Initial revision

2 files changed, 1111 insertions, 0 deletions

diff --git a/include/net.h b/include/net.h
new file mode 100644
index 0000000..d4985ca
--- /dev/null
+++ b/include/net.h
@@ -0,0 +1,358 @@
+/*
+ *	LiMon Monitor (LiMon) - Network.
+ *
+ *	Copyright 1994 - 2000 Neil Russell.
+ *	(See License)
+ *
+ *
+ * History
+ *	9/16/00	  bor  adapted to TQM823L/STK8xxL board, RARP/TFTP boot added
+ */
+
+#ifndef __NET_H__
+#define __NET_H__
+
+#if !defined(CONFIG_NET_MULTI) && defined(CONFIG_8xx)
+#include <commproc.h>
+#if defined(FEC_ENET) || defined(SCC_ENET)
+#define CONFIG_NET_MULTI
+#endif
+#endif
+#include <asm/byteorder.h>	/* for nton* / ntoh* stuff */
+
+
+/*
+ *	The number of receive packet buffers, and the required packet buffer
+ *	alignment in memory.
+ *
+ */
+
+#define PKTBUFSRX	4
+#define PKTALIGN	32
+
+typedef ulong		IPaddr_t;
+
+
+
+/*
+ * The current receive packet handler.  Called with a pointer to the
+ * application packet, and a protocol type (PORT_BOOTPC or PORT_TFTP).
+ * All other packets are dealt with without calling the handler.
+ */
+typedef void	rxhand_f(uchar *, unsigned, unsigned, unsigned);
+
+/*
+ *	A timeout handler.  Called after time interval has expired.
+ */
+typedef void	thand_f(void);
+
+#ifdef CONFIG_NET_MULTI
+
+#define NAMESIZE 16
+
+enum eth_state_t {
+	ETH_STATE_INIT,
+	ETH_STATE_PASSIVE,
+	ETH_STATE_ACTIVE
+};
+
+struct eth_device {
+	char name[NAMESIZE];
+	unsigned char enetaddr[6];
+	int iobase;
+	int state;
+
+	int  (*init) (struct eth_device*, bd_t*);
+	int  (*send) (struct eth_device*, volatile void* pachet, int length);
+	int  (*recv) (struct eth_device*);
+	void (*halt) (struct eth_device*);
+
+	struct eth_device *next;
+	void *priv;
+};
+
+extern int eth_initialize(bd_t *bis);		/* Initialize network subsystem */
+extern int eth_register(struct eth_device* dev);/* Register network device	*/
+extern void eth_try_another(int first_restart);	/* Change the device		*/
+extern struct eth_device *eth_get_dev(void);	/* get the current device MAC	*/
+extern void eth_set_enetaddr(int num, char* a);	/* Set new MAC address		*/
+#endif
+
+extern int eth_init(bd_t *bis);			/* Initialize the device	*/
+extern int eth_send(volatile void *packet, int length);	   /* Send a packet	*/
+extern int eth_rx(void);			/* Check for received packets	*/
+extern void eth_halt(void);			/* stop SCC			*/
+
+
+/**********************************************************************/
+/*
+ *	Protocol headers.
+ */
+
+/*
+ *	Ethernet header
+ */
+typedef struct {
+	uchar		et_dest[6];	/* Destination node		*/
+	uchar		et_src[6];	/* Source node			*/
+	ushort		et_protlen;	/* Protocol or length		*/
+	uchar		et_dsap;	/* 802 DSAP			*/
+	uchar		et_ssap;	/* 802 SSAP			*/
+	uchar		et_ctl;		/* 802 control			*/
+	uchar		et_snap1;	/* SNAP				*/
+	uchar		et_snap2;
+	uchar		et_snap3;
+	ushort		et_prot;	/* 802 protocol			*/
+} Ethernet_t;
+
+#define ETHER_HDR_SIZE	14		/* Ethernet header size		*/
+#define E802_HDR_SIZE	22		/* 802 ethernet header size	*/
+#define PROT_IP		0x0800		/* IP protocol			*/
+#define PROT_ARP	0x0806		/* IP ARP protocol		*/
+#define PROT_RARP	0x8035		/* IP ARP protocol		*/
+
+#define IPPROTO_ICMP	 1	/* Internet Control Message Protocol	*/
+#define IPPROTO_UDP	17	/* User Datagram Protocol		*/
+
+/*
+ *	Internet Protocol (IP) header.
