ipxe/src/arch/i386/interface/pxe/pxe_undi.c

/** @file
 *
 * PXE UNDI API
 *
 */

/*
 * Copyright (C) 2004 Michael Brown <mbrown@fensystems.co.uk>.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

FILE_LICENCE ( GPL2_OR_LATER );

#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <byteswap.h>
#include <basemem_packet.h>
#include <ipxe/netdevice.h>
#include <ipxe/iobuf.h>
#include <ipxe/device.h>
#include <ipxe/pci.h>
#include <ipxe/if_ether.h>
#include <ipxe/ip.h>
#include <ipxe/arp.h>
#include <ipxe/rarp.h>
#include "pxe.h"

/**
 * Count of outstanding transmitted packets
 *
 * This is incremented each time PXENV_UNDI_TRANSMIT is called, and
 * decremented each time that PXENV_UNDI_ISR is called with the TX
 * queue empty, stopping when the count reaches zero.  This allows us
 * to provide a pessimistic approximation of TX completion events to
 * the PXE NBP simply by monitoring the netdev's TX queue.
 */
static int undi_tx_count = 0;

struct net_device *pxe_netdev = NULL;

/**
 * Set network device as current PXE network device
 *
 * @v netdev		Network device, or NULL
 */
void pxe_set_netdev ( struct net_device *netdev ) {
	if ( pxe_netdev )
		netdev_put ( pxe_netdev );
	pxe_netdev = NULL;
	if ( netdev )
		pxe_netdev = netdev_get ( netdev );
}

/**
 * Open PXE network device
 *
 * @ret rc		Return status code
 */
static int pxe_netdev_open ( void ) {
	int rc;

	if ( ( rc = netdev_open ( pxe_netdev ) ) != 0 )
		return rc;

	netdev_irq ( pxe_netdev, 1 );
	return 0;
}

/**
 * Close PXE network device
 *
 */
static void pxe_netdev_close ( void ) {
	netdev_irq ( pxe_netdev, 0 );
	netdev_close ( pxe_netdev );
	undi_tx_count = 0;
}

/**
 * Dump multicast address list
 *
 * @v mcast		PXE multicast address list
 */
static void pxe_dump_mcast_list ( struct s_PXENV_UNDI_MCAST_ADDRESS *mcast ) {
	struct ll_protocol *ll_protocol = pxe_netdev->ll_protocol;
	unsigned int i;

	for ( i = 0 ; i < mcast->MCastAddrCount ; i++ ) {
		DBG ( " %s", ll_protocol->ntoa ( mcast->McastAddr[i] ) );
	}
}

/* PXENV_UNDI_STARTUP
 *
 * Status: working
 */
PXENV_EXIT_t pxenv_undi_startup ( struct s_PXENV_UNDI_STARTUP *undi_startup ) {
	DBG ( "PXENV_UNDI_STARTUP\n" );

	undi_startup->Status = PXENV_STATUS_SUCCESS;
	return PXENV_EXIT_SUCCESS;
}

/* PXENV_UNDI_CLEANUP
 *
 * Status: working
 */
PXENV_EXIT_t pxenv_undi_cleanup ( struct s_PXENV_UNDI_CLEANUP *undi_cleanup ) {
	DBG ( "PXENV_UNDI_CLEANUP\n" );

	pxe_netdev_close();

	undi_cleanup->Status = PXENV_STATUS_SUCCESS;
	return PXENV_EXIT_SUCCESS;
}

/* PXENV_UNDI_INITIALIZE
 *
 * Status: working
 */
PXENV_EXIT_t pxenv_undi_initialize ( struct s_PXENV_UNDI_INITIALIZE
				     *undi_initialize ) {
	DBG ( "PXENV_UNDI_INITIALIZE protocolini %08x\n",
	      undi_initialize->ProtocolIni );

	undi_initialize->Status = PXENV_STATUS_SUCCESS;
	return PXENV_EXIT_SUCCESS;
}

/* PXENV_UNDI_RESET_ADAPTER
 *
 * Status: working
 */
PXENV_EXIT_t pxenv_undi_reset_adapter ( struct s_PXENV_UNDI_RESET
					*undi_reset_adapter ) {
	int rc;

