src/interface/linux/linux_smbios.c

   1 /*
   2  * Copyright (C) 2013 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., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA.
  18  */
  19
  20 FILE_LICENCE ( GPL2_OR_LATER );
  21
  22 #include <errno.h>
  23 #include <ipxe/linux_api.h>
  24 #include <ipxe/linux_sysfs.h>
  25 #include <ipxe/linux.h>
  26 #include <ipxe/umalloc.h>
  27 #include <ipxe/init.h>
  28 #include <ipxe/smbios.h>
  29
  30 /** SMBIOS entry point filename */
  31 static const char smbios_entry_filename[] =
  32         "/sys/firmware/dmi/tables/smbios_entry_point";
  33
  34 /** SMBIOS filename */
  35 static const char smbios_filename[] = "/sys/firmware/dmi/tables/DMI";
  36
  37 /** Cache SMBIOS data */
  38 static userptr_t smbios_data;
  39
  40 /**
  41  * Find SMBIOS
  42  *
  43  * @v smbios            SMBIOS entry point descriptor structure to fill in
  44  * @ret rc              Return status code
  45  */
  46 static int linux_find_smbios ( struct smbios *smbios ) {
  47         struct smbios3_entry *smbios3_entry;
  48         struct smbios_entry *smbios_entry;
  49         userptr_t entry;
  50         void *data;
  51         int len;
  52         int rc;
  53
  54         /* Read entry point file */
  55         len = linux_sysfs_read ( smbios_entry_filename, &entry );
  56         if ( len < 0 ) {
  57                 rc = len;
  58                 DBGC ( smbios, "SMBIOS could not read %s: %s\n",
  59                        smbios_entry_filename, strerror ( rc ) );
  60                 goto err_entry;
  61         }
  62         data = user_to_virt ( entry, 0 );
  63         smbios3_entry = data;
  64         smbios_entry = data;
  65         if ( ( len >= ( ( int ) sizeof ( *smbios3_entry ) ) ) &&
  66              ( smbios3_entry->signature == SMBIOS3_SIGNATURE ) ) {
  67                 smbios->version = SMBIOS_VERSION ( smbios3_entry->major,
  68                                                    smbios3_entry->minor );
  69         } else if ( ( len >= ( ( int ) sizeof ( *smbios_entry ) ) ) &&
  70                     ( smbios_entry->signature == SMBIOS_SIGNATURE ) ) {
  71                 smbios->version = SMBIOS_VERSION ( smbios_entry->major,
  72                                                    smbios_entry->minor );
  73         } else {
  74                 DBGC ( smbios, "SMBIOS invalid entry point %s:\n",
  75                        smbios_entry_filename );
  76                 DBGC_HDA ( smbios, 0, data, len );
  77                 rc = -EINVAL;
  78                 goto err_version;
  79         }
  80
  81         /* Read SMBIOS file */
  82         len = linux_sysfs_read ( smbios_filename, &smbios_data );
  83         if ( len < 0 ) {
  84                 rc = len;
  85                 DBGC ( smbios, "SMBIOS could not read %s: %s\n",
  86                        smbios_filename, strerror ( rc ) );
  87                 goto err_read;
  88         }
  89
  90         /* Populate SMBIOS descriptor */
  91         smbios->address = smbios_data;
  92         smbios->len = len;
  93         smbios->count = 0;
  94
  95         /* Free entry point */
  96         ufree ( entry );
  97
  98         return 0;
  99
 100         ufree ( smbios_data );
 101  err_read:
 102  err_version:
 103         ufree ( entry );
 104  err_entry:
 105         return rc;
 106 }
 107
 108 /**
 109  * Free cached SMBIOS data
 110  *
 111  */
 112 static void linux_smbios_shutdown ( int booting __unused ) {
 113
 114         /* Clear SMBIOS data pointer */
 115         smbios_clear();
 116
 117         /* Free SMBIOS data */
 118         ufree ( smbios_data );
 119 }
 120
 121 /** SMBIOS shutdown function */
 122 struct startup_fn linux_smbios_startup_fn __startup_fn ( STARTUP_NORMAL ) = {
 123         .name = "linux_smbios",
 124         .shutdown = linux_smbios_shutdown,
 125 };
 126
 127 PROVIDE_SMBIOS ( linux