+ */
+typedef struct {
+	uchar		ip_hl_v;	/* header length and version	*/
+	uchar		ip_tos;		/* type of service		*/
+	ushort		ip_len;		/* total length			*/
+	ushort		ip_id;		/* identification		*/
+	ushort		ip_off;		/* fragment offset field	*/
+	uchar		ip_ttl;		/* time to live			*/
+	uchar		ip_p;		/* protocol			*/
+	ushort		ip_sum;		/* checksum			*/
+	IPaddr_t	ip_src;		/* Source IP address		*/
+	IPaddr_t	ip_dst;		/* Destination IP address	*/
+	ushort		udp_src;	/* UDP source port		*/
+	ushort		udp_dst;	/* UDP destination port		*/
+	ushort		udp_len;	/* Length of UDP packet		*/
+	ushort		udp_xsum;	/* Checksum			*/
+} IP_t;
+
+#define IP_HDR_SIZE_NO_UDP	(sizeof (IP_t) - 8)
+#define IP_HDR_SIZE		(sizeof (IP_t))
+
+
+/*
+ *	Address Resolution Protocol (ARP) header.
+ */
+typedef struct
+{
+	ushort		ar_hrd;		/* Format of hardware address	*/
+#   define ARP_ETHER	    1		/* Ethernet  hardware address	*/
+	ushort		ar_pro;		/* Format of protocol address	*/
+	uchar		ar_hln;		/* Length of hardware address	*/
+	uchar		ar_pln;		/* Length of protocol address	*/
+	ushort		ar_op;		/* Operation			*/
+#   define ARPOP_REQUEST    1		/* Request  to resolve  address	*/
+#   define ARPOP_REPLY	    2		/* Response to previous request	*/
+
+#   define RARPOP_REQUEST   3		/* Request  to resolve  address	*/
+#   define RARPOP_REPLY	    4		/* Response to previous request */
+
+	/*
+         * The remaining fields are variable in size, according to
+         * the sizes above, and are defined as appropriate for
+         * specific hardware/protocol combinations.
+	 */
+	uchar		ar_data[0];
+#if 0
+	uchar		ar_sha[];	/* Sender hardware address	*/
+	uchar		ar_spa[];	/* Sender protocol address	*/
+	uchar		ar_tha[];	/* Target hardware address	*/
+	uchar		ar_tpa[];	/* Target protocol address	*/
+#endif /* 0 */
+} ARP_t;
+
+#define ARP_HDR_SIZE	(8+20)		/* Size assuming ethernet	*/
+
+/*
+ * ICMP stuff (just enough to handle (host) redirect messages)
+ */
+#define ICMP_REDIRECT		5	/* Redirect (change route)	*/
+
+/* Codes for REDIRECT. */
+#define ICMP_REDIR_NET		0	/* Redirect Net			*/
+#define ICMP_REDIR_HOST		1	/* Redirect Host		*/
+
+typedef struct icmphdr {
+	uchar		type;
+	uchar		code;
+	ushort		checksum;
+	union {
+		struct {
+			ushort	id;
+			ushort	sequence;
+		} echo;
+		ulong	gateway;
+		struct {
+			ushort	__unused;
+			ushort	mtu;
+		} frag;
+	} un;
+} ICMP_t;
+
+
+
+/*
+ * Maximum packet size; used to allocate packet storage.
+ * TFTP packets can be 524 bytes + IP header + ethernet header.
+ * Lets be conservative, and go for 38 * 16.  (Must also be
+ * a multiple of 32 bytes).
+ */
+/*
+ * AS.HARNOIS : Better to set PKTSIZE to maximum size because
+ * traffic type is not always controlled
+ * maximum packet size =  1518
+ * maximum packet size and multiple of 32 bytes =  1536
+ */
+#define PKTSIZE			1518
+#define PKTSIZE_ALIGN		1536
+/*#define PKTSIZE		608*/
+
+/*
+ * Maximum receive ring size; that is, the number of packets
+ * we can buffer before overflow happens. Basically, this just
+ * needs to be enough to prevent a packet being discarded while
+ * we are processing the previous one.
+ */
+#define RINGSZ		4
+#define RINGSZ_LOG2	2
+
+/**********************************************************************/
+/*
+ *	Globals.
+ *
+ * Note:
+ *
+ * All variables of type IPaddr_t are stored in NETWORK byte order
+ * (big endian).
