Add qemu 2.4.0

Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>

1 files changed, 1209 insertions, 0 deletions

diff --git a/qemu/roms/ipxe/src/interface/efi/efi_snp.c b/qemu/roms/ipxe/src/interface/efi/efi_snp.c
new file mode 100644
index 000000000..67fba342e
--- /dev/null
+++ b/qemu/roms/ipxe/src/interface/efi/efi_snp.c
@@ -0,0 +1,1209 @@
+/*
+ * Copyright (C) 2008 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <byteswap.h>
+#include <ipxe/netdevice.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/in.h>
+#include <ipxe/version.h>
+#include <ipxe/efi/efi.h>
+#include <ipxe/efi/efi_driver.h>
+#include <ipxe/efi/efi_strings.h>
+#include <ipxe/efi/efi_utils.h>
+#include <ipxe/efi/efi_snp.h>
+#include <usr/autoboot.h>
+
+/** List of SNP devices */
+static LIST_HEAD ( efi_snp_devices );
+
+/** Network devices are currently claimed for use by iPXE */
+static int efi_snp_claimed;
+
+/**
+ * Set EFI SNP mode state
+ *
+ * @v snp		SNP interface
+ */
+static void efi_snp_set_state ( struct efi_snp_device *snpdev ) {
+	struct net_device *netdev = snpdev->netdev;
+	EFI_SIMPLE_NETWORK_MODE *mode = &snpdev->mode;
+
+	/* Calculate state */
+	if ( ! snpdev->started ) {
+		/* Start() method not called; report as Stopped */
+		mode->State = EfiSimpleNetworkStopped;
+	} else if ( ! netdev_is_open ( netdev ) ) {
+		/* Network device not opened; report as Started */
+		mode->State = EfiSimpleNetworkStarted;
+	} else if ( efi_snp_claimed ) {
+		/* Network device opened but claimed for use by iPXE; report
+		 * as Started to inhibit receive polling.
+		 */
+		mode->State = EfiSimpleNetworkStarted;
+	} else {
+		/* Network device opened and available for use via SNP; report
+		 * as Initialized.
+		 */
+		mode->State = EfiSimpleNetworkInitialized;
+	}
+}
+
+/**
+ * Set EFI SNP mode based on iPXE net device parameters
+ *
+ * @v snp		SNP interface
+ */
+static void efi_snp_set_mode ( struct efi_snp_device *snpdev ) {
+	struct net_device *netdev = snpdev->netdev;
+	EFI_SIMPLE_NETWORK_MODE *mode = &snpdev->mode;
+	struct ll_protocol *ll_protocol = netdev->ll_protocol;
+	unsigned int ll_addr_len = ll_protocol->ll_addr_len;
+
+	mode->HwAddressSize = ll_addr_len;
+	mode->MediaHeaderSize = ll_protocol->ll_header_len;
+	mode->MaxPacketSize = netdev->max_pkt_len;
+	mode->ReceiveFilterMask = ( EFI_SIMPLE_NETWORK_RECEIVE_UNICAST |
+				    EFI_SIMPLE_NETWORK_RECEIVE_MULTICAST |
+				    EFI_SIMPLE_NETWORK_RECEIVE_BROADCAST );
+	assert ( ll_addr_len <= sizeof ( mode->CurrentAddress ) );
+	memcpy ( &mode->CurrentAddress, netdev->ll_addr, ll_addr_len );
+	memcpy ( &mode->BroadcastAddress, netdev->ll_broadcast, ll_addr_len );
+	ll_protocol->init_addr ( netdev->hw_addr, &mode->PermanentAddress );
+	mode->IfType = ntohs ( ll_protocol->ll_proto );
+	mode->MacAddressChangeable = TRUE;
+	mode->MediaPresentSupported = TRUE;
+	mode->MediaPresent = ( netdev_link_ok ( netdev ) ? TRUE : FALSE );
+}
+
+/**
+ * Poll net device and count received packets
+ *
+ * @v snpdev		SNP device
+ */
+static void efi_snp_poll ( struct efi_snp_device *snpdev ) {
+	struct io_buffer *iobuf;
+	unsigned int before = 0;
+	unsigned int after = 0;
+	unsigned int arrived;
+
+	/* We have to report packet arrivals, and this is the easiest
+	 * way to fake it.