	DBG ( "PXENV_UNDI_RESET_ADAPTER" );
	pxe_dump_mcast_list ( &undi_reset_adapter->R_Mcast_Buf );
	DBG ( "\n" );

	pxe_netdev_close();
	if ( ( rc = pxe_netdev_open() ) != 0 ) {
		DBG ( "PXENV_UNDI_RESET_ADAPTER could not reopen %s: %s\n",
		      pxe_netdev->name, strerror ( rc ) );
		undi_reset_adapter->Status = PXENV_STATUS ( rc );
		return PXENV_EXIT_FAILURE;
	}

	undi_reset_adapter->Status = PXENV_STATUS_SUCCESS;
	return PXENV_EXIT_SUCCESS;
}

/* PXENV_UNDI_SHUTDOWN
 *
 * Status: working
 */
PXENV_EXIT_t pxenv_undi_shutdown ( struct s_PXENV_UNDI_SHUTDOWN
				   *undi_shutdown ) {
	DBG ( "PXENV_UNDI_SHUTDOWN\n" );

	pxe_netdev_close();

	undi_shutdown->Status = PXENV_STATUS_SUCCESS;
	return PXENV_EXIT_SUCCESS;
}

/* PXENV_UNDI_OPEN
 *
 * Status: working
 */
PXENV_EXIT_t pxenv_undi_open ( struct s_PXENV_UNDI_OPEN *undi_open ) {
	int rc;

	DBG ( "PXENV_UNDI_OPEN flag %04x filter %04x",
	      undi_open->OpenFlag, undi_open->PktFilter );
	pxe_dump_mcast_list ( &undi_open->R_Mcast_Buf );
	DBG ( "\n" );

	if ( ( rc = pxe_netdev_open() ) != 0 ) {
		DBG ( "PXENV_UNDI_OPEN could not open %s: %s\n",
		      pxe_netdev->name, strerror ( rc ) );
		undi_open->Status = PXENV_STATUS ( rc );
		return PXENV_EXIT_FAILURE;
	}

	undi_open->Status = PXENV_STATUS_SUCCESS;
	return PXENV_EXIT_SUCCESS;
}

/* PXENV_UNDI_CLOSE
 *
 * Status: working
 */
PXENV_EXIT_t pxenv_undi_close ( struct s_PXENV_UNDI_CLOSE *undi_close ) {
	DBG ( "PXENV_UNDI_CLOSE\n" );

	pxe_netdev_close();

	undi_close->Status = PXENV_STATUS_SUCCESS;
	return PXENV_EXIT_SUCCESS;
}

/* PXENV_UNDI_TRANSMIT
 *
 * Status: working
 */
PXENV_EXIT_t pxenv_undi_transmit ( struct s_PXENV_UNDI_TRANSMIT
				   *undi_transmit ) {
	struct s_PXENV_UNDI_TBD tbd;
	struct DataBlk *datablk;
	struct io_buffer *iobuf;
	struct net_protocol *net_protocol;
	struct ll_protocol *ll_protocol = pxe_netdev->ll_protocol;
	char destaddr[MAX_LL_ADDR_LEN];
	const void *ll_dest;
	size_t ll_hlen = ll_protocol->ll_header_len;
	size_t len;
	unsigned int i;
	int rc;

	DBG2 ( "PXENV_UNDI_TRANSMIT" );

	/* Forcibly enable interrupts at this point, to work around
	 * callers that never call PXENV_UNDI_OPEN before attempting
	 * to use the UNDI API.
	 */
	netdev_irq ( pxe_netdev, 1 );

	/* Identify network-layer protocol */
	switch ( undi_transmit->Protocol ) {
	case P_IP:	net_protocol = &ipv4_protocol;	break;
	case P_ARP:	net_protocol = &arp_protocol;	break;
	case P_RARP:	net_protocol = &rarp_protocol;	break;
	case P_UNKNOWN:
		net_protocol = NULL;
		ll_hlen = 0;
		break;
	default:
		DBG2 ( " %02x invalid protocol\n", undi_transmit->Protocol );
		undi_transmit->Status = PXENV_STATUS_UNDI_INVALID_PARAMETER;
		return PXENV_EXIT_FAILURE;
	}
	DBG2 ( " %s", ( net_protocol ? net_protocol->name : "RAW" ) );

