int32_t Ymodem_Receive (uint8_t *buf)
{
uint8_t packet_data[PACKET_1K_SIZE + PACKET_OVERHEAD], file_size[FILE_SIZE_LENGTH], *file_ptr, *buf_ptr;
int32_t i, j, packet_length, session_done, file_done, packets_received, errors, session_begin, size = 0;

/* Initialize FlashDestination variable */
FlashDestination = ApplicationAddress;

for (session_done = 0, errors = 0, session_begin = 0;
{
for (packets_received = 0, file_done = 0, buf_ptr = buf;
{
switch (Receive_Packet(packet_data, &packet_length, NAK_TIMEOUT))
{
case 0:
errors = 0;
switch (packet_length)
{
/* Abort by sender */
case - 1:
Send_Byte(ACK);
return 0;
/* End of transmission */
case 0:
Send_Byte(ACK);
file_done = 1;
break;
/* Normal packet */
default:
if ((packet_data[PACKET_SEQNO_INDEX] & 0xff) != (packets_received & 0xff))
{
Send_Byte(NAK);
}
else
{
if (packets_received == 0)
{
/* Filename packet */
if (packet_data[PACKET_HEADER] != 0)
{
/* Filename packet has valid data */
for (i = 0, file_ptr = packet_data + PACKET_HEADER; (*file_ptr != 0) && (i < FILE_NAME_LENGTH)
{
file_name[i++] = *file_ptr++;
}
file_name[i++] = '\0';
for (i = 0, file_ptr ++; (*file_ptr != ' ') && (i < FILE_SIZE_LENGTH)
{
file_size[i++] = *file_ptr++;
}
file_size[i++] = '\0';
Str2Int(file_size, &size);

/* Test the size of the image to be sent */
/* Image size is greater than Flash size */
if (size > (FLASH_SIZE - 1))
{
/* End session */
Send_Byte(CA);
Send_Byte(CA);
return -1;
}

/* Erase the needed pages where the user application will be loaded */
/* Define the number of page to be erased */
NbrOfPage = FLASH_PagesMask(size);

/* Erase the FLASH pages */
for (EraseCounter = 0; (EraseCounter < NbrOfPage) && (FLASHStatus == FLASH_COMPLETE); EraseCounter++)
{
FLASHStatus = FLASH_ErasePage(FlashDestination + (PageSize * EraseCounter));
}
Send_Byte(ACK);
Send_Byte(CRC16);
}
/* Filename packet is empty, end session */
else
{
Send_Byte(ACK);
file_done = 1;
session_done = 1;
break;
}
}
/* Data packet */
else
{
memcpy(buf_ptr, packet_data + PACKET_HEADER, packet_length);
RamSource = (uint32_t)buf;
for (j = 0;(j < packet_length) && (FlashDestination < ApplicationAddress + size);j += 4)
{
/* Program the data received into STM32F10x Flash */
FLASH_ProgramWord(FlashDestination, *(uint32_t*)RamSource);

if (*(uint32_t*)FlashDestination != *(uint32_t*)RamSource)
{
/* End session */
Send_Byte(CA);
Send_Byte(CA);
return -2;
}
FlashDestination += 4;
RamSource += 4;
}
Send_Byte(ACK);
}
packets_received ++;
session_begin = 1;
}
}
break;
case 1:
Send_Byte(CA);
Send_Byte(CA);
return -3;
default:
if (session_begin > 0)
{
errors ++;
}
if (errors > MAX_ERRORS)
{
Send_Byte(CA);
Send_Byte(CA);
return 0;
}
Send_Byte(CRC16);
break;
}
if (file_done != 0)
{
break;
}
}
if (session_done != 0)
{
break;
}
}
return (int32_t)size;
}

memcpy(buf_ptr, packet_data + PACKET_HEADER, packet_length);
                  RamSource = (uint32_t)buf;
                  for (j = 0;(j < packet_length) && (FlashDestination <  ApplicationAddress + size);j += 4)
                  {
                    /* Program the data received into STM32F10x Flash */
                    FLASH_ProgramWord(FlashDestination, *(uint32_t*)RamSource);

                    if (*(uint32_t*)FlashDestination != *(uint32_t*)RamSource)
                    {
                      /* End session */
                      Send_Byte(CA);
                      Send_Byte(CA);
                      return -2;
                    }
                    FlashDestination += 4;
                    RamSource += 4;
                  }

uint8_t temp_array[1024];
memcpy(temp_array, packet_data + PACKET_HEADER, packet_length);