+	 */
+	list_for_each_entry ( iobuf, &snpdev->netdev->rx_queue, list )
+		before++;
+	netdev_poll ( snpdev->netdev );
+	list_for_each_entry ( iobuf, &snpdev->netdev->rx_queue, list )
+		after++;
+	arrived = ( after - before );
+
+	snpdev->rx_count_interrupts += arrived;
+	snpdev->rx_count_events += arrived;
+}
+
+/**
+ * Change SNP state from "stopped" to "started"
+ *
+ * @v snp		SNP interface
+ * @ret efirc		EFI status code
+ */
+static EFI_STATUS EFIAPI
+efi_snp_start ( EFI_SIMPLE_NETWORK_PROTOCOL *snp ) {
+	struct efi_snp_device *snpdev =
+		container_of ( snp, struct efi_snp_device, snp );
+
+	DBGC2 ( snpdev, "SNPDEV %p START\n", snpdev );
+
+	/* Fail if net device is currently claimed for use by iPXE */
+	if ( efi_snp_claimed )
+		return EFI_NOT_READY;
+
+	snpdev->started = 1;
+	efi_snp_set_state ( snpdev );
+	return 0;
+}
+
+/**
+ * Change SNP state from "started" to "stopped"
+ *
+ * @v snp		SNP interface
+ * @ret efirc		EFI status code
+ */
+static EFI_STATUS EFIAPI
+efi_snp_stop ( EFI_SIMPLE_NETWORK_PROTOCOL *snp ) {
+	struct efi_snp_device *snpdev =
+		container_of ( snp, struct efi_snp_device, snp );
+
+	DBGC2 ( snpdev, "SNPDEV %p STOP\n", snpdev );
+
+	/* Fail if net device is currently claimed for use by iPXE */
+	if ( efi_snp_claimed )
+		return EFI_NOT_READY;
+
+	snpdev->started = 0;
+	efi_snp_set_state ( snpdev );
+	return 0;
+}
+
+/**
+ * Open the network device
+ *
+ * @v snp		SNP interface
+ * @v extra_rx_bufsize	Extra RX buffer size, in bytes
+ * @v extra_tx_bufsize	Extra TX buffer size, in bytes
+ * @ret efirc		EFI status code
+ */
+static EFI_STATUS EFIAPI
+efi_snp_initialize ( EFI_SIMPLE_NETWORK_PROTOCOL *snp,
+		     UINTN extra_rx_bufsize, UINTN extra_tx_bufsize ) {
+	struct efi_snp_device *snpdev =
+		container_of ( snp, struct efi_snp_device, snp );
+	int rc;
+
+	DBGC2 ( snpdev, "SNPDEV %p INITIALIZE (%ld extra RX, %ld extra TX)\n",
+		snpdev, ( ( unsigned long ) extra_rx_bufsize ),
+		( ( unsigned long ) extra_tx_bufsize ) );
+
+	/* Fail if net device is currently claimed for use by iPXE */
+	if ( efi_snp_claimed )
+		return EFI_NOT_READY;
+
+	if ( ( rc = netdev_open ( snpdev->netdev ) ) != 0 ) {
+		DBGC ( snpdev, "SNPDEV %p could not open %s: %s\n",
+		       snpdev, snpdev->netdev->name, strerror ( rc ) );
+		return EFIRC ( rc );
+	}
+	efi_snp_set_state ( snpdev );
+
+	return 0;
+}
+
+/**
+ * Reset the network device
+ *
+ * @v snp		SNP interface
+ * @v ext_verify	Extended verification required
+ * @ret efirc		EFI status code
+ */
+static EFI_STATUS EFIAPI
+efi_snp_reset ( EFI_SIMPLE_NETWORK_PROTOCOL *snp, BOOLEAN ext_verify ) {
+	struct efi_snp_device *snpdev =
+		container_of ( snp, struct efi_snp_device, snp );
+	int rc;
+
+	DBGC2 ( snpdev, "SNPDEV %p RESET (%s extended verification)\n",
+		snpdev, ( ext_verify ? "with" : "without" ) );
+
+	/* Fail if net device is currently claimed for use by iPXE */
+	if ( efi_snp_claimed )
+		return EFI_NOT_READY;
+
+	netdev_close ( snpdev->netdev );
+	efi_snp_set_state ( snpdev );
+
+	if ( ( rc = netdev_open ( snpdev->netdev ) ) != 0 ) {
+		DBGC ( snpdev, "SNPDEV %p could not reopen %s: %s\n",
+		       snpdev, snpdev->netdev->name, strerror ( rc ) );
+		return EFIRC ( rc );
+	}
+	efi_snp_set_state ( snpdev );
+
+	return 0;
+}
+
+/**
+ * Shut down the network device
+ *
+ * @v snp		SNP interface
+ * @ret efirc		EFI status code
+ */
+static EFI_STATUS EFIAPI
+efi_snp_shutdown ( EFI_SIMPLE_NETWORK_PROTOCOL *snp ) {
+	struct efi_snp_device *snpdev =
+		container_of ( snp, struct efi_snp_device, snp );
+
+	DBGC2 ( snpdev, "SNPDEV %p SHUTDOWN\n", snpdev );
+
+	/* Fail if net device is currently claimed for use by iPXE */
+	if ( efi_snp_claimed )
+		return EFI_NOT_READY;
+
+	netdev_close ( snpdev->netdev );
+	efi_snp_set_state ( snpdev );
+
+	return 0;
+}
+
+/**
+ * Manage receive filters
+ *
+ * @v snp		SNP interface
+ * @v enable		Receive filters to enable
+ * @v disable		Receive filters to disable
+ * @v mcast_reset	Reset multicast filters
+ * @v mcast_count	Number of multicast filters
+ * @v mcast		Multicast filters
+ * @ret efirc		EFI status code
+ */
+static EFI_STATUS EFIAPI
+efi_snp_receive_filters ( EFI_SIMPLE_NETWORK_PROTOCOL *snp, UINT32 enable,
+			  UINT32 disable, BOOLEAN mcast_reset,
+			  UINTN mcast_count, EFI_MAC_ADDRESS *mcast ) {
+	struct efi_snp_device *snpdev =
+		container_of ( snp, struct efi_snp_device, snp );
+	unsigned int i;
+
+	DBGC2 ( snpdev, "SNPDEV %p RECEIVE_FILTERS %08x&~%08x%s %ld mcast\n",
+		snpdev, enable, disable, ( mcast_reset ? " reset" : "" ),
+		( ( unsigned long ) mcast_count ) );
+	for ( i = 0 ; i < mcast_count ; i++ ) {
+		DBGC2_HDA ( snpdev, i, &mcast[i],
+			    snpdev->netdev->ll_protocol->ll_addr_len );
+	}
+
+	/* Fail if net device is currently claimed for use by iPXE */
+	if ( efi_snp_claimed )
+		return EFI_NOT_READY;
+
+	/* Lie through our teeth, otherwise MNP refuses to accept us */
+	return 0;
+}
+
+/**
+ * Set station address
+ *
+ * @v snp		SNP interface
+ * @v reset		Reset to permanent address
+ * @v new		New station address
+ * @ret efirc		EFI status code
+ */
+static EFI_STATUS EFIAPI
+efi_snp_station_address ( EFI_SIMPLE_NETWORK_PROTOCOL *snp, BOOLEAN reset,
