/***************************************************************************
 *   Copyright (C) 2011 by Broadcom Corporation                            *
 *   Evan Hunter - ehunter@broadcom.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     *
 *   (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, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.           *
 ***************************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <helper/time_support.h>
#include <jtag/jtag.h>
#include "target/target.h"
#include "target/target_type.h"
#include "rtos.h"
#include "helper/log.h"
#include "helper/types.h"
#include "rtos_standard_stackings.h"

#define FREERTOS_MAX_PRIORITIES	63

#define FreeRTOS_STRUCT(int_type, ptr_type, list_prev_offset)

struct FreeRTOS_params {
	const char *target_name;
	const unsigned char thread_count_width;
	const unsigned char pointer_width;
	const unsigned char list_next_offset;
	const unsigned char list_width;
	const unsigned char list_elem_next_offset;
	const unsigned char list_elem_content_offset;
	const unsigned char thread_stack_offset;
	const unsigned char thread_name_offset;
	const struct rtos_register_stacking *stacking_info;
};

const struct FreeRTOS_params FreeRTOS_params_list[] = {
	{
	"cortex_m",			/* target_name */
	4,						/* thread_count_width; */
	4,						/* pointer_width; */
	16,						/* list_next_offset; */
	20,						/* list_width; */
	8,						/* list_elem_next_offset; */
	12,						/* list_elem_content_offset */
	0,						/* thread_stack_offset; */
	52,						/* thread_name_offset; */
	&rtos_standard_Cortex_M3_stacking,	/* stacking_info */
	},
	{
	"hla_target",			/* target_name */
	4,						/* thread_count_width; */
	4,						/* pointer_width; */
	16,						/* list_next_offset; */
	20,						/* list_width; */
	8,						/* list_elem_next_offset; */
	12,						/* list_elem_content_offset */
	0,						/* thread_stack_offset; */
	52,						/* thread_name_offset; */
	&rtos_standard_Cortex_M3_stacking,	/* stacking_info */
	},
	{
	"nds32_v3",			/* target_name */
	4,						/* thread_count_width; */
	4,						/* pointer_width; */
	16,						/* list_next_offset; */
	20,						/* list_width; */
	8,						/* list_elem_next_offset; */
	12,						/* list_elem_content_offset */
	0,						/* thread_stack_offset; */
	52,						/* thread_name_offset; */
	&rtos_standard_NDS32_N1068_stacking,	/* stacking_info */
	},
};

#define FREERTOS_NUM_PARAMS ((int)(sizeof(FreeRTOS_params_list)/sizeof(struct FreeRTOS_params)))

static int FreeRTOS_detect_rtos(struct target *target);
static int FreeRTOS_create(struct target *target);
static int FreeRTOS_update_threads(struct rtos *rtos);
static int FreeRTOS_get_thread_reg_list(struct rtos *rtos, int64_t thread_id, char **hex_reg_list);
static int FreeRTOS_get_symbol_list_to_lookup(symbol_table_elem_t *symbol_list[]);

struct rtos_type FreeRTOS_rtos = {
	.name = "FreeRTOS",

	.detect_rtos = FreeRTOS_detect_rtos,
	.create = FreeRTOS_create,
	.update_threads = FreeRTOS_update_threads,
	.get_thread_reg_list = FreeRTOS_get_thread_reg_list,
	.get_symbol_list_to_lookup = FreeRTOS_get_symbol_list_to_lookup,
};

enum FreeRTOS_symbol_values {
	FreeRTOS_VAL_pxCurrentTCB = 0,
	FreeRTOS_VAL_pxReadyTasksLists = 1,
	FreeRTOS_VAL_xDelayedTaskList1 = 2,
	FreeRTOS_VAL_xDelayedTaskList2 = 3,
	FreeRTOS_VAL_pxDelayedTaskList = 4,
	FreeRTOS_VAL_pxOverflowDelayedTaskList = 5,
	FreeRTOS_VAL_xPendingReadyList = 6,
	FreeRTOS_VAL_xTasksWaitingTermination = 7,
	FreeRTOS_VAL_xSuspendedTaskList = 8,
	FreeRTOS_VAL_uxCurrentNumberOfTasks = 9,
	FreeRTOS_VAL_uxTopUsedPriority = 10,
};

static char *FreeRTOS_symbol_list[] = {
	"pxCurrentTCB",
	"pxReadyTasksLists",
	"xDelayedTaskList1",
	"xDelayedTaskList2",
	"pxDelayedTaskList",
	"pxOverflowDelayedTaskList",
	"xPendingReadyList",
	"xTasksWaitingTermination",
	"xSuspendedTaskList",
	"uxCurrentNumberOfTasks",
	"uxTopUsedPriority",
	NULL
};

