Xmodem源代码

    #include "at91rm9200.h"
//#include "embedded_services.h"
#include "lib_AT91RM9200.h"


#define XMODEM_SOH 0x01
#define XMODEM_STX 0x02
#define XMODEM_EOT 0x04
#define XMODEM_ACK 0x06
#define XMODEM_NAK 0x15
#define XMODEM_ESC 0x1b
#define XMODEM_CAN 0x18
#define CRCCHR 'C'

#define XMODEM_PACKET_SIZE 2 // packet + packetCRC
#define XMODEM_CRC_SIZE 2 // crcLSB + crcMSB
#define XMODEM_DATA_SIZE_SOH 128 // data 128 corresponding to SOH header
#define XMODEM_DATA_SIZE_STX 1024 // data 1024 corresponding to STX header

#define XMODEM_TIMEOUT 1000
// "ROM Entry" Service
//AT91S_RomBoot const *pAT91;
static const unsigned short crc16tab[256]= {
 0x0000,0x1021,0x2042,0x3063,0x4084,0x50a5,0x60c6,0x70e7,
 0x8108,0x9129,0xa14a,0xb16b,0xc18c,0xd1ad,0xe1ce,0xf1ef,
 0x1231,0x0210,0x3273,0x2252,0x52b5,0x4294,0x72f7,0x62d6,
 0x9339,0x8318,0xb37b,0xa35a,0xd3bd,0xc39c,0xf3ff,0xe3de,
 0x2462,0x3443,0x0420,0x1401,0x64e6,0x74c7,0x44a4,0x5485,
 0xa56a,0xb54b,0x8528,0x9509,0xe5ee,0xf5cf,0xc5ac,0xd58d,
 0x3653,0x2672,0x1611,0x0630,0x76d7,0x66f6,0x5695,0x46b4,
 0xb75b,0xa77a,0x9719,0x8738,0xf7df,0xe7fe,0xd79d,0xc7bc,
 0x48c4,0x58e5,0x6886,0x78a7,0x0840,0x1861,0x2802,0x3823,
 0xc9cc,0xd9ed,0xe98e,0xf9af,0x8948,0x9969,0xa90a,0xb92b,
 0x5af5,0x4ad4,0x7ab7,0x6a96,0x1a71,0x0a50,0x3a33,0x2a12,
 0xdbfd,0xcbdc,0xfbbf,0xeb9e,0x9b79,0x8b58,0xbb3b,0xab1a,
 0x6ca6,0x7c87,0x4ce4,0x5cc5,0x2c22,0x3c03,0x0c60,0x1c41,
 0xedae,0xfd8f,0xcdec,0xddcd,0xad2a,0xbd0b,0x8d68,0x9d49,
 0x7e97,0x6eb6,0x5ed5,0x4ef4,0x3e13,0x2e32,0x1e51,0x0e70,
 0xff9f,0xefbe,0xdfdd,0xcffc,0xbf1b,0xaf3a,0x9f59,0x8f78,
 0x9188,0x81a9,0xb1ca,0xa1eb,0xd10c,0xc12d,0xf14e,0xe16f,
 0x1080,0x00a1,0x30c2,0x20e3,0x5004,0x4025,0x7046,0x6067,
 0x83b9,0x9398,0xa3fb,0xb3da,0xc33d,0xd31c,0xe37f,0xf35e,
 0x02b1,0x1290,0x22f3,0x32d2,0x4235,0x5214,0x6277,0x7256,
 0xb5ea,0xa5cb,0x95a8,0x8589,0xf56e,0xe54f,0xd52c,0xc50d,
 0x34e2,0x24c3,0x14a0,0x0481,0x7466,0x6447,0x5424,0x4405,
 0xa7db,0xb7fa,0x8799,0x97b8,0xe75f,0xf77e,0xc71d,0xd73c,
 0x26d3,0x36f2,0x0691,0x16b0,0x6657,0x7676,0x4615,0x5634,
 0xd94c,0xc96d,0xf90e,0xe92f,0x99c8,0x89e9,0xb98a,0xa9ab,
 0x5844,0x4865,0x7806,0x6827,0x18c0,0x08e1,0x3882,0x28a3,
 0xcb7d,0xdb5c,0xeb3f,0xfb1e,0x8bf9,0x9bd8,0xabbb,0xbb9a,
 0x4a75,0x5a54,0x6a37,0x7a16,0x0af1,0x1ad0,0x2ab3,0x3a92,
 0xfd2e,0xed0f,0xdd6c,0xcd4d,0xbdaa,0xad8b,0x9de8,0x8dc9,
 0x7c26,0x6c07,0x5c64,0x4c45,0x3ca2,0x2c83,0x1ce0,0x0cc1,
 0xef1f,0xff3e,0xcf5d,0xdf7c,0xaf9b,0xbfba,0x8fd9,0x9ff8,
 0x6e17,0x7e36,0x4e55,0x5e74,0x2e93,0x3eb2,0x0ed1,0x1ef0
};
unsigned char xbuff[200];
extern int Get_Timer(void);
extern void RST_Timer(void);
unsigned short crc16_ccitt(const unsigned char *buf, int len);
int Xmodem_Recv(unsigned char *dest, unsigned int maxsize, unsigned int *size);
int Check(const unsigned char *buf, int sz);

