Initial revision

1 files changed, 1424 insertions, 0 deletions

diff --git a/src/core/pxe_export.c b/src/core/pxe_export.c
new file mode 100644
index 000000000..0199de287
--- /dev/null
+++ b/src/core/pxe_export.c
@@ -0,0 +1,1424 @@
+/* PXE API interface for Etherboot.
+ *
+ * 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.
+ */
+
+/* Tags used in this file:
+ *
+ * FIXME : obvious
+ * PXESPEC : question over interpretation of the PXE spec.
+ */
+
+#ifdef PXE_EXPORT
+
+#include "etherboot.h"
+#include "pxe.h"
+#include "pxe_export.h"
+#include "pxe_callbacks.h"
+#include "nic.h"
+#include "pci.h"
+#include "dev.h"
+#include "cpu.h"
+#include "timer.h"
+
+#if TRACE_PXE
+#define DBG(...) printf ( __VA_ARGS__ )
+#else
+#define DBG(...)
+#endif
+
+/* Not sure why this isn't a globally-used structure within Etherboot.
+ * (Because I didn't want to use packed to prevent gcc from aligning
+ * source however it liked. Also nstype is a u16, not a uint. - Ken)
+ */
+typedef	struct {
+	char dest[ETH_ALEN];
+	char source[ETH_ALEN];
+	unsigned int nstype;
+} media_header_t;
+static const char broadcast_mac[] = { 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF };
+
+/* Global pointer to currently installed PXE stack */
+pxe_stack_t *pxe_stack = NULL;
+
+/* Various startup/shutdown routines.  The startup/shutdown call
+ * sequence is incredibly badly defined in the Intel PXE spec, for
+ * example:
+ *
+ *   PXENV_UNDI_INITIALIZE says that the parameters used to initialize
+ *   the adaptor should be those supplied to the most recent
+ *   PXENV_UNDI_STARTUP call.  PXENV_UNDI_STARTUP takes no parameters.
+ *
+ *   PXENV_UNDI_CLEANUP says that the rest of the API will not be
+ *   available after making this call.  Figure 3-3 ("Early UNDI API
+ *   usage") shows a call to PXENV_UNDI_CLEANUP being followed by a
+ *   call to the supposedly now unavailable PXENV_STOP_UNDI.
+ *
+ *   PXENV_UNLOAD_BASE_STACK talks about freeing up the memory
+ *   occupied by the PXE stack.  Figure 4-3 ("PXE IPL") shows a call
+ *   to PXENV_STOP_UNDI being made after the call to
+ *   PXENV_UNLOAD_BASE_STACK, by which time the entire PXE stack
+ *   should have been freed (and, potentially, zeroed).
+ *
+ *   Nothing, anywhere, seems to mention who's responsible for freeing
+ *   up the base memory allocated for the stack segment.  It's not
+ *   even clear whether or not this is expected to be in free base
+ *   memory rather than claimed base memory.
+ *
+ * Consequently, we adopt a rather defensive strategy, designed to
+ * work with any conceivable sequence of initialisation or shutdown
+ * calls.  We have only two things that we care about:
+ *
+ *   1. Have we hooked INT 1A and INT 15,E820(etc.)?
+ *   2. Is the NIC initialised?
+ *
+ * The NIC should never be initialised without the vectors being
+ * hooked, similarly the vectors should never be unhooked with the NIC
+ * still initialised.  We do, however, want to be able to have the
+ * vectors hooked with the NIC shutdown.  We therefore have three
+ * possible states:
+ *
+ *   1. Ready to unload: interrupts unhooked, NIC shutdown.
+ *   2. Midway: interrupts hooked, NIC shutdown.
+ *   3. Fully ready: interrupts hooked, NIC initialised.
+ *
+ * We provide the three states CAN_UNLOAD, MIDWAY and READY to define
+ * these, and the call pxe_ensure_state() to ensure that the stack is
+ * in the specified state.  All our PXE API call implementations
+ * should use this call to ensure that the state is as required for
+ * that PXE API call.  This enables us to cope with whatever the
+ * end-user's interpretation of the PXE spec may be.  It even allows
+ * for someone calling e.g. PXENV_START_UNDI followed by
+ * PXENV_UDP_WRITE, without bothering with any of the intervening
+ * calls.
+ *
+ * pxe_ensure_state() returns 1 for success, 0 for failure.  In the
+ * event of failure (which can arise from e.g. asking for state READY
+ * when we don't know where our NIC is), the error code
+ * PXENV_STATUS_UNDI_INVALID_STATE should be returned to the user.
+ * The macros ENSURE_XXX() can be used to achieve this without lots of
+ * duplicated code.
+ */
+
+/* pxe_[un]hook_stack are architecture-specific and provided in
+ * pxe_callbacks.c
+ */
+
+int pxe_initialise_nic ( void ) {
+	if ( pxe_stack->state >= READY ) return 1;
+
+	/* Check if NIC is initialised.  nic.dev.disable is set to 0
+	 * when disable() is called, so we use this.
+	 */
+	if ( nic.dev.disable ) {
+		/* NIC may have been initialised independently
+		 * (e.g. when we set up the stack prior to calling the
+		 * NBP).
+		 */
+		pxe_stack->state = READY;
+		return 1;
+	}
+
+	/* If we already have a NIC defined, reuse that one with
+	 * PROBE_AWAKE.  If one was specifed via PXENV_START_UNDI, try
+	 * that one first.  Otherwise, set PROBE_FIRST.
+	 */
+	if ( nic.dev.state.pci.dev.use_specified == 1 ) {
+		nic.dev.how_probe = PROBE_NEXT;
+		DBG ( " initialising NIC specified via START_UNDI" );
+	} else if ( nic.dev.state.pci.dev.driver ) {
+		DBG ( " reinitialising NIC" );
+		nic.dev.how_probe = PROBE_AWAKE;
+	} else {
+		DBG ( " probing for any NIC" );
+		nic.dev.how_probe = PROBE_FIRST;
+	}
+	
+	/* Call probe routine to bring up the NIC */
+	if ( eth_probe ( &nic.dev ) != PROBE_WORKED ) {
+		DBG ( " failed" );
+		return 0;
+	}
+	pxe_stack->state = READY;
+	return 1;
+}
+
+int pxe_shutdown_nic ( void ) {
+	if ( pxe_stack->state <= MIDWAY ) return 1;
+
+	eth_irq ( DISABLE );
+	eth_disable();
+	pxe_stack->state = MIDWAY;
+	return 1;
+}
+
+int ensure_pxe_state ( pxe_stack_state_t wanted ) {
+	int success = 1;
+
+	if ( ! pxe_stack ) return 0;
+	if ( wanted >= MIDWAY )
+		success = success & hook_pxe_stack();
+	if ( wanted > MIDWAY ) {
+		success = success & pxe_initialise_nic();
+	} else {
+		success = success & pxe_shutdown_nic();
+	}
+	if ( wanted < MIDWAY )
+		success = success & unhook_pxe_stack();
+	return success;
+}
+
+#define ENSURE_CAN_UNLOAD(structure) if ( ! ensure_pxe_state(CAN_UNLOAD) ) { \
+			structure->Status = PXENV_STATUS_UNDI_INVALID_STATE; \
+			return PXENV_EXIT_FAILURE; }
+#define ENSURE_MIDWAY(structure) if ( ! ensure_pxe_state(MIDWAY) ) { \
+			structure->Status = PXENV_STATUS_UNDI_INVALID_STATE; \
+			return PXENV_EXIT_FAILURE; }
+#define ENSURE_READY(structure) if ( ! ensure_pxe_state(READY) ) { \
+			structure->Status = PXENV_STATUS_UNDI_INVALID_STATE; \
+			return PXENV_EXIT_FAILURE; }
+
+/*****************************************************************************
+ *
+ * Actual PXE API calls
+ *
+ *****************************************************************************/
+
+/* PXENV_START_UNDI
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_start_undi ( t_PXENV_START_UNDI *start_undi ) {
+	unsigned char bus, devfn;
+	struct pci_probe_state *pci = &nic.dev.state.pci;
+	struct dev *dev = &nic.dev;
+
+	DBG ( "PXENV_START_UNDI" );
+	ENSURE_MIDWAY(start_undi);
+
+	/* Record PCI bus & devfn passed by caller, so we know which
+	 * NIC they want to use.
