/**************************************************************************//**
* @brief Writes data after the last occupied location and returns the updated
* value for the last occupied location
*
* @param data is the pointer to the data that will be written to the flash
* @param length is the length of the data that will be written to the flash
*
* @return \b flash_write_count is the last occupied location
******************************************************************************/
unsigned int
flash_write_wear_level(unsigned int *data, unsigned int length)
{
unsigned int ii, index;
unsigned int flash_write_count;
flash_read_data(&flash_write_count, 0 ,1);
switch(flash_write_count){
// the case of a un-initialized array, brandnew device
case 0xFFFF:
flash_write_count = 1;
flash_write_data(&flash_write_count, 0 ,1);
flash_write_data(data, 1 ,length);
break;
// the case of having reached 50000 writes, reset the counter to 1
case 0xC350:
flash_write_count = 1;
flash_erase_segment(0, SIZE_OF_STORAGE_ARRAY);
flash_write_data(&flash_write_count, 0 ,1);
flash_write_data(data, 1 ,length);
break;
// Normal operation, find the end of the current array, store new data
default:
// search the array for the end of the flash storage array, look for 0xFFFF
for(ii=0;ii<SIZE_OF_STORAGE_ARRAY;ii=ii+length+1)
{
flash_read_data(&flash_write_count, ii ,1);
if(flash_write_count == 0xFFFF)
{
flash_read_data(&flash_write_count, 0 ,1);
index = ii;
ii = SIZE_OF_STORAGE_ARRAY;
}
}
// before writing to segment, check to see if we are out of bound
if(index+length+1 > SIZE_OF_STORAGE_ARRAY )
{
// if we have reached the end, delete the entire array, increment counter and restart
flash_read_data(&flash_write_count, 0 ,1);
flash_erase_segment(0, SIZE_OF_STORAGE_ARRAY);
flash_write_count++;
flash_write_data(&flash_write_count, 0 ,1);
flash_write_data(data, 1 ,length);
} else
{
// Normal write to Flash array
flash_write_data(&flash_write_count, index ,1);
flash_write_data(data, index+1 ,length);
}
break;
}
return flash_write_count;
}
// *************************************************************************************************
// @fn db_clear
// @brief Clear the dataabase
// @param none
// @return none
// *************************************************************************************************
void db_clear(void)
{
u8 i;
for (i = 0; i < MAX_TABLES; ++i)
{
memset(&tables[i], 0, sizeof(db_table_t));
flash_erase_segment((u8*)tables_in_flash[i]);
}
memset(&info, 0, sizeof(db_info_t));
flash_erase_segment((u8*)info_in_flash);
}
// *************************************************************************************************
// @fn db_save
// @brief save a encryption key for a door
// @param id, key
// @return status, 0 = success, 1 = db full
// *************************************************************************************************
u8 db_save(u16 id, u8 key[16])
{
u8 i, j;
u8 empty_found = 0, empty_i = 0, empty_j = 0;
// first find if the record already exists
for (i = 0; i < MAX_TABLES; ++i)
{
for (j = 0; j < RECORDS_PER_TABLE; ++j)
{
if (tables[i].records[j].id == id)
{
// found it
// erase
flash_erase_segment((u8*)tables_in_flash[i]);
// update RAM first
memcpy(tables[i].records[j].key, key, 16);
// calculat new crc
tables[i].crc = crc_compute((u8*)&tables[i], RECORDS_PER_TABLE * sizeof(db_record_t));
// write only one segment
flash_write_segment((u8*)tables_in_flash[i], (u8*)(&tables[i]));
return 0;
}
else if (!empty_found && !tables[i].records[j].id)
{
empty_i = i;
empty_j = j;
empty_found = 1;
}
}
}
// is database all full?
if (!empty_found) return 1;
// erase
flash_erase_segment((u8*)tables_in_flash[empty_i]);
// write to a new slot
tables[empty_i].records[empty_j].id = id;
memcpy(tables[empty_i].records[empty_j].key, key, 16);
// calculat new crc
tables[empty_i].crc = crc_compute((u8*)&tables[empty_i], RECORDS_PER_TABLE * sizeof(db_record_t));
// write only one segment
flash_write_segment((u8*)tables_in_flash[empty_i], (u8*)(&tables[empty_i]));
return 0;
}
/* returns 1 if the id was expected and set, 0 otherwise */
static void set_node_id(unsigned char id)
{
TIMER_ID_INPUT = UINT_MAX;
if(flash_write_byte((unsigned char *) NODE_ID_LOCATION, id) != 0)
{
flash_erase_segment((unsigned int *) NODE_ID_LOCATION);
flash_write_byte((unsigned char *) NODE_ID_LOCATION, id);
}
node_id = id;
printf("this node id is now 0x%02X\r\n", id);
}
u16 db_id(void)
{
if (info.id && info.id != 0xFFFFu)
return info.id;
info.id = 0;
while (!info.id || info.id == 0xFFFFu)
{
info.id ^= TA0R;
info.id ^= crc_compute((u8*)&sDate, sizeof(struct date));
info.id ^= crc_compute((u8*)&sTime, sizeof(struct time));
info.id ^= crc_compute((u8*)&sBatt, sizeof(struct batt));
}
flash_erase_segment((u8*)info_in_flash);
info.crc = crc_compute((u8*)&info, sizeof(db_info_t) - 2);
flash_write_segment((u8*)info_in_flash, (u8*)(&info));
return info.id;
}