+			  EFI_MAC_ADDRESS *new ) {
+	struct efi_snp_device *snpdev =
+		container_of ( snp, struct efi_snp_device, snp );
+	struct ll_protocol *ll_protocol = snpdev->netdev->ll_protocol;
+
+	DBGC2 ( snpdev, "SNPDEV %p STATION_ADDRESS %s\n", snpdev,
+		( reset ? "reset" : ll_protocol->ntoa ( new ) ) );
+
+	/* Fail if net device is currently claimed for use by iPXE */
+	if ( efi_snp_claimed )
+		return EFI_NOT_READY;
+
+	/* Set the MAC address */
+	if ( reset )
+		new = &snpdev->mode.PermanentAddress;
+	memcpy ( snpdev->netdev->ll_addr, new, ll_protocol->ll_addr_len );
+
+	/* MAC address changes take effect only on netdev_open() */
+	if ( netdev_is_open ( snpdev->netdev ) ) {
+		DBGC ( snpdev, "SNPDEV %p MAC address changed while net "
+		       "device open\n", snpdev );
+	}
+
+	return 0;
+}
+
+/**
+ * Get (or reset) statistics
+ *
+ * @v snp		SNP interface
+ * @v reset		Reset statistics
+ * @v stats_len		Size of statistics table
+ * @v stats		Statistics table
+ * @ret efirc		EFI status code
+ */
+static EFI_STATUS EFIAPI
+efi_snp_statistics ( EFI_SIMPLE_NETWORK_PROTOCOL *snp, BOOLEAN reset,
+		     UINTN *stats_len, EFI_NETWORK_STATISTICS *stats ) {
+	struct efi_snp_device *snpdev =
+		container_of ( snp, struct efi_snp_device, snp );
+	EFI_NETWORK_STATISTICS stats_buf;
+
+	DBGC2 ( snpdev, "SNPDEV %p STATISTICS%s", snpdev,
+		( reset ? " reset" : "" ) );
+
+	/* Fail if net device is currently claimed for use by iPXE */
+	if ( efi_snp_claimed )
+		return EFI_NOT_READY;
+
+	/* Gather statistics */
+	memset ( &stats_buf, 0, sizeof ( stats_buf ) );
+	stats_buf.TxGoodFrames = snpdev->netdev->tx_stats.good;
+	stats_buf.TxDroppedFrames = snpdev->netdev->tx_stats.bad;
+	stats_buf.TxTotalFrames = ( snpdev->netdev->tx_stats.good +
+				    snpdev->netdev->tx_stats.bad );
+	stats_buf.RxGoodFrames = snpdev->netdev->rx_stats.good;
+	stats_buf.RxDroppedFrames = snpdev->netdev->rx_stats.bad;
+	stats_buf.RxTotalFrames = ( snpdev->netdev->rx_stats.good +
+				    snpdev->netdev->rx_stats.bad );
+	if ( *stats_len > sizeof ( stats_buf ) )
+		*stats_len = sizeof ( stats_buf );
+	if ( stats )
+		memcpy ( stats, &stats_buf, *stats_len );
+
+	/* Reset statistics if requested to do so */
+	if ( reset ) {
+		memset ( &snpdev->netdev->tx_stats, 0,
+			 sizeof ( snpdev->netdev->tx_stats ) );
+		memset ( &snpdev->netdev->rx_stats, 0,
+			 sizeof ( snpdev->netdev->rx_stats ) );
+	}
+
+	return 0;
+}
+
+/**
+ * Convert multicast IP address to MAC address
+ *
+ * @v snp		SNP interface
+ * @v ipv6		Address is IPv6
+ * @v ip		IP address
+ * @v mac		MAC address
+ * @ret efirc		EFI status code
+ */
+static EFI_STATUS EFIAPI
+efi_snp_mcast_ip_to_mac ( EFI_SIMPLE_NETWORK_PROTOCOL *snp, BOOLEAN ipv6,
+			  EFI_IP_ADDRESS *ip, EFI_MAC_ADDRESS *mac ) {
+	struct efi_snp_device *snpdev =
+		container_of ( snp, struct efi_snp_device, snp );
+	struct ll_protocol *ll_protocol = snpdev->netdev->ll_protocol;
+	const char *ip_str;
+	int rc;
+
+	ip_str = ( ipv6 ? "(IPv6)" /* FIXME when we have inet6_ntoa() */ :
+		   inet_ntoa ( *( ( struct in_addr * ) ip ) ) );
+	DBGC2 ( snpdev, "SNPDEV %p MCAST_IP_TO_MAC %s\n", snpdev, ip_str );
+
+	/* Fail if net device is currently claimed for use by iPXE */
+	if ( efi_snp_claimed )
+		return EFI_NOT_READY;
+
+	/* Try to hash the address */
+	if ( ( rc = ll_protocol->mc_hash ( ( ipv6 ? AF_INET6 : AF_INET ),
+					   ip, mac ) ) != 0 ) {
+		DBGC ( snpdev, "SNPDEV %p could not hash %s: %s\n",
+		       snpdev, ip_str, strerror ( rc ) );
+		return EFIRC ( rc );
+	}
+
+	return 0;
+}
+
+/**
+ * Read or write non-volatile storage
+ *
+ * @v snp		SNP interface
+ * @v read		Operation is a read
+ * @v offset		Starting offset within NVRAM
+ * @v len		Length of data buffer
+ * @v data		Data buffer
+ * @ret efirc		EFI status code
+ */
+static EFI_STATUS EFIAPI
+efi_snp_nvdata ( EFI_SIMPLE_NETWORK_PROTOCOL *snp, BOOLEAN read,
+		 UINTN offset, UINTN len, VOID *data ) {
+	struct efi_snp_device *snpdev =
+		container_of ( snp, struct efi_snp_device, snp );
+
+	DBGC2 ( snpdev, "SNPDEV %p NVDATA %s %lx+%lx\n", snpdev,
+		( read ? "read" : "write" ), ( ( unsigned long ) offset ),
+		( ( unsigned long ) len ) );
+	if ( ! read )
+		DBGC2_HDA ( snpdev, offset, data, len );
+
+	/* Fail if net device is currently claimed for use by iPXE */
+	if ( efi_snp_claimed )
+		return EFI_NOT_READY;
+
+	return EFI_UNSUPPORTED;
+}
+
+/**
+ * Read interrupt status and TX recycled buffer status
+ *
+ * @v snp		SNP interface
+ * @v interrupts	Interrupt status, or NULL
+ * @v txbufs		Recycled transmit buffer address, or NULL
+ * @ret efirc		EFI status code
+ */
+static EFI_STATUS EFIAPI
+efi_snp_get_status ( EFI_SIMPLE_NETWORK_PROTOCOL *snp,
+		     UINT32 *interrupts, VOID **txbufs ) {
+	struct efi_snp_device *snpdev =
+		container_of ( snp, struct efi_snp_device, snp );
+
+	DBGC2 ( snpdev, "SNPDEV %p GET_STATUS", snpdev );
+
+	/* Fail if net device is currently claimed for use by iPXE */
+	if ( efi_snp_claimed )
+		return EFI_NOT_READY;
+
+	/* Poll the network device */
+	efi_snp_poll ( snpdev );
+
+	/* Interrupt status.  In practice, this seems to be used only
+	 * to detect TX completions.