	/* Calculate total packet length */
	copy_from_real ( &tbd, undi_transmit->TBD.segment,
			 undi_transmit->TBD.offset, sizeof ( tbd ) );
	len = tbd.ImmedLength;
	DBG2 ( " %04x:%04x+%x", tbd.Xmit.segment, tbd.Xmit.offset,
	       tbd.ImmedLength );
	for ( i = 0 ; i < tbd.DataBlkCount ; i++ ) {
		datablk = &tbd.DataBlock[i];
		len += datablk->TDDataLen;
		DBG2 ( " %04x:%04x+%x", datablk->TDDataPtr.segment,
		       datablk->TDDataPtr.offset, datablk->TDDataLen );
	}

	/* Allocate and fill I/O buffer */
	iobuf = alloc_iob ( ll_hlen + len );
	if ( ! iobuf ) {
		DBG2 ( " could not allocate iobuf\n" );
		undi_transmit->Status = PXENV_STATUS_OUT_OF_RESOURCES;
		return PXENV_EXIT_FAILURE;
	}
	iob_reserve ( iobuf, ll_hlen );
	copy_from_real ( iob_put ( iobuf, tbd.ImmedLength ), tbd.Xmit.segment,
			 tbd.Xmit.offset, tbd.ImmedLength );
	for ( i = 0 ; i < tbd.DataBlkCount ; i++ ) {
		datablk = &tbd.DataBlock[i];
		copy_from_real ( iob_put ( iobuf, datablk->TDDataLen ),
				 datablk->TDDataPtr.segment,
				 datablk->TDDataPtr.offset,
				 datablk->TDDataLen );
	}

	/* Add link-layer header, if required to do so */
	if ( net_protocol != NULL ) {

		/* Calculate destination address */
		if ( undi_transmit->XmitFlag == XMT_DESTADDR ) {
			copy_from_real ( destaddr,
					 undi_transmit->DestAddr.segment,
					 undi_transmit->DestAddr.offset,
					 ll_protocol->ll_addr_len );
			ll_dest = destaddr;
			DBG2 ( " DEST %s", ll_protocol->ntoa ( ll_dest ) );
		} else {
			ll_dest = pxe_netdev->ll_broadcast;
			DBG2 ( " BCAST" );
		}

		/* Add link-layer header */
		if ( ( rc = ll_protocol->push ( pxe_netdev, iobuf, ll_dest,
						pxe_netdev->ll_addr,
						net_protocol->net_proto ))!=0){
			DBG2 ( " could not add link-layer header: %s\n",
			       strerror ( rc ) );
			free_iob ( iobuf );
			undi_transmit->Status = PXENV_STATUS ( rc );
			return PXENV_EXIT_FAILURE;
		}
	}

	/* Flag transmission as in-progress.  Do this before starting
	 * to transmit the packet, because the ISR may trigger before
	 * we return from netdev_tx().
	 */
	undi_tx_count++;

	/* Transmit packet */
	DBG2 ( "\n" );
	if ( ( rc = netdev_tx ( pxe_netdev, iobuf ) ) != 0 ) {
		DBG2 ( "PXENV_UNDI_TRANSMIT could not transmit: %s\n",
		       strerror ( rc ) );
		undi_tx_count--;
		undi_transmit->Status = PXENV_STATUS ( rc );
		return PXENV_EXIT_FAILURE;
	}

	undi_transmit->Status = PXENV_STATUS_SUCCESS;
	return PXENV_EXIT_SUCCESS;
}

/* PXENV_UNDI_SET_MCAST_ADDRESS
 *
 * Status: working (for NICs that support receive-all-multicast)
 */
PXENV_EXIT_t
pxenv_undi_set_mcast_address ( struct s_PXENV_UNDI_SET_MCAST_ADDRESS
			       *undi_set_mcast_address ) {
	DBG ( "PXENV_UNDI_SET_MCAST_ADDRESS" );
	pxe_dump_mcast_list ( &undi_set_mcast_address->R_Mcast_Buf );
	DBG ( "\n" );

	undi_set_mcast_address->Status = PXENV_STATUS_SUCCESS;
	return PXENV_EXIT_SUCCESS;
}