/* TODO: */
/* this is not safe for little endian yet */
/* may be problems reading if sizes are not 32 bit long integers. */
/* test mallocs for failure */

static int FreeRTOS_update_threads(struct rtos *rtos)
{
	int i = 0;
	int retval;
	int tasks_found = 0;
	const struct FreeRTOS_params *param;

	if (rtos->rtos_specific_params == NULL)
		return -1;

	param = (const struct FreeRTOS_params *) rtos->rtos_specific_params;

	if (rtos->symbols == NULL) {
		LOG_ERROR("No symbols for FreeRTOS");
		return -3;
	}

	if (rtos->symbols[FreeRTOS_VAL_uxCurrentNumberOfTasks].address == 0) {
		LOG_ERROR("Don't have the number of threads in FreeRTOS");
		return -2;
	}

	int thread_list_size = 0;
	retval = target_read_buffer(rtos->target,
			rtos->symbols[FreeRTOS_VAL_uxCurrentNumberOfTasks].address,
			param->thread_count_width,
			(uint8_t *)&thread_list_size);

	if (retval != ERROR_OK) {
		LOG_ERROR("Could not read FreeRTOS thread count from target");
		return retval;
	}

	/* wipe out previous thread details if any */
	rtos_free_threadlist(rtos);

	/* read the current thread */
	retval = target_read_buffer(rtos->target,
			rtos->symbols[FreeRTOS_VAL_pxCurrentTCB].address,
			param->pointer_width,
			(uint8_t *)&rtos->current_thread);
	if (retval != ERROR_OK) {
		LOG_ERROR("Error reading current thread in FreeRTOS thread list");
		return retval;
	}

	if ((thread_list_size  == 0) || (rtos->current_thread == 0)) {
		/* Either : No RTOS threads - there is always at least the current execution though */
		/* OR     : No current thread - all threads suspended - show the current execution
		 * of idling */
		char tmp_str[] = "Current Execution";
		thread_list_size++;
		tasks_found++;
		rtos->thread_details = malloc(
				sizeof(struct thread_detail) * thread_list_size);
		if (!rtos->thread_details) {
			LOG_ERROR("Error allocating memory for %d threads", thread_list_size);
			return ERROR_FAIL;
		}
		rtos->thread_details->threadid = 1;
		rtos->thread_details->exists = true;
		rtos->thread_details->display_str = NULL;
		rtos->thread_details->extra_info_str = NULL;
		rtos->thread_details->thread_name_str = malloc(sizeof(tmp_str));
		strcpy(rtos->thread_details->thread_name_str, tmp_str);

		if (thread_list_size == 1) {
			rtos->thread_count = 1;
			return ERROR_OK;
		}
	} else {
		/* create space for new thread details */
		rtos->thread_details = malloc(
				sizeof(struct thread_detail) * thread_list_size);
		if (!rtos->thread_details) {
			LOG_ERROR("Error allocating memory for %d threads", thread_list_size);
			return ERROR_FAIL;
		}
	}

	/* Find out how many lists are needed to be read from pxReadyTasksLists, */
	int64_t max_used_priority = 0;
	retval = target_read_buffer(rtos->target,
			rtos->symbols[FreeRTOS_VAL_uxTopUsedPriority].address,
			param->pointer_width,
			(uint8_t *)&max_used_priority);
	if (retval != ERROR_OK)
		return retval;
	if (max_used_priority > FREERTOS_MAX_PRIORITIES) {
		LOG_ERROR("FreeRTOS maximum used priority is unreasonably big, not proceeding: %" PRId64 "",
			max_used_priority);
		return ERROR_FAIL;
	}