+	 */
+	if ( interrupts ) {
+		*interrupts = 0;
+		/* Report TX completions once queue is empty; this
+		 * avoids having to add hooks in the net device layer.
+		 */
+		if ( snpdev->tx_count_interrupts &&
+		     list_empty ( &snpdev->netdev->tx_queue ) ) {
+			*interrupts |= EFI_SIMPLE_NETWORK_TRANSMIT_INTERRUPT;
+			snpdev->tx_count_interrupts--;
+		}
+		/* Report RX */
+		if ( snpdev->rx_count_interrupts ) {
+			*interrupts |= EFI_SIMPLE_NETWORK_RECEIVE_INTERRUPT;
+			snpdev->rx_count_interrupts--;
+		}
+		DBGC2 ( snpdev, " INTS:%02x", *interrupts );
+	}
+
+	/* TX completions.  It would be possible to design a more
+	 * idiotic scheme for this, but it would be a challenge.
+	 * According to the UEFI header file, txbufs will be filled in
+	 * with a list of "recycled transmit buffers" (i.e. completed
+	 * TX buffers).  Observant readers may care to note that
+	 * *txbufs is a void pointer.  Precisely how a list of
+	 * completed transmit buffers is meant to be represented as an
+	 * array of voids is left as an exercise for the reader.
+	 *
+	 * The only users of this interface (MnpDxe/MnpIo.c and
+	 * PxeBcDxe/Bc.c within the EFI dev kit) both just poll until
+	 * seeing a non-NULL result return in txbufs.  This is valid
+	 * provided that they do not ever attempt to transmit more
+	 * than one packet concurrently (and that TX never times out).
+	 */
+	if ( txbufs ) {
+		if ( snpdev->tx_count_txbufs &&
+		     list_empty ( &snpdev->netdev->tx_queue ) ) {
+			*txbufs = "Which idiot designed this API?";
+			snpdev->tx_count_txbufs--;
+		} else {
+			*txbufs = NULL;
+		}
+		DBGC2 ( snpdev, " TX:%s", ( *txbufs ? "some" : "none" ) );
+	}
+
+	DBGC2 ( snpdev, "\n" );
+	return 0;
+}
+
+/**
+ * Start packet transmission
+ *
+ * @v snp		SNP interface
+ * @v ll_header_len	Link-layer header length, if to be filled in
+ * @v len		Length of data buffer
+ * @v data		Data buffer
+ * @v ll_src		Link-layer source address, if specified
+ * @v ll_dest		Link-layer destination address, if specified
+ * @v net_proto		Network-layer protocol (in host order)
+ * @ret efirc		EFI status code
+ */
+static EFI_STATUS EFIAPI
+efi_snp_transmit ( EFI_SIMPLE_NETWORK_PROTOCOL *snp,
+		   UINTN ll_header_len, UINTN len, VOID *data,
+		   EFI_MAC_ADDRESS *ll_src, EFI_MAC_ADDRESS *ll_dest,
+		   UINT16 *net_proto ) {
+	struct efi_snp_device *snpdev =
+		container_of ( snp, struct efi_snp_device, snp );
+	struct ll_protocol *ll_protocol = snpdev->netdev->ll_protocol;
+	struct io_buffer *iobuf;
+	size_t payload_len;
+	int rc;
+
+	DBGC2 ( snpdev, "SNPDEV %p TRANSMIT %p+%lx", snpdev, data,
+		( ( unsigned long ) len ) );
+	if ( ll_header_len ) {
+		if ( ll_src ) {
+			DBGC2 ( snpdev, " src %s",
+				ll_protocol->ntoa ( ll_src ) );
+		}
+		if ( ll_dest ) {
+			DBGC2 ( snpdev, " dest %s",
+				ll_protocol->ntoa ( ll_dest ) );
+		}
+		if ( net_proto ) {
+			DBGC2 ( snpdev, " proto %04x", *net_proto );
+		}
+	}
+	DBGC2 ( snpdev, "\n" );
+
+	/* Fail if net device is currently claimed for use by iPXE */
+	if ( efi_snp_claimed )
+		return EFI_NOT_READY;
+
+	/* Sanity checks */
+	if ( ll_header_len ) {
+		if ( ll_header_len != ll_protocol->ll_header_len ) {
+			DBGC ( snpdev, "SNPDEV %p TX invalid header length "
+			       "%ld\n", snpdev,
+			       ( ( unsigned long ) ll_header_len ) );
+			rc = -EINVAL;
+			goto err_sanity;
+		}
+		if ( len < ll_header_len ) {
+			DBGC ( snpdev, "SNPDEV %p invalid packet length %ld\n",
+			       snpdev, ( ( unsigned long ) len ) );
+			rc = -EINVAL;
+			goto err_sanity;
+		}
+		if ( ! ll_dest ) {
+			DBGC ( snpdev, "SNPDEV %p TX missing destination "
+			       "address\n", snpdev );
+			rc = -EINVAL;
+			goto err_sanity;
+		}
+		if ( ! net_proto ) {
+			DBGC ( snpdev, "SNPDEV %p TX missing network "
+			       "protocol\n", snpdev );
+			rc = -EINVAL;
+			goto err_sanity;
+		}
+		if ( ! ll_src )
+			ll_src = &snpdev->mode.CurrentAddress;
+	}
+
+	/* Allocate buffer */
+	payload_len = ( len - ll_protocol->ll_header_len );
+	iobuf = alloc_iob ( MAX_LL_HEADER_LEN + ( ( payload_len > IOB_ZLEN ) ?