/* PXENV_UNDI_SET_STATION_ADDRESS
 *
 * Status: working
 */
PXENV_EXIT_t 
pxenv_undi_set_station_address ( struct s_PXENV_UNDI_SET_STATION_ADDRESS
				 *undi_set_station_address ) {
	struct ll_protocol *ll_protocol = pxe_netdev->ll_protocol;

	DBG ( "PXENV_UNDI_SET_STATION_ADDRESS %s",
	      ll_protocol->ntoa ( undi_set_station_address->StationAddress ) );

	/* If adapter is open, the change will have no effect; return
	 * an error
	 */
	if ( netdev_is_open ( pxe_netdev ) ) {
		DBG ( " failed: netdev is open\n" );
		undi_set_station_address->Status =
			PXENV_STATUS_UNDI_INVALID_STATE;
		return PXENV_EXIT_FAILURE;
	}

	/* Update MAC address */
	memcpy ( pxe_netdev->ll_addr,
		 &undi_set_station_address->StationAddress,
		 ll_protocol->ll_addr_len );

	DBG ( "\n" );
	undi_set_station_address->Status = PXENV_STATUS_SUCCESS;
	return PXENV_EXIT_SUCCESS;
}

/* PXENV_UNDI_SET_PACKET_FILTER
 *
 * Status: won't implement (would require driver API changes for no
 * real benefit)
 */
PXENV_EXIT_t
pxenv_undi_set_packet_filter ( struct s_PXENV_UNDI_SET_PACKET_FILTER
			       *undi_set_packet_filter ) {

	DBG ( "PXENV_UNDI_SET_PACKET_FILTER %02x\n",
	      undi_set_packet_filter->filter );

	/* Pretend that we succeeded, otherwise the 3Com DOS UNDI
	 * driver refuses to load.  (We ignore the filter value in the
	 * PXENV_UNDI_OPEN call anyway.)
	 */
	undi_set_packet_filter->Status = PXENV_STATUS_SUCCESS;

	return PXENV_EXIT_SUCCESS;
}

/* PXENV_UNDI_GET_INFORMATION
 *
 * Status: working
 */
PXENV_EXIT_t pxenv_undi_get_information ( struct s_PXENV_UNDI_GET_INFORMATION
					  *undi_get_information ) {
	struct device *dev = pxe_netdev->dev;
	struct ll_protocol *ll_protocol = pxe_netdev->ll_protocol;
	size_t ll_addr_len = ll_protocol->ll_addr_len;

	DBG ( "PXENV_UNDI_GET_INFORMATION" );

	undi_get_information->BaseIo = dev->desc.ioaddr;
	undi_get_information->IntNumber = dev->desc.irq;
	/* Cheat: assume all cards can cope with this */
	undi_get_information->MaxTranUnit = ETH_MAX_MTU;
	undi_get_information->HwType = ntohs ( ll_protocol->ll_proto );
	undi_get_information->HwAddrLen = ll_addr_len;
	assert ( ll_addr_len <=
		 sizeof ( undi_get_information->CurrentNodeAddress ) );
	memcpy ( &undi_get_information->CurrentNodeAddress,
		 pxe_netdev->ll_addr,
		 sizeof ( undi_get_information->CurrentNodeAddress ) );
	ll_protocol->init_addr ( pxe_netdev->hw_addr,
				 &undi_get_information->PermNodeAddress );
	undi_get_information->ROMAddress = 0;
		/* nic.rom_info->rom_segment; */
	/* We only provide the ability to receive or transmit a single
	 * packet at a time.  This is a bootloader, not an OS.
	 */
	undi_get_information->RxBufCt = 1;
	undi_get_information->TxBufCt = 1;