	symbol_address_t *list_of_lists =
		malloc(sizeof(symbol_address_t) *
			(max_used_priority+1 + 5));
	if (!list_of_lists) {
		LOG_ERROR("Error allocating memory for %" PRId64 " priorities", max_used_priority);
		return ERROR_FAIL;
	}

	int num_lists;
	for (num_lists = 0; num_lists <= max_used_priority; num_lists++)
		list_of_lists[num_lists] = rtos->symbols[FreeRTOS_VAL_pxReadyTasksLists].address +
			num_lists * param->list_width;

	list_of_lists[num_lists++] = rtos->symbols[FreeRTOS_VAL_xDelayedTaskList1].address;
	list_of_lists[num_lists++] = rtos->symbols[FreeRTOS_VAL_xDelayedTaskList2].address;
	list_of_lists[num_lists++] = rtos->symbols[FreeRTOS_VAL_xPendingReadyList].address;
	list_of_lists[num_lists++] = rtos->symbols[FreeRTOS_VAL_xSuspendedTaskList].address;
	list_of_lists[num_lists++] = rtos->symbols[FreeRTOS_VAL_xTasksWaitingTermination].address;

	for (i = 0; i < num_lists; i++) {
		if (list_of_lists[i] == 0)
			continue;

		/* Read the number of threads in this list */
		int64_t list_thread_count = 0;
		retval = target_read_buffer(rtos->target,
				list_of_lists[i],
				param->thread_count_width,
				(uint8_t *)&list_thread_count);
		if (retval != ERROR_OK) {
			LOG_ERROR("Error reading number of threads in FreeRTOS thread list");
			free(list_of_lists);
			return retval;
		}

		if (list_thread_count == 0)
			continue;

		/* Read the location of first list item */
		uint64_t prev_list_elem_ptr = -1;
		uint64_t list_elem_ptr = 0;
		retval = target_read_buffer(rtos->target,
				list_of_lists[i] + param->list_next_offset,
				param->pointer_width,
				(uint8_t *)&list_elem_ptr);
		if (retval != ERROR_OK) {
			LOG_ERROR("Error reading first thread item location in FreeRTOS thread list");
			free(list_of_lists);
			return retval;
		}

		while ((list_thread_count > 0) && (list_elem_ptr != 0) &&
				(list_elem_ptr != prev_list_elem_ptr) &&
				(tasks_found < thread_list_size)) {
			/* Get the location of the thread structure. */
			rtos->thread_details[tasks_found].threadid = 0;
			retval = target_read_buffer(rtos->target,
					list_elem_ptr + param->list_elem_content_offset,
					param->pointer_width,
					(uint8_t *)&(rtos->thread_details[tasks_found].threadid));
			if (retval != ERROR_OK) {
				LOG_ERROR("Error reading thread list item object in FreeRTOS thread list");
				free(list_of_lists);
				return retval;
			}

			/* get thread name */

			#define FREERTOS_THREAD_NAME_STR_SIZE (200)
			char tmp_str[FREERTOS_THREAD_NAME_STR_SIZE];

			/* Read the thread name */
			retval = target_read_buffer(rtos->target,
					rtos->thread_details[tasks_found].threadid + param->thread_name_offset,
					FREERTOS_THREAD_NAME_STR_SIZE,
					(uint8_t *)&tmp_str);
			if (retval != ERROR_OK) {
				LOG_ERROR("Error reading first thread item location in FreeRTOS thread list");
				free(list_of_lists);
				return retval;
			}
			tmp_str[FREERTOS_THREAD_NAME_STR_SIZE-1] = '\x00';

			if (tmp_str[0] == '\x00')
				strcpy(tmp_str, "No Name");

			rtos->thread_details[tasks_found].thread_name_str =
				malloc(strlen(tmp_str)+1);
			strcpy(rtos->thread_details[tasks_found].thread_name_str, tmp_str);
			rtos->thread_details[tasks_found].display_str = NULL;
			rtos->thread_details[tasks_found].exists = true;

			if (rtos->thread_details[tasks_found].threadid == rtos->current_thread) {
				char running_str[] = "Running";
				rtos->thread_details[tasks_found].extra_info_str = malloc(
						sizeof(running_str));
				strcpy(rtos->thread_details[tasks_found].extra_info_str,
					running_str);
			} else
				rtos->thread_details[tasks_found].extra_info_str = NULL;