+						  payload_len : IOB_ZLEN ) );
+	if ( ! iobuf ) {
+		DBGC ( snpdev, "SNPDEV %p TX could not allocate %ld-byte "
+		       "buffer\n", snpdev, ( ( unsigned long ) len ) );
+		rc = -ENOMEM;
+		goto err_alloc_iob;
+	}
+	iob_reserve ( iobuf, ( MAX_LL_HEADER_LEN -
+			       ll_protocol->ll_header_len ) );
+	memcpy ( iob_put ( iobuf, len ), data, len );
+
+	/* Create link-layer header, if specified */
+	if ( ll_header_len ) {
+		iob_pull ( iobuf, ll_protocol->ll_header_len );
+		if ( ( rc = ll_protocol->push ( snpdev->netdev,
+						iobuf, ll_dest, ll_src,
+						htons ( *net_proto ) )) != 0 ){
+			DBGC ( snpdev, "SNPDEV %p TX could not construct "
+			       "header: %s\n", snpdev, strerror ( rc ) );
+			goto err_ll_push;
+		}
+	}
+
+	/* Transmit packet */
+	if ( ( rc = netdev_tx ( snpdev->netdev, iob_disown ( iobuf ) ) ) != 0){
+		DBGC ( snpdev, "SNPDEV %p TX could not transmit: %s\n",
+		       snpdev, strerror ( rc ) );
+		goto err_tx;
+	}
+
+	/* Record transmission as outstanding */
+	snpdev->tx_count_interrupts++;
+	snpdev->tx_count_txbufs++;
+
+	return 0;
+
+ err_tx:
+ err_ll_push:
+	free_iob ( iobuf );
+ err_alloc_iob:
+ err_sanity:
+	return EFIRC ( rc );
+}
+
+/**
+ * Receive packet
+ *
+ * @v snp		SNP interface
+ * @v ll_header_len	Link-layer header length, if to be filled in
+ * @v len		Length of data buffer
+ * @v data		Data buffer
+ * @v ll_src		Link-layer source address, if specified
+ * @v ll_dest		Link-layer destination address, if specified
+ * @v net_proto		Network-layer protocol (in host order)
+ * @ret efirc		EFI status code
+ */
+static EFI_STATUS EFIAPI
+efi_snp_receive ( EFI_SIMPLE_NETWORK_PROTOCOL *snp,
+		  UINTN *ll_header_len, UINTN *len, VOID *data,
+		  EFI_MAC_ADDRESS *ll_src, EFI_MAC_ADDRESS *ll_dest,
+		  UINT16 *net_proto ) {
+	struct efi_snp_device *snpdev =
+		container_of ( snp, struct efi_snp_device, snp );
+	struct ll_protocol *ll_protocol = snpdev->netdev->ll_protocol;
+	struct io_buffer *iobuf;
+	const void *iob_ll_dest;
+	const void *iob_ll_src;
+	uint16_t iob_net_proto;
+	unsigned int iob_flags;
+	int rc;
+
+	DBGC2 ( snpdev, "SNPDEV %p RECEIVE %p(+%lx)", snpdev, data,
+		( ( unsigned long ) *len ) );
+
+	/* Fail if net device is currently claimed for use by iPXE */
+	if ( efi_snp_claimed )
+		return EFI_NOT_READY;
+
+	/* Poll the network device */
+	efi_snp_poll ( snpdev );
+
+	/* Dequeue a packet, if one is available */
+	iobuf = netdev_rx_dequeue ( snpdev->netdev );
+	if ( ! iobuf ) {
+		DBGC2 ( snpdev, "\n" );
+		rc = -EAGAIN;
+		goto out_no_packet;
+	}
+	DBGC2 ( snpdev, "+%zx\n", iob_len ( iobuf ) );
+
+	/* Return packet to caller */
+	memcpy ( data, iobuf->data, iob_len ( iobuf ) );
+	*len = iob_len ( iobuf );
+
+	/* Attempt to decode link-layer header */
+	if ( ( rc = ll_protocol->pull ( snpdev->netdev, iobuf, &iob_ll_dest,
+					&iob_ll_src, &iob_net_proto,
+					&iob_flags ) ) != 0 ) {
+		DBGC ( snpdev, "SNPDEV %p could not parse header: %s\n",
+		       snpdev, strerror ( rc ) );
+		goto out_bad_ll_header;
+	}
+
+	/* Return link-layer header parameters to caller, if required */
+	if ( ll_header_len )
+		*ll_header_len = ll_protocol->ll_header_len;
+	if ( ll_src )
+		memcpy ( ll_src, iob_ll_src, ll_protocol->ll_addr_len );
+	if ( ll_dest )
+		memcpy ( ll_dest, iob_ll_dest, ll_protocol->ll_addr_len );
+	if ( net_proto )
+		*net_proto = ntohs ( iob_net_proto );
+
+	rc = 0;
+
+ out_bad_ll_header:
+	free_iob ( iobuf );
+ out_no_packet:
+	return EFIRC ( rc );
+}
+
+/**
+ * Poll event
+ *
+ * @v event		Event
+ * @v context		Event context
+ */
+static VOID EFIAPI efi_snp_wait_for_packet ( EFI_EVENT event,
+					     VOID *context ) {
+	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
+	struct efi_snp_device *snpdev = context;
+
+	DBGCP ( snpdev, "SNPDEV %p WAIT_FOR_PACKET\n", snpdev );
+
+	/* Do nothing unless the net device is open */
+	if ( ! netdev_is_open ( snpdev->netdev ) )
+		return;
+
+	/* Do nothing if net device is currently claimed for use by iPXE */
+	if ( efi_snp_claimed )
+		return;
+
+	/* Poll the network device */
+	efi_snp_poll ( snpdev );
+
+	/* Fire event if packets have been received */
+	if ( snpdev->rx_count_events != 0 ) {
+		DBGC2 ( snpdev, "SNPDEV %p firing WaitForPacket event\n",
+			snpdev );
+		bs->SignalEvent ( event );
+		snpdev->rx_count_events--;
+	}
+}
+
+/** SNP interface */
+static EFI_SIMPLE_NETWORK_PROTOCOL efi_snp_device_snp = {
+	.Revision	= EFI_SIMPLE_NETWORK_PROTOCOL_REVISION,
+	.Start		= efi_snp_start,
+	.Stop		= efi_snp_stop,
+	.Initialize	= efi_snp_initialize,
+	.Reset		= efi_snp_reset,
+	.Shutdown	= efi_snp_shutdown,
