/*

   * (C) Copyright 2001-2015

   * Wolfgang Denk, DENX Software Engineering, wd@denx.de.

   * Joe Hershberger, National Instruments

   *

   * SPDX-License-Identifier:	GPL-2.0+

   */
  
  #include <common.h>
  #include <command.h>

  #include <dm.h>

  #include <environment.h>

  #include <net.h>

  #include <miiphy.h>

  #include <phy.h>

  #include <asm/errno.h>

  #include <dm/device-internal.h>

  #include <dm/uclass-internal.h>

  DECLARE_GLOBAL_DATA_PTR;

  void eth_parse_enetaddr(const char *addr, uchar *enetaddr)
  {
  	char *end;
  	int i;
  
  	for (i = 0; i < 6; ++i) {
  		enetaddr[i] = addr ? simple_strtoul(addr, &end, 16) : 0;
  		if (addr)
  			addr = (*end) ? end + 1 : end;
  	}
  }
  
  int eth_getenv_enetaddr(char *name, uchar *enetaddr)
  {
  	eth_parse_enetaddr(getenv(name), enetaddr);

  	return is_valid_ethaddr(enetaddr);

  }
  
  int eth_setenv_enetaddr(char *name, const uchar *enetaddr)
  {
  	char buf[20];
  
  	sprintf(buf, "%pM", enetaddr);
  
  	return setenv(name, buf);
  }

  int eth_getenv_enetaddr_by_index(const char *base_name, int index,
  				 uchar *enetaddr)

  {
  	char enetvar[32];

  	sprintf(enetvar, index ? "%s%daddr" : "%saddr", base_name, index);

  	return eth_getenv_enetaddr(enetvar, enetaddr);
  }

  static inline int eth_setenv_enetaddr_by_index(const char *base_name, int index,

  				 uchar *enetaddr)
  {
  	char enetvar[32];
  	sprintf(enetvar, index ? "%s%daddr" : "%saddr", base_name, index);
  	return eth_setenv_enetaddr(enetvar, enetaddr);
  }

  static int eth_mac_skip(int index)
  {
  	char enetvar[15];
  	char *skip_state;

  	sprintf(enetvar, index ? "eth%dmacskip" : "ethmacskip", index);

  	skip_state = getenv(enetvar);
  	return skip_state != NULL;

  }

  static void eth_current_changed(void);

  /*
   * CPU and board-specific Ethernet initializations.  Aliased function
   * signals caller to move on
   */
  static int __def_eth_init(bd_t *bis)
  {
  	return -1;
  }
  int cpu_eth_init(bd_t *bis) __attribute__((weak, alias("__def_eth_init")));
  int board_eth_init(bd_t *bis) __attribute__((weak, alias("__def_eth_init")));
  
  static void eth_common_init(void)
  {
  	bootstage_mark(BOOTSTAGE_ID_NET_ETH_START);
  #if defined(CONFIG_MII) || defined(CONFIG_CMD_MII) || defined(CONFIG_PHYLIB)
  	miiphy_init();
  #endif
  
  #ifdef CONFIG_PHYLIB
  	phy_init();
  #endif

  	/*
  	 * If board-specific initialization exists, call it.
  	 * If not, call a CPU-specific one
  	 */
  	if (board_eth_init != __def_eth_init) {
  		if (board_eth_init(gd->bd) < 0)
  			printf("Board Net Initialization Failed
  ");
  	} else if (cpu_eth_init != __def_eth_init) {
  		if (cpu_eth_init(gd->bd) < 0)
  			printf("CPU Net Initialization Failed
  ");
  	} else {
  		printf("Net Initialization Skipped
  ");
  	}
  }

  #ifdef CONFIG_DM_ETH
  /**
   * struct eth_device_priv - private structure for each Ethernet device
   *
   * @state: The state of the Ethernet MAC driver (defined by enum eth_state_t)
   */
  struct eth_device_priv {
  	enum eth_state_t state;
  };
  
  /**
   * struct eth_uclass_priv - The structure attached to the uclass itself
   *
   * @current: The Ethernet device that the network functions are using
   */
  struct eth_uclass_priv {
  	struct udevice *current;
  };

