ymodem.c

xscale pxa255 bootloader 程序

#include "ymodem.h"
#include <string.h>
#include "mylib.h"

int Uart_RecvByteTimeout(char * ch)
{

	int rx;	
	int time = 0;
	
	while(time < 15000)
	{
		rx = getc();
		if(rx != -1){ //Receive data ready	
			*ch = rx;
			return 0;
		}
		
		delayus(100);
		time++;
	}

	return -1;
}






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 short crc16_ccitt(const char *buf, int len)
{
	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;
}

//return -1 接收超时 -2接收帧错误   其他值是接收长度
static int RxPacket(receive_packet_data *prxpacket)     // continuous data receive
{
	
	int i;
	unsigned short crc;

	if (-1 ==  Uart_RecvByteTimeout(&prxpacket->packet_Nbr))
		return -1;
	if (-1 ==  Uart_RecvByteTimeout(&prxpacket->packet_Nbr_cmp))
		return -1;
		
	for(i = 0; i < prxpacket->rxlen; i++)
		if (-1 ==  Uart_RecvByteTimeout(prxpacket->data + i))
			return -1;
			
	if (-1 ==  Uart_RecvByteTimeout(&prxpacket->checksum1))
		return -1;
	if (-1 ==  Uart_RecvByteTimeout(&prxpacket->checksum2))
		return -1;	
	
	if ( prxpacket->packet_Nbr + prxpacket->packet_Nbr_cmp != 0xff) 
		return -2;
	if (prxpacket->blknum != prxpacket->packet_Nbr)
		return -2;
	
	crc = prxpacket->checksum1;
	crc = (crc << 8) + prxpacket->checksum2;
	
	if( crc16_ccitt(prxpacket->data, prxpacket->rxlen) == crc)
		return prxpacket->rxlen;
	else
		return -2;

} 


static receive_packet_data rxData;

int ymodem_download( char *rxbuf)
{

	char head;
	char *pdata;
	int packetnum;
	int trytimes;
	int rxpack;
	char eto;
	while (1) {	
	    while (1) { //接收第一包
			putc(MODEM_C);
			if(-1 != Uart_RecvByteTimeout (&head)) {		
				if(head == MODEM_SOH){    
					rxData.rxlen = 128;	
					break;
				} else if (head == MODEM_STX){ // 1024 byte buffer incoming 
					rxData.rxlen = 1024;
					break;
				}else if (head == 0x1b){  //ESC
					return -1;
				}
			}
		}
		
		rxData.blknum = 0;
		if (RxPacket(&rxData) > 0)
			pdata = rxbuf;
		else
			continue;
		
		packetnum =rxData.packet_Nbr;
		if (packetnum == 0){
			rxData.blknum = 1;
			//filename 		
		} else if (packetnum == 1){
			memcpy (pdata, rxData.data, rxData.rxlen);
			pdata += rxData.rxlen;
			rxData.blknum = 2;
		}else{
			continue;
		}
		putc(MODEM_ACK);
		putc(MODEM_C);
		
		eto = 0;
		
		trytimes = MODEM_MAX_RETRIES;
		while (trytimes--){		
			if(-1 != Uart_RecvByteTimeout (&head)){				
				switch(head){				
					case MODEM_SOH: 		// 128 byte buffer incoming        
						rxData.rxlen = 128;
						rxpack = RxPacket(&rxData);
						
						if (eto == 2){
							putc(MODEM_ACK);
						 	goto sucess ;
						}
						
						if (rxpack > 0){
							memcpy (pdata, rxData.data, rxData.rxlen);
							rxData.blknum++;
							pdata += rxData.rxlen;						
							trytimes = MODEM_MAX_RETRIES;
							putc(MODEM_ACK);
						}else if(rxpack == -2){
							trytimes = MODEM_MAX_RETRIES;
							putc(MODEM_NAK);
						}
						break;	
								
					case MODEM_STX: // 1024 byte buffer incoming 
						rxData.rxlen = 1024;
						trytimes = 10;
						rxpack = RxPacket(&rxData);
						if (eto == 2){
							putc(MODEM_ACK);
						 	goto sucess ;
						}
						if (rxpack > 0){
							memcpy (pdata, rxData.data, rxData.rxlen);
							rxData.blknum++;
							pdata += rxData.rxlen;						
							trytimes = MODEM_MAX_RETRIES;
							putc(MODEM_ACK);
						}else if(rxpack == -2){
							trytimes = MODEM_MAX_RETRIES;
							putc(MODEM_NAK);
						}
						break;
						
					case MODEM_CAN: // sender has canceled ! 
						trytimes = 0 ; //接收取消重新接收
						break;
						
					case MODEM_EOT: // all packets have been sent 
						if(eto == 0 ){
							putc(MODEM_NAK);
							eto = 1;
							break;
						}else{ 
							putc(MODEM_ACK);
							putc(MODEM_C);
							eto = 2;							
						}
												
					default: // error ! 
						break;   // 接收头错误
				}
			}		
		}
		
		putc(MODEM_CAN);  //取消传输
		putc(MODEM_CAN);
		putc(MODEM_CAN);
		putc(MODEM_CAN);				
	}
	
sucess: 
	return pdata - rxbuf;
	
}