src/arch/i386/drivers/net/undiload.c

   1 /*
   2  * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * License, or any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17  */
  18
  19 FILE_LICENCE ( GPL2_OR_LATER );
  20
  21 #include <stdint.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <pxe.h>
  25 #include <realmode.h>
  26 #include <bios.h>
  27 #include <pnpbios.h>
  28 #include <basemem.h>
  29 #include <gpxe/pci.h>
  30 #include <undi.h>
  31 #include <undirom.h>
  32 #include <undiload.h>
  33
  34 /** @file
  35  *
  36  * UNDI load/unload
  37  *
  38  */
  39
  40 /** Parameter block for calling UNDI loader */
  41 static struct s_UNDI_LOADER __bss16 ( undi_loader );
  42 #define undi_loader __use_data16 ( undi_loader )
  43
  44 /** UNDI loader entry point */
  45 static SEGOFF16_t __bss16 ( undi_loader_entry );
  46 #define undi_loader_entry __use_data16 ( undi_loader_entry )
  47
  48 /**
  49  * Call UNDI loader to create a pixie
  50  *
  51  * @v undi              UNDI device
  52  * @v undirom           UNDI ROM
  53  * @ret rc              Return status code
  54  */
  55 int undi_load ( struct undi_device *undi, struct undi_rom *undirom ) {
  56         struct s_PXE ppxe;
  57         unsigned int fbms_seg;
  58         uint16_t exit;
  59         int rc;
  60
  61         /* Only one UNDI instance may be loaded at any given time */
  62         if ( undi_loader_entry.segment ) {
  63                 DBG ( "UNDI %p cannot load multiple instances\n", undi );
  64                 return -EBUSY;
  65         }
  66
  67         /* Set up START_UNDI parameters */
  68         memset ( &undi_loader, 0, sizeof ( undi_loader ) );
  69         undi_loader.AX = undi->pci_busdevfn;
  70         undi_loader.BX = undi->isapnp_csn;
  71         undi_loader.DX = undi->isapnp_read_port;
  72         undi_loader.ES = BIOS_SEG;
  73         undi_loader.DI = find_pnp_bios();
  74
  75         /* Allocate base memory for PXE stack */
  76         undi->restore_fbms = get_fbms();
  77         fbms_seg = ( undi->restore_fbms << 6 );
  78         fbms_seg -= ( ( undirom->code_size + 0x0f ) >> 4 );
  79         undi_loader.UNDI_CS = fbms_seg;
  80         fbms_seg -= ( ( undirom->data_size + 0x0f ) >> 4 );
  81         undi_loader.UNDI_DS = fbms_seg;
  82
  83         /* Debug info */
  84         DBGC ( undi, "UNDI %p loading UNDI ROM %p to CS %04x DS %04x for ",
  85                undi, undirom, undi_loader.UNDI_CS, undi_loader.UNDI_DS );
  86         if ( undi->pci_busdevfn != UNDI_NO_PCI_BUSDEVFN ) {
  87                 unsigned int bus = ( undi->pci_busdevfn >> 8 );
  88                 unsigned int devfn = ( undi->pci_busdevfn & 0xff );
  89                 DBGC ( undi, "PCI %02x:%02x.%x\n",
  90                        bus, PCI_SLOT ( devfn ), PCI_FUNC ( devfn ) );
  91         }
  92         if ( undi->isapnp_csn != UNDI_NO_ISAPNP_CSN ) {
  93                 DBGC ( undi, "ISAPnP(%04x) CSN %04x\n",
  94                        undi->isapnp_read_port, undi->isapnp_csn );
  95         }
  96
  97         /* Call loader */
  98         undi_loader_entry = undirom->loader_entry;
  99         __asm__ __volatile__ ( REAL_CODE ( "pushw %%ds\n\t"
 100                                            "pushw %%ax\n\t"
 101                                            "lcall *undi_loader_entry\n\t"
 102                                            "addw $4, %%sp\n\t" )
 103                                : "=a" ( exit )
 104                                : "a" ( __from_data16 ( &undi_loader ) )
 105                                : "ebx", "ecx", "edx", "esi", "edi", "ebp" );
 106
 107         /* UNDI API calls may rudely change the status of A20 and not
 108          * bother to restore it afterwards.  Intel is known to be
 109          * guilty of this.
 110          *
 111          * Note that we will return to this point even if A20 gets
 112          * screwed up by the UNDI driver, because Etherboot always
 113          * resides in an even megabyte of RAM.
 114          */
 115         gateA20_set();
 116
 117         if ( exit != PXENV_EXIT_SUCCESS ) {
 118                 /* Clear entry point */
 119                 memset ( &undi_loader_entry, 0, sizeof ( undi_loader_entry ) );
 120
 121                 rc = -undi_loader.Status;
 122                 if ( rc == 0 ) /* Paranoia */
 123                         rc = -EIO;
 124                 DBGC ( undi, "UNDI %p loader failed: %s\n",
 125                        undi, strerror ( rc ) );
 126                 return rc;
 127         }
 128
 129         /* Populate PXE device structure */
 130         undi->pxenv = undi_loader.PXENVptr;
 131         undi->ppxe = undi_loader.PXEptr;
 132         copy_from_real ( &ppxe, undi->ppxe.segment, undi->ppxe.offset,
 133                          sizeof ( ppxe ) );
 134         undi->entry = ppxe.EntryPointSP;
 135         DBGC ( undi, "UNDI %p loaded PXENV+ %04x:%04x !PXE %04x:%04x "
 136                "entry %04x:%04x\n", undi, undi->pxenv.segment,
 137                undi->pxenv.offset, undi->ppxe.segment, undi->ppxe.offset,
 138                undi->entry.segment, undi->entry.offset );
 139
 140         /* Update free base memory counter */
 141         undi->fbms = ( fbms_seg >> 6 );
 142         set_fbms ( undi->fbms );
 143         DBGC ( undi, "UNDI %p using [%d,%d) kB of base memory\n",
 144                undi, undi->fbms, undi->restore_fbms );
 145
 146         return 0;
 147 }
 148
 149 /**
 150  * Unload a pixie
 151  *
 152  * @v undi              UNDI device
 153  * @ret rc              Return status code
 154  *
 155  * Erases the PXENV+ and !PXE signatures, and frees the used base
 156  * memory (if possible).
 157  */
 158 int undi_unload ( struct undi_device *undi ) {
 159         static uint32_t dead = 0xdeaddead;
 160
 161         DBGC ( undi, "UNDI %p unloading\n", undi );
 162
 163         /* Clear entry point */
 164         memset ( &undi_loader_entry, 0, sizeof ( undi_loader_entry ) );
 165
 166         /* Erase signatures */
 167         if ( undi->pxenv.segment )
 168                 put_real ( dead, undi->pxenv.segment, undi->pxenv.offset );
 169         if ( undi->ppxe.segment )
 170                 put_real ( dead, undi->ppxe.segment, undi->ppxe.offset );
 171
 172         /* Free base memory, if possible */
 173         if ( undi->fbms == get_fbms() ) {
 174                 DBGC ( undi, "UNDI %p freeing [%d,%d) kB of base memory\n",
 175                        undi, undi->fbms, undi->restore_fbms );
 176                 set_fbms ( undi->restore_fbms );
 177                 return 0;
 178         } else {
 179                 DBGC ( undi, "UNDI %p leaking [%d,%d) kB of base memory\n",
 180                        undi, undi->fbms, undi->restore_fbms );
 181                 return -EBUSY;
 182         }
 183 }