+	 *
+	 * If they don't match our already-existing NIC structure, set
+	 * values to ensure that the specified NIC is used at the next
+	 * call to pxe_intialise_nic().
+	 */
+	bus = ( start_undi->ax >> 8 ) & 0xff;
+	devfn = start_undi->ax & 0xff;
+
+	if ( ( pci->dev.driver == NULL ) ||
+	     ( pci->dev.bus != bus ) || ( pci->dev.devfn != devfn ) ) {
+		/* This is quite a bit of a hack and relies on
+		 * knowledge of the internal operation of Etherboot's
+		 * probe mechanism.
+		 */
+		DBG ( " set PCI %hhx:%hhx.%hhx",
+		      bus, PCI_SLOT(devfn), PCI_FUNC(devfn) );
+		dev->type = BOOT_NIC;
+		dev->to_probe = PROBE_PCI;
+		memset ( &dev->state, 0, sizeof(dev->state) );
+		pci->advance = 1;
+		pci->dev.use_specified = 1;
+		pci->dev.bus = bus;
+		pci->dev.devfn = devfn;
+	}
+
+	start_undi->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_UNDI_STARTUP
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_undi_startup ( t_PXENV_UNDI_STARTUP *undi_startup ) {
+	DBG ( "PXENV_UNDI_STARTUP" );
+	ENSURE_MIDWAY(undi_startup);
+
+	undi_startup->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_UNDI_CLEANUP
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_undi_cleanup ( t_PXENV_UNDI_CLEANUP *undi_cleanup ) {
+	DBG ( "PXENV_UNDI_CLEANUP" );
+	ENSURE_CAN_UNLOAD ( undi_cleanup );
+
+	undi_cleanup->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_UNDI_INITIALIZE
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_undi_initialize ( t_PXENV_UNDI_INITIALIZE
+				     *undi_initialize ) {
+	DBG ( "PXENV_UNDI_INITIALIZE" );
+	ENSURE_MIDWAY ( undi_initialize );
+
+	undi_initialize->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_UNDI_RESET_ADAPTER
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_undi_reset_adapter ( t_PXENV_UNDI_RESET_ADAPTER
+					*undi_reset_adapter ) {
+	DBG ( "PXENV_UNDI_RESET_ADAPTER" );
+
+	ENSURE_MIDWAY ( undi_reset_adapter );
+	ENSURE_READY ( undi_reset_adapter );
+
+	undi_reset_adapter->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_UNDI_SHUTDOWN
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_undi_shutdown ( t_PXENV_UNDI_SHUTDOWN *undi_shutdown ) {
+	DBG ( "PXENV_UNDI_SHUTDOWN" );
+	ENSURE_MIDWAY ( undi_shutdown );
+
+	undi_shutdown->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_UNDI_OPEN
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_undi_open ( t_PXENV_UNDI_OPEN *undi_open ) {
+	DBG ( "PXENV_UNDI_OPEN" );
+	ENSURE_READY ( undi_open );
+
+	/* PXESPEC: This is where we choose to enable interrupts.
+	 * Can't actually find where we're meant to in the PXE spec,
+	 * but this should work.
+	 */
+	eth_irq ( ENABLE );
+
+	undi_open->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_UNDI_CLOSE
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_undi_close ( t_PXENV_UNDI_CLOSE *undi_close ) {
+	DBG ( "PXENV_UNDI_CLOSE" );
+	ENSURE_MIDWAY ( undi_close );
+
+	undi_close->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_UNDI_TRANSMIT
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_undi_transmit ( t_PXENV_UNDI_TRANSMIT *undi_transmit ) {
+	t_PXENV_UNDI_TBD *tbd;
+	const char *dest;
+	unsigned int type;
+	unsigned int length;
+	const char *data;
+	media_header_t *media_header;
+
+	DBG ( "PXENV_UNDI_TRANSMIT" );
+	ENSURE_READY ( undi_transmit );
+
+	/* We support only the "immediate" portion of the TBD.  Who
+	 * knows what Intel's "engineers" were smoking when they came
+	 * up with the array of transmit data blocks...
+	 */
+	tbd = SEGOFF16_TO_PTR ( undi_transmit->TBD );
+	if ( tbd->DataBlkCount > 0 ) {
+		undi_transmit->Status = PXENV_STATUS_UNDI_INVALID_PARAMETER;
+		return PXENV_EXIT_FAILURE;
+	}
+	data = SEGOFF16_TO_PTR ( tbd->Xmit );
+	length = tbd->ImmedLength;
+
+	/* If destination is broadcast, we need to supply the MAC address */
+	if ( undi_transmit->XmitFlag == XMT_BROADCAST ) {
+		dest = broadcast_mac;
+	} else {
+		dest = SEGOFF16_TO_PTR ( undi_transmit->DestAddr );
+	}
+
+	/* We can't properly support P_UNKNOWN without rewriting all
+	 * the driver transmit() methods, so we cheat: if P_UNKNOWN is
+	 * specified we rip the destination address and type out of
+	 * the pre-assembled packet, then skip over the header.