  /* eth_errno - This stores the most recent failure code from DM functions */
  static int eth_errno;

  static struct eth_uclass_priv *eth_get_uclass_priv(void)
  {
  	struct uclass *uc;
  
  	uclass_get(UCLASS_ETH, &uc);
  	assert(uc);
  	return uc->priv;
  }
  
  static void eth_set_current_to_next(void)
  {
  	struct eth_uclass_priv *uc_priv;
  
  	uc_priv = eth_get_uclass_priv();
  	if (uc_priv->current)
  		uclass_next_device(&uc_priv->current);
  	if (!uc_priv->current)
  		uclass_first_device(UCLASS_ETH, &uc_priv->current);
  }

  /*
   * Typically this will simply return the active device.
   * In the case where the most recent active device was unset, this will attempt
   * to return the first device. If that device doesn't exist or fails to probe,
   * this function will return NULL.
   */

  struct udevice *eth_get_dev(void)
  {
  	struct eth_uclass_priv *uc_priv;
  
  	uc_priv = eth_get_uclass_priv();
  	if (!uc_priv->current)

  		eth_errno = uclass_first_device(UCLASS_ETH,

  				    &uc_priv->current);
  	return uc_priv->current;
  }

  /*
   * Typically this will just store a device pointer.
   * In case it was not probed, we will attempt to do so.
   * dev may be NULL to unset the active device.
   */

  static void eth_set_dev(struct udevice *dev)
  {

  	if (dev && !device_active(dev))
  		eth_errno = device_probe(dev);

  	eth_get_uclass_priv()->current = dev;
  }

  /*
   * Find the udevice that either has the name passed in as devname or has an
   * alias named devname.
   */
  struct udevice *eth_get_dev_by_name(const char *devname)
  {
  	int seq = -1;
  	char *endp = NULL;
  	const char *startp = NULL;
  	struct udevice *it;
  	struct uclass *uc;
  
  	/* Must be longer than 3 to be an alias */
  	if (strlen(devname) > strlen("eth")) {
  		startp = devname + strlen("eth");
  		seq = simple_strtoul(startp, &endp, 10);
  	}
  
  	uclass_get(UCLASS_ETH, &uc);
  	uclass_foreach_dev(it, uc) {

  		/*
  		 * We need the seq to be valid, so try to probe it.
  		 * If the probe fails, the seq will not match since it will be
  		 * -1 instead of what we are looking for.
  		 * We don't care about errors from probe here. Either they won't
  		 * match an alias or it will match a literal name and we'll pick
  		 * up the error when we try to probe again in eth_set_dev().
  		 */

  		device_probe(it);
  		/*
  		 * Check for the name or the sequence number to match
  		 */
  		if (strcmp(it->name, devname) == 0 ||
  		    (endp > startp && it->seq == seq))
  			return it;
  	}
  
  	return NULL;
  }

  unsigned char *eth_get_ethaddr(void)
  {
  	struct eth_pdata *pdata;
  
  	if (eth_get_dev()) {
  		pdata = eth_get_dev()->platdata;
  		return pdata->enetaddr;
  	}
  
  	return NULL;
  }
  
  /* Set active state without calling start on the driver */
  int eth_init_state_only(void)
  {
  	struct udevice *current;
  	struct eth_device_priv *priv;
  
  	current = eth_get_dev();
  	if (!current || !device_active(current))
  		return -EINVAL;
  
  	priv = current->uclass_priv;
  	priv->state = ETH_STATE_ACTIVE;
  
  	return 0;
  }
  
  /* Set passive state without calling stop on the driver */
  void eth_halt_state_only(void)
  {
  	struct udevice *current;
  	struct eth_device_priv *priv;
  
  	current = eth_get_dev();
  	if (!current || !device_active(current))
  		return;
  
  	priv = current->uclass_priv;
  	priv->state = ETH_STATE_PASSIVE;
  }
  
  int eth_get_dev_index(void)
  {
  	if (eth_get_dev())
  		return eth_get_dev()->seq;
  	return -1;
  }

  static int eth_write_hwaddr(struct udevice *dev)
  {
  	struct eth_pdata *pdata = dev->platdata;
  	int ret = 0;
  
  	if (!dev || !device_active(dev))
  		return -EINVAL;
  
