linux_xmload.c

在uclinux／linux下通过串口以ＸＭＬＯＡＤ协议与ＰＣ终端通讯

/* xmloac.c for down soft to uclinux
*	
	Copyright (C) 2007/3/27  wangwudong  <[e-mail]>,
	255k libmit
	1000ms	timeout
	use:
		xmload [filename]
	
*/
#include <errno.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <asm/termbits.h>


#define TIMEOUT 		1000
#define	MAX_DOWNLOAD_SIZE	1024*128
#define MAXERRORS		10	//10
#define SOH 0x01
#define STX 0x02
#define EOT 0x04
#define ACK 0x06
#define NAK 0x15
#define CAN 0x18
#define BS  0x08

typedef	int	BOOL;


#define	FALSE	((BOOL) 0)
#define	TRUE	((BOOL) 1)

#define 	STDIN 		0 /*标准输入文件描述符*/
#define	STDOUT		1


/*错误日志,调试用*/
char msg[1024] = "erro is ";


/*向终端写一个字节*/
static __inline void WriteByte(char cc) 
{ 
	//write(STDOUT, cc, 1);/*不知道为什么发不了数,有时间再看看*/	
	//sprintf(&msg[strlen(msg)],"\n?\n");/*调试显示用*/
	
	/*向终端发送一个字符*/
	fputc(cc, stdout);
	/*必需要的,否则不能立即显示*/
	fflush(stdout);	
}

/*从终端等待一个字节*/

int  ReadByteWithTimeout(unsigned int msecs) 
{
	
	/*nfds为select函数的返回值	result暂存结果*/
	int nfds,result;
	
	/*读操作文件描述集*/	
	fd_set readset;
	
	/*时间变量,超时参数*/
	struct timeval timeout;
	
	/*秒和微秒分别计算*/
	timeout.tv_sec = msecs / 1000;
	timeout.tv_usec = (msecs % 1000) * 1000;
	
	
	/*下面第一种是采用循环查迅法,附带超时处理,效率不高,影响传输速度*/
	/*result = 0;
	
	for(i = 0 ; i < 20 && result <= 0 ; i++)
	{	
	
		ioctl(STDIN, FIONREAD, &result);
		
		usleep(1);
		
	}
	if ( result >0)
	{
		sprintf(&msg[strlen(msg)]," (%d)",result);
		result = fgetc(stdin) & 0xff;	
		sprintf(&msg[strlen(msg)],"%x ",result);	
	}
	else 
	{	
		result = -1;
	}	*/
	
	/*select有很强大的功能,对阻塞通道可以多个同时监控并可以超时返回*/
	for( ; ; )
	{

		FD_ZERO(&readset);	
		FD_SET(STDIN, &readset);
	
		//遇到ctrl+c继续注意:STDIN 和 stdin的区别
		if (((nfds = select( STDIN +1, &readset, NULL, NULL, &timeout)) == -1) && 
			(errno == EINTR))
		{
			/*如果因信号中断退出,则继续,但实际上终端以不是行输入,则不会出现组合键的中断信号*/
			//sprintf(&msg[strlen(msg)],"errno == EINTRr!\n");
			continue;	
		}		
		if (nfds == -1)
		{
			result = -1;
			//sprintf(&msg[strlen(msg)],"\nerr!\n ");	
			break;
		}
		/*检测是否是该通道的事件*/
		if (FD_ISSET(STDIN, &readset))
	 	{	
			/*第一种方法读有影响,可揣摩*/
			//result = read(stdin, &cc, 1) & 0xff;
			
			/*安全起见,还是与调前面的未知数*/
			result = fgetc(stdin) & 0xff;	
			//sprintf(&msg[strlen(msg)],"%x ",result);
			break;	
		}
		else 
		{
			/*超时事件或其它事件都做超时处理*/
			errno = EINVAL;
			result = -1;
			//sprintf(&msg[strlen(msg)],"... ");	
			break;
			
		}
	}
	
		return result ;
	