+	 */
+	switch ( undi_transmit->Protocol ) {
+	case P_IP:	type = IP;	break;
+	case P_ARP:	type = ARP;	break;
+	case P_RARP:	type = RARP;	break;
+	case P_UNKNOWN:
+		media_header = (media_header_t*)data;
+		dest = media_header->dest;
+		type = ntohs ( media_header->nstype );
+		data += ETH_HLEN;
+		length -= ETH_HLEN;
+		break;
+	default:
+		undi_transmit->Status = PXENV_STATUS_UNDI_INVALID_PARAMETER;
+		return PXENV_EXIT_FAILURE;
+	}
+
+	/* Send the packet */
+	eth_transmit ( dest, type, length, data );
+	
+	undi_transmit->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_UNDI_SET_MCAST_ADDRESS
+ *
+ * Status: stub (no PXE multicast support)
+ */
+PXENV_EXIT_t pxenv_undi_set_mcast_address ( t_PXENV_UNDI_SET_MCAST_ADDRESS
+					    *undi_set_mcast_address ) {
+	DBG ( "PXENV_UNDI_SET_MCAST_ADDRESS" );
+	/* ENSURE_READY ( undi_set_mcast_address ); */
+	undi_set_mcast_address->Status = PXENV_STATUS_UNSUPPORTED;
+	return PXENV_EXIT_FAILURE;
+}
+
+/* PXENV_UNDI_SET_STATION_ADDRESS
+ *
+ * Status: working (deliberately incomplete)
+ */
+PXENV_EXIT_t pxenv_undi_set_station_address ( t_PXENV_UNDI_SET_STATION_ADDRESS
+					      *undi_set_station_address ) {
+	DBG ( "PXENV_UNDI_SET_STATION_ADDRESS" );
+	ENSURE_READY ( undi_set_station_address );
+
+	/* We don't offer a facility to set the MAC address; this
+	 * would require adding extra code to all the Etherboot
+	 * drivers, for very little benefit.  If we're setting it to
+	 * the current value anyway then return success, otherwise
+	 * return UNSUPPORTED.
+	 */
+	if ( memcmp ( nic.node_addr,
+		      &undi_set_station_address->StationAddress,
+		      ETH_ALEN ) == 0 ) {
+		undi_set_station_address->Status = PXENV_STATUS_SUCCESS;
+		return PXENV_EXIT_SUCCESS;
+	}
+	undi_set_station_address->Status = PXENV_STATUS_UNSUPPORTED;
+	return PXENV_EXIT_FAILURE;
+}
+
+/* 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 ( t_PXENV_UNDI_SET_PACKET_FILTER
+					    *undi_set_packet_filter ) {
+	DBG ( "PXENV_UNDI_SET_PACKET_FILTER" );
+	/* ENSURE_READY ( undi_set_packet_filter ); */
+	undi_set_packet_filter->Status = PXENV_STATUS_UNSUPPORTED;
+	return PXENV_EXIT_FAILURE;
+}
+
+/* PXENV_UNDI_GET_INFORMATION
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_undi_get_information ( t_PXENV_UNDI_GET_INFORMATION
+					  *undi_get_information ) {
+	DBG ( "PXENV_UNDI_GET_INFORMATION" );
+	ENSURE_READY ( undi_get_information );
+
+	undi_get_information->BaseIo = nic.ioaddr;
+	undi_get_information->IntNumber = nic.irqno;
+	/* Cheat: assume all cards can cope with this */
+	undi_get_information->MaxTranUnit = ETH_MAX_MTU;
+	/* Cheat: we only ever have Ethernet cards */
+	undi_get_information->HwType = ETHER_TYPE;
+	undi_get_information->HwAddrLen = ETH_ALEN;
+	/* Cheat: assume card is always configured with its permanent
+	 * node address.  This is a valid assumption within Etherboot
+	 * at the time of writing.
+	 */
+	memcpy ( &undi_get_information->CurrentNodeAddress, nic.node_addr,
+		 ETH_ALEN );
+	memcpy ( &undi_get_information->PermNodeAddress, nic.node_addr,
+		 ETH_ALEN );
+	undi_get_information->ROMAddress = 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;
+	undi_get_information->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_UNDI_GET_STATISTICS
+ *
+ * Status: won't implement (would require driver API changes for no
+ * real benefit)
+ */
+PXENV_EXIT_t pxenv_undi_get_statistics ( t_PXENV_UNDI_GET_STATISTICS
+					 *undi_get_statistics ) {
+	DBG ( "PXENV_UNDI_GET_STATISTICS" );
+	/* ENSURE_READY ( undi_get_statistics ); */
+	undi_get_statistics->Status = PXENV_STATUS_UNSUPPORTED;
+	return PXENV_EXIT_FAILURE;
+}
+
+/* PXENV_UNDI_CLEAR_STATISTICS
+ *
+ * Status: won't implement (would require driver API changes for no
+ * real benefit)
+ */
+PXENV_EXIT_t pxenv_undi_clear_statistics ( t_PXENV_UNDI_CLEAR_STATISTICS
+					   *undi_clear_statistics ) {
+	DBG ( "PXENV_UNDI_CLEAR_STATISTICS" );
+	/* ENSURE_READY ( undi_clear_statistics ); */
+	undi_clear_statistics->Status = PXENV_STATUS_UNSUPPORTED;
+	return PXENV_EXIT_FAILURE;
+}
+
+/* PXENV_UNDI_INITIATE_DIAGS
+ *
+ * Status: won't implement (would require driver API changes for no
+ * real benefit)
+ */
+PXENV_EXIT_t pxenv_undi_initiate_diags ( t_PXENV_UNDI_INITIATE_DIAGS
+					 *undi_initiate_diags ) {
+	DBG ( "PXENV_UNDI_INITIATE_DIAGS" );
+	/* ENSURE_READY ( undi_initiate_diags ); */
+	undi_initiate_diags->Status = PXENV_STATUS_UNSUPPORTED;
+	return PXENV_EXIT_FAILURE;
+}
+
+/* PXENV_UNDI_FORCE_INTERRUPT
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_undi_force_interrupt ( t_PXENV_UNDI_FORCE_INTERRUPT
+					  *undi_force_interrupt ) {
+	DBG ( "PXENV_UNDI_FORCE_INTERRUPT" );
+	ENSURE_READY ( undi_force_interrupt );
+
+	eth_irq ( FORCE );
+	undi_force_interrupt->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_UNDI_GET_MCAST_ADDRESS
+ *
+ * Status: stub (no PXE multicast support)
+ */
+PXENV_EXIT_t pxenv_undi_get_mcast_address ( t_PXENV_UNDI_GET_MCAST_ADDRESS
+					    *undi_get_mcast_address ) {
+	DBG ( "PXENV_UNDI_GET_MCAST_ADDRESS" );
+	/* ENSURE_READY ( undi_get_mcast_address ); */
+	undi_get_mcast_address->Status = PXENV_STATUS_UNSUPPORTED;
+	return PXENV_EXIT_FAILURE;
+}
+
+/* PXENV_UNDI_GET_NIC_TYPE
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_undi_get_nic_type ( t_PXENV_UNDI_GET_NIC_TYPE
+				       *undi_get_nic_type ) {
+	struct dev *dev = &nic.dev;
+	
+	DBG ( "PXENV_UNDI_GET_NIC_TYPE" );
+	ENSURE_READY ( undi_get_nic_type );
+	
+	if ( dev->to_probe == PROBE_PCI ) {
+		struct pci_device *pci = &dev->state.pci.dev;
+
+		undi_get_nic_type->NicType = PCI_NIC;
+		undi_get_nic_type->info.pci.Vendor_ID = pci->vendor;
+		undi_get_nic_type->info.pci.Dev_ID = pci->dev_id;
+		undi_get_nic_type->info.pci.Base_Class = pci->class >> 8;
+		undi_get_nic_type->info.pci.Sub_Class = pci->class & 0xff;
+		undi_get_nic_type->info.pci.BusDevFunc =
+			( pci->bus << 8 ) | pci->devfn;
+		/* Cheat: these fields are probably unnecessary, and
+		 * would require adding extra code to pci.c.
