Add PXE driver-scanning code, capable of locating all PXE ROMs in a system

and matching them up to (e.g. PCI) devices.

src/arch/i386/drivers/bus/pxedrv.c

@@ -0,0 +1,223 @@
+/*
+ * Copyright (C) 2007 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.
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pxe.h>
+#include <realmode.h>
+
+/** @file
+ *
+ * PXE drivers
+ *
+ */
+
+static LIST_HEAD ( pxe_drivers );
+
+/**
+ * Parse PXE ROM ID structure
+ *
+ * @v pxedrv		PXE driver
+ * @v pxeromid		Offset within ROM to PXE ROM ID structure
+ * @ret rc		Return status code
+ */
+static int pxedrv_parse_pxeromid ( struct pxe_driver *pxedrv,
+				   unsigned int pxeromid ) {
+	struct undi_rom_id undi_rom_id;
+	unsigned int undiloader;
+
+	DBGC ( pxedrv, "PXEDRV %p has PXE ROM ID at %04x:%04x\n", pxedrv,
+	       pxedrv->rom_segment, pxeromid );
+
+	/* Read PXE ROM ID structure and verify */
+	copy_from_real ( &undi_rom_id, pxedrv->rom_segment, pxeromid,
+			 sizeof ( undi_rom_id ) );
+	if ( undi_rom_id.Signature != UNDI_ROM_ID_SIGNATURE ) {
+		DBGC ( pxedrv, "PXEDRV %p has bad PXE ROM ID signature "
+		       "%08lx\n", pxedrv, undi_rom_id.Signature );
+		return -EINVAL;
+	}
+
+	/* Check for UNDI loader */
+	undiloader = undi_rom_id.UNDILoader;
+	if ( ! undiloader ) {
+		DBGC ( pxedrv, "PXEDRV %p has no UNDI loader\n", pxedrv );
+		return -EINVAL;
+	}
+
+	/* Fill in PXE driver loader fields */
+	pxedrv->loader.segment = pxedrv->rom_segment;
+	pxedrv->loader.offset = undiloader;
+	pxedrv->code_size = undi_rom_id.CodeSize;
+	pxedrv->data_size = undi_rom_id.DataSize;
+
+	DBGC ( pxedrv, "PXEDRV %p has UNDI loader at %04x:%04x "
+	       "(code %04x data %04x)\n", pxedrv, pxedrv->loader.segment,
+	       pxedrv->loader.offset, pxedrv->code_size, pxedrv->data_size );
+	return 0;
+}
+
+/**
+ * Parse PCI expansion header
+ *
+ * @v pxedrv		PXE driver
+ * @v pcirheader	Offset within ROM to PCI expansion header
+ */
+static int pxedrv_parse_pcirheader ( struct pxe_driver *pxedrv,
+				     unsigned int pcirheader ) {
+	struct pcir_header pcir_header;
+
+	DBGC ( pxedrv, "PXEDRV %p has PCI expansion header at %04x:%04x\n",
+	       pxedrv, pxedrv->rom_segment, pcirheader );
+
+	/* Read PCI expansion header and verify */
+	copy_from_real ( &pcir_header, pxedrv->rom_segment, pcirheader,
+			 sizeof ( pcir_header ) );
+	if ( pcir_header.signature != PCIR_SIGNATURE ) {
+		DBGC ( pxedrv, "PXEDRV %p has bad PCI expansion header "
+		       "signature %08lx\n", pxedrv, pcir_header.signature );
+		return -EINVAL;
+	}
+	DBGC ( pxedrv, "PXEDRV %p is a PCI ROM\n", pxedrv );
+
+	/* Fill in PXE driver PCI device fields */
+	pxedrv->bus_type = PCI_NIC;
+	pxedrv->bus_id.pci.vendor_id = pcir_header.vendor_id;
+	pxedrv->bus_id.pci.device_id = pcir_header.device_id;
+
+	DBGC ( pxedrv, "PXEDRV %p is for PCI devices %04x:%04x\n", pxedrv,
+	       pxedrv->bus_id.pci.vendor_id, pxedrv->bus_id.pci.device_id );
+	return 0;
+	
+}
+
+/**