+ */
+
+/* net.c */
+/** BOOTP EXTENTIONS **/
+extern IPaddr_t		NetOurGatewayIP;	/* Our gateway IP addresse	*/
+extern IPaddr_t		NetOurSubnetMask;	/* Our subnet mask (0 = unknown)*/
+extern IPaddr_t		NetOurDNSIP;	 /* Our Domain Name Server (0 = unknown)*/
+extern char		NetOurNISDomain[32];	/* Our NIS domain		*/
+extern char		NetOurHostName[32];	/* Our hostname			*/
+extern char		NetOurRootPath[64];	/* Our root path		*/
+extern ushort		NetBootFileSize;	/* Our boot file size in blocks	*/
+/** END OF BOOTP EXTENTIONS **/
+extern ulong		NetBootFileXferSize;	/* size of bootfile in bytes	*/
+extern uchar		NetOurEther[6];		/* Our ethernet address		*/
+extern uchar		NetServerEther[6];	/* Boot server enet address	*/
+extern IPaddr_t		NetOurIP;		/* Our    IP addr (0 = unknown)	*/
+extern IPaddr_t		NetServerIP;		/* Server IP addr (0 = unknown)	*/
+extern volatile uchar * NetTxPacket;		/* THE transmit packet		*/
+extern volatile uchar * NetRxPackets[PKTBUFSRX];/* Receive packets		*/
+extern volatile uchar * NetRxPkt;		/* Current receive packet	*/
+extern int		NetRxPktLen;		/* Current rx packet length	*/
+extern unsigned		NetIPID;		/* IP ID (counting)		*/
+extern uchar		NetBcastAddr[6];	/* Ethernet boardcast address	*/
+
+extern int		NetState;		/* Network loop state		*/
+#define NETLOOP_CONTINUE	1
+#define NETLOOP_RESTART		2
+#define NETLOOP_SUCCESS		3
+#define NETLOOP_FAIL		4
+
+#ifdef CONFIG_NET_MULTI
+extern int		NetRestartWrap;		/* Tried all network devices	*/
+#endif
+
+typedef enum { BOOTP, RARP, ARP, TFTP, DHCP } proto_t;
+
+/* from net/net.c */
+extern char	BootFile[128];			/* Boot File name		*/
+
+/* Initialize the network adapter */
+extern int	NetLoop(proto_t);
+
+/* Shutdown adapters and cleanup */
+extern void	NetStop(void);
+
+/* Load failed.	 Start again. */
+extern void	NetStartAgain(void);
+
+/* Set ethernet header */
+extern void	NetSetEther(volatile uchar *, uchar *, uint);
+
+/* Set IP header */
+extern void	NetSetIP(volatile uchar *, IPaddr_t, int, int, int);
+
+/* Checksum */
+extern int	NetCksumOk(uchar *, int);	/* Return true if cksum OK	*/
+extern uint	NetCksum(uchar *, int);		/* Calculate the checksum	*/
+
+/* Set callbacks */
+extern void	NetSetHandler(rxhand_f *);	/* Set RX packet handler	*/
+extern void	NetSetTimeout(int, thand_f *);	/* Set timeout handler		*/
+
+/* Transmit "NetTxPacket" */
+extern void	NetSendPacket(volatile uchar *, int);
+
+/* Processes a received packet */
+extern void	NetReceive(volatile uchar *, int);
+
+/* Print an IP address on the console */
+extern void	print_IPaddr (IPaddr_t);
+
+/*
+ * The following functions are a bit ugly, but necessary to deal with
+ * alignment restrictions on ARM.
+ *
+ * We're using inline functions, which had the smallest memory
+ * footprint in our tests.
+ */
+/* return IP *in network byteorder* */
+static inline IPaddr_t NetReadIP(void *from)
+{
+	IPaddr_t ip;
+	memcpy((void*)&ip, from, sizeof(ip));
+	return ip;
+}
+
+/* return ulong *in network byteorder* */
+static inline ulong NetReadLong(ulong *from)
+{
+	ulong l;
+	memcpy((void*)&l, (void*)from, sizeof(l));
+	return l;
+}
+
+/* write IP *in network byteorder* */
+static inline void NetWriteIP(void *to, IPaddr_t ip)
+{
+	memcpy(to, (void*)&ip, sizeof(ip));
+}
+
+/* copy IP */
+static inline void NetCopyIP(void *to, void *from)
+{
+	memcpy(to, from, sizeof(IPaddr_t));
+}
+
+/* copy ulong */
+static inline void NetCopyLong(ulong *to, ulong *from)
+{
+	memcpy((void*)to, (void*)from, sizeof(ulong));
+}
+
+/* Convert an IP address to a string */
+extern void	ip_to_string (IPaddr_t x, char *s);
+
+/* read an IP address from a environment variable */
+extern IPaddr_t getenv_IPaddr (char *);
+
+/* copy a filename (allow for "..." notation, limit length) */
+extern void	copy_filename (uchar *dst, uchar *src, int size);
+
+/**********************************************************************/
+
+#endif /* __NET_H__ */
diff --git a/net/net.c b/net/net.c
new file mode 100644
index 0000000..cc3bec6
--- /dev/null
+++ b/net/net.c
@@ -0,0 +1,753 @@
+/*
+ *	Copied from Linux Monitor (LiMon) - Networking.
+ *
+ *	Copyright 1994 - 2000 Neil Russell.
