rarp.c

关于s3c2440之bootloader的源代码

/*
 * vivi/net/rarp.c 
 *
 * Based on u-boot
 *
 * $Id: rarp.c,v 1.0 2004/08/12 11:14:01 kingmonkey Exp $
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Description: net rarp protocol routines .
 *
 */ 

#include "config.h"
#include "printk.h"
#include "command.h"
#include "net.h"
#include "bootp.h"
#include "rarp.h"
#include "tftp.h"


#define TIMEOUT		5		/* Seconds before trying BOOTP again */

#ifndef	CONFIG_NET_RETRY_COUNT
# define TIMEOUT_COUNT	5		/* # of timeouts before giving up  */
#else
# define TIMEOUT_COUNT  (CONFIG_NET_RETRY_COUNT)
#endif

#undef DEBUG
int		RarpTry;
/*
 *	Handle a RARP received packet.
 */
static void
RarpHandler(uchar * dummi0, unsigned dummi1, unsigned dummi2, unsigned dummi3)
{
#ifdef	DEBUG
	printk("Good RARP,Go ......\n");
#endif
	TftpStart();
}

/*
 *	Timeout on BOOTP request.
 */
static void
RarpTimeout(void)
{
	if (RarpTry >= TIMEOUT_COUNT) {
		printk("\nRetry count exceeded; starting again\n");
		NetStartAgain();
	} else {
		NetSetTimeout (TIMEOUT * CFG_HZ, RarpTimeout);
		RarpRequest();
	}
}

void
RarpRequest (void)
{
	int i;
	volatile uchar *pkt;
	ARP_t *	rarp;

//	printk("RARP broadcast %d\n", ++RarpTry);
	pkt = NetTxPacket;

	pkt += NetSetEther(pkt, NetBcastAddr, PROT_RARP);

	rarp = (ARP_t *)pkt;

	rarp->ar_hrd = htons (ARP_ETHER);
	rarp->ar_pro = htons (PROT_IP);
	rarp->ar_hln = 6;
	rarp->ar_pln = 4;
	rarp->ar_op  = htons (RARPOP_REQUEST);
	memcpy (&rarp->ar_data[0],  NetOurEther, 6);	/* source ET addr */
	memcpy (&rarp->ar_data[6],  &NetOurIP,   4);	/* source IP addr */
	memcpy (&rarp->ar_data[10], NetOurEther, 6);	/* dest ET addr = source ET addr ??*/
	
	/* dest. IP addr set to broadcast */
	for (i = 0; i <= 3; i++) {
		rarp->ar_data[16 + i] = 0xff;
	}

	NetSendPacket(NetTxPacket, (pkt - NetTxPacket) + ARP_HDR_SIZE);

	NetSetTimeout(TIMEOUT * CFG_HZ, RarpTimeout);
	NetSetHandler(RarpHandler);
}