+ * Create PXE driver for expansion ROM
+ *
+ * @v rom_segment	ROM segment address
+ * @ret rc		Return status code
+ */
+static int pxedrv_probe_rom ( unsigned int rom_segment ) {
+	struct pxe_driver *pxedrv = NULL;
+	struct undi_rom rom;
+	unsigned int pxeromid;
+	unsigned int pcirheader;
+	int rc;
+
+	/* Read expansion ROM header and verify */
+	copy_from_real ( &rom, rom_segment, 0, sizeof ( rom ) );
+	if ( rom.Signature != ROM_SIGNATURE ) {
+		rc = -EINVAL;
+		goto err;
+	}
+
+	/* Allocate memory for PXE driver */
+	pxedrv = malloc ( sizeof ( *pxedrv ) );
+	if ( ! pxedrv ) {
+		DBG ( "Could not allocate PXE driver structure\n" );
+		rc = -ENOMEM;
+		goto err;
+	}
+	memset ( pxedrv, 0, sizeof ( *pxedrv ) );
+	DBGC ( pxedrv, "PXEDRV %p using expansion ROM at %04x:0000 (%zdkB)\n",
+	       pxedrv, rom_segment, ( rom.ROMLength / 2 ) );
+	pxedrv->rom_segment = rom_segment;
+
+	/* Check for and parse PXE ROM ID */
+	pxeromid = rom.PXEROMID;
+	if ( ! pxeromid ) {
+		DBGC ( pxedrv, "PXEDRV %p has no PXE ROM ID\n", pxedrv );
+		rc = -EINVAL;
+		goto err;
+	}
+	if ( ( rc = pxedrv_parse_pxeromid ( pxedrv, pxeromid ) ) != 0 )
+		goto err;
+
+	/* Parse PCIR header, if present */
+	pcirheader = rom.PCIRHeader;
+	if ( pcirheader )
+		pxedrv_parse_pcirheader ( pxedrv, pcirheader );
+
+	/* Add to PXE driver list and return */
+	DBGC ( pxedrv, "PXEDRV %p registered\n", pxedrv );
+	list_add ( &pxedrv->list, &pxe_drivers );
+	return 0;
+
+ err:
+	free ( pxedrv );
+	return rc;
+}
+
+/**
+ * Create PXE drivers for all possible expansion ROMs
+ *
+ * @ret 
+ */
+static void pxedrv_probe_all_roms ( void ) {
+	static int probed = 0;
+	unsigned int rom_segment;
+
+	/* Perform probe only once */
+	if ( probed )
+		return;
+
+	DBG ( "Scanning for PXE expansion ROMs\n" );
+
+	/* Scan through expansion ROM region at 2kB intervals */
+	for ( rom_segment = 0xc000 ; rom_segment < 0x10000 ;
+	      rom_segment += 0x80 ) {
+		pxedrv_probe_rom ( rom_segment );
+	}
+
+	probed = 1;
+}
+
+/**
+ * Find PXE driver for PCI device
+ *
+ * @v vendor_id		PCI vendor ID
+ * @v device_id		PCI device ID
+ * @v rombase		ROM base address, or 0 for any
+ * @ret pxedrv		PXE driver, or NULL
+ */
+struct pxe_driver * pxedrv_find_pci_driver ( unsigned int vendor_id,
+					     unsigned int device_id,
+					     unsigned int rombase ) {
+	struct pxe_driver *pxedrv;
+
+	pxedrv_probe_all_roms();
+
+	list_for_each_entry ( pxedrv, &pxe_drivers, list ) {
+		if ( pxedrv->bus_type != PCI_NIC )
+			continue;
+		if ( pxedrv->bus_id.pci.vendor_id != vendor_id )
+			continue;
+		if ( pxedrv->bus_id.pci.device_id != device_id )
+			continue;
+		if ( rombase && ( ( pxedrv->rom_segment << 4 ) != rombase ) )
+			continue;
+		DBGC ( pxedrv, "PXEDRV %p matched PCI %04x:%04x (%08x)\n",
+		       pxedrv, vendor_id, device_id, rombase );
+		return pxedrv;
+	}
+
+	DBG ( "No PXE driver matched PCI %04x:%04x (%08x)\n",
+	      vendor_id, device_id, rombase );
+	return NULL;
+}