+ *	(See License)
+ *	Copyright 2000 Roland Borde
+ *	Copyright 2000 Paolo Scaffardi
+ *	Copyright 2000-2002 Wolfgang Denk, wd@denx.de
+ */
+
+/*
+ * General Desription:
+ *
+ * The user interface supports commands for BOOTP, RARP, and TFTP.
+ * Also, we support ARP internally. Depending on available data,
+ * these interact as follows:
+ *
+ * BOOTP:
+ *
+ *	Prerequisites:	- own ethernet address
+ *	We want:	- own IP address
+ *			- TFTP server IP address
+ *			- name of bootfile
+ *	Next step:	ARP
+ *
+ * RARP:
+ *
+ *	Prerequisites:	- own ethernet address
+ *	We want:	- own IP address
+ *			- TFTP server IP address
+ *	Next step:	ARP
+ *
+ * ARP:
+ *
+ *	Prerequisites:	- own ethernet address
+ *			- own IP address
+ *			- TFTP server IP address
+ *	We want:	- TFTP server ethernet address
+ *	Next step:	TFTP
+ *
+ * DHCP:
+ *
+ *     Prerequisites:   - own ethernet address
+ *     We want:         - IP, Netmask, ServerIP, Gateway IP
+ *                      - bootfilename, lease time
+ *     Next step:       - TFTP
+ *
+ * TFTP:
+ *
+ *	Prerequisites:	- own ethernet address
+ *			- own IP address
+ *			- TFTP server IP address
+ *			- TFTP server ethernet address
+ *			- name of bootfile (if unknown, we use a default name
+ *			  derived from our own IP address)
+ *	We want:	- load the boot file
+ *	Next step:	none
+ */
+
+
+#include <common.h>
+#include <watchdog.h>
+#include <command.h>
+#include <net.h>
+#include "bootp.h"
+#include "tftp.h"
+#include "rarp.h"
+#include "arp.h"
+
+#if (CONFIG_COMMANDS & CFG_CMD_NET)
+
+#if 0
+#define ET_DEBUG
+#endif
+
+/** BOOTP EXTENTIONS **/
+
+IPaddr_t	NetOurSubnetMask=0;		/* Our subnet mask (0=unknown)	*/
+IPaddr_t	NetOurGatewayIP=0;		/* Our gateways IP address	*/
+IPaddr_t	NetOurDNSIP=0;			/* Our DNS IP address		*/
+char		NetOurNISDomain[32]={0,};	/* Our NIS domain		*/
+char		NetOurHostName[32]={0,};	/* Our hostname			*/
+char		NetOurRootPath[64]={0,};	/* Our bootpath			*/
+ushort		NetBootFileSize=0;		/* Our bootfile size in blocks	*/
+
+/** END OF BOOTP EXTENTIONS **/
+
+ulong		NetBootFileXferSize;	/* The actual transferred size of the bootfile (in bytes) */
+uchar		NetOurEther[6];		/* Our ethernet address			*/
+uchar		NetServerEther[6] =	/* Boot server enet address		*/
+			{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
+IPaddr_t	NetOurIP;		/* Our IP addr (0 = unknown)		*/
+IPaddr_t	NetServerIP;		/* Our IP addr (0 = unknown)		*/
+volatile uchar *NetRxPkt;		/* Current receive packet		*/
+int		NetRxPktLen;		/* Current rx packet length		*/
+unsigned	NetIPID;		/* IP packet ID				*/
+uchar		NetBcastAddr[6] =	/* Ethernet bcast address		*/
+			{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
+int		NetState;		/* Network loop state			*/
+#ifdef CONFIG_NET_MULTI
+int		NetRestartWrap = 0;	/* Tried all network devices		*/
+static int	NetRestarted = 0;	/* Network loop restarted		*/
+static int	NetDevExists = 0;	/* At least one device configured	*/
+#endif
+
+char		BootFile[128];		/* Boot File name			*/
+
+volatile uchar	PktBuf[(PKTBUFSRX+1) * PKTSIZE_ALIGN + PKTALIGN];
+
+volatile uchar *NetRxPackets[PKTBUFSRX]; /* Receive packets			*/
+
+static rxhand_f *packetHandler;		/* Current RX packet handler		*/
+static thand_f *timeHandler;		/* Current timeout handler		*/
+static ulong	timeValue;		/* Current timeout value		*/
+volatile uchar *NetTxPacket = 0;	/* THE transmit packet			*/
+
+static int net_check_prereq (proto_t protocol);
+
+/**********************************************************************/
+/*
+ *	Main network processing loop.
+ */
+
+int
+NetLoop(proto_t protocol)
+{
+	DECLARE_GLOBAL_DATA_PTR;
+
+	bd_t *bd = gd->bd;
+
+#ifdef CONFIG_NET_MULTI
+	NetRestarted = 0;
+	NetDevExists = 0;
+#endif
+
+	if (!NetTxPacket) {
+		int	i;
+
+		/*
+		 *	Setup packet buffers, aligned correctly.