+		 */
+		undi_get_nic_type->info.pci.Prog_Intf = 0;
+		undi_get_nic_type->info.pci.Rev = 0;
+		undi_get_nic_type->info.pci.SubVendor_ID = 0xffff;
+		undi_get_nic_type->info.pci.SubDevice_ID = 0xffff;
+	} else if ( dev->to_probe == PROBE_ISA ) {
+		/* const struct isa_driver *isa = dev->state.isa.driver; */
+
+		undi_get_nic_type->NicType = PnP_NIC;
+		/* Don't think anything fills these fields in, and
+		 * probably no-one will ever be interested in them.
+		 */
+		undi_get_nic_type->info.pnp.EISA_Dev_ID = 0;
+		undi_get_nic_type->info.pnp.Base_Class = 0;
+		undi_get_nic_type->info.pnp.Sub_Class = 0;
+		undi_get_nic_type->info.pnp.Prog_Intf = 0;
+		undi_get_nic_type->info.pnp.CardSelNum = 0;
+	} else {
+		/* PXESPEC: There doesn't seem to be an "unknown type"
+		 * defined.
+		 */
+		undi_get_nic_type->NicType = 0;
+	}
+	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 ( t_PXENV_UNDI_GET_IFACE_INFO
+					 *undi_get_iface_info ) {
+	DBG ( "PXENV_UNDI_GET_IFACE_INFO" );
+	ENSURE_READY ( undi_get_iface_info );
+
+	/* Just hand back some info, doesn't really matter what it is.
+	 * Most PXE stacks seem to take this approach.
+	 */
+	sprintf ( undi_get_iface_info->IfaceType, "Etherboot" );
+	undi_get_iface_info->LinkSpeed = 10000000; /* 10 Mbps */
+	undi_get_iface_info->ServiceFlags = 0;
+	memset ( undi_get_iface_info->Reserved, 0,
+		 sizeof(undi_get_iface_info->Reserved) );
+	undi_get_iface_info->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_UNDI_ISR
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_undi_isr ( t_PXENV_UNDI_ISR *undi_isr ) {
+	media_header_t *media_header = (media_header_t*)nic.packet;
+
+	DBG ( "PXENV_UNDI_ISR" );
+	/* We can't call ENSURE_READY, because this could be being
+	 * called as part of an interrupt service routine.  Instead,
+	 * we should simply die if we're not READY.
+	 */
+	if ( ( pxe_stack == NULL ) || ( pxe_stack->state < READY ) ) {
+		undi_isr->Status = PXENV_STATUS_UNDI_INVALID_STATE;
+		return PXENV_EXIT_FAILURE;
+	}
+	
+	/* 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 :
+		/* Is there a packet waiting?  If so, disable
+		 * interrupts on the NIC and return "it's ours".  Do
+		 * *not* necessarily acknowledge the interrupt; this
+		 * can happen later when eth_poll(1) is called.  As
+		 * long as the interrupt is masked off so that it
+		 * doesn't immediately retrigger the 8259A then all
+		 * should be well.
+		 */
+		DBG ( " START" );
+		if ( eth_poll ( 0 ) ) {
+			DBG ( " OURS" );
+			eth_irq ( DISABLE );
+			undi_isr->FuncFlag = PXENV_UNDI_ISR_OUT_OURS;
+		} else {
+			DBG ( " NOT_OURS" );
+			undi_isr->FuncFlag = PXENV_UNDI_ISR_OUT_NOT_OURS;
+		}
+		break;
+	case PXENV_UNDI_ISR_IN_PROCESS :
+		/* Call poll(), return packet.  If no packet, return "done".
+		 */
+		DBG ( " PROCESS" );
+		if ( eth_poll ( 1 ) ) {
+			DBG ( " RECEIVE %d", nic.packetlen );
+			if ( nic.packetlen > sizeof(pxe_stack->packet) ) {
+				/* Should never happen */
+				undi_isr->FuncFlag = PXENV_UNDI_ISR_OUT_DONE;
+				undi_isr->Status =
+					PXENV_STATUS_OUT_OF_RESOURCES;
+				return PXENV_EXIT_FAILURE;
+			}
+			undi_isr->FuncFlag = PXENV_UNDI_ISR_OUT_RECEIVE;
+			undi_isr->BufferLength = nic.packetlen;
+			undi_isr->FrameLength = nic.packetlen;
+			undi_isr->FrameHeaderLength = ETH_HLEN;
+			memcpy ( pxe_stack->packet, nic.packet, nic.packetlen);
+			PTR_TO_SEGOFF16 ( pxe_stack->packet, undi_isr->Frame );
+			switch ( ntohs(media_header->nstype) ) {
+			case IP :	undi_isr->ProtType = P_IP;	break;
+			case ARP :	undi_isr->ProtType = P_ARP;	break;
+			case RARP :	undi_isr->ProtType = P_RARP;	break;
+			default :	undi_isr->ProtType = P_UNKNOWN;
+			}
+			if ( memcmp ( media_header->dest, broadcast_mac,
+				      sizeof(broadcast_mac) ) ) {
+				undi_isr->PktType = XMT_BROADCAST;
+			} else {
+				undi_isr->PktType = XMT_DESTADDR;
+			}
+			break;
+		} else {
+			/* No break - fall through to IN_GET_NEXT */
+		}
+	case PXENV_UNDI_ISR_IN_GET_NEXT :
+		/* We only ever return one frame at a time */
+		DBG ( " GET_NEXT DONE" );
+		/* Re-enable interrupts */
+		eth_irq ( ENABLE );
+		/* Force an interrupt if there's a packet still
+		 * waiting, since we only handle one packet per
+		 * interrupt.