}

/*读空终端的输入字节存储区*/

static void ReadFlush() 
{
	while(ReadByteWithTimeout(1000) >= 0);	
}




int XModemReceive(char *name)
{

	FILE	*fp;
	int bufLen = MAX_DOWNLOAD_SIZE;	
	unsigned int errors = 0;
	unsigned int wantBlockNo = 1;
	unsigned int length = 0;
	int crc = 1;		//use crc by send 'C', use checksum by send NAK
	char nak = 'C';
	int crc_val;
	unsigned char expectedCksum;
	
	static char *blockBuf, *bufBase;	
	
	

	
	/*分配文件临时缓冲空间*/
	if(!(bufBase = malloc(bufLen)))
	{
		sprintf(stderr, "no memory\n");
		  return(0);
	}	
	blockBuf = bufBase;
	//("start xmodem!\n");
	fflush(stdout);
	ReadFlush();
	
	/* Ask for CRC; if we get errors, we will go with checksum */
	WriteByte(nak);	

	
	//("WriteByte(nak)\n");

	
	
	for (;;) 
	{
		int blockBegin;
		int blockNo, blockNoOnesCompl;
		int blockLength;
		int cksum = 0;
		int crcHi = 0;
		int crcLo = 0;

		blockBegin = ReadByteWithTimeout(TIMEOUT);
		if (blockBegin < 0)
		{
			
			sprintf(&msg[strlen(msg)],"Read blockBegin timeout!\n");		
			goto timeout;
		}

		nak = NAK;

		switch (blockBegin) 
		{
		case SOH:
		case STX:
			break;

		case EOT:
			WriteByte(ACK);
			//("WriteByte(ACK): done\n");			
			goto done;

		default:
			//("blockBegin error!\n");	
			sprintf(&msg[strlen(msg)],"blockBegin error!!\n");	
			errors--;
			goto error;
		}

		/* block no */
		blockNo = ReadByteWithTimeout(TIMEOUT);
		if (blockNo < 0)
		{
			
			sprintf(&msg[strlen(msg)],"blockNo timeout!\n");			
			goto timeout;
		}

		/* block no one's compliment */
		blockNoOnesCompl = ReadByteWithTimeout(TIMEOUT);
		if (blockNoOnesCompl < 0)
		{
			
			sprintf(&msg[strlen(msg)],"blockNoOnesCompl timeout!\n");			
			goto timeout;
		}

		if (( blockNo + blockNoOnesCompl ) != 255 ) 
		{
			
			sprintf(&msg[strlen(msg)],
				"bad block ones compl(blockNo is %x,blockNoOnesCompl is %x)\n",
				blockNo, blockNoOnesCompl);			
			goto error;
		}

		blockLength = (blockBegin == SOH) ? 128 : 1024;

		{
			int i, j;
			
			crc_val = 0;			
			expectedCksum = 0;

			for (i = 0; i < blockLength; i++) 
			{
				int cc = ReadByteWithTimeout(TIMEOUT);
				if (cc < 0)
				{					
					sprintf(&msg[strlen(msg)]," read block byte timeout!(i is %d)\n", i);					
					goto timeout;
				}
				
				blockBuf[i] = cc;		

				//crc 或 checksum 计算加在读数据后
				if (crc) 
				{
					crc_val = crc_val ^ cc << 8;
					for (j = 0; j < 8; j++)
						if (crc_val & 0x8000)
							crc_val = crc_val << 1 ^ 0x1021;
						else
							crc_val = crc_val << 1;
				} 
				else 
				{
					expectedCksum += cc;
				}
			}
		}
		if (crc) 
		{
			crcHi = ReadByteWithTimeout(TIMEOUT);
			if (crcHi < 0) 
			{				
				sprintf(&msg[strlen(msg)]," read crcHi timeout!\n");
				goto timeout;
			}

			crcLo = ReadByteWithTimeout(TIMEOUT);
			if (crcLo < 0) 
			{
				
				sprintf(&msg[strlen(msg)]," read crcLo timeout!\n");
				goto timeout;
			}			
			
			if ((crcHi != ((crc_val>>8) & 0xff)) ||
			    (crcLo != (crc_val & 0xff))) 
			{
				
