offset + len) % rttbuf->size);
+
+		if (ret != ERROR_OK)
+			return ret;
+	}
+
+	*length = len;
+
+	return ERROR_OK;
+}
+
+int target_rtt_read_callback(const struct rtt_control *ctrl,
+		struct rtt_sink_list **sinks, size_t num_channels,
+		struct target *target, void *user_data)
+{
+	size_t channel;
+
+	num_channels = MIN(num_channels, ctrl->num_up_buffers);
+
+	for (channel = 0; channel < num_channels; channel++) {
+		int ret;
+		struct rtt_buffer rttbuf;
+		size_t length;
+		struct rtt_sink_list *tmp;
+
+		if (!sinks[channel])
+			continue;
+
+		ret = read_rtt_buffer(target, ctrl, channel, RTT_CHANNEL_TYPE_UP,
+			&rttbuf);
+
+		if (ret != ERROR_OK) {
+			LOG_ERROR("Failed to read RTT buffer of up-channel %zu", channel);
+			return ret;
+		}
+
+		if (!buffer_is_active(&rttbuf)) {
+			LOG_WARNING("Up-channel %zu is not active", channel);
+			continue;
+		}
+
+		if (rttbuf.size < RTT_MIN_BUFFER_SIZE) {
+			LOG_WARNING("Up-channel %zu is not large enough", channel);
+			continue;
+		}
+
+		length = sizeof(rtt_buffer);
+		ret = read_from_channel(target, &rttbuf, rtt_buffer, &length);
+
+		if (ret != ERROR_OK) {
+			LOG_ERROR("Failed to read from RTT up-channel %zu", channel);
+			return ret;
+		}
+
+		for (tmp = sinks[channel]; tmp; tmp = tmp->next)
+			tmp->read(channel, rtt_buffer, length, tmp->user_data);
+	}
+
+	return ERROR_OK;
+}

src/target/rtt.h

@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2016-2017 by Marc Schink
+ * openocd-dev@marcschink.de
+ *
+ * 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
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef OPENOCD_TARGET_RTT_H
+#define OPENOCD_TARGET_RTT_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <target/target.h>
+#include <rtt/rtt.h>
+
+int target_rtt_start(const struct rtt_control *ctrl, struct target *target,
+		void *user_data);
+int target_rtt_stop(struct target *target, void *user_data);
+int target_rtt_find_control_block(target_addr_t *address, size_t length,
+		const char *id, size_t id_length, bool *found, struct target *target,
+		void *uer_data);
+int target_rtt_read_control_block(target_addr_t address,
+		struct rtt_control *ctrl, struct target *target, void *user_data);
+int target_rtt_write_callback(struct rtt_control *ctrl,
+		unsigned int channel, const uint8_t *buffer, size_t *length,
+		struct target *target, void *user_data);
+int target_rtt_read_callback(const struct rtt_control *ctrl,
+		struct rtt_sink_list **sinks, size_t length, struct target *target,
+		void *user_data);
+int target_rtt_read_buffer_info(const struct rtt_control *ctrl,
+		unsigned int channel, enum rtt_channel_type type,
+		struct rtt_buffer_info *info, struct target *target, void *user_data);
+
+#endif /* OPENOCD_TARGET_RTT_H */

src/target/target.c

@@ -651,13 +651,14 @@ static int target_process_reset(struct command_context *cmd_ctx, enum target_res
 	jtag_poll_set_enabled(false);
 
 	sprintf(buf, "ocd_process_reset %s", n->name);
-	retval = Jim_Eval(cmd_ctx->interp, buf);
+	retval = Jim_Eval(cmd_ctx->interp->interp, buf);
 
 	jtag_poll_set_enabled(save_poll);
 
 	if (retval != JIM_OK) {
-		Jim_MakeErrorMessage(cmd_ctx->interp);
-		command_print(NULL, "%s\n", Jim_GetString(Jim_GetResult(cmd_ctx->interp), NULL));
+		Jim_MakeErrorMessage(cmd_ctx->interp->interp);
+		command_print(NULL, "%s\n",
+			Jim_GetString(Jim_GetResult(cmd_ctx->interp->interp), NULL));
 		return ERROR_FAIL;
 	}
 
@@ -1293,7 +1294,7 @@ static int target_init(struct command_context *cmd_ctx)
 		return retval;
 
 	retval = target_register_timer_callback(&handle_target,
-			polling_interval, 1, cmd_ctx->interp);
+			polling_interval, 1, cmd_ctx->interp->interp);
 	if (ERROR_OK != retval)
 		return retval;
 
@@ -1870,6 +1871,17 @@ int target_free_working_area(struct target *target, struct working_area *area)
 	return target_free_working_area_restore(target, area, 1);
 }
 
+static void target_destroy(struct target *target)
+{
+	if (target->type->deinit_target)
+		target->type->deinit_target(target);
+
+	free(target->type);
+	free(target->trace_info);
+	free(target->cmd_name);
+	free(target);
+}
+
 void target_quit(void)
 {
 	struct target_event_callback *pe = target_event_callbacks;