src/include/pxe.h

@@ -62,6 +62,113 @@ union u_PXENV_ANY {
 
 typedef union u_PXENV_ANY PXENV_ANY_t;
 
+/** An UNDI expansion ROM */
+struct undi_rom {
+	/** Signature
+	 *
+	 * Must be equal to @c ROM_SIGNATURE
+	 */
+	UINT16_t Signature;
+	/** ROM length in 512-byte blocks */
+	UINT8_t ROMLength;
+	/** Unused */
+	UINT8_t unused[0x13];
+	/** Offset of the PXE ROM ID structure */
+	UINT16_t PXEROMID;
+	/** Offset of the PCI ROM structure */
+	UINT16_t PCIRHeader;
+} PACKED;
+
+/** Signature for an expansion ROM */
+#define ROM_SIGNATURE 0xaa55
+
+/** An UNDI ROM ID structure */
+struct undi_rom_id {
+	/** Signature
+	 *
+	 * Must be equal to @c UNDI_ROM_ID_SIGNATURE
+	 */
+	UINT32_t Signature;
+	/** Length of structure */
+	UINT8_t StructLength;
+	/** Checksum */
+	UINT8_t StructCksum;
+	/** Structure revision
+	 *
+	 * Must be zero.
+	 */
+	UINT8_t StructRev;
+	/** UNDI revision
+	 *
+	 * Version 2.1.0 is encoded as the byte sequence 0x00, 0x01, 0x02.
+	 */
+	UINT8_t UNDIRev[3];
+	/** Offset to UNDI loader */
+	UINT16_t UNDILoader;
+	/** Minimum required stack segment size */
+	UINT16_t StackSize;
+	/** Minimum required data segment size */
+	UINT16_t DataSize;
+	/** Minimum required code segment size */
+	UINT16_t CodeSize;
+} PACKED;
+
+/** Signature for an UNDI ROM ID structure */
+#define UNDI_ROM_ID_SIGNATURE \
+	( ( 'U' << 0 ) + ( 'N' << 8 ) + ( 'D' << 16 ) + ( 'I' << 24 ) )
+
+/** A PCI expansion header */
+struct pcir_header {
+	/** Signature
+	 *
+	 * Must be equal to @c PCIR_SIGNATURE
+	 */
+	uint32_t signature;
+	/** PCI vendor ID */
+	uint16_t vendor_id;
+	/** PCI device ID */
+	uint16_t device_id;
+} PACKED;
+
+/** Signature for an UNDI ROM ID structure */
+#define PCIR_SIGNATURE \
+	( ( 'P' << 0 ) + ( 'C' << 8 ) + ( 'I' << 16 ) + ( 'R' << 24 ) )
+
+/** A PXE PCI device ID */
+struct pxe_pci_device_id {
+	/** PCI vendor ID */
+	unsigned int vendor_id;
+	/** PCI device ID */
+	unsigned int device_id;
+};
+
+/** A PXE device ID */
+union pxe_device_id {
+	/** PCI device ID */
+	struct pxe_pci_device_id pci;
+};
+
+/** A PXE driver */
+struct pxe_driver {
+	/** List of PXE drivers */
+	struct list_head list;
+	/** ROM segment address */
+	unsigned int rom_segment;
+	/** UNDI loader entry point */
+	SEGOFF16_t loader;
+	/** Code segment size */
+	size_t code_size;
+	/** Data segment size */
+	size_t data_size;
+	/** Bus type
+	 *
+	 * Values are as used by @c PXENV_UNDI_GET_NIC_TYPE
+	 */
+	unsigned int bus_type;
+	/** Device ID */
+	union pxe_device_id bus_id;
+};
+
 /** A PXE device */
 struct pxe_device {
 	/** Generic device */
@@ -83,8 +190,8 @@ struct pxe_device {
 	MAC_ADDR_t hwaddr;
 	/** Assigned IRQ number */
 	UINT16_t irq;
-	/** ROM address */
-	SEGSEL_t rom;
+	/** ROM segment address */
+	SEGSEL_t rom_segment;
 };
 
 /**
@@ -112,6 +219,10 @@ extern int pxe_call ( struct pxe_device *pxe, unsigned int function,
 extern int undi_probe ( struct pxe_device *pxe );
 extern void undi_remove ( struct pxe_device *pxe );
 
+extern struct pxe_driver * pxedrv_find_pci_driver ( unsigned int vendor_id,
+						    unsigned int device_id,
+						    unsigned int rombase );
+
 extern struct net_device *pxe_netdev;
 
 #endif /* PXE_H */