xmodem.c

MIPS架构Xmodem和Ymodem源码程序

	 * character in the response.
	 */
	if (xip->pktcnt == -1)
		c = getchar();
	return(c);
}

/* getPacket():
 * Used by Xdown to retrieve packets.
 */
static int getPacket(uchar *tmppkt, struct xinfo *xip)
{
	int		i;
	char	*pkt;
	uchar	seq[2];

	if (getbytes(seq,2,1) != 2)
		return(-1);

	if (xip->flags & VERIFY) {
		if (getbytes(tmppkt,xip->pktlen,1) != xip->pktlen)
			return(-1);
		for(i=0;i<xip->pktlen;i++) {
			if (tmppkt[i] != ((char *)xip->dataddr)[i]) {
				if (xip->errcnt++ == 0)
					xip->firsterrat = (char *)(xip->dataddr+i);
			}
		}
		pkt = (char *)tmppkt;
	}
	else {
		if (getbytes((char *)xip->dataddr,xip->pktlen,1) != xip->pktlen)
			return(-1);
		pkt = (char *)xip->dataddr;
	}

	if (xip->flags & USECRC) {
		ushort	crc, xcrc;
		
    	/* An "endian independent way to combine the CRC bytes. */
    	crc  = (ushort)getchar() << 8;
	    crc += (ushort)getchar();
		xcrc = xcrc16((uchar *)pkt,(ulong)(xip->pktlen));
		if (crc != xcrc) {
			rputchar(NAK);
			//Mtrace("CRC %04x != %04x",crc,xcrc);
			return(0);
		}
	}
	else {
		uchar	csum, xcsum;

		xcsum = (uchar)getchar();
		csum = 0;
		for(i=0;i<xip->pktlen;i++)
			csum += *pkt++;
		if (csum != xcsum) {
			rputchar(NAK);
			//Mtrace("CSUM %02x != %02x (%d)",csum,xcsum,xip->pktlen);
			return(0);
		}
		//Mtrace("CSUM %02x (%d)",csum,xip->pktlen);
	}

	/* Test the sequence number compliment...
	 */
	if ((uchar)seq[0] != (uchar)~seq[1]) {
		rputchar(NAK);
		//Mtrace("SNOCMP %02x != %02x",(uchar)seq[0],(uchar)~(seq[1]));
		return(0);
	}

	/* Verify that the incoming sequence number is the expected value...
	 */
	if ((uchar)seq[0] !=  xip->sno) {
		/* If the incoming sequence number is one less than the expected
		 * sequence number, then we assume that the sender did not recieve
		 * our previous ACK, and they are resending the previously received
		 * packet.  In that case, we send  ACK and don't process the
		 * incoming packet...
	 	 */
		if ((uchar)seq[0] == xip->sno-1) {
			//Mtrace("R_ACK");
			rputchar(ACK);
			return(0);
		}

		/* Otherwise, something's messed up...
		 */
		rputchar(CAN);
		//Mtrace("SNO: %02x != %02x",seq[0],xip->sno);
		return(-1);
	}

	/* First packet of YMODEM contains information about the transfer:
	 * FILENAME SP FILESIZE SP MOD_DATE SP FILEMODE SP FILE_SNO
	 * Only the FILENAME is required and if others are present, then none
	 * can be skipped.
	 */
	if ((xip->flags & YMODEM) && (xip->pktcnt == 0)) {
		char *slash, *space, *fname;

		slash = strrchr((char *)(xip->dataddr),'/');
		space = strchr((char *)(xip->dataddr),' ');
		if (slash)
			fname = slash+1;
		else
			fname = (char *)(xip->dataddr);
		//Mtrace("<fname=%s>",fname);
		if (space) {
			*space = 0;
			xip->size = atoi(space+1);
		}
		strcpy(xip->fname,fname);
		if (fname[0])
			xip->filcnt++;
	}
	else
		xip->dataddr += xip->pktlen;
	xip->sno++;
	xip->pktcnt++;
	xip->xfertot += xip->pktlen;
	//Mtrace("ACK");
	rputchar(ACK);
	if (xip->flags & YMODEM) {
		if (xip->fname[0] == 0) {
			printf("\nRcvd %d file%c\n",
				xip->filcnt,xip->filcnt > 1 ? 's' : ' ');
			return(1);
		}
	}
	return(0);
}

/* Xup():
 * Called when a transfer from target to host is being made (considered
 * an upload).
 */
static int Xup(struct xinfo *xip)
{
	unsigned char	c, buf[PKTLEN_128];
	int		done, pktlen;
	long	actualsize;

	//Mtrace("Xup starting");

	actualsize = xip->size;

	if (xip->size & 0x7f) {
		xip->size += 128;
		xip->size &= 0xffffff80L;
	}

	printf("Upload %ld bytes from 0x%lx\n",xip->size,(ulong)xip->base);

	/* Startup synchronization... */
	/* Wait to receive a NAK or 'C' from receiver. */
	done = 0;
	while(!done) {
		c = (uchar)getchar();
		switch(c) {
		case NAK:
			done = 1;
			//Mtrace("CSM");
			break;
		case 'C':
			xip->flags |= USECRC;
			done = 1;
			//Mtrace("CRC");
			break;
		case 'q':	/* ELS addition, not part of XMODEM spec. */
			return(0);
		default:
			break;
		}
	}