+		 */
+		NetTxPacket = &PktBuf[0] + (PKTALIGN - 1);
+		NetTxPacket -= (ulong)NetTxPacket % PKTALIGN;
+		for (i = 0; i < PKTBUFSRX; i++) {
+			NetRxPackets[i] = NetTxPacket + (i+1)*PKTSIZE_ALIGN;
+		}
+	}
+
+	eth_halt();
+	eth_init(bd);
+
+restart:
+#ifdef CONFIG_NET_MULTI
+	memcpy (NetOurEther, eth_get_dev()->enetaddr, 6);
+#else
+	memcpy (NetOurEther, bd->bi_enetaddr, 6);
+#endif
+
+	NetState = NETLOOP_CONTINUE;
+
+	/*
+	 *	Start the ball rolling with the given start function.  From
+	 *	here on, this code is a state machine driven by received
+	 *	packets and timer events.
+	 */
+
+	switch (protocol) {
+	case TFTP:
+		NetCopyIP(&NetOurIP, &bd->bi_ip_addr);
+		NetServerIP	= getenv_IPaddr ("serverip");
+		NetOurGatewayIP = getenv_IPaddr ("gatewayip");
+		NetOurSubnetMask= getenv_IPaddr ("netmask");
+		break;
+	case BOOTP:
+	case RARP:
+		/*
+                 * initialize our IP addr to 0 in order to accept ANY
+                 * IP addr assigned to us by the BOOTP / RARP server
+		 */
+		NetOurIP = 0;
+		NetServerIP = 0;
+		break;
+	default:
+		break;
+	}
+
+	switch (net_check_prereq (protocol)) {
+	case 1:
+		/* network not configured */
+		return 0;
+
+#ifdef CONFIG_NET_MULTI
+	case 2:
+		/* network device not configured */
+		break;
+#endif /* CONFIG_NET_MULTI */
+
+	case 0:
+#ifdef CONFIG_NET_MULTI
+		NetDevExists = 1;
+#endif
+		switch (protocol) {
+		case TFTP:
+			/* always use ARP to get server ethernet address */
+			ArpTry = 0;
+			ArpRequest ();
+			break;
+
+#if (CONFIG_COMMANDS & CFG_CMD_DHCP)
+		case DHCP:
+			/* Start with a clean slate... */
+			NetOurIP = 0;
+			NetServerIP = 0;
+			DhcpRequest();		/* Basically same as BOOTP */
+			break;
+#endif /* CFG_CMD_DHCP */
+
+		case BOOTP:
+			BootpTry = 0;
+			BootpRequest ();
+			break;
+
+		case RARP:
+			RarpTry = 0;
+			RarpRequest ();
+			break;
+		default:
+			break;
+		}
+
+		NetBootFileXferSize = 0;
+		break;
+	}
+
+
+	/*
+	 *	Main packet reception loop.  Loop receiving packets until
+	 *	someone sets `NetQuit'.
+	 */
+	for (;;) {
+		WATCHDOG_RESET();
+#ifdef CONFIG_SHOW_ACTIVITY
+		{
+			extern void show_activity(int arg);
+			show_activity(1);
+		}
+#endif
+		/*
+		 *	Check the ethernet for a new packet.  The ethernet
+		 *	receive routine will process it.
+		 */
+			eth_rx();
+
+		/*
+		 *	Abort if ctrl-c was pressed.
+		 */
+		if (ctrlc()) {
+		        eth_halt();
+			printf("\nAbort\n");
+			return 0;
+		}
+
+
+		/*
+		 *	Check for a timeout, and run the timeout handler
+		 *	if we have one.