  	/* seq is valid since the device is active */
  	if (eth_get_ops(dev)->write_hwaddr && !eth_mac_skip(dev->seq)) {
  		if (!is_valid_ethaddr(pdata->enetaddr)) {
  			printf("
  Error: %s address %pM illegal value
  ",
  			       dev->name, pdata->enetaddr);
  			return -EINVAL;
  		}
  
  		ret = eth_get_ops(dev)->write_hwaddr(dev);
  		if (ret)
  			printf("
  Warning: %s failed to set MAC address
  ",
  			       dev->name);
  	}
  
  	return ret;
  }

  static int on_ethaddr(const char *name, const char *value, enum env_op op,
  	int flags)
  {
  	int index;
  	int retval;
  	struct udevice *dev;
  
  	/* look for an index after "eth" */
  	index = simple_strtoul(name + 3, NULL, 10);
  
  	retval = uclass_find_device_by_seq(UCLASS_ETH, index, false, &dev);
  	if (!retval) {
  		struct eth_pdata *pdata = dev->platdata;
  		switch (op) {
  		case env_op_create:
  		case env_op_overwrite:
  			eth_parse_enetaddr(value, pdata->enetaddr);
  			break;
  		case env_op_delete:
  			memset(pdata->enetaddr, 0, 6);
  		}
  	}
  
  	return 0;
  }
  U_BOOT_ENV_CALLBACK(ethaddr, on_ethaddr);

  int eth_init(void)
  {
  	struct udevice *current;
  	struct udevice *old_current;

  	int ret = -ENODEV;

  
  	current = eth_get_dev();
  	if (!current) {
  		printf("No ethernet found.
  ");
  		return -ENODEV;
  	}
  
  	old_current = current;
  	do {
  		debug("Trying %s
  ", current->name);
  
  		if (device_active(current)) {

  			ret = eth_get_ops(current)->start(current);
  			if (ret >= 0) {

  				struct eth_device_priv *priv =
  					current->uclass_priv;
  
  				priv->state = ETH_STATE_ACTIVE;
  				return 0;
  			}

  		} else {

  			ret = eth_errno;

  		}

  		debug("FAIL
  ");

  		/*
  		 * If ethrotate is enabled, this will change "current",
  		 * otherwise we will drop out of this while loop immediately
  		 */

  		eth_try_another(0);

  		/* This will ensure the new "current" attempted to probe */

  		current = eth_get_dev();
  	} while (old_current != current);

  	return ret;

  }
  
  void eth_halt(void)
  {
  	struct udevice *current;
  	struct eth_device_priv *priv;
  
  	current = eth_get_dev();
  	if (!current || !device_active(current))
  		return;
  
  	eth_get_ops(current)->stop(current);
  	priv = current->uclass_priv;
  	priv->state = ETH_STATE_PASSIVE;
  }
  
  int eth_send(void *packet, int length)
  {
  	struct udevice *current;

  	int ret;

  
  	current = eth_get_dev();
  	if (!current)
  		return -ENODEV;
  
  	if (!device_active(current))
  		return -EINVAL;

  	ret = eth_get_ops(current)->send(current, packet, length);
  	if (ret < 0) {
  		/* We cannot completely return the error at present */
  		debug("%s: send() returned error %d
  ", __func__, ret);
  	}
  	return ret;

  }
  
  int eth_rx(void)
  {
  	struct udevice *current;

  	uchar *packet;
  	int ret;
  	int i;

  
  	current = eth_get_dev();
  	if (!current)
  		return -ENODEV;
  
  	if (!device_active(current))
  		return -EINVAL;

  	/* Process up to 32 packets at one time */
  	for (i = 0; i < 32; i++) {
  		ret = eth_get_ops(current)->recv(current, &packet);
  		if (ret > 0)
  			net_process_received_packet(packet, ret);

  		if (ret >= 0 && eth_get_ops(current)->free_pkt)
  			eth_get_ops(current)->free_pkt(current, packet, ret);
  		if (ret <= 0)

  			break;
  	}
  	if (ret == -EAGAIN)
  		ret = 0;

  	if (ret < 0) {
  		/* We cannot completely return the error at present */
  		debug("%s: recv() returned error %d
  ", __func__, ret);
  	}

  	return ret;

  }

  int eth_initialize(void)
  {
  	int num_devices = 0;
  	struct udevice *dev;

  	eth_common_init();