+		 */
+		if ( eth_poll ( 0 ) ) {
+			DBG ( " (RETRIGGER)" );
+			eth_irq ( FORCE );
+		}
+		undi_isr->FuncFlag = PXENV_UNDI_ISR_OUT_DONE;
+		break;
+	default :
+		/* Should never happen */
+		undi_isr->FuncFlag = PXENV_UNDI_ISR_OUT_DONE;
+		undi_isr->Status = PXENV_STATUS_UNDI_INVALID_PARAMETER;
+		return PXENV_EXIT_FAILURE;
+	}
+
+	undi_isr->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_STOP_UNDI
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_stop_undi ( t_PXENV_STOP_UNDI *stop_undi ) {
+	DBG ( "PXENV_STOP_UNDI" );
+
+	if ( ! ensure_pxe_state(CAN_UNLOAD) ) {
+		stop_undi->Status = PXENV_STATUS_KEEP_UNDI;
+		return PXENV_EXIT_FAILURE;
+	}
+
+	stop_undi->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_TFTP_OPEN
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_tftp_open ( t_PXENV_TFTP_OPEN *tftp_open ) {
+	struct tftpreq_info_t request;
+	struct tftpblk_info_t block;
+
+	DBG ( "PXENV_TFTP_OPEN" );
+	ENSURE_READY ( tftp_open );
+
+	/* Change server address if different */
+	if ( tftp_open->ServerIPAddress && 
+	     tftp_open->ServerIPAddress!=arptable[ARP_SERVER].ipaddr.s_addr ) {
+		memset(arptable[ARP_SERVER].node, 0, ETH_ALEN ); /* kill arp */
+		arptable[ARP_SERVER].ipaddr.s_addr=tftp_open->ServerIPAddress;
+	}
+	/* Ignore gateway address; we can route properly */
+	/* Fill in request structure */
+	request.name = tftp_open->FileName;
+	request.port = ntohs(tftp_open->TFTPPort);
+#ifdef WORK_AROUND_BPBATCH_BUG        
+	/* Force use of port 69; BpBatch tries to use port 4 for some         
+	* bizarre reason.         */        
+	request.port = TFTP_PORT;
+#endif
+	request.blksize = tftp_open->PacketSize;
+	DBG ( " %@:%d/%s (%d)", tftp_open->ServerIPAddress,
+	      request.port, request.name, request.blksize );
+	if ( !request.blksize ) request.blksize = TFTP_DEFAULTSIZE_PACKET;
+	/* Make request and get first packet */
+	if ( !tftp_block ( &request, &block ) ) {
+		tftp_open->Status = PXENV_STATUS_TFTP_FILE_NOT_FOUND;
+		return PXENV_EXIT_FAILURE;
+	}
+	/* Fill in PacketSize */
+	tftp_open->PacketSize = request.blksize;
+	/* Store first block for later retrieval by TFTP_READ */
+	pxe_stack->tftpdata.magic_cookie = PXE_TFTP_MAGIC_COOKIE;
+	pxe_stack->tftpdata.len = block.len;
+	pxe_stack->tftpdata.eof = block.eof;
+	memcpy ( pxe_stack->tftpdata.data, block.data, block.len );
+
+	tftp_open->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_TFTP_CLOSE
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_tftp_close ( t_PXENV_TFTP_CLOSE *tftp_close ) {
+	DBG ( "PXENV_TFTP_CLOSE" );
+	ENSURE_READY ( tftp_close );
+	tftp_close->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_TFTP_READ
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_tftp_read ( t_PXENV_TFTP_READ *tftp_read ) {
+	struct tftpblk_info_t block;
+
+	DBG ( "PXENV_TFTP_READ" );
+	ENSURE_READY ( tftp_read );
+
+	/* Do we have a block pending */
+	if ( pxe_stack->tftpdata.magic_cookie == PXE_TFTP_MAGIC_COOKIE ) {
+		block.data = pxe_stack->tftpdata.data;
+		block.len = pxe_stack->tftpdata.len;
+		block.eof = pxe_stack->tftpdata.eof;
+		block.block = 1; /* Will be the first block */
+		pxe_stack->tftpdata.magic_cookie = 0;
+	} else {
+		if ( !tftp_block ( NULL, &block ) ) {
+			tftp_read->Status = PXENV_STATUS_TFTP_FILE_NOT_FOUND;
+			return PXENV_EXIT_FAILURE;
+		}
+	}
+
+	/* Return data */
+	tftp_read->PacketNumber = block.block;
+	tftp_read->BufferSize = block.len;
+	memcpy ( SEGOFF16_TO_PTR(tftp_read->Buffer), block.data, block.len );
+	DBG ( " %d to %hx:%hx", block.len, tftp_read->Buffer.segment,
+	      tftp_read->Buffer.offset );
+ 
+	tftp_read->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_TFTP_READ_FILE
+ *
+ * Status: working
+ */
+
+int pxe_tftp_read_block ( unsigned char *data, unsigned int block __unused, unsigned int len, int eof ) {
+	if ( pxe_stack->readfile.buffer ) {
+		if ( pxe_stack->readfile.offset + len >=
+		     pxe_stack->readfile.bufferlen ) return -1;
+		memcpy ( pxe_stack->readfile.buffer +
+			 pxe_stack->readfile.offset, data, len );
+	}
+	pxe_stack->readfile.offset += len;
+	return eof ? 0 : 1;
+}
+
+PXENV_EXIT_t pxenv_tftp_read_file ( t_PXENV_TFTP_READ_FILE *tftp_read_file ) {
+	int rc;
+
+	DBG ( "PXENV_TFTP_READ_FILE %s to [%x,%x)", tftp_read_file->FileName,
+	      tftp_read_file->Buffer, tftp_read_file->Buffer + tftp_read_file->BufferSize );
+	ENSURE_READY ( tftp_read_file );
+
+	/* inserted by Klaus Wittemeier */
+	/* KERNEL_BUF stores the name of the last required file */
+	/* This is a fix to make Microsoft Remote Install Services work (RIS) */
+	memcpy(KERNEL_BUF, tftp_read_file->FileName, sizeof(KERNEL_BUF));
+	/* end of insertion */
+
+	pxe_stack->readfile.buffer = phys_to_virt ( tftp_read_file->Buffer );
+	pxe_stack->readfile.bufferlen = tftp_read_file->BufferSize;
+	pxe_stack->readfile.offset = 0;
+
+	rc = tftp ( tftp_read_file->FileName, pxe_tftp_read_block );
+	if ( rc ) {
+		tftp_read_file->Status = PXENV_STATUS_FAILURE;
+		return PXENV_EXIT_FAILURE;
+	}
+	tftp_read_file->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_TFTP_GET_FSIZE
+ *
+ * Status: working, though ugly (we actually read the whole file,
+ * because it's too ugly to make Etherboot request the tsize option
+ * and hand it to us).