				sprintf(&msg[strlen(msg)],"crc error!\n");
				goto error;
			}
			
		} 
		else 
		{
			cksum = ReadByteWithTimeout(TIMEOUT);
			if (cksum < 0)
			{
				
				sprintf(&msg[strlen(msg)]," read chksum timeout!\n");
				goto timeout;
			}
			
			if (cksum != expectedCksum) 
			{
				
				sprintf(&msg[strlen(msg)],"checksum error! \n");
				goto error;
			}
		}

		if (blockNo == ((wantBlockNo - 1) & 0xff)) 
		{
			/* a repeat of the last block is ok, just ignore it. */
			/* this also ignores the initial block 0 which is */
			/* meta data. */
			goto next;
		} 
		else if (blockNo != (wantBlockNo & 0xff)) 
		{
			
			sprintf(&msg[strlen(msg)],"unexpected block no! \n");
			goto error;
		}

		wantBlockNo++;
		length += blockLength;

		if (length > bufLen) 
		{
			
			sprintf(&msg[strlen(msg)],"out of space(length is %d)\n",length);
			goto error;
		}

		blockBuf += blockLength;	//接收成功,指针加上收到字节数
next:
		errors = 0;
		WriteByte(ACK);
		//("Receive one block OK!\n");
		continue;

error:		
timeout:
		//("Timeout.\n");
		errors++;
		if (errors == MAXERRORS) 
		{
			/* Abort */
			int i;

			// if using crc, try again w/o crc
			if (nak == 'C') 
			{				
				nak = NAK;
				errors = 0;
				crc = 0;		//use checksum
				goto timeout;
			}
			
			for (i = 0; i < 5; i ++)
				WriteByte(CAN);
			for (i = 0; i < 5; i ++)
				WriteByte(BS);
			puts(" too many errors; giving up\n");
			
			free(bufBase);
			
			return -1;
		}

		ReadFlush();		
				
		WriteByte(nak);		

		
		//("WriteByte(nak)\n");
	}

done:
	//("\nxmodem done.\n");
	ReadFlush();
	
	if( length > 0)
	{
		fp = fopen(name, "w");
		fwrite(bufBase,1,length,fp);
		fclose(fp);
		chmod(name, 777);
	}
	free(bufBase);
	return length;
}

int main(int argc, char * argv[])
{
	/*argv[0] argv[1]*/
	/*xmload mytest*/
	char *name;
	int tmp;
	
	struct termios  newterm ;	
	int saveflag ;
	
	name = argv[1];
	if(argc==2 && name[0] == '?')
	{
		printf("Default download name : xmload \n");
		printf("Set new download name : xmload destination_address \n");	
		return 0;
	}	
	if(argc<2)
	{
		name = "/tmp/tt";
	}
		
	//printf("Now download file by xmodem to %s...\n", name);	 
	
	
	
	
	
	/*错误日志初始化*/	
	sprintf(msg,"\n erro is \n");
	
	/**/
	
	
	/*设置终端为非行输入,去掉终端回显*/
	
	tcgetattr( STDIN, &newterm );
	
	newterm.c_iflag = 0;
	newterm.c_oflag &= ~OPOST;
	newterm.c_lflag &= ~ ( ECHO | ISIG | ICANON );	
	newterm.c_cc[VMIN] = 1;
	newterm.c_cc[VTIME] = 0;	
	
	tcsetattr(STDIN, TCSANOW, &newterm);
	
	
	
	//system("stty raw");
		
	
	/*必需设置终端输入无缓冲,否则getc一次后数据都读进来了,影响select的事件触发*/
	setbuf(stdin,NULL);	/*!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*/
	
	/*输出不必要设置,但必需每次putc后,fflush()一次*/
	//setbuf(stdout,NULL);	/*!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*/
	
	tmp = XModemReceive( name );
	
	/*恢复终端为行输入,回显*/
	//system("stty cooked echo");	
	newterm.c_iflag |= BRKINT | IGNPAR | ISTRIP | ICRNL | IXON;
				newterm.c_oflag |= OPOST;
				newterm.c_lflag |= ECHO | ISIG | ICANON;
	
		
	tcsetattr( STDIN, TCSANOW, &newterm);
	
	fflush(stdout);
	
	if ( tmp <0 )
	{
		printf("%s",msg);	
	}
	printf("\nfile[%s] length is %d...\n",name, tmp);	
	
	return 0;
}