Das U-Boot: Universal Boot Loader
authorwdenk <wdenk>
Thu, 31 Oct 2002 22:12:35 +0000 (22:12 +0000)
committerwdenk <wdenk>
Thu, 31 Oct 2002 22:12:35 +0000 (22:12 +0000)
include/net.h [new file with mode: 0644]
net/net.c [new file with mode: 0644]

diff --git a/include/net.h b/include/net.h
new file mode 100644 (file)
index 0000000..d4985ca
--- /dev/null
@@ -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 (file)
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));
+}