+ */
+PXENV_EXIT_t pxenv_tftp_get_fsize ( t_PXENV_TFTP_GET_FSIZE *tftp_get_fsize ) {
+	int rc;
+
+	DBG ( "PXENV_TFTP_GET_FSIZE" );
+	ENSURE_READY ( tftp_get_fsize );
+
+	pxe_stack->readfile.buffer = NULL;
+	pxe_stack->readfile.bufferlen = 0;
+	pxe_stack->readfile.offset = 0;
+
+	rc = tftp ( tftp_get_fsize->FileName, pxe_tftp_read_block );
+	if ( rc ) {
+		tftp_get_fsize->FileSize = 0;
+		tftp_get_fsize->Status = PXENV_STATUS_FAILURE;
+		return PXENV_EXIT_FAILURE;
+	}
+	tftp_get_fsize->FileSize = pxe_stack->readfile.offset;
+	tftp_get_fsize->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_UDP_OPEN
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_udp_open ( t_PXENV_UDP_OPEN *udp_open ) {
+	DBG ( "PXENV_UDP_OPEN" );
+	ENSURE_READY ( udp_open );
+
+	if ( udp_open->src_ip &&
+	     udp_open->src_ip != arptable[ARP_CLIENT].ipaddr.s_addr ) {
+		/* Overwrite our IP address */
+		DBG ( " with new IP %@", udp_open->src_ip );
+		arptable[ARP_CLIENT].ipaddr.s_addr = udp_open->src_ip;
+	}
+
+	udp_open->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_UDP_CLOSE
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_udp_close ( t_PXENV_UDP_CLOSE *udp_close ) {
+	DBG ( "PXENV_UDP_CLOSE" );
+	ENSURE_READY ( udp_close );
+	udp_close->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_UDP_READ
+ *
+ * Status: working
+ */
+int await_pxe_udp ( int ival __unused, void *ptr,
+		    unsigned short ptype __unused,
+		    struct iphdr *ip, struct udphdr *udp,
+		    struct tcphdr *tcp __unused ) {
+	t_PXENV_UDP_READ *udp_read = (t_PXENV_UDP_READ*)ptr;
+	uint16_t d_port;
+	size_t size;
+
+	/* Ignore non-UDP packets */
+	if ( !udp ) {
+		DBG ( " non-UDP" );
+		return 0;
+	}
+	
+	/* Check dest_ip */
+	if ( udp_read->dest_ip && ( udp_read->dest_ip != ip->dest.s_addr ) ) {
+		DBG ( " wrong dest IP (got %@, wanted %@)",
+		      ip->dest.s_addr, udp_read->dest_ip );
+		return 0;
+	}
+
+	/* Check dest_port */
+	d_port = ntohs ( udp_read->d_port );
+	if ( d_port && ( d_port != ntohs(udp->dest) ) ) {
+		DBG ( " wrong dest port (got %d, wanted %d)",
+		      ntohs(udp->dest), d_port );
+		return 0;
+	}
+
+	/* Copy packet to buffer and fill in information */
+	udp_read->src_ip = ip->src.s_addr;
+	udp_read->s_port = udp->src; /* Both in network order */
+	size = ntohs(udp->len) - sizeof(*udp);
+	/* Workaround: NTLDR expects us to fill these in, even though
+	 * PXESPEC clearly defines them as input parameters.
+	 */
+	udp_read->dest_ip = ip->dest.s_addr;
+	udp_read->d_port = udp->dest;
+	DBG ( " %@:%d->%@:%d (%d)",
+	      udp_read->src_ip, ntohs(udp_read->s_port),
+	      udp_read->dest_ip, ntohs(udp_read->d_port), size );
+	if ( udp_read->buffer_size < size ) {
+		/* PXESPEC: what error code should we actually return? */
+		DBG ( " buffer too small (%d)", udp_read->buffer_size );
+		udp_read->Status = PXENV_STATUS_OUT_OF_RESOURCES;
+		return 0;
+	}
+	memcpy ( SEGOFF16_TO_PTR ( udp_read->buffer ), &udp->payload, size );
+	udp_read->buffer_size = size;
+
+	return 1;
+}
+
+PXENV_EXIT_t pxenv_udp_read ( t_PXENV_UDP_READ *udp_read ) {
+	DBG ( "PXENV_UDP_READ" );
+	ENSURE_READY ( udp_read );
+
+	/* Use await_reply with a timeout of zero */
+	/* Allow await_reply to change Status if necessary */
+	udp_read->Status = PXENV_STATUS_FAILURE;
+	if ( ! await_reply ( await_pxe_udp, 0, udp_read, 0 ) ) {
+		return PXENV_EXIT_FAILURE;
+	}
+
+	udp_read->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_UDP_WRITE
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_udp_write ( t_PXENV_UDP_WRITE *udp_write ) {
+	uint16_t src_port;
+	uint16_t dst_port;
+	struct udppacket *packet = (struct udppacket *)nic.packet;
+	int packet_size;
+
+	DBG ( "PXENV_UDP_WRITE" );
+	ENSURE_READY ( udp_write );
+
+	/* PXE spec says source port is 2069 if not specified */
+	src_port = ntohs(udp_write->src_port);
+	if ( src_port == 0 ) src_port = 2069;
+	dst_port = ntohs(udp_write->dst_port);
+	DBG ( " %d->%@:%d (%d)", src_port, udp_write->ip, dst_port,
+	      udp_write->buffer_size );
+	
+	/* FIXME: we ignore the gateway specified, since we're
+	 * confident of being able to do our own routing.  We should
+	 * probably allow for multiple gateways.
+	 */
+	
+	/* Copy payload to packet buffer */
+	packet_size = ( (void*)&packet->payload - (void*)packet )
+		+ udp_write->buffer_size;
+	if ( packet_size > ETH_FRAME_LEN ) {
+		udp_write->Status = PXENV_STATUS_OUT_OF_RESOURCES;
+		return PXENV_EXIT_FAILURE;
+	}
+	memcpy ( &packet->payload, SEGOFF16_TO_PTR(udp_write->buffer),
+		 udp_write->buffer_size );
+
+	/* Transmit packet */
+	if ( ! udp_transmit ( udp_write->ip, src_port, dst_port,
+			      packet_size, packet ) ) {
+		udp_write->Status = PXENV_STATUS_FAILURE;
+		return PXENV_EXIT_FAILURE;
+	}
+
+	udp_write->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_UNLOAD_STACK
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_unload_stack ( t_PXENV_UNLOAD_STACK *unload_stack ) {
+	int success;
+
+	DBG ( "PXENV_UNLOAD_STACK" );
+	success = ensure_pxe_state ( CAN_UNLOAD );
+
+	/* We need to call cleanup() at some point.  The network card
+	 * has already been disabled by ENSURE_CAN_UNLOAD(), but for
+	 * the sake of completeness we should call the console_fini()
+	 * etc. that are part of cleanup().
+	 *
+	 * There seems to be a lack of consensus on which is the final
+	 * PXE API call to make, but it's a fairly safe bet that all
+	 * the potential shutdown sequences will include a call to
+	 * PXENV_UNLOAD_STACK at some point, so we may as well do it
+	 * here.