	DBG ( " io %04x irq %d mtu %d %s %s\n",
	      undi_get_information->BaseIo, undi_get_information->IntNumber,
	      undi_get_information->MaxTranUnit, ll_protocol->name,
	      ll_protocol->ntoa ( &undi_get_information->CurrentNodeAddress ));
	undi_get_information->Status = PXENV_STATUS_SUCCESS;
	return PXENV_EXIT_SUCCESS;
}

/* PXENV_UNDI_GET_STATISTICS
 *
 * Status: working
 */
PXENV_EXIT_t pxenv_undi_get_statistics ( struct s_PXENV_UNDI_GET_STATISTICS
					 *undi_get_statistics ) {
	DBG ( "PXENV_UNDI_GET_STATISTICS" );

	undi_get_statistics->XmtGoodFrames = pxe_netdev->tx_stats.good;
	undi_get_statistics->RcvGoodFrames = pxe_netdev->rx_stats.good;
	undi_get_statistics->RcvCRCErrors = pxe_netdev->rx_stats.bad;
	undi_get_statistics->RcvResourceErrors = pxe_netdev->rx_stats.bad;

	DBG ( " txok %d rxok %d rxcrc %d rxrsrc %d\n",
	      undi_get_statistics->XmtGoodFrames,
	      undi_get_statistics->RcvGoodFrames,
	      undi_get_statistics->RcvCRCErrors,
	      undi_get_statistics->RcvResourceErrors );
	undi_get_statistics->Status = PXENV_STATUS_SUCCESS;
	return PXENV_EXIT_SUCCESS;
}

/* PXENV_UNDI_CLEAR_STATISTICS
 *
 * Status: working
 */
PXENV_EXIT_t pxenv_undi_clear_statistics ( struct s_PXENV_UNDI_CLEAR_STATISTICS
					   *undi_clear_statistics ) {
	DBG ( "PXENV_UNDI_CLEAR_STATISTICS\n" );

	memset ( &pxe_netdev->tx_stats, 0, sizeof ( pxe_netdev->tx_stats ) );
	memset ( &pxe_netdev->rx_stats, 0, sizeof ( pxe_netdev->rx_stats ) );

	undi_clear_statistics->Status = PXENV_STATUS_SUCCESS;
	return PXENV_EXIT_SUCCESS;
}

/* PXENV_UNDI_INITIATE_DIAGS
 *
 * Status: won't implement (would require driver API changes for no
 * real benefit)
 */
PXENV_EXIT_t pxenv_undi_initiate_diags ( struct s_PXENV_UNDI_INITIATE_DIAGS
					 *undi_initiate_diags ) {
	DBG ( "PXENV_UNDI_INITIATE_DIAGS failed: unsupported\n" );

	undi_initiate_diags->Status = PXENV_STATUS_UNSUPPORTED;
	return PXENV_EXIT_FAILURE;
}

/* PXENV_UNDI_FORCE_INTERRUPT
 *
 * Status: won't implement (would require driver API changes for no
 * perceptible benefit)
 */
PXENV_EXIT_t pxenv_undi_force_interrupt ( struct s_PXENV_UNDI_FORCE_INTERRUPT
					  *undi_force_interrupt ) {
	DBG ( "PXENV_UNDI_FORCE_INTERRUPT failed: unsupported\n" );

	undi_force_interrupt->Status = PXENV_STATUS_UNSUPPORTED;
	return PXENV_EXIT_FAILURE;
}

/* PXENV_UNDI_GET_MCAST_ADDRESS
 *
 * Status: working
 */
PXENV_EXIT_t
pxenv_undi_get_mcast_address ( struct s_PXENV_UNDI_GET_MCAST_ADDRESS
			       *undi_get_mcast_address ) {
	struct ll_protocol *ll_protocol = pxe_netdev->ll_protocol;
	struct in_addr ip = { .s_addr = undi_get_mcast_address->InetAddr };
	int rc;

