/***************************************************************************
 *   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.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, 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 "rtos_standard_stackings.h"

#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_m3",                      // 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
		}

};


#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
};

#define FREERTOS_NUM_SYMBOLS (sizeof(FreeRTOS_symbol_list)/sizeof(char*))

// 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_OUTPUT("No symbols for FreeRTOS\r\n");
		return -3;
	}

	if ( rtos->symbols[FreeRTOS_VAL_uxCurrentNumberOfTasks].address == 0 )
	{
		LOG_OUTPUT("Don't have the number of threads in FreeRTOS \r\n");
		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_OUTPUT("Could not read FreeRTOS thread count from target\r\n");
		return retval;
	}


	// wipe out previous thread details if any
	if ( rtos->thread_details != NULL )
	{
		int j;
		for( j = 0; j < rtos->thread_count; j++ )
		{
			if ( rtos->thread_details[j].display_str != NULL )
			{
				free( rtos->thread_details[j].display_str );
				rtos->thread_details[j].display_str = NULL;
			}
			if ( rtos->thread_details[j].thread_name_str != NULL )
			{
				free( rtos->thread_details[j].thread_name_str );
				rtos->thread_details[j].thread_name_str = NULL;
			}
			if ( rtos->thread_details[j].extra_info_str != NULL )
			{
				free( rtos->thread_details[j].extra_info_str );
				rtos->thread_details[j].extra_info_str = NULL;
			}
		}
		free( rtos->thread_details );
		rtos->thread_details = NULL;
	}


	// 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_OUTPUT("Error reading current thread in FreeRTOS thread list\r\n");
		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 = (struct thread_detail*) malloc( sizeof( struct thread_detail ) * thread_list_size );
		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 = (char*) 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 = (struct thread_detail*) malloc( sizeof( struct thread_detail ) * thread_list_size );
	}


	// 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;

	symbol_address_t* list_of_lists = (symbol_address_t *)malloc( sizeof( symbol_address_t ) * ( max_used_priority+1 + 5 ) );

	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_OUTPUT("Error reading number of threads in FreeRTOS thread list\r\n");
			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_OUTPUT("Error reading first thread item location in FreeRTOS thread list\r\n");
			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_OUTPUT("Error reading thread list item object in FreeRTOS thread list\r\n");
				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_OUTPUT("Error reading first thread item location in FreeRTOS thread list\r\n");
				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 = (char*)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 = (char*) 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_OUTPUT("Error reading next thread item location in FreeRTOS thread list\r\n");
				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_OUTPUT("Error reading stack frame from FreeRTOS thread\r\n");
		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 = (symbol_table_elem_t *) malloc( sizeof( symbol_table_elem_t ) * FREERTOS_NUM_SYMBOLS );

	for( i = 0; i < FREERTOS_NUM_SYMBOLS; 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_OUTPUT("Error reading first thread item location in FreeRTOS thread list\r\n");
		return retval;
	}
	tmp_str[FREERTOS_THREAD_NAME_STR_SIZE-1] = '\x00';

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

	*info = (char*)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;
	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_OUTPUT("Could not find target in FreeRTOS compatibility list\r\n");
		return -1;
	}

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