+	 */
+	cleanup();
+
+	if ( ! success ) {
+		unload_stack->Status = PXENV_STATUS_KEEP_ALL;
+		return PXENV_EXIT_FAILURE;
+	}
+
+	unload_stack->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_GET_CACHED_INFO
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_get_cached_info ( t_PXENV_GET_CACHED_INFO
+				     *get_cached_info ) {
+	BOOTPLAYER *cached_info = &pxe_stack->cached_info;
+	DBG ( "PXENV_GET_CACHED_INFO %d", get_cached_info->PacketType );
+	ENSURE_READY ( get_cached_info );
+
+	/* Fill in cached_info structure in our pxe_stack */
+
+	/* I don't think there's actually any way we can be called in
+	 * the middle of a DHCP request... 
+	 */
+	cached_info->opcode = BOOTP_REP;
+	/* We only have Ethernet drivers */
+	cached_info->Hardware = ETHER_TYPE;
+	cached_info->Hardlen = ETH_ALEN;
+	/* PXESPEC: "Client sets" says the spec, but who's filling in
+	 * this structure?  It ain't the client.
+	 */
+	cached_info->Gatehops = 0;
+	cached_info->ident = 0;
+	cached_info->seconds = 0;
+	cached_info->Flags = BOOTP_BCAST;
+	/* PXESPEC: What do 'Client' and 'Your' IP address refer to? */
+	cached_info->cip = arptable[ARP_CLIENT].ipaddr.s_addr;
+	cached_info->yip = arptable[ARP_CLIENT].ipaddr.s_addr;
+	cached_info->sip = arptable[ARP_SERVER].ipaddr.s_addr;
+	/* PXESPEC: Does "GIP" mean "Gateway" or "Relay agent"? */
+	cached_info->gip = arptable[ARP_GATEWAY].ipaddr.s_addr;
+	memcpy ( cached_info->CAddr, arptable[ARP_CLIENT].node, ETH_ALEN );
+	/* Nullify server name */
+	cached_info->Sname[0] = '\0';
+	memcpy ( cached_info->bootfile, KERNEL_BUF,
+		 sizeof(cached_info->bootfile) );
+	/* Copy DHCP vendor options */
+	memcpy ( &cached_info->vendor.d, BOOTP_DATA_ADDR->bootp_reply.bp_vend,
+		 sizeof(cached_info->vendor.d) );
+	
+	/* Copy to user-specified buffer, or set pointer to our buffer */
+	get_cached_info->BufferLimit = sizeof(*cached_info);
+	/* PXESPEC: says to test for Buffer == NULL *and* BufferSize =
+	 * 0, but what are we supposed to do with a null buffer of
+	 * non-zero size?!
+	 */
+	if ( IS_NULL_SEGOFF16 ( get_cached_info->Buffer ) ) {
+		/* Point back to our buffer */
+		PTR_TO_SEGOFF16 ( cached_info, get_cached_info->Buffer );
+		get_cached_info->BufferSize = sizeof(*cached_info);
+	} else {
+		/* Copy to user buffer */
+		size_t size = sizeof(*cached_info);
+		void *buffer = SEGOFF16_TO_PTR ( get_cached_info->Buffer );
+		if ( get_cached_info->BufferSize < size )
+			size = get_cached_info->BufferSize;
+		DBG ( " to %x", virt_to_phys ( buffer ) );
+		memcpy ( buffer, cached_info, size );
+		/* PXESPEC: Should we return an error if the user
+		 * buffer is too small?  We do return the actual size
+		 * of the buffer via BufferLimit, so the user does
+		 * have a way to detect this already.
+		 */
+	}
+
+	get_cached_info->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_RESTART_TFTP
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_restart_tftp ( t_PXENV_RESTART_TFTP *restart_tftp ) {
+	PXENV_EXIT_t tftp_exit;
+
+	DBG ( "PXENV_RESTART_TFTP" );
+	ENSURE_READY ( restart_tftp );
+
+	/* Words cannot describe the complete mismatch between the PXE
+	 * specification and any possible version of reality...
+	 */
+	restart_tftp->Buffer = PXE_LOAD_ADDRESS; /* Fixed by spec, apparently */
+	restart_tftp->BufferSize = get_free_base_memory() - PXE_LOAD_ADDRESS; /* Near enough */
+	DBG ( "(" );
+	tftp_exit = pxe_api_call ( PXENV_TFTP_READ_FILE, (t_PXENV_ANY*)restart_tftp );
+	DBG ( ")" );
+	if ( tftp_exit != PXENV_EXIT_SUCCESS ) return tftp_exit;
+
+	/* Fire up the new NBP */
+	restart_tftp->Status = xstartpxe();
+
+	/* Not sure what "SUCCESS" actually means, since we can only
+	 * return if the new NBP failed to boot...
+	 */
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_START_BASE
+ *
+ * Status: won't implement (requires major structural changes)
+ */
+PXENV_EXIT_t pxenv_start_base ( t_PXENV_START_BASE *start_base ) {
+	DBG ( "PXENV_START_BASE" );
+	/* ENSURE_READY ( start_base ); */
+	start_base->Status = PXENV_STATUS_UNSUPPORTED;
+	return PXENV_EXIT_FAILURE;
+}
+
+/* PXENV_STOP_BASE
+ *
+ * Status: working
+ */
+PXENV_EXIT_t pxenv_stop_base ( t_PXENV_STOP_BASE *stop_base ) {
+	DBG ( "PXENV_STOP_BASE" );
+
+	/* The only time we will be called is when the NBP is trying
+	 * to shut down the PXE stack.  There's nothing we need to do
+	 * in this call.
+	 */
+
+	stop_base->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* PXENV_UNDI_LOADER
+ *
+ * Status: working
+ *
+ * NOTE: This is not a genuine PXE API call; the loader has a separate
+ * entry point.  However, to simplify the mapping of the PXE API to
+ * the internal Etherboot API, both are directed through the same
+ * interface.
+ */
+PXENV_EXIT_t pxenv_undi_loader ( undi_loader_t *loader ) {
+	uint32_t loader_phys = virt_to_phys ( loader );
+
+	DBG ( "PXENV_UNDI_LOADER" );
+	
+	/* Set UNDI DS as our real-mode stack */
+	use_undi_ds_for_rm_stack ( loader->undi_ds );
+
+	/* FIXME: These lines are borrowed from main.c.  There should
+	 * probably be a single initialise() function that does all
+	 * this, but it's currently split interestingly between main()
+	 * and main_loop()...
+	 */
+	console_init();
+	cpu_setup();
+	setup_timers();
+	gateA20_set();
+	print_config();
+	get_memsizes();
+	cleanup();
+	relocate();
+	cleanup();
+	console_init();
+	init_heap();
+
+	/* We have relocated; the loader pointer is now invalid */
+	loader = phys_to_virt ( loader_phys );
+
+	/* Install PXE stack to area specified by NBP */
+	install_pxe_stack ( VIRTUAL ( loader->undi_cs, 0 ) );
+	
+	/* Call pxenv_start_undi to set parameters.  Why the hell PXE
+	 * requires these parameters to be provided twice is beyond
+	 * the wit of any sane man.  Don't worry if it fails; the NBP
+	 * should call PXENV_START_UNDI separately anyway.