	DBG ( "PXENV_UNDI_GET_MCAST_ADDRESS %s", inet_ntoa ( ip ) );

	if ( ( rc = ll_protocol->mc_hash ( AF_INET, &ip,
				      undi_get_mcast_address->MediaAddr ))!=0){
		DBG ( " failed: %s\n", strerror ( rc ) );
		undi_get_mcast_address->Status = PXENV_STATUS ( rc );
		return PXENV_EXIT_FAILURE;
	}
	DBG ( "=>%s\n",
	      ll_protocol->ntoa ( undi_get_mcast_address->MediaAddr ) );

	undi_get_mcast_address->Status = PXENV_STATUS_SUCCESS;
	return PXENV_EXIT_SUCCESS;
}

/* PXENV_UNDI_GET_NIC_TYPE
 *
 * Status: working
 */
PXENV_EXIT_t pxenv_undi_get_nic_type ( struct s_PXENV_UNDI_GET_NIC_TYPE
				       *undi_get_nic_type ) {
	struct device *dev = pxe_netdev->dev;

	DBG ( "PXENV_UNDI_GET_NIC_TYPE" );

	memset ( &undi_get_nic_type->info, 0,
		 sizeof ( undi_get_nic_type->info ) );

	switch ( dev->desc.bus_type ) {
	case BUS_TYPE_PCI: {
		struct pci_nic_info *info = &undi_get_nic_type->info.pci;

		undi_get_nic_type->NicType = PCI_NIC;
		info->Vendor_ID = dev->desc.vendor;
		info->Dev_ID = dev->desc.device;
		info->Base_Class = PCI_BASE_CLASS ( dev->desc.class );
		info->Sub_Class = PCI_SUB_CLASS ( dev->desc.class );
		info->Prog_Intf = PCI_PROG_INTF ( dev->desc.class );
		info->BusDevFunc = dev->desc.location;
		/* Cheat: remaining fields are probably unnecessary,
		 * and would require adding extra code to pci.c.
		 */
		undi_get_nic_type->info.pci.SubVendor_ID = 0xffff;
		undi_get_nic_type->info.pci.SubDevice_ID = 0xffff;
		DBG ( " PCI %02x:%02x.%x %04x:%04x (%04x:%04x) %02x%02x%02x "
		      "rev %02x\n", PCI_BUS ( info->BusDevFunc ),
		      PCI_SLOT ( info->BusDevFunc ),
		      PCI_FUNC ( info->BusDevFunc ), info->Vendor_ID,
		      info->Dev_ID, info->SubVendor_ID, info->SubDevice_ID,
		      info->Base_Class, info->Sub_Class, info->Prog_Intf,
		      info->Rev );
		break; }
	case BUS_TYPE_ISAPNP: {
		struct pnp_nic_info *info = &undi_get_nic_type->info.pnp;

		undi_get_nic_type->NicType = PnP_NIC;
		info->EISA_Dev_ID = ( ( dev->desc.vendor << 16 ) |
				      dev->desc.device );
		info->CardSelNum = dev->desc.location;
		/* Cheat: remaining fields are probably unnecessary,
		 * and would require adding extra code to isapnp.c.
		 */
		DBG ( " ISAPnP CSN %04x %08x %02x%02x%02x\n",
		      info->CardSelNum, info->EISA_Dev_ID,
		      info->Base_Class, info->Sub_Class, info->Prog_Intf );
		break; }
	default:
		DBG ( " failed: unknown bus type\n" );
		undi_get_nic_type->Status = PXENV_STATUS_FAILURE;
		return PXENV_EXIT_FAILURE;
	}

	undi_get_nic_type->Status = PXENV_STATUS_SUCCESS;
	return PXENV_EXIT_SUCCESS;
}

/* PXENV_UNDI_GET_IFACE_INFO
 *
 * Status: working
 */
PXENV_EXIT_t pxenv_undi_get_iface_info ( struct s_PXENV_UNDI_GET_IFACE_INFO
					 *undi_get_iface_info ) {
	DBG ( "PXENV_UNDI_GET_IFACE_INFO" );

	/* Just hand back some info, doesn't really matter what it is.
	 * Most PXE stacks seem to take this approach.
	 */
	snprintf ( ( char * ) undi_get_iface_info->IfaceType,
		   sizeof ( undi_get_iface_info->IfaceType ), "DIX+802.3" );
	undi_get_iface_info->LinkSpeed = 10000000; /* 10 Mbps */
	undi_get_iface_info->ServiceFlags =
		( SUPPORTED_BROADCAST | SUPPORTED_MULTICAST |
		  SUPPORTED_SET_STATION_ADDRESS | SUPPORTED_RESET |
		  SUPPORTED_OPEN_CLOSE | SUPPORTED_IRQ );
	memset ( undi_get_iface_info->Reserved, 0,
		 sizeof(undi_get_iface_info->Reserved) );