  
  	/*
  	 * Devices need to write the hwaddr even if not started so that Linux
  	 * will have access to the hwaddr that u-boot stored for the device.
  	 * This is accomplished by attempting to probe each device and calling
  	 * their write_hwaddr() operation.
  	 */
  	uclass_first_device(UCLASS_ETH, &dev);
  	if (!dev) {
  		printf("No ethernet found.
  ");
  		bootstage_error(BOOTSTAGE_ID_NET_ETH_START);
  	} else {

  		char *ethprime = getenv("ethprime");
  		struct udevice *prime_dev = NULL;
  
  		if (ethprime)
  			prime_dev = eth_get_dev_by_name(ethprime);
  		if (prime_dev) {
  			eth_set_dev(prime_dev);
  			eth_current_changed();
  		} else {
  			eth_set_dev(NULL);
  		}

  		bootstage_mark(BOOTSTAGE_ID_NET_ETH_INIT);
  		do {
  			if (num_devices)
  				printf(", ");
  
  			printf("eth%d: %s", dev->seq, dev->name);

  			if (ethprime && dev == prime_dev)
  				printf(" [PRIME]");

  			eth_write_hwaddr(dev);
  
  			uclass_next_device(&dev);
  			num_devices++;
  		} while (dev);
  
  		putc('
  ');
  	}
  
  	return num_devices;
  }
  
  static int eth_post_bind(struct udevice *dev)
  {
  	if (strchr(dev->name, ' ')) {
  		printf("
  Error: eth device name \"%s\" has a space!
  ",
  		       dev->name);
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static int eth_pre_unbind(struct udevice *dev)
  {
  	/* Don't hang onto a pointer that is going away */
  	if (dev == eth_get_uclass_priv()->current)
  		eth_set_dev(NULL);
  
  	return 0;
  }
  
  static int eth_post_probe(struct udevice *dev)
  {
  	struct eth_device_priv *priv = dev->uclass_priv;
  	struct eth_pdata *pdata = dev->platdata;
  	unsigned char env_enetaddr[6];
  
  	priv->state = ETH_STATE_INIT;
  
  	/* Check if the device has a MAC address in ROM */
  	if (eth_get_ops(dev)->read_rom_hwaddr)
  		eth_get_ops(dev)->read_rom_hwaddr(dev);
  
  	eth_getenv_enetaddr_by_index("eth", dev->seq, env_enetaddr);

  	if (!is_zero_ethaddr(env_enetaddr)) {
  		if (!is_zero_ethaddr(pdata->enetaddr) &&

  		    memcmp(pdata->enetaddr, env_enetaddr, 6)) {
  			printf("
  Warning: %s MAC addresses don't match:
  ",
  			       dev->name);
  			printf("Address in SROM is         %pM
  ",
  			       pdata->enetaddr);
  			printf("Address in environment is  %pM
  ",
  			       env_enetaddr);
  		}
  
  		/* Override the ROM MAC address */
  		memcpy(pdata->enetaddr, env_enetaddr, 6);

  	} else if (is_valid_ethaddr(pdata->enetaddr)) {

  		eth_setenv_enetaddr_by_index("eth", dev->seq, pdata->enetaddr);
  		printf("
  Warning: %s using MAC address from ROM
  ",
  		       dev->name);

  	} else if (is_zero_ethaddr(pdata->enetaddr)) {

  #ifdef CONFIG_NET_RANDOM_ETHADDR
  		net_random_ethaddr(pdata->enetaddr);
  		printf("
  Warning: %s (eth%d) using random MAC address - %pM
  ",
  		       dev->name, dev->seq, pdata->enetaddr);
  #else

  		printf("
  Error: %s address not set.
  ",
  		       dev->name);
  		return -EINVAL;

  #endif

  	}
  
  	return 0;
  }
  
  static int eth_pre_remove(struct udevice *dev)
  {
  	eth_get_ops(dev)->stop(dev);
  
  	return 0;
  }
  
  UCLASS_DRIVER(eth) = {
  	.name		= "eth",
  	.id		= UCLASS_ETH,
  	.post_bind	= eth_post_bind,
  	.pre_unbind	= eth_pre_unbind,
  	.post_probe	= eth_post_probe,
  	.pre_remove	= eth_pre_remove,
  	.priv_auto_alloc_size = sizeof(struct eth_uclass_priv),
  	.per_device_auto_alloc_size = sizeof(struct eth_device_priv),

  	.flags		= DM_UC_FLAG_SEQ_ALIAS,

  };
  #endif
  
  #ifndef CONFIG_DM_ETH

  #ifdef CONFIG_API

  static struct {
  	uchar data[PKTSIZE];
  	int length;
  } eth_rcv_bufs[PKTBUFSRX];

  static unsigned int eth_rcv_current, eth_rcv_last;

