undirom.c

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/*
 * 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.
 */

FILE_LICENCE ( GPL2_OR_LATER );

#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <pxe.h>
#include <realmode.h>
#include <undirom.h>

/** @file
 *
 * UNDI expansion ROMs
 *
 */

/** List of all UNDI ROMs */
static LIST_HEAD ( undiroms );

/**
 * Parse PXE ROM ID structure
 *
 * @v undirom           UNDI ROM
 * @v pxeromid          Offset within ROM to PXE ROM ID structure
 * @ret rc              Return status code
 */
static int undirom_parse_pxeromid ( struct undi_rom *undirom,
                                   unsigned int pxeromid ) {
        struct undi_rom_id undi_rom_id;
        unsigned int undiloader;

        DBGC ( undirom, "UNDIROM %p has PXE ROM ID at %04x:%04x\n", undirom,
               undirom->rom_segment, pxeromid );

        /* Read PXE ROM ID structure and verify */
        copy_from_real ( &undi_rom_id, undirom->rom_segment, pxeromid,
                         sizeof ( undi_rom_id ) );
        if ( undi_rom_id.Signature != UNDI_ROM_ID_SIGNATURE ) {
                DBGC ( undirom, "UNDIROM %p has bad PXE ROM ID signature "
                       "%08x\n", undirom, undi_rom_id.Signature );
                return -EINVAL;
        }

        /* Check for UNDI loader */
        undiloader = undi_rom_id.UNDILoader;
        if ( ! undiloader ) {
                DBGC ( undirom, "UNDIROM %p has no UNDI loader\n", undirom );
                return -EINVAL;
        }

        /* Fill in UNDI ROM loader fields */
        undirom->loader_entry.segment = undirom->rom_segment;
        undirom->loader_entry.offset = undiloader;
        undirom->code_size = undi_rom_id.CodeSize;
        undirom->data_size = undi_rom_id.DataSize;

        DBGC ( undirom, "UNDIROM %p has UNDI loader at %04x:%04x "
               "(code %04zx data %04zx)\n", undirom,
               undirom->loader_entry.segment, undirom->loader_entry.offset,
               undirom->code_size, undirom->data_size );
        return 0;
}

/**
 * Parse PCI expansion header
 *
 * @v undirom           UNDI ROM
 * @v pcirheader        Offset within ROM to PCI expansion header
 */
static int undirom_parse_pcirheader ( struct undi_rom *undirom,
                                     unsigned int pcirheader ) {
        struct pcir_header pcir_header;

        DBGC ( undirom, "UNDIROM %p has PCI expansion header at %04x:%04x\n",
               undirom, undirom->rom_segment, pcirheader );

        /* Read PCI expansion header and verify */
        copy_from_real ( &pcir_header, undirom->rom_segment, pcirheader,
                         sizeof ( pcir_header ) );
        if ( pcir_header.signature != PCIR_SIGNATURE ) {
                DBGC ( undirom, "UNDIROM %p has bad PCI expansion header "
                       "signature %08x\n", undirom, pcir_header.signature );
                return -EINVAL;
        }

        /* Fill in UNDI ROM PCI device fields */
        undirom->bus_type = PCI_NIC;
        undirom->bus_id.pci.vendor_id = pcir_header.vendor_id;
        undirom->bus_id.pci.device_id = pcir_header.device_id;

        DBGC ( undirom, "UNDIROM %p is for PCI devices %04x:%04x\n", undirom,
               undirom->bus_id.pci.vendor_id, undirom->bus_id.pci.device_id );
        return 0;
        
}

/**
 * Probe UNDI ROM
 *
 * @v rom_segment       ROM segment address
 * @ret rc              Return status code
 */
static int undirom_probe ( unsigned int rom_segment ) {
        struct undi_rom *undirom = NULL;
        struct undi_rom_header romheader;
        size_t rom_len;
        unsigned int pxeromid;
        unsigned int pcirheader;
        int rc;

        /* Read expansion ROM header and verify */
        copy_from_real ( &romheader, rom_segment, 0, sizeof ( romheader ) );
        if ( romheader.Signature != ROM_SIGNATURE ) {
                rc = -EINVAL;
                goto err;
        }
        rom_len = ( romheader.ROMLength * 512 );

        /* Allocate memory for UNDI ROM */
        undirom = zalloc ( sizeof ( *undirom ) );
        if ( ! undirom ) {
                DBG ( "Could not allocate UNDI ROM structure\n" );
                rc = -ENOMEM;
                goto err;
        }
        DBGC ( undirom, "UNDIROM %p trying expansion ROM at %04x:0000 "
               "(%zdkB)\n", undirom, rom_segment, ( rom_len / 1024 ) );
        undirom->rom_segment = rom_segment;

        /* Check for and parse PXE ROM ID */
        pxeromid = romheader.PXEROMID;
        if ( ! pxeromid ) {
                DBGC ( undirom, "UNDIROM %p has no PXE ROM ID\n", undirom );
                rc = -EINVAL;
                goto err;
        }
        if ( pxeromid > rom_len ) {
                DBGC ( undirom, "UNDIROM %p PXE ROM ID outside ROM\n",
                       undirom );
                rc = -EINVAL;
                goto err;
        }
        if ( ( rc = undirom_parse_pxeromid ( undirom, pxeromid ) ) != 0 )
                goto err;

        /* Parse PCIR header, if present */
        pcirheader = romheader.PCIRHeader;
        if ( pcirheader )
                undirom_parse_pcirheader ( undirom, pcirheader );

        /* Add to UNDI ROM list and return */
        DBGC ( undirom, "UNDIROM %p registered\n", undirom );
        list_add ( &undirom->list, &undiroms );
        return 0;

 err:
        free ( undirom );
        return rc;
}

/**
 * Create UNDI ROMs for all possible expansion ROMs
 *
 * @ret 
 */
static void undirom_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 512 byte intervals */
        for ( rom_segment = 0xc000 ; rom_segment < 0x10000 ;
              rom_segment += 0x20 ) {
                undirom_probe ( rom_segment );
        }

        probed = 1;
}

/**
 * Find UNDI ROM 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 undirom         UNDI ROM, or NULL
 */
struct undi_rom * undirom_find_pci ( unsigned int vendor_id,
                                     unsigned int device_id,
                                     unsigned int rombase ) {
        struct undi_rom *undirom;

        undirom_probe_all_roms();

        list_for_each_entry ( undirom, &undiroms, list ) {
                if ( undirom->bus_type != PCI_NIC )
                        continue;
                if ( undirom->bus_id.pci.vendor_id != vendor_id )
                        continue;
                if ( undirom->bus_id.pci.device_id != device_id )
                        continue;
                if ( rombase && ( ( undirom->rom_segment << 4 ) != rombase ) )
                        continue;
                DBGC ( undirom, "UNDIROM %p matched PCI %04x:%04x (%08x)\n",
                       undirom, vendor_id, device_id, rombase );
                return undirom;
        }

        DBG ( "No UNDI ROM matched PCI %04x:%04x (%08x)\n",
              vendor_id, device_id, rombase );
        return NULL;
}