+		 */
+		if (timeHandler && (get_timer(0) > timeValue)) {
+			thand_f *x;
+
+			x = timeHandler;
+			timeHandler = (thand_f *)0;
+			(*x)();
+		}
+
+
+		switch (NetState) {
+
+		case NETLOOP_RESTART:
+#ifdef CONFIG_NET_MULTI
+			NetRestarted = 1;
+#endif
+			goto restart;
+
+		case NETLOOP_SUCCESS:
+			if (NetBootFileXferSize > 0) {
+				char buf[10];
+				printf("Bytes transferred = %ld (%lx hex)\n",
+					NetBootFileXferSize,
+					NetBootFileXferSize);
+				sprintf(buf, "%lx", NetBootFileXferSize);
+				setenv("filesize", buf);
+			}
+			eth_halt();
+			return NetBootFileXferSize;
+
+		case NETLOOP_FAIL:
+			return 0;
+		}
+	}
+}
+
+/**********************************************************************/
+
+static void
+startAgainTimeout(void)
+{
+	NetState = NETLOOP_RESTART;
+}
+
+static void
+startAgainHandler(uchar * pkt, unsigned dest, unsigned src, unsigned len)
+{
+	/* Totally ignore the packet */
+}
+
+void
+NetStartAgain(void)
+{
+#ifndef CONFIG_NET_MULTI
+	NetSetTimeout(10 * CFG_HZ, startAgainTimeout);
+	NetSetHandler(startAgainHandler);
+#else
+	DECLARE_GLOBAL_DATA_PTR;
+
+	eth_halt();
+	eth_try_another(!NetRestarted);
+	eth_init(gd->bd);
+	if (NetRestartWrap)
+	{
+		NetRestartWrap = 0;
+		if (NetDevExists)
+		{
+			NetSetTimeout(10 * CFG_HZ, startAgainTimeout);
+			NetSetHandler(startAgainHandler);
+		}
+		else
+		{
+			NetState = NETLOOP_FAIL;
+		}
+	}
+	else
+	{
+		NetState = NETLOOP_RESTART;
+	}
+#endif
+}
+
+/**********************************************************************/
+/*
+ *	Miscelaneous bits.
+ */
+
+void
+NetSetHandler(rxhand_f * f)
+{
+	packetHandler = f;
+}
+
+
+void
+NetSetTimeout(int iv, thand_f * f)
+{
+	if (iv == 0) {
+		timeHandler = (thand_f *)0;
+	} else {
+		timeHandler = f;
+		timeValue = get_timer(0) + iv;
+	}
+}
+
+
+void
+NetSendPacket(volatile uchar * pkt, int len)
+{
+	(void) eth_send(pkt, len);
+}
+
+
+
+void
+NetReceive(volatile uchar * pkt, int len)
+{
+	Ethernet_t *et;
+	IP_t	*ip;
+	ARP_t	*arp;
+	IPaddr_t tmp;
+	int	x;
+
+
+	NetRxPkt = pkt;
+	NetRxPktLen = len;
+	et = (Ethernet_t *)pkt;
+
+	x = ntohs(et->et_protlen);
+
+	if (x < 1514) {
+		/*
+		 *	Got a 802 packet.  Check the other protocol field.
+		 */
+		x = ntohs(et->et_prot);
+		ip = (IP_t *)(pkt + E802_HDR_SIZE);
+		len -= E802_HDR_SIZE;
+	} else {
+		ip = (IP_t *)(pkt + ETHER_HDR_SIZE);
+		len -= ETHER_HDR_SIZE;
+	}
+
+#ifdef ET_DEBUG
+	printf("Receive from protocol 0x%x\n", x);
+#endif
+
+	switch (x) {
+
+	case PROT_ARP:
+		/*
+		 * We have to deal with two types of ARP packets:
+                 * - REQUEST packets will be answered by sending  our
+                 *   IP address - if we know it.
+                 * - REPLY packates are expected only after we asked
+                 *   for the TFTP server's or the gateway's ethernet
+                 *   address; so if we receive such a packet, we set
+                 *   the server ethernet address
+		 */
+#ifdef ET_DEBUG
+		printf("Got ARP\n");
+#endif
+		arp = (ARP_t *)ip;
+		if (len < ARP_HDR_SIZE) {
+			printf("bad length %d < %d\n", len, ARP_HDR_SIZE);
+			return;
+		}
+		if (ntohs(arp->ar_hrd) != ARP_ETHER) {
+			return;
+		}
+		if (ntohs(arp->ar_pro) != PROT_IP) {
+			return;
+		}
+		if (arp->ar_hln != 6) {
+			return;
+		}
+		if (arp->ar_pln != 4) {
+			return;
+		}
+
+		if (NetOurIP == 0) {
+			return;
+		}
+
+		if (NetReadIP(&arp->ar_data[16]) != NetOurIP) {
+			return;
+		}
+
+		switch (ntohs(arp->ar_op)) {