			tasks_found++;
			list_thread_count--;

			prev_list_elem_ptr = list_elem_ptr;
			list_elem_ptr = 0;
			retval = target_read_buffer(rtos->target,
					prev_list_elem_ptr + param->list_elem_next_offset,
					param->pointer_width,
					(uint8_t *)&list_elem_ptr);
			if (retval != ERROR_OK) {
				LOG_ERROR("Error reading next thread item location in FreeRTOS thread list");
				free(list_of_lists);
				return retval;
			}
		}
	}

	free(list_of_lists);
	rtos->thread_count = tasks_found;
	return 0;
}

static int FreeRTOS_get_thread_reg_list(struct rtos *rtos, int64_t thread_id, char **hex_reg_list)
{
	int retval;
	const struct FreeRTOS_params *param;
	int64_t stack_ptr = 0;

	*hex_reg_list = NULL;
	if (rtos == NULL)
		return -1;

	if (thread_id == 0)
		return -2;

	if (rtos->rtos_specific_params == NULL)
		return -1;

	param = (const struct FreeRTOS_params *) rtos->rtos_specific_params;

	/* Read the stack pointer */
	retval = target_read_buffer(rtos->target,
			thread_id + param->thread_stack_offset,
			param->pointer_width,
			(uint8_t *)&stack_ptr);
	if (retval != ERROR_OK) {
		LOG_ERROR("Error reading stack frame from FreeRTOS thread");
		return retval;
	}

	return rtos_generic_stack_read(rtos->target, param->stacking_info, stack_ptr, hex_reg_list);
}

static int FreeRTOS_get_symbol_list_to_lookup(symbol_table_elem_t *symbol_list[])
{
	unsigned int i;
	*symbol_list = malloc(
			sizeof(symbol_table_elem_t) * ARRAY_SIZE(FreeRTOS_symbol_list));

	for (i = 0; i < ARRAY_SIZE(FreeRTOS_symbol_list); i++)
		(*symbol_list)[i].symbol_name = FreeRTOS_symbol_list[i];

	return 0;
}

#if 0

static int FreeRTOS_set_current_thread(struct rtos *rtos, threadid_t thread_id)
{
	return 0;
}

static int FreeRTOS_get_thread_ascii_info(struct rtos *rtos, threadid_t thread_id, char **info)
{
	int retval;
	const struct FreeRTOS_params *param;

	if (rtos == NULL)
		return -1;

	if (thread_id == 0)
		return -2;

	if (rtos->rtos_specific_params == NULL)
		return -3;

	param = (const struct FreeRTOS_params *) rtos->rtos_specific_params;

#define FREERTOS_THREAD_NAME_STR_SIZE (200)
	char tmp_str[FREERTOS_THREAD_NAME_STR_SIZE];

	/* Read the thread name */
	retval = target_read_buffer(rtos->target,
			thread_id + param->thread_name_offset,
			FREERTOS_THREAD_NAME_STR_SIZE,
			(uint8_t *)&tmp_str);
	if (retval != ERROR_OK) {
		LOG_ERROR("Error reading first thread item location in FreeRTOS thread list");
		return retval;
	}
	tmp_str[FREERTOS_THREAD_NAME_STR_SIZE-1] = '\x00';

	if (tmp_str[0] == '\x00')
		strcpy(tmp_str, "No Name");

	*info = malloc(strlen(tmp_str)+1);
	strcpy(*info, tmp_str);
	return 0;
}

#endif

static int FreeRTOS_detect_rtos(struct target *target)
{
	if ((target->rtos->symbols != NULL) &&
			(target->rtos->symbols[FreeRTOS_VAL_pxReadyTasksLists].address != 0)) {
		/* looks like FreeRTOS */
		return 1;
	}
	return 0;
}

static int FreeRTOS_create(struct target *target)
{
	int i = 0;
	while ((i < FREERTOS_NUM_PARAMS) &&
			(0 != strcmp(FreeRTOS_params_list[i].target_name, target->type->name))) {
		i++;
	}
	if (i >= FREERTOS_NUM_PARAMS) {
		LOG_ERROR("Could not find target in FreeRTOS compatibility list");
		return -1;
	}

	target->rtos->rtos_specific_params = (void *) &FreeRTOS_params_list[i];
	return 0;
}