int Xmodem_Recv(unsigned char *dest,unsigned int maxsize, unsigned int *size)
{
 unsigned char c;
 unsigned int xrecvpkt = 0;
 unsigned int tmticks = 0;
 unsigned int csr = 0;
 unsigned int i, j, xlen = 0;
 unsigned int xdatasize, cnt = maxsize;
 AT91PS_USART pUsart;
 
 pUsart = (AT91PS_USART) AT91C_BASE_DBGU;
// pAT91 = AT91C_ROM_BOOT_ADDRESS;
 
 while ((csr & AT91C_US_RXRDY) == 0)
 {

  tmticks = Get_Timer();
  if(tmticks > XMODEM_TIMEOUT)
  {
  AT91F_US_PutChar( (AT91PS_USART) pUsart, CRCCHR);
  RST_Timer();
  }
  csr = AT91C_BASE_DBGU->DBGU_CSR;
  if (csr & (AT91C_US_PARE | AT91C_US_FRAME | AT91C_US_OVRE | AT91C_US_RXBRK)) 
  {
  AT91C_BASE_DBGU->DBGU_CR = AT91C_US_RSTSTA;  
  } 
 }

 for(;;) 
 {
  tmticks = Get_Timer();
   
  if ( (csr & AT91C_US_RXRDY) && (xrecvpkt == 0) ) 
  {
  c = (unsigned char)AT91F_US_GetChar( (AT91PS_USART) pUsart);
  switch (c) 
  {
  case XMODEM_STX:
  xdatasize = XMODEM_DATA_SIZE_STX;
  xrecvpkt = 1;
  i = 0;
  RST_Timer();  
  break;
  case XMODEM_SOH:
  xdatasize = XMODEM_DATA_SIZE_SOH;
  xrecvpkt = 1;
  i = 0;
  RST_Timer();  
  break;
  case XMODEM_EOT:
  AT91F_US_PutChar( (AT91PS_USART) pUsart, XMODEM_ACK);
  *size = xlen;
  return 0;
  case XMODEM_ESC:
  case XMODEM_CAN:
  AT91F_US_PutChar( (AT91PS_USART) pUsart, XMODEM_ACK);
  return 1;
  break;
  default:
  break;
  }
  }  
  else if ((csr & AT91C_US_RXRDY) && (xrecvpkt == 1)) 
  {
  c = (unsigned char)AT91F_US_GetChar( (AT91PS_USART) pUsart);
  xbuff[i] = c;
  i++;
  if(i >= (xdatasize + XMODEM_PACKET_SIZE + XMODEM_CRC_SIZE))
  {
   
  if ((xbuff[0] == (unsigned char)(~xbuff[1])) && Check(&xbuff[2], xdatasize)) 
  {
   
  if (cnt >= xdatasize) 
  {
  for(j = 0; j < xdatasize; j++)
  {
  dest[xlen+j] = xbuff[j+2];
  }

  xlen += xdatasize;
  cnt -= xdatasize;
  }
  else
  {
  AT91F_US_PutChar((AT91PS_USART) pUsart, XMODEM_CAN);
  return 1;
  }
   
  xrecvpkt = 0; 
  AT91F_US_PutChar( (AT91PS_USART) pUsart, XMODEM_ACK);
   
  }
  else
  {
  xrecvpkt = 0;
  AT91F_US_PutChar( (AT91PS_USART) pUsart, XMODEM_NAK);
  }
  }  
  }
  else if((xrecvpkt == 1) && (tmticks > XMODEM_TIMEOUT))
  {
  xrecvpkt = 0;
  AT91F_US_PutChar( (AT91PS_USART) pUsart, XMODEM_NAK);
   
  }
  
  csr = AT91C_BASE_DBGU->DBGU_CSR;
  if (csr & (AT91C_US_PARE | AT91C_US_FRAME | AT91C_US_OVRE | AT91C_US_RXBRK)) 
  {
  AT91C_BASE_DBGU->DBGU_CR = AT91C_US_RSTSTA;  
  }  
 }  

}

int Check(const unsigned char *buf, int sz)
{
   

 unsigned short crc, tcrc;
  // Call Open methods:
 
 //pAT91->CRCCCITT(&buf[0], sz, &crc);
 
 crc = crc16_ccitt(&buf[0], sz);
 tcrc = ((unsigned short)(buf[sz]) << 8) + (unsigned short)(buf[sz+1]);
 if (crc == tcrc)
 {
  return 1;
 }
 return 0;
}

unsigned short crc16_ccitt(const unsigned char *buf, int len)  //快速crc校验
{
 register int counter;
 register unsigned short crc = 0;
 for( counter = 0; counter < len; counter++)
  crc = (crc<<8) ^ crc16tab[((crc>>8) ^ *(char *)buf++)&0x00FF];
 return crc;
}