+		case ARPOP_REQUEST:		/* reply with our IP address	*/
+#ifdef ET_DEBUG
+			printf("Got ARP REQUEST, return our IP\n");
+#endif
+			NetSetEther((uchar *)et, et->et_src, PROT_ARP);
+			arp->ar_op = htons(ARPOP_REPLY);
+			memcpy   (&arp->ar_data[10], &arp->ar_data[0], 6);
+			NetCopyIP(&arp->ar_data[16], &arp->ar_data[6]);
+			memcpy   (&arp->ar_data[ 0], NetOurEther, 6);
+			NetCopyIP(&arp->ar_data[ 6], &NetOurIP);
+			NetSendPacket((uchar *)et,((uchar *)arp-pkt)+ARP_HDR_SIZE);
+			return;
+		case ARPOP_REPLY:		/* set TFTP server eth addr	*/
+#ifdef ET_DEBUG
+			printf("Got ARP REPLY, set server/gtwy eth addr\n");
+#endif
+			memcpy (NetServerEther, &arp->ar_data[0], 6);
+			(*packetHandler)(0,0,0,0);	/* start TFTP */
+			return;
+		default:
+#ifdef ET_DEBUG
+			printf("Unexpected ARP opcode 0x%x\n", ntohs(arp->ar_op));
+#endif
+			return;
+		}
+
+	case PROT_RARP:
+#ifdef ET_DEBUG
+		printf("Got RARP\n");
+#endif
+		arp = (ARP_t *)ip;
+		if (len < ARP_HDR_SIZE) {
+			printf("bad length %d < %d\n", len, ARP_HDR_SIZE);
+			return;
+		}
+
+		if ((ntohs(arp->ar_op) != RARPOP_REPLY) ||
+			(ntohs(arp->ar_hrd) != ARP_ETHER)   ||
+			(ntohs(arp->ar_pro) != PROT_IP)     ||
+			(arp->ar_hln != 6) || (arp->ar_pln != 4)) {
+
+			printf("invalid RARP header\n");
+		} else {
+			NetCopyIP(&NetOurIP,    &arp->ar_data[16]);
+			NetCopyIP(&NetServerIP, &arp->ar_data[ 6]);
+			memcpy (NetServerEther, &arp->ar_data[ 0], 6);
+
+			(*packetHandler)(0,0,0,0);
+		}
+		break;
+
+	case PROT_IP:
+#ifdef ET_DEBUG
+		printf("Got IP\n");
+#endif
+		if (len < IP_HDR_SIZE) {
+			debug ("len bad %d < %d\n", len, IP_HDR_SIZE);
+			return;
+		}
+		if (len < ntohs(ip->ip_len)) {
+			printf("len bad %d < %d\n", len, ntohs(ip->ip_len));
+			return;
+		}
+		len = ntohs(ip->ip_len);
+#ifdef ET_DEBUG
+		printf("len=%d, v=%02x\n", len, ip->ip_hl_v & 0xff);
+#endif
+		if ((ip->ip_hl_v & 0xf0) != 0x40) {
+			return;
+		}
+		if (ip->ip_off & htons(0x1fff)) { /* Can't deal w/ fragments */
+			return;
+		}
+		if (!NetCksumOk((uchar *)ip, IP_HDR_SIZE_NO_UDP / 2)) {
+			printf("checksum bad\n");
+			return;
+		}
+		tmp = NetReadIP(&ip->ip_dst);
+		if (NetOurIP && tmp != NetOurIP && tmp != 0xFFFFFFFF) {
+			return;
+		}
+		/*
+		 * watch for ICMP host redirects
+		 *
+                 * There is no real handler code (yet). We just watch
+                 * for ICMP host redirect messages. In case anybody
+                 * sees these messages: please contact me
+                 * (wd@denx.de), or - even better - send me the
+                 * necessary fixes :-)
+		 *
+                 * Note: in all cases where I have seen this so far
+                 * it was a problem with the router configuration,
+                 * for instance when a router was configured in the
+                 * BOOTP reply, but the TFTP server was on the same
+                 * subnet. So this is probably a warning that your
+                 * configuration might be wrong. But I'm not really
+                 * sure if there aren't any other situations.
+		 */
+		if (ip->ip_p == IPPROTO_ICMP) {
+			ICMP_t *icmph = (ICMP_t *)&(ip->udp_src);
+
+			if (icmph->type != ICMP_REDIRECT)
+				return;
+			if (icmph->code != ICMP_REDIR_HOST)
+				return;
+			puts (" ICMP Host Redirect to ");
+			print_IPaddr(icmph->un.gateway);
+			putc(' ');
+		} else if (ip->ip_p != IPPROTO_UDP) {	/* Only UDP packets */
+			return;
+		}
+
+		/*
+		 *	IP header OK.  Pass the packet to the current handler.
