/***************************************************************************
 *                                                                         *
 *   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_ecos_stackings.h"

static int eCos_detect_rtos( struct target* target );
static int eCos_create( struct target* target );
static int eCos_update_threads( struct rtos* rtos);
static int eCos_get_thread_reg_list(struct rtos *rtos, int64_t thread_id, char ** hex_reg_list );
static int eCos_get_symbol_list_to_lookup(symbol_table_elem_t * symbol_list[]);

struct eCos_thread_state
{
	int value;
	char * desc;
};


struct eCos_thread_state eCos_thread_states[] =
{
    { 0,  "Ready" },
    { 1,  "Sleeping" },
    { 2,  "Countsleep" },
    { 4,  "Suspended" },
    { 8,  "Creating" },
    { 16,  "Exited" }
};

#define ECOS_NUM_STATES (sizeof(eCos_thread_states)/sizeof(struct eCos_thread_state))

struct eCos_params
{
	char *                               target_name;
	unsigned char                        pointer_width;
	unsigned char                        thread_stack_offset;
	unsigned char                        thread_name_offset;
	unsigned char                        thread_state_offset;
	unsigned char                        thread_next_offset;
	unsigned char                        thread_uniqueid_offset;
	const struct rtos_register_stacking* stacking_info;
};

const struct eCos_params eCos_params_list[] =
{
	{ "cortex_m3",                       // target_name
          4,                                 // pointer_width;
          0x0c,                              // thread_stack_offset;
          0x9c,                              // thread_name_offset;
          0x3c,                              // thread_state_offset;
          0xa0,                              // thread_next_offset
          0x4c,                              // thread_uniqueid_offset
          &rtos_eCos_Cortex_M3_stacking      // stacking_info
	}

};

#define ECOS_NUM_PARAMS ((int)(sizeof(eCos_params_list)/sizeof(struct eCos_params)))

enum eCos_symbol_values
{
	eCos_VAL_thread_list     	= 0,
	eCos_VAL_current_thread_ptr	= 1
};

static char* eCos_symbol_list[] =
{
		"Cyg_Thread::thread_list",
		"Cyg_Scheduler_Base::current_thread",
		NULL
};



#define ECOS_NUM_SYMBOLS (sizeof(eCos_symbol_list)/sizeof(char*))


const struct rtos_type eCos_rtos =
{
	.name                      = "eCos",

	.detect_rtos               = eCos_detect_rtos,
	.create                    = eCos_create,
	.update_threads            = eCos_update_threads,
	.get_thread_reg_list       = eCos_get_thread_reg_list,
	.get_symbol_list_to_lookup = eCos_get_symbol_list_to_lookup,

};

static int eCos_update_threads( struct rtos* rtos)
{
	int retval;
	int tasks_found = 0;
	int thread_list_size = 0;
	const struct eCos_params* param;

	if ( rtos == NULL )
	{
		return -1;
	}

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

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

	if ( rtos->symbols == NULL )
	{
		LOG_OUTPUT("No symbols for eCos\r\n");
		return -4;
	}

	if ( rtos->symbols[eCos_VAL_thread_list].address == 0 )
	{
		LOG_OUTPUT("Don't have the thread list head\r\n");
		return -2;
	}


	// 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;
	}


	// determine the number of current threads
	uint32_t thread_list_head = rtos->symbols[eCos_VAL_thread_list].address;
	uint32_t thread_index;
	target_read_buffer( rtos->target, thread_list_head, param->pointer_width, (uint8_t *) &thread_index );
	uint32_t first_thread = thread_index;
	do
	{
		thread_list_size++;
		retval = target_read_buffer( rtos->target, thread_index + param->thread_next_offset, param->pointer_width, (uint8_t *) &thread_index );
	} while( thread_index!=first_thread );

	// read the current thread id
	uint32_t current_thread_addr;
	retval = target_read_buffer( rtos->target, rtos->symbols[eCos_VAL_current_thread_ptr].address, 4, (uint8_t *)&current_thread_addr);
	rtos->current_thread = 0;
	retval = target_read_buffer( rtos->target, current_thread_addr + param->thread_uniqueid_offset, 2, (uint8_t *)&rtos->current_thread);
	if ( retval != ERROR_OK )
	{
		LOG_OUTPUT("Could not read eCos current thread from target\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 == 0 )
		{
			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 );
	}

	// loop over all threads
	thread_index = first_thread;
	do
	{

		#define ECOS_THREAD_NAME_STR_SIZE (200)
		char tmp_str[ECOS_THREAD_NAME_STR_SIZE];
		unsigned int i = 0;
		uint32_t name_ptr = 0;
		uint32_t prev_thread_ptr;

		// Save the thread pointer
		uint16_t thread_id;
		retval = target_read_buffer( rtos->target, thread_index + param->thread_uniqueid_offset, 2, (uint8_t *)&thread_id);
		if ( retval != ERROR_OK )
		{
			LOG_OUTPUT("Could not read eCos thread id from target\r\n");
			return retval;
		}
		rtos->thread_details[tasks_found].threadid = thread_id;