+	 */
+	pxenv_start_undi ( &loader->start_undi );
+	/* Unhook stack; the loader is not meant to hook int 1a etc,
+	 * but the call the pxenv_start_undi will cause it to happen.
+	 */
+	ENSURE_CAN_UNLOAD ( loader );
+
+	/* Fill in addresses of !PXE and PXENV+ structures */
+	PTR_TO_SEGOFF16 ( &pxe_stack->pxe, loader->pxe_ptr );
+	PTR_TO_SEGOFF16 ( &pxe_stack->pxenv, loader->pxenv_ptr );
+	
+	loader->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
+/* API call dispatcher
+ *
+ * Status: complete
+ */
+PXENV_EXIT_t pxe_api_call ( int opcode, t_PXENV_ANY *params ) {
+	PXENV_EXIT_t ret = PXENV_EXIT_FAILURE;
+
+	/* Set default status in case child routine fails to do so */
+	params->Status = PXENV_STATUS_FAILURE;
+
+	DBG ( "[" );
+
+	/* Hand off to relevant API routine */
+	switch ( opcode ) {
+	case PXENV_START_UNDI:
+		ret = pxenv_start_undi ( &params->start_undi );
+		break;
+	case PXENV_UNDI_STARTUP:
+		ret = pxenv_undi_startup ( &params->undi_startup );
+		break;
+	case PXENV_UNDI_CLEANUP:
+		ret = pxenv_undi_cleanup ( &params->undi_cleanup );
+		break;
+	case PXENV_UNDI_INITIALIZE:
+		ret = pxenv_undi_initialize ( &params->undi_initialize );
+		break;
+	case PXENV_UNDI_RESET_ADAPTER:
+		ret = pxenv_undi_reset_adapter ( &params->undi_reset_adapter );
+		break;
+	case PXENV_UNDI_SHUTDOWN:
+		ret = pxenv_undi_shutdown ( &params->undi_shutdown );
+		break;
+	case PXENV_UNDI_OPEN:
+		ret = pxenv_undi_open ( &params->undi_open );
+		break;
+	case PXENV_UNDI_CLOSE:
+		ret = pxenv_undi_close ( &params->undi_close );
+		break;
+	case PXENV_UNDI_TRANSMIT:
+		ret = pxenv_undi_transmit ( &params->undi_transmit );
+		break;
+	case PXENV_UNDI_SET_MCAST_ADDRESS:
+		ret = pxenv_undi_set_mcast_address (
+				             &params->undi_set_mcast_address );
+		break;
+	case PXENV_UNDI_SET_STATION_ADDRESS:
+		ret = pxenv_undi_set_station_address (
+					   &params->undi_set_station_address );
+		break;
+	case PXENV_UNDI_SET_PACKET_FILTER:
+		ret = pxenv_undi_set_packet_filter (
+					     &params->undi_set_packet_filter );
+		break;
+	case PXENV_UNDI_GET_INFORMATION:
+		ret = pxenv_undi_get_information (
+					       &params->undi_get_information );
+		break;
+	case PXENV_UNDI_GET_STATISTICS:
+		ret = pxenv_undi_get_statistics (
+					        &params->undi_get_statistics );
+		break;
+	case PXENV_UNDI_CLEAR_STATISTICS:
+		ret = pxenv_undi_clear_statistics (
+					      &params->undi_clear_statistics );
+		break;
+	case PXENV_UNDI_INITIATE_DIAGS:
+		ret = pxenv_undi_initiate_diags (
+						&params->undi_initiate_diags );
+		break;
+	case PXENV_UNDI_FORCE_INTERRUPT:
+		ret = pxenv_undi_force_interrupt (
+					       &params->undi_force_interrupt );
+		break;
+	case PXENV_UNDI_GET_MCAST_ADDRESS:
+		ret = pxenv_undi_get_mcast_address (
+					     &params->undi_get_mcast_address );
+		break;
+	case PXENV_UNDI_GET_NIC_TYPE:
+		ret = pxenv_undi_get_nic_type ( &params->undi_get_nic_type );
+		break;
+	case PXENV_UNDI_GET_IFACE_INFO:
+		ret = pxenv_undi_get_iface_info (
+					        &params->undi_get_iface_info );
+		break;
+	case PXENV_UNDI_ISR:
+		ret = pxenv_undi_isr ( &params->undi_isr );
+		break;
+	case PXENV_STOP_UNDI:
+		ret = pxenv_stop_undi ( &params->stop_undi );
+		break;
+	case PXENV_TFTP_OPEN:
+		ret = pxenv_tftp_open ( &params->tftp_open );
+		break;
+	case PXENV_TFTP_CLOSE:
+		ret = pxenv_tftp_close ( &params->tftp_close );
+		break;
+	case PXENV_TFTP_READ:
+		ret = pxenv_tftp_read ( &params->tftp_read );
+		break;
+	case PXENV_TFTP_READ_FILE:
+		ret = pxenv_tftp_read_file ( &params->tftp_read_file );
+		break;
+	case PXENV_TFTP_GET_FSIZE:
+		ret = pxenv_tftp_get_fsize ( &params->tftp_get_fsize );
+		break;
+	case PXENV_UDP_OPEN:
+		ret = pxenv_udp_open ( &params->udp_open );
+		break;
+	case PXENV_UDP_CLOSE:
+		ret = pxenv_udp_close ( &params->udp_close );
+		break;
+	case PXENV_UDP_READ:
+		ret = pxenv_udp_read ( &params->udp_read );
+		break;
+	case PXENV_UDP_WRITE:
+		ret = pxenv_udp_write ( &params->udp_write );
+		break;
+	case PXENV_UNLOAD_STACK:
+		ret = pxenv_unload_stack ( &params->unload_stack );
+		break;
+	case PXENV_GET_CACHED_INFO:
+		ret = pxenv_get_cached_info ( &params->get_cached_info );
+		break;
+	case PXENV_RESTART_TFTP:
+		ret = pxenv_restart_tftp ( &params->restart_tftp );
+		break;
+	case PXENV_START_BASE:
+		ret = pxenv_start_base ( &params->start_base );
+		break;
+	case PXENV_STOP_BASE:
+		ret = pxenv_stop_base ( &params->stop_base );
+		break;
+	case PXENV_UNDI_LOADER:
+		ret = pxenv_undi_loader ( &params->loader );
+		break;
+		
+	default:
+		DBG ( "PXENV_UNKNOWN_%hx", opcode );
+		params->Status = PXENV_STATUS_UNSUPPORTED;
+		ret = PXENV_EXIT_FAILURE;
+		break;
+	}
+
+	if ( params->Status != PXENV_STATUS_SUCCESS ) {
+		DBG ( " %hx", params->Status );
+	}
+	if ( ret != PXENV_EXIT_SUCCESS ) {
+		DBG ( ret == PXENV_EXIT_FAILURE ? " err" : " ??" );
+	}
+	DBG ( "]" );
+
+	return ret;
+}
+
+#endif /* PXE_EXPORT */