+		 */
+		(*packetHandler)((uchar *)ip +IP_HDR_SIZE,
+						ntohs(ip->udp_dst),
+						ntohs(ip->udp_src),
+						ntohs(ip->udp_len) - 8);
+
+		break;
+	}
+}
+
+
+/**********************************************************************/
+
+static int net_check_prereq (proto_t protocol)
+{
+	switch (protocol) {
+	case ARP:	/* nothing to do */
+			break;
+
+	case TFTP:
+			if (NetServerIP == 0) {
+				puts ("*** ERROR: `serverip' not set\n");
+				return (1);
+			}
+
+			if (NetOurIP == 0) {
+				puts ("*** ERROR: `ipaddr' not set\n");
+				return (1);
+			}
+			/* Fall through */
+
+	case DHCP:
+	case RARP:
+	case BOOTP:
+			if (memcmp(NetOurEther, "\0\0\0\0\0\0", 6) == 0) {
+#ifdef CONFIG_NET_MULTI
+			    extern int eth_get_dev_index (void);
+			    int num = eth_get_dev_index();
+
+			    switch (num) {
+			    case -1:
+				puts ("*** ERROR: No ethernet found.\n");
+				return (1);
+			    case 0:
+				puts ("*** ERROR: `ethaddr' not set\n");
+				break;
+			    default:
+			        printf ("*** ERROR: `eth%daddr' not set\n",
+					num);
+				break;
+			    }
+
+			    NetStartAgain ();
+			    return (2);
+#else
+			    puts ("*** ERROR: `ethaddr' not set\n");
+			    return (1);
+#endif
+			}
+			/* Fall through */
+	}
+	return (0);	/* OK */
+}
+/**********************************************************************/
+
+int
+NetCksumOk(uchar * ptr, int len)
+{
+	return !((NetCksum(ptr, len) + 1) & 0xfffe);
+}
+
+
+unsigned
+NetCksum(uchar * ptr, int len)
+{
+	ulong	xsum;
+
+	xsum = 0;
+	while (len-- > 0)
+		xsum += *((ushort *)ptr)++;
+	xsum = (xsum & 0xffff) + (xsum >> 16);
+	xsum = (xsum & 0xffff) + (xsum >> 16);
+	return (xsum & 0xffff);
+}
+
+
+void
+NetSetEther(volatile uchar * xet, uchar * addr, uint prot)
+{
+	Ethernet_t *et = (Ethernet_t *)xet;
+
+	memcpy (et->et_dest, addr, 6);
+	memcpy (et->et_src, NetOurEther, 6);
+	et->et_protlen = htons(prot);
+}
+
+
+void
+NetSetIP(volatile uchar * xip, IPaddr_t dest, int dport, int sport, int len)
+{
+	volatile IP_t *ip = (IP_t *)xip;
+
+	/*
+	 *	If the data is an odd number of bytes, zero the
+	 *	byte after the last byte so that the checksum
+	 *	will work.
+	 */
+	if (len & 1)
+		xip[IP_HDR_SIZE + len] = 0;
+
+	/*
+	 *	Construct an IP and UDP header.
+			(need to set no fragment bit - XXX)
+	 */
+	ip->ip_hl_v  = 0x45;		/* IP_HDR_SIZE / 4 (not including UDP) */
+	ip->ip_tos   = 0;
+	ip->ip_len   = htons(IP_HDR_SIZE + len);
+	ip->ip_id    = htons(NetIPID++);
+	ip->ip_off   = htons(0x4000);	/* No fragmentation */
+	ip->ip_ttl   = 255;
+	ip->ip_p     = 17;		/* UDP */
+	ip->ip_sum   = 0;
+	NetCopyIP((void*)&ip->ip_src, &NetOurIP); /* already in network byte order */
+	NetCopyIP((void*)&ip->ip_dst, &dest);	   /* - "" - */
+	ip->udp_src  = htons(sport);
+	ip->udp_dst  = htons(dport);
+	ip->udp_len  = htons(8 + len);
+	ip->udp_xsum = 0;
+	ip->ip_sum   = ~NetCksum((uchar *)ip, IP_HDR_SIZE_NO_UDP / 2);
+}
+
+void copy_filename (uchar *dst, uchar *src, int size)
+{
+	if (*src && (*src == '"')) {
+		++src;
+		--size;
+	}
+
+	while ((--size > 0) && *src && (*src != '"')) {
+		*dst++ = *src++;
+	}
+	*dst = '\0';
+}
+
+#endif /* CFG_CMD_NET */
+
+void ip_to_string (IPaddr_t x, char *s)
+{
+    x = ntohl(x);
+    sprintf (s,"%d.%d.%d.%d",
+    	(int)((x >> 24) & 0xff),
+	(int)((x >> 16) & 0xff),
+	(int)((x >>  8) & 0xff),
+	(int)((x >>  0) & 0xff)
+    );
+}
+
+void print_IPaddr (IPaddr_t x)
+{
+    char tmp[16];
+
+    ip_to_string(x, tmp);
+
+    puts(tmp);
+}
+
+IPaddr_t getenv_IPaddr (char *var)
+{
+	IPaddr_t addr;
+	char *s, *e;
+	int i;
+
+	s = getenv (var);
+
+	for (addr=0, i=0; i<4; ++i) {
+		ulong val = s ? simple_strtoul(s, &e, 10) : 0;
+		addr <<= 8;
+		addr |= (val & 0xFF);
+		if (s) {
+			s = (*e) ? e+1 : e;
+		}
+	}
+
+	return (htonl(addr));
+}