		// read the name pointer
		retval = target_read_buffer( rtos->target, thread_index + param->thread_name_offset, param->pointer_width, (uint8_t *)&name_ptr);
		if ( retval != ERROR_OK )
		{
			LOG_OUTPUT("Could not read eCos thread name pointer from target\r\n");
			return retval;
		}

		// Read the thread name
		retval = target_read_buffer( rtos->target, name_ptr, ECOS_THREAD_NAME_STR_SIZE, (uint8_t *)&tmp_str);
		if ( retval != ERROR_OK )
		{
			LOG_OUTPUT("Error reading thread name from eCos target\r\n");
			return retval;
		}
		tmp_str[ECOS_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 );

		// Read the thread status
		int64_t thread_status = 0;
		retval = target_read_buffer( rtos->target, thread_index + param->thread_state_offset, 4, (uint8_t *)&thread_status);
		if ( retval != ERROR_OK )
		{
			LOG_OUTPUT("Error reading thread state from eCos target\r\n");
			return retval;
		}

		for( i = 0; (i < ECOS_NUM_STATES) && (eCos_thread_states[i].value!=thread_status); i++ )
		{
		}

		char * state_desc;
		if  (i < ECOS_NUM_STATES)
		{
			state_desc = eCos_thread_states[i].desc;
		}
		else
		{
			state_desc = "Unknown state";
		}

		rtos->thread_details[tasks_found].extra_info_str = (char*)malloc( strlen(state_desc)+1 );
		strcpy( rtos->thread_details[tasks_found].extra_info_str, state_desc );

		rtos->thread_details[tasks_found].exists = true;

		rtos->thread_details[tasks_found].display_str = NULL;


		tasks_found++;
		prev_thread_ptr = thread_index;

		// Get the location of the next thread structure.
		thread_index = rtos->symbols[eCos_VAL_thread_list].address;
		retval = target_read_buffer( rtos->target, prev_thread_ptr + param->thread_next_offset, param->pointer_width, (uint8_t *) &thread_index );
		if ( retval != ERROR_OK )
		{
			LOG_OUTPUT("Error reading next thread pointer in eCos thread list\r\n");
			return retval;
		}
	}
	while( thread_index!=first_thread );

	rtos->thread_count = tasks_found;
	return 0;
}

static int eCos_get_thread_reg_list(struct rtos *rtos, int64_t thread_id, char ** hex_reg_list )
{

	int retval;
	const struct eCos_params* param;

	*hex_reg_list = NULL;

	if ( rtos == NULL )
	{
		return -1;
	}

	if ( thread_id == 0 )
	{
		return -2;
	}

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

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


	// Find the thread with that thread id
	uint16_t id=0;
	uint32_t thread_list_head = rtos->symbols[eCos_VAL_thread_list].address;
	uint32_t thread_index;
	target_read_buffer( rtos->target, thread_list_head, param->pointer_width, (uint8_t *) &thread_index );
	bool done=false;
	while(!done)
	{
		retval = target_read_buffer( rtos->target, thread_index + param->thread_uniqueid_offset, 2, (uint8_t*)&id);
		if ( retval != ERROR_OK )
		{
			LOG_OUTPUT("Error reading unique id from eCos thread\r\n");
			return retval;
		}

		if( id==thread_id )
		{
			done=true;
			break;
		}
		target_read_buffer( rtos->target, thread_index + param->thread_next_offset, param->pointer_width, (uint8_t *) &thread_index );
	}

	if(done)
	{
		// Read the stack pointer
		int64_t stack_ptr = 0;
		retval = target_read_buffer( rtos->target, thread_index + param->thread_stack_offset, param->pointer_width, (uint8_t*)&stack_ptr);
		if ( retval != ERROR_OK )
		{
			LOG_OUTPUT("Error reading stack frame from eCos thread\r\n");
			return retval;
		}

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

	return -1;
}



static int eCos_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 ) * ECOS_NUM_SYMBOLS );

	for( i = 0; i < ECOS_NUM_SYMBOLS; i++ )
	{
		(*symbol_list)[i].symbol_name = eCos_symbol_list[i];
	}

	return 0;
}

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

static int eCos_create( struct target* target )
{
	int i = 0;
	while ( ( i < ECOS_NUM_PARAMS ) && ( 0 != strcmp( eCos_params_list[i].target_name, target->type->name ) ) )
	{
		i++;
	}
	if ( i >= ECOS_NUM_PARAMS )
	{
		LOG_OUTPUT("Could not find target in eCos compatibility list\r\n");
		return -1;
	}

	target->rtos->rtos_specific_params = (void*) &eCos_params_list[i];
	target->rtos->current_thread = 0;
	target->rtos->thread_details = NULL;
	return 0;
}