  #endif

  static struct eth_device *eth_devices;
  struct eth_device *eth_current;

  static void eth_set_current_to_next(void)
  {
  	eth_current = eth_current->next;
  }

  static void eth_set_dev(struct eth_device *dev)
  {
  	eth_current = dev;
  }

  struct eth_device *eth_get_dev_by_name(const char *devname)

  {
  	struct eth_device *dev, *target_dev;

  	BUG_ON(devname == NULL);

  	if (!eth_devices)
  		return NULL;
  
  	dev = eth_devices;
  	target_dev = NULL;
  	do {
  		if (strcmp(devname, dev->name) == 0) {
  			target_dev = dev;
  			break;
  		}
  		dev = dev->next;
  	} while (dev != eth_devices);
  
  	return target_dev;
  }

  struct eth_device *eth_get_dev_by_index(int index)
  {
  	struct eth_device *dev, *target_dev;

  
  	if (!eth_devices)
  		return NULL;
  
  	dev = eth_devices;
  	target_dev = NULL;
  	do {

  		if (dev->index == index) {

  			target_dev = dev;
  			break;
  		}
  		dev = dev->next;

  	} while (dev != eth_devices);
  
  	return target_dev;
  }

  int eth_get_dev_index(void)

  {

  	if (!eth_current)

  		return -1;

  	return eth_current->index;

  }

  static int on_ethaddr(const char *name, const char *value, enum env_op op,
  	int flags)
  {
  	int index;
  	struct eth_device *dev;
  
  	if (!eth_devices)
  		return 0;
  
  	/* look for an index after "eth" */
  	index = simple_strtoul(name + 3, NULL, 10);
  
  	dev = eth_devices;
  	do {
  		if (dev->index == index) {
  			switch (op) {
  			case env_op_create:
  			case env_op_overwrite:
  				eth_parse_enetaddr(value, dev->enetaddr);
  				break;
  			case env_op_delete:
  				memset(dev->enetaddr, 0, 6);
  			}
  		}
  	} while (dev != eth_devices);
  
  	return 0;
  }
  U_BOOT_ENV_CALLBACK(ethaddr, on_ethaddr);

  int eth_write_hwaddr(struct eth_device *dev, const char *base_name,
  		   int eth_number)
  {
  	unsigned char env_enetaddr[6];
  	int ret = 0;

  	eth_getenv_enetaddr_by_index(base_name, eth_number, env_enetaddr);

  	if (!is_zero_ethaddr(env_enetaddr)) {
  		if (!is_zero_ethaddr(dev->enetaddr) &&

  		    memcmp(dev->enetaddr, env_enetaddr, 6)) {

  			printf("
  Warning: %s MAC addresses don't match:
  ",

  			       dev->name);

  			printf("Address in SROM is         %pM
  ",

  			       dev->enetaddr);

  			printf("Address in environment is  %pM
  ",

  			       env_enetaddr);

  		}
  
  		memcpy(dev->enetaddr, env_enetaddr, 6);

  	} else if (is_valid_ethaddr(dev->enetaddr)) {

  		eth_setenv_enetaddr_by_index(base_name, eth_number,
  					     dev->enetaddr);
  		printf("
  Warning: %s using MAC address from net device
  ",

  		       dev->name);

  	} else if (is_zero_ethaddr(dev->enetaddr)) {

  #ifdef CONFIG_NET_RANDOM_ETHADDR
  		net_random_ethaddr(dev->enetaddr);
  		printf("
  Warning: %s (eth%d) using random MAC address - %pM
  ",
  		       dev->name, eth_number, dev->enetaddr);
  #else

  		printf("
  Error: %s address not set.
  ",
  		       dev->name);
  		return -EINVAL;

  #endif

  	}

  	if (dev->write_hwaddr && !eth_mac_skip(eth_number)) {

  		if (!is_valid_ethaddr(dev->enetaddr)) {

  			printf("
  Error: %s address %pM illegal value
  ",

  			       dev->name, dev->enetaddr);

  			return -EINVAL;
  		}

  		ret = dev->write_hwaddr(dev);

  		if (ret)

  			printf("
  Warning: %s failed to set MAC address
  ",
  			       dev->name);