	DBG ( " %s %dbps flags %08x\n", undi_get_iface_info->IfaceType,
	      undi_get_iface_info->LinkSpeed,
	      undi_get_iface_info->ServiceFlags );
	undi_get_iface_info->Status = PXENV_STATUS_SUCCESS;
	return PXENV_EXIT_SUCCESS;
}

/* PXENV_UNDI_GET_STATE
 *
 * Status: impossible
 */
PXENV_EXIT_t pxenv_undi_get_state ( struct s_PXENV_UNDI_GET_STATE
				    *undi_get_state ) {
	DBG ( "PXENV_UNDI_GET_STATE failed: unsupported\n" );

	undi_get_state->Status = PXENV_STATUS_UNSUPPORTED;
	return PXENV_EXIT_FAILURE;
};

/* PXENV_UNDI_ISR
 *
 * Status: working
 */
PXENV_EXIT_t pxenv_undi_isr ( struct s_PXENV_UNDI_ISR *undi_isr ) {
	struct io_buffer *iobuf;
	size_t len;
	struct ll_protocol *ll_protocol;
	const void *ll_dest;
	const void *ll_source;
	uint16_t net_proto;
	size_t ll_hlen;
	struct net_protocol *net_protocol;
	unsigned int prottype;
	int rc;

	/* Use coloured debug, since UNDI ISR messages are likely to
	 * be interspersed amongst other UNDI messages.
	 */
	DBGC2 ( &pxenv_undi_isr, "PXENV_UNDI_ISR" );

	/* Just in case some idiot actually looks at these fields when
	 * we weren't meant to fill them in...
	 */
	undi_isr->BufferLength = 0;
	undi_isr->FrameLength = 0;
	undi_isr->FrameHeaderLength = 0;
	undi_isr->ProtType = 0;
	undi_isr->PktType = 0;

	switch ( undi_isr->FuncFlag ) {
	case PXENV_UNDI_ISR_IN_START :
		DBGC2 ( &pxenv_undi_isr, " START" );

		/* Call poll().  This should acknowledge the device
		 * interrupt and queue up any received packet.
		 */
		netdev_poll ( pxe_netdev );

		/* A 100% accurate determination of "OURS" vs "NOT
		 * OURS" is difficult to achieve without invasive and
		 * unpleasant changes to the driver model.  We settle
		 * for always returning "OURS" if interrupts are
		 * currently enabled.
		 *
		 * Returning "NOT OURS" when interrupts are disabled
		 * allows us to avoid a potential interrupt storm when
		 * we are on a shared interrupt line; if we were to
		 * always return "OURS" then the other device's ISR
		 * may never be called.
		 */
		if ( netdev_irq_enabled ( pxe_netdev ) ) {
			DBGC2 ( &pxenv_undi_isr, " OURS" );
			undi_isr->FuncFlag = PXENV_UNDI_ISR_OUT_OURS;
		} else {
			DBGC2 ( &pxenv_undi_isr, " NOT OURS" );
			undi_isr->FuncFlag = PXENV_UNDI_ISR_OUT_NOT_OURS;
		}

		/* Disable interrupts */
		netdev_irq ( pxe_netdev, 0 );

		break;
	case PXENV_UNDI_ISR_IN_PROCESS :
	case PXENV_UNDI_ISR_IN_GET_NEXT :
		DBGC2 ( &pxenv_undi_isr, " %s",
			( ( undi_isr->FuncFlag == PXENV_UNDI_ISR_IN_PROCESS ) ?
			  "PROCESS" : "GET_NEXT" ) );