        /*  look for ymodem
	if (xip->flags & YMODEM) {
		//Mtrace("SNO_0");
		xip->sno = 0;
		xip->pktcnt = -1;
		memset((char *)buf,0,PKTLEN_128);
		sprintf(buf,"%s",xip->fname);
		pktlen = xip->pktlen;
		xip->pktlen = PKTLEN_128;
		putPacket(buf,xip);
		xip->pktlen = pktlen;
	}
        */
	done = 0;
	xip->sno = 1;
	xip->pktcnt = 0;
	while(!done) {
		c = (uchar)putPacket((uchar *)(xip->dataddr),xip);
		switch(c) {
		case ACK:
			xip->sno++;
			xip->pktcnt++;
			xip->size -= xip->pktlen;
			xip->dataddr += xip->pktlen;
			//Mtrace("A");
			break;
		case NAK:
			//Mtrace("N");
			break;
		case CAN:
			done = -1;
			//Mtrace("C");
			break;
		case EOT:
			done = -1;
			//Mtrace("E");
			break;
		default:
			done = -1;
			//Mtrace("<%2x>",c);
			break;
		}
		if (xip->size <= 0) {
			rputchar(EOT);
			getchar();	/* Flush the ACK */
			break;
		}
		//Mtrace("!");
	}

	//Mtrace("Xup_almost");
	/*
	if ((done != -1) && (xip->flags & YMODEM)) { 
		xip->sno = 0;
		memset((char *)buf,0,PKTLEN_128);
		pktlen = xip->pktlen;
		xip->pktlen = PKTLEN_128;
		putPacket(buf,xip);
		xip->pktlen = pktlen;
	}
	*/
	//Mtrace("Xup_done.");
	return(0);
}


/* Xdown():
 * Called when a transfer from host to target is being made (considered
 * an download).
 */

static int Xdown(struct xinfo *xip)
{
	long	timeout;
	char	c, *tmppkt;
	int	done;
         /*
	tmppkt = malloc(PKTLEN_1K);
	if (!tmppkt) {
		//Mtrace("malloc failed");
		return(-1);
	}
        */
nextfile:
	/*if (xip->flags & YMODEM)
		xip->sno = 0x00;
	else*/
		xip->sno = 0x01;
	xip->pktcnt = 0;
	xip->errcnt = 0;
	xip->xfertot = 0;
	xip->firsterrat = 0;

	/* Startup synchronization... */
	/* Continuously send NAK or 'C' until sender responds. */
restart:
	//Mtrace("Xdown");
	while(1) {
		if (xip->flags & USECRC)
			rputchar('C');
		else
			rputchar(NAK);
		timeout = LoopsPerSecond * xip->nakresend;
		while(!gotachar() && timeout)
			timeout--;
		if (timeout)
			break;
	}

	done = 0;
	//Mtrace("Got response");
	while(done == 0) {
		c = (char)getchar();
		switch(c) {
		case SOH:				/* 128-byte incoming packet */
			//Mtrace("O");
			xip->pktlen = 128;
			done = getPacket(tmppkt,xip);
			if (done < 0)
				//Mtrace("GP_%d",done);
			if (!done && (xip->pktcnt == 1) && (xip->flags & YMODEM))
				goto restart;
			break;
		case STX:				/* 1024-byte incoming packet */
			//Mtrace("T");
			xip->pktlen = 1024;
			done = getPacket(tmppkt,xip);
			if (done < 0)
				//Mtrace("GP_%d",done);
			if (!done && (xip->pktcnt == 1) && (xip->flags & YMODEM))
				goto restart;
			break;
		case CAN:
			//Mtrace("C");
			done = -1;
			break;
		case EOT:
			//Mtrace("E");
			rputchar(ACK);
/*			
			if (xip->flags & YMODEM) {


#if INCLUDE_TFS
				if (!xip->size)
					xip->size = xip->pktcnt * xip->pktlen;
				if (xip->fname[0])
					tfsadd(xip->fname,0,0,(uchar *)xip->base,xip->size);
				xip->dataddr = xip->base;
#endif

				goto nextfile;
			}
			else {*/
				done = xip->xfertot;
				printf("\nRcvd %d pkt%c (%d bytes)\n",xip->pktcnt,
				xip->pktcnt > 1 ? 's' : ' ',xip->xfertot);

		 		/* If the transfer is complete and no file add is to
				 * be done, then we flush d-cache and invalidate
				 * i-cache across the memory space that was just
				 * copied to.  This is necessary in case the
		 		 * binary data that was just transferred is code.
				 */
				/*
				flushDcache((char *)xip->base,xip->xfertot);
				invalidateIcache((char *)xip->base,xip->xfertot);
							
			}*/
			
			break;
		case ESC:		/* User-invoked abort */
			//Mtrace("X");
			done = -1;
			break;
		default:
			//Mtrace("<%02x>",c);
			done = -1;
			break;
		}
		//Mtrace("!");
	}
	if (xip->flags & VERIFY) {
		if (xip->errcnt)
			printf("%d errors, first at 0x%lx\n",
				xip->errcnt,(ulong)(xip->firsterrat));
		else
			printf("verification passed\n");
	}
	free(tmppkt);
	return(done);
}