  	}

  
  	return ret;
  }

  int eth_register(struct eth_device *dev)
  {
  	struct eth_device *d;

  	static int index;

  	assert(strlen(dev->name) < sizeof(dev->name));

  	if (!eth_devices) {

  		eth_devices = dev;
  		eth_current = dev;

  		eth_current_changed();

  	} else {

  		for (d = eth_devices; d->next != eth_devices; d = d->next)

  			;

  		d->next = dev;
  	}
  
  	dev->state = ETH_STATE_INIT;
  	dev->next  = eth_devices;

  	dev->index = index++;

  
  	return 0;
  }

  int eth_unregister(struct eth_device *dev)
  {
  	struct eth_device *cur;
  
  	/* No device */
  	if (!eth_devices)

  		return -ENODEV;

  
  	for (cur = eth_devices; cur->next != eth_devices && cur->next != dev;
  	     cur = cur->next)
  		;
  
  	/* Device not found */
  	if (cur->next != dev)

  		return -ENODEV;

  
  	cur->next = dev->next;
  
  	if (eth_devices == dev)
  		eth_devices = dev->next == eth_devices ? NULL : dev->next;
  
  	if (eth_current == dev) {
  		eth_current = eth_devices;
  		eth_current_changed();
  	}
  
  	return 0;
  }

  int eth_initialize(void)

  {

  	int num_devices = 0;

  	eth_devices = NULL;
  	eth_current = NULL;

  	eth_common_init();

  	if (!eth_devices) {

  		puts("No ethernet found.
  ");

  		bootstage_error(BOOTSTAGE_ID_NET_ETH_START);

  	} else {
  		struct eth_device *dev = eth_devices;

  		char *ethprime = getenv("ethprime");

  		bootstage_mark(BOOTSTAGE_ID_NET_ETH_INIT);

  		do {

  			if (dev->index)

  				puts(", ");

  
  			printf("%s", dev->name);

  			if (ethprime && strcmp(dev->name, ethprime) == 0) {

  				eth_current = dev;

  				puts(" [PRIME]");

  			}

  			if (strchr(dev->name, ' '))

  				puts("
  Warning: eth device name has a space!"
  					"
  ");

  			eth_write_hwaddr(dev, "eth", dev->index);

  			dev = dev->next;

  			num_devices++;

  		} while (dev != eth_devices);

  		eth_current_changed();

  		putc('
  ');

  	}

  	return num_devices;

  }

  #ifdef CONFIG_MCAST_TFTP
  /* Multicast.
   * mcast_addr: multicast ipaddr from which multicast Mac is made

   * join: 1=join, 0=leave.

   */

  int eth_mcast_join(struct in_addr mcast_ip, int join)

  {

  	u8 mcast_mac[6];

  	if (!eth_current || !eth_current->mcast)

  		return -1;

  	mcast_mac[5] = htonl(mcast_ip.s_addr) & 0xff;
  	mcast_mac[4] = (htonl(mcast_ip.s_addr)>>8) & 0xff;
  	mcast_mac[3] = (htonl(mcast_ip.s_addr)>>16) & 0x7f;

  	mcast_mac[2] = 0x5e;
  	mcast_mac[1] = 0x0;
  	mcast_mac[0] = 0x1;
  	return eth_current->mcast(eth_current, mcast_mac, join);
  }

  /* the 'way' for ethernet-CRC-32. Spliced in from Linux lib/crc32.c
   * and this is the ethernet-crc method needed for TSEC -- and perhaps

   * some other adapter -- hash tables
   */
  #define CRCPOLY_LE 0xedb88320

  u32 ether_crc(size_t len, unsigned char const *p)

  {
  	int i;
  	u32 crc;
  	crc = ~0;
  	while (len--) {
  		crc ^= *p++;
  		for (i = 0; i < 8; i++)
  			crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0);
  	}
  	/* an reverse the bits, cuz of way they arrive -- last-first */
  	crc = (crc >> 16) | (crc << 16);
  	crc = (crc >> 8 & 0x00ff00ff) | (crc << 8 & 0xff00ff00);
  	crc = (crc >> 4 & 0x0f0f0f0f) | (crc << 4 & 0xf0f0f0f0);
  	crc = (crc >> 2 & 0x33333333) | (crc << 2 & 0xcccccccc);
  	crc = (crc >> 1 & 0x55555555) | (crc << 1 & 0xaaaaaaaa);
  	return crc;
  }
  
  #endif

  int eth_init(void)