		/* Some dumb NBPs (e.g. emBoot's winBoot/i) never call
		 * PXENV_UNDI_ISR with FuncFlag=PXENV_UNDI_ISR_START;
		 * they just sit in a tight polling loop merrily
		 * violating the PXE spec with repeated calls to
		 * PXENV_UNDI_ISR_IN_PROCESS.  Force extra polls to
		 * cope with these out-of-spec clients.
		 */
		netdev_poll ( pxe_netdev );

		/* If we have not yet marked a TX as complete, and the
		 * netdev TX queue is empty, report the TX completion.
		 */
		if ( undi_tx_count && list_empty ( &pxe_netdev->tx_queue ) ) {
			DBGC2 ( &pxenv_undi_isr, " TXC" );
			undi_tx_count--;
			undi_isr->FuncFlag = PXENV_UNDI_ISR_OUT_TRANSMIT;
			break;
		}

		/* Remove first packet from netdev RX queue */
		iobuf = netdev_rx_dequeue ( pxe_netdev );
		if ( ! iobuf ) {
			DBGC2 ( &pxenv_undi_isr, " DONE" );
			/* No more packets remaining */
			undi_isr->FuncFlag = PXENV_UNDI_ISR_OUT_DONE;
			/* Re-enable interrupts */
			netdev_irq ( pxe_netdev, 1 );
			break;
		}

		/* Copy packet to base memory buffer */
		len = iob_len ( iobuf );
		DBGC2 ( &pxenv_undi_isr, " RX" );
		if ( len > sizeof ( basemem_packet ) ) {
			/* Should never happen */
			DBGC2 ( &pxenv_undi_isr, " overlength (%zx)", len );
			len = sizeof ( basemem_packet );
		}
		memcpy ( basemem_packet, iobuf->data, len );

		/* Strip link-layer header */
		ll_protocol = pxe_netdev->ll_protocol;
		if ( ( rc = ll_protocol->pull ( pxe_netdev, iobuf, &ll_dest,
						&ll_source, &net_proto )) !=0){
			/* Assume unknown net_proto and no ll_source */
			net_proto = 0;
			ll_source = NULL;
		}
		ll_hlen = ( len - iob_len ( iobuf ) );

		/* Determine network-layer protocol */
		switch ( net_proto ) {
		case htons ( ETH_P_IP ):
			net_protocol = &ipv4_protocol;
			prottype = P_IP;
			break;
		case htons ( ETH_P_ARP ):
			net_protocol = &arp_protocol;
			prottype = P_ARP;
			break;
		case htons ( ETH_P_RARP ):
			net_protocol = &rarp_protocol;
			prottype = P_RARP;
			break;
		default:
			net_protocol = NULL;
			prottype = P_UNKNOWN;
			break;
		}

		/* Fill in UNDI_ISR structure */
		undi_isr->FuncFlag = PXENV_UNDI_ISR_OUT_RECEIVE;
		undi_isr->BufferLength = len;
		undi_isr->FrameLength = len;
		undi_isr->FrameHeaderLength = ll_hlen;
		undi_isr->Frame.segment = rm_ds;
		undi_isr->Frame.offset = __from_data16 ( basemem_packet );
		undi_isr->ProtType = prottype;
		undi_isr->PktType = XMT_DESTADDR;
		DBGC2 ( &pxenv_undi_isr, " %04x:%04x+%x(%x) %s hlen %d",
			undi_isr->Frame.segment, undi_isr->Frame.offset,
			undi_isr->BufferLength, undi_isr->FrameLength,
			( net_protocol ? net_protocol->name : "RAW" ),
			undi_isr->FrameHeaderLength );

		/* Free packet */
		free_iob ( iobuf );
		break;
	default :
		DBGC2 ( &pxenv_undi_isr, " INVALID(%04x)\n",
			undi_isr->FuncFlag );

		/* Should never happen */
		undi_isr->FuncFlag = PXENV_UNDI_ISR_OUT_DONE;
		undi_isr->Status = PXENV_STATUS_UNDI_INVALID_PARAMETER;
		return PXENV_EXIT_FAILURE;
	}

	DBGC2 ( &pxenv_undi_isr, "\n" );
	undi_isr->Status = PXENV_STATUS_SUCCESS;
	return PXENV_EXIT_SUCCESS;
}