//Write to Flash ROM.
//
// location - flash program memory address
// src - pointer to data to write
// size - number of bytes to write to flash
//
// Here is the sequence of events:
// 1.) Goes to the beginning of the first erase block for this address
// 2.) Reads n records to ram, where n is the PIC's flash erase size
// 3.) Erases block in flash
// 4.) Modifies block in RAM
// 5.) Writes changed block back to FLASH. Writes in chunks defined by PIC's flash write size
// 6.) Goes back to step1 if there is still more data to be written
void rom_w(int32 location, char *src, int16 size)
{
#define EEPROM_ERASE_SIZE getenv("FLASH_ERASE_SIZE")
#define EEPROM_WRITE_SIZE getenv("FLASH_WRITE_SIZE")
int8 block[EEPROM_ERASE_SIZE];
int32 block_start;
int8 i;
int8 num;
block_start = location & (~((int32)EEPROM_ERASE_SIZE-1));
i=location-block_start;
while (size)
{
read_program_memory(block_start, block, sizeof(block)); //read entire block to ram buffer
if (size>(EEPROM_ERASE_SIZE-i)) {num=EEPROM_ERASE_SIZE-i;} else {num=size;}
memcpy(&block[i],src,num); //modify ram buffer
erase_program_eeprom(block_start); //erase entire block
write_program_memory(block_start, block, sizeof(block)); //write modified block
src+=num;
block_start+=EEPROM_ERASE_SIZE;
i=0;
size-=num;
}
}
/* ========================================================================= */
void bootloader(void)
{
uint32 addr;
uint16 addr_low;
uint8 addr_high = 0;
uint8 reclen;
uint8 rectype;
uint8 idx;
uint8 buffer[HEX_LINE_LEN_MAX];
uint8 ch;
bool hexend = 0;
#if getenv("FLASH_ERASE_SIZE")>2
uint16 next_addr = 0;
#endif
/* until end of HEX file */
while(hexend == 0)
{
/* get one line of the HEX file via RS232 until we receive CR or */
/* we reached the end of the buffer */
idx = 0;
do
{
/* get one byte */
ch = getch();
/* save to buffer */
buffer[idx] = ch;
/* increment buffer index */
idx++;
}
while(ch != 0x0A);
/* get record length */
reclen = get_hexbyte(&buffer[HEX_LEN_START]);
/* check for proper checksum */
if (check_checksum(&buffer[HEX_LEN_START], reclen) != 0)
{
/* checkum error - send negative acknowledge */
putc(NAK);
}
else
{
/* checkum ok */
/* get address */
addr_low = make16(get_hexbyte(&buffer[HEX_ADDR_START]),
get_hexbyte(&buffer[HEX_ADDR_START+2]));
/* make 32 bit address */
addr = make32(addr_high, addr_low);
/* get record type */
rectype = get_hexbyte(&buffer[HEX_TYPE_START]);
if (rectype == HEX_DATA_REC)
{
/* only program code memory */
if ((addr_high < 0x30) && (addr >= RESET_VECTOR))
{
for (idx=0; idx < reclen; idx++)
{
buffer[idx] = get_hexbyte(&buffer[HEX_DATA_START+(idx*2)]);
}
#if getenv("FLASH_ERASE_SIZE") > getenv("FLASH_WRITE_SIZE")
#if defined(__PCM__)
if ((addr_low!=next_addr)&&(addr_low&(getenv("FLASH_ERASE_SIZE")-1)!=0))
#else
if ((addr_low!=next_addr)&&(addr_low&(getenv("FLASH_ERASE_SIZE")/2-1)!=0))
#endif
erase_program_eeprom(addr);
next_addr = addr_low + 1;
#endif
write_program_memory(addr, buffer, reclen);
}
}
else if (rectype == HEX_EOF_REC)
{
hexend = 1;
}
else if (rectype == HEX_EXTADDR_REC)
{
/* to save resources, only take lower byte - this */
/* allows 24 bit addresses => enough for PIC18F */
//addr_high = make16(get_hexbyte(&buffer[HEX_DATA_START]),
// get_hexbyte(&buffer[HEX_DATA_START+2]));
addr_high = get_hexbyte(&buffer[HEX_DATA_START+2]);
}
/* send positive acknowledge */
putc(ACK);
}
}
}