  {

  	struct eth_device *old_current;

  	if (!eth_current) {

  		puts("No ethernet found.
  ");

  		return -ENODEV;

  	}

  
  	old_current = eth_current;
  	do {

  		debug("Trying %s
  ", eth_current->name);

  		if (eth_current->init(eth_current, gd->bd) >= 0) {

  			eth_current->state = ETH_STATE_ACTIVE;

  			return 0;

  		}

  		debug("FAIL
  ");

  
  		eth_try_another(0);
  	} while (old_current != eth_current);

  	return -ETIMEDOUT;

  }
  
  void eth_halt(void)
  {
  	if (!eth_current)
  		return;
  
  	eth_current->halt(eth_current);
  
  	eth_current->state = ETH_STATE_PASSIVE;
  }

  int eth_send(void *packet, int length)

  {
  	if (!eth_current)

  		return -ENODEV;

  
  	return eth_current->send(eth_current, packet, length);
  }
  
  int eth_rx(void)
  {
  	if (!eth_current)

  		return -ENODEV;

  
  	return eth_current->recv(eth_current);
  }

  #endif /* ifndef CONFIG_DM_ETH */

  #ifdef CONFIG_API

  static void eth_save_packet(void *packet, int length)

  {

  	char *p = packet;

  	int i;
  
  	if ((eth_rcv_last+1) % PKTBUFSRX == eth_rcv_current)
  		return;
  
  	if (PKTSIZE < length)
  		return;
  
  	for (i = 0; i < length; i++)
  		eth_rcv_bufs[eth_rcv_last].data[i] = p[i];
  
  	eth_rcv_bufs[eth_rcv_last].length = length;
  	eth_rcv_last = (eth_rcv_last + 1) % PKTBUFSRX;
  }

  int eth_receive(void *packet, int length)

  {

  	char *p = packet;

  	void *pp = push_packet;
  	int i;
  
  	if (eth_rcv_current == eth_rcv_last) {
  		push_packet = eth_save_packet;
  		eth_rx();
  		push_packet = pp;
  
  		if (eth_rcv_current == eth_rcv_last)
  			return -1;
  	}

  	length = min(eth_rcv_bufs[eth_rcv_current].length, length);

  
  	for (i = 0; i < length; i++)
  		p[i] = eth_rcv_bufs[eth_rcv_current].data[i];
  
  	eth_rcv_current = (eth_rcv_current + 1) % PKTBUFSRX;
  	return length;
  }
  #endif /* CONFIG_API */

  static void eth_current_changed(void)
  {
  	char *act = getenv("ethact");
  	/* update current ethernet name */
  	if (eth_get_dev()) {
  		if (act == NULL || strcmp(act, eth_get_name()) != 0)
  			setenv("ethact", eth_get_name());
  	}
  	/*
  	 * remove the variable completely if there is no active
  	 * interface
  	 */
  	else if (act != NULL)
  		setenv("ethact", NULL);
  }

  void eth_try_another(int first_restart)
  {

  	static void *first_failed;

  	char *ethrotate;

  
  	/*
  	 * Do not rotate between network interfaces when
  	 * 'ethrotate' variable is set to 'no'.
  	 */

  	ethrotate = getenv("ethrotate");
  	if ((ethrotate != NULL) && (strcmp(ethrotate, "no") == 0))

  		return;

  	if (!eth_get_dev())

  		return;

  	if (first_restart)

  		first_failed = eth_get_dev();

  	eth_set_current_to_next();

  	eth_current_changed();

  	if (first_failed == eth_get_dev())

  		net_restart_wrap = 1;

  }

  void eth_set_current(void)
  {

  	static char *act;
  	static int  env_changed_id;

  	int	env_id;

  	env_id = get_env_id();
  	if ((act == NULL) || (env_changed_id != env_id)) {
  		act = getenv("ethact");
  		env_changed_id = env_id;
  	}

  
  	if (act == NULL) {
  		char *ethprime = getenv("ethprime");
  		void *dev = NULL;
  
  		if (ethprime)
  			dev = eth_get_dev_by_name(ethprime);
  		if (dev)
  			eth_set_dev(dev);
  		else
  			eth_set_dev(NULL);
  	} else {

  		eth_set_dev(eth_get_dev_by_name(act));

  	}

  	eth_current_changed();

  }

  const char *eth_get_name(void)

  {

  	return eth_get_dev() ? eth_get_dev()->name : "unknown";

  }