+	.ReceiveFilters	= efi_snp_receive_filters,
+	.StationAddress	= efi_snp_station_address,
+	.Statistics	= efi_snp_statistics,
+	.MCastIpToMac	= efi_snp_mcast_ip_to_mac,
+	.NvData		= efi_snp_nvdata,
+	.GetStatus	= efi_snp_get_status,
+	.Transmit	= efi_snp_transmit,
+	.Receive	= efi_snp_receive,
+};
+
+/******************************************************************************
+ *
+ * Component name protocol
+ *
+ ******************************************************************************
+ */
+
+/**
+ * Look up driver name
+ *
+ * @v name2		Component name protocol
+ * @v language		Language to use
+ * @v driver_name	Driver name to fill in
+ * @ret efirc		EFI status code
+ */
+static EFI_STATUS EFIAPI
+efi_snp_get_driver_name ( EFI_COMPONENT_NAME2_PROTOCOL *name2,
+			  CHAR8 *language __unused, CHAR16 **driver_name ) {
+	struct efi_snp_device *snpdev =
+		container_of ( name2, struct efi_snp_device, name2 );
+
+	*driver_name = snpdev->driver_name;
+	return 0;
+}
+
+/**
+ * Look up controller name
+ *
+ * @v name2     		Component name protocol
+ * @v device		Device
+ * @v child		Child device, or NULL
+ * @v language		Language to use
+ * @v driver_name	Device name to fill in
+ * @ret efirc		EFI status code
+ */
+static EFI_STATUS EFIAPI
+efi_snp_get_controller_name ( EFI_COMPONENT_NAME2_PROTOCOL *name2,
+			      EFI_HANDLE device __unused,
+			      EFI_HANDLE child __unused,
+			      CHAR8 *language __unused,
+			      CHAR16 **controller_name ) {
+	struct efi_snp_device *snpdev =
+		container_of ( name2, struct efi_snp_device, name2 );
+
+	*controller_name = snpdev->controller_name;
+	return 0;
+}
+
+/******************************************************************************
+ *
+ * Load file protocol
+ *
+ ******************************************************************************
+ */
+
+/**
+ * Load file
+ *
+ * @v loadfile		Load file protocol
+ * @v path		File path
+ * @v booting		Loading as part of a boot attempt
+ * @ret efirc		EFI status code
+ */
+static EFI_STATUS EFIAPI
+efi_snp_load_file ( EFI_LOAD_FILE_PROTOCOL *load_file,
+		    EFI_DEVICE_PATH_PROTOCOL *path __unused,
+		    BOOLEAN booting, UINTN *len __unused,
+		    VOID *data __unused ) {
+	struct efi_snp_device *snpdev =
+		container_of ( load_file, struct efi_snp_device, load_file );
+	struct net_device *netdev = snpdev->netdev;
+
+	/* Fail unless this is a boot attempt */
+	if ( ! booting ) {
+		DBGC ( snpdev, "SNPDEV %p cannot load non-boot file\n",
+		       snpdev );
+		return EFI_UNSUPPORTED;
+	}
+
+	/* Claim network devices for use by iPXE */
+	efi_snp_claim();
+
+	/* Boot from network device */
+	ipxe ( netdev );
+
+	/* Release network devices for use via SNP */
+	efi_snp_release();
+
+	/* Assume boot process was aborted */
+	return EFI_ABORTED;
+}
+
+/** Load file protocol */
+static EFI_LOAD_FILE_PROTOCOL efi_snp_load_file_protocol = {
+	.LoadFile	= efi_snp_load_file,
+};
+
+/******************************************************************************
+ *
+ * iPXE network driver
+ *
+ ******************************************************************************
+ */
+
+/**
+ * Locate SNP device corresponding to network device
+ *
+ * @v netdev		Network device
+ * @ret snp		SNP device, or NULL if not found
+ */
+static struct efi_snp_device * efi_snp_demux ( struct net_device *netdev ) {
+	struct efi_snp_device *snpdev;
+
+	list_for_each_entry ( snpdev, &efi_snp_devices, list ) {
+		if ( snpdev->netdev == netdev )
+			return snpdev;
+	}
+	return NULL;
+}
+
+/**
+ * Create SNP device
+ *
+ * @v netdev		Network device
+ * @ret rc		Return status code
+ */
+static int efi_snp_probe ( struct net_device *netdev ) {
+	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
+	struct efi_device *efidev;
+	struct efi_snp_device *snpdev;
+	union {
+		EFI_DEVICE_PATH_PROTOCOL *path;
+		void *interface;
+	} path;
+	EFI_DEVICE_PATH_PROTOCOL *path_end;
+	MAC_ADDR_DEVICE_PATH *macpath;
+	size_t path_prefix_len = 0;
+	EFI_STATUS efirc;
+	int rc;
+
+	/* Find parent EFI device */
+	efidev = efidev_parent ( netdev->dev );
+	if ( ! efidev ) {
+		DBG ( "SNP skipping non-EFI device %s\n", netdev->name );
+		rc = 0;
+		goto err_no_efidev;
+	}
+
+	/* Allocate the SNP device */
+	snpdev = zalloc ( sizeof ( *snpdev ) );
+	if ( ! snpdev ) {
+		rc = -ENOMEM;
+		goto err_alloc_snp;
+	}
+	snpdev->netdev = netdev_get ( netdev );
+	snpdev->efidev = efidev;
+
+	/* Sanity check */
+	if ( netdev->ll_protocol->ll_addr_len > sizeof ( EFI_MAC_ADDRESS ) ) {
+		DBGC ( snpdev, "SNPDEV %p cannot support link-layer address "
+		       "length %d for %s\n", snpdev,
+		       netdev->ll_protocol->ll_addr_len, netdev->name );
+		rc = -ENOTSUP;
+		goto err_ll_addr_len;
+	}
+
+	/* Populate the SNP structure */
+	memcpy ( &snpdev->snp, &efi_snp_device_snp, sizeof ( snpdev->snp ) );
+	snpdev->snp.Mode = &snpdev->mode;
+	if ( ( efirc = bs->CreateEvent ( EVT_NOTIFY_WAIT, TPL_NOTIFY,
+					 efi_snp_wait_for_packet, snpdev,
+					 &snpdev->snp.WaitForPacket ) ) != 0 ){
+		rc = -EEFI ( efirc );
+		DBGC ( snpdev, "SNPDEV %p could not create event: %s\n",
+		       snpdev, strerror ( rc ) );
+		goto err_create_event;
+	}
+
+	/* Populate the SNP mode structure */
+	snpdev->mode.State = EfiSimpleNetworkStopped;
+	efi_snp_set_mode ( snpdev );
+
+	/* Populate the NII structure */
+	snpdev->nii.Revision =
+		EFI_NETWORK_INTERFACE_IDENTIFIER_PROTOCOL_REVISION;
+	strncpy ( snpdev->nii.StringId, "iPXE",
+		  sizeof ( snpdev->nii.StringId ) );
+
+	/* Populate the component name structure */
+	efi_snprintf ( snpdev->driver_name,
+		       ( sizeof ( snpdev->driver_name ) /
+			 sizeof ( snpdev->driver_name[0] ) ),
+		       "%s %s", product_short_name, netdev->dev->driver_name );
+	efi_snprintf ( snpdev->controller_name,
+		       ( sizeof ( snpdev->controller_name ) /
+			 sizeof ( snpdev->controller_name[0] ) ),
+		       "%s %s (%s, %s)", product_short_name,
+		       netdev->dev->driver_name, netdev->dev->name,
+		       netdev_addr ( netdev ) );
+	snpdev->name2.GetDriverName = efi_snp_get_driver_name;
+	snpdev->name2.GetControllerName = efi_snp_get_controller_name;
+	snpdev->name2.SupportedLanguages = "en";
+
+	/* Populate the load file protocol structure */
+	memcpy ( &snpdev->load_file, &efi_snp_load_file_protocol,
+		 sizeof ( snpdev->load_file ) );
+
+	/* Populate the device name */
+	efi_snprintf ( snpdev->name, ( sizeof ( snpdev->name ) /
+				       sizeof ( snpdev->name[0] ) ),
+		       "%s", netdev->name );
+
+	/* Get the parent device path */
+	if ( ( efirc = bs->OpenProtocol ( efidev->device,
+					  &efi_device_path_protocol_guid,
+					  &path.interface, efi_image_handle,
+					  efidev->device,
+					  EFI_OPEN_PROTOCOL_GET_PROTOCOL ))!=0){
+		rc = -EEFI ( efirc );
+		DBGC ( snpdev, "SNPDEV %p cannot get %p %s device path: %s\n",
+		       snpdev, efidev->device,
+		       efi_handle_name ( efidev->device ), strerror ( rc ) );
+		goto err_open_device_path;
+	}
+
+	/* Allocate the new device path */
+	path_end = efi_devpath_end ( path.path );
+	path_prefix_len = ( ( ( void * ) path_end ) - ( ( void * ) path.path ));
+	snpdev->path = zalloc ( path_prefix_len + sizeof ( *macpath ) +
+				sizeof ( *path_end ) );
+	if ( ! snpdev->path ) {
+		rc = -ENOMEM;
+		goto err_alloc_device_path;
+	}
+
+	/* Populate the device path */
+	memcpy ( snpdev->path, path.path, path_prefix_len );
+	macpath = ( ( ( void * ) snpdev->path ) + path_prefix_len );
+	path_end = ( ( void * ) ( macpath + 1 ) );
+	memset ( macpath, 0, sizeof ( *macpath ) );
+	macpath->Header.Type = MESSAGING_DEVICE_PATH;
+	macpath->Header.SubType = MSG_MAC_ADDR_DP;
+	macpath->Header.Length[0] = sizeof ( *macpath );
+	memcpy ( &macpath->MacAddress, netdev->ll_addr,
+		 sizeof ( macpath->MacAddress ) );
+	macpath->IfType = ntohs ( netdev->ll_protocol->ll_proto );
+	memset ( path_end, 0, sizeof ( *path_end ) );
+	path_end->Type = END_DEVICE_PATH_TYPE;
+	path_end->SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;
+	path_end->Length[0] = sizeof ( *path_end );
+
+	/* Install the SNP */
+	if ( ( efirc = bs->InstallMultipleProtocolInterfaces (
+			&snpdev->handle,
+			&efi_simple_network_protocol_guid, &snpdev->snp,
+			&efi_device_path_protocol_guid, snpdev->path,
+			&efi_nii_protocol_guid, &snpdev->nii,
+			&efi_nii31_protocol_guid, &snpdev->nii,
+			&efi_component_name2_protocol_guid, &snpdev->name2,
+			&efi_load_file_protocol_guid, &snpdev->load_file,
+			NULL ) ) != 0 ) {
+		rc = -EEFI ( efirc );
+		DBGC ( snpdev, "SNPDEV %p could not install protocols: "
+		       "%s\n", snpdev, strerror ( rc ) );
+		goto err_install_protocol_interface;
+	}
+
+	/* Add as child of EFI parent device */
+	if ( ( rc = efi_child_add ( efidev->device, snpdev->handle ) ) != 0 ) {
+		DBGC ( snpdev, "SNPDEV %p could not become child of %p %s: "
+		       "%s\n", snpdev, efidev->device,
+		       efi_handle_name ( efidev->device ), strerror ( rc ) );
+		goto err_efi_child_add;
+	}
+
+	/* Install HII */
+	if ( ( rc = efi_snp_hii_install ( snpdev ) ) != 0 ) {
+		DBGC ( snpdev, "SNPDEV %p could not install HII: %s\n",
+		       snpdev, strerror ( rc ) );
+		/* HII fails on several platforms.  It's
+		 * non-essential, so treat this as a non-fatal
+		 * error.
+		 */
+	}
+
+	/* Add to list of SNP devices */
+	list_add ( &snpdev->list, &efi_snp_devices );
+
+	/* Close device path */
+	bs->CloseProtocol ( efidev->device, &efi_device_path_protocol_guid,
+			    efi_image_handle, efidev->device );
+
+	DBGC ( snpdev, "SNPDEV %p installed for %s as device %p %s\n",
+	       snpdev, netdev->name, snpdev->handle,
+	       efi_handle_name ( snpdev->handle ) );
+	return 0;
+
+	if ( snpdev->package_list )
+		efi_snp_hii_uninstall ( snpdev );
+	efi_child_del ( efidev->device, snpdev->handle );
+ err_efi_child_add:
+	bs->UninstallMultipleProtocolInterfaces (
+			snpdev->handle,
+			&efi_simple_network_protocol_guid, &snpdev->snp,
+			&efi_device_path_protocol_guid, snpdev->path,
+			&efi_nii_protocol_guid, &snpdev->nii,
+			&efi_nii31_protocol_guid, &snpdev->nii,
+			&efi_component_name2_protocol_guid, &snpdev->name2,
+			&efi_load_file_protocol_guid, &snpdev->load_file,
+			NULL );
+ err_install_protocol_interface:
+	free ( snpdev->path );
+ err_alloc_device_path:
+	bs->CloseProtocol ( efidev->device, &efi_device_path_protocol_guid,
+			    efi_image_handle, efidev->device );
+ err_open_device_path:
+	bs->CloseEvent ( snpdev->snp.WaitForPacket );
+ err_create_event:
+ err_ll_addr_len:
+	netdev_put ( netdev );
+	free ( snpdev );
+ err_alloc_snp:
+ err_no_efidev:
+	return rc;
+}
+
+/**
+ * Handle SNP device or link state change
+ *
+ * @v netdev		Network device
+ */
+static void efi_snp_notify ( struct net_device *netdev ) {
+	struct efi_snp_device *snpdev;
+
+	/* Locate SNP device */
+	snpdev = efi_snp_demux ( netdev );
+	if ( ! snpdev ) {
+		DBG ( "SNP skipping non-SNP device %s\n", netdev->name );
+		return;
+	}
+
+	/* Update link state */
+	snpdev->mode.MediaPresent =
+		( netdev_link_ok ( netdev ) ? TRUE : FALSE );
+	DBGC ( snpdev, "SNPDEV %p link is %s\n", snpdev,
+	       ( snpdev->mode.MediaPresent ? "up" : "down" ) );
+
+	/* Update mode state */
+	efi_snp_set_state ( snpdev );
+}
+
+/**
+ * Destroy SNP device
+ *
+ * @v netdev		Network device
+ */
+static void efi_snp_remove ( struct net_device *netdev ) {
+	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
+	struct efi_snp_device *snpdev;
+
+	/* Locate SNP device */
+	snpdev = efi_snp_demux ( netdev );
+	if ( ! snpdev ) {
+		DBG ( "SNP skipping non-SNP device %s\n", netdev->name );
+		return;
+	}
+
+	/* Uninstall the SNP */
+	if ( snpdev->package_list )
+		efi_snp_hii_uninstall ( snpdev );
+	efi_child_del ( snpdev->efidev->device, snpdev->handle );
+	list_del ( &snpdev->list );
+	bs->UninstallMultipleProtocolInterfaces (
+			snpdev->handle,
+			&efi_simple_network_protocol_guid, &snpdev->snp,
+			&efi_device_path_protocol_guid, snpdev->path,
+			&efi_nii_protocol_guid, &snpdev->nii,
+			&efi_nii31_protocol_guid, &snpdev->nii,
+			&efi_component_name2_protocol_guid, &snpdev->name2,
+			&efi_load_file_protocol_guid, &snpdev->load_file,
+			NULL );
+	free ( snpdev->path );
+	bs->CloseEvent ( snpdev->snp.WaitForPacket );
+	netdev_put ( snpdev->netdev );
+	free ( snpdev );
+}
+
+/** SNP driver */
+struct net_driver efi_snp_driver __net_driver = {
+	.name = "SNP",
+	.probe = efi_snp_probe,
+	.notify = efi_snp_notify,
+	.remove = efi_snp_remove,
+};
+
+/**
+ * Find SNP device by EFI device handle
+ *
+ * @v handle		EFI device handle
+ * @ret snpdev		SNP device, or NULL
+ */
+struct efi_snp_device * find_snpdev ( EFI_HANDLE handle ) {
+	struct efi_snp_device *snpdev;
+
+	list_for_each_entry ( snpdev, &efi_snp_devices, list ) {
+		if ( snpdev->handle == handle )
+			return snpdev;
+	}
+	return NULL;
+}
+
+/**
+ * Get most recently opened SNP device
+ *
+ * @ret snpdev		Most recently opened SNP device, or NULL
+ */
+struct efi_snp_device * last_opened_snpdev ( void ) {
+	struct net_device *netdev;
+
+	netdev = last_opened_netdev();
+	if ( ! netdev )
+		return NULL;
+
+	return efi_snp_demux ( netdev );
+}
+
+/**
+ * Set SNP claimed/released state
+ *
+ * @v claimed		Network devices are claimed for use by iPXE
+ */
+void efi_snp_set_claimed ( int claimed ) {
+	struct efi_snp_device *snpdev;
+
+	/* Claim SNP devices */
+	efi_snp_claimed = claimed;
+
+	/* Update SNP mode state for each interface */
+	list_for_each_entry ( snpdev, &efi_snp_devices, list )
+		efi_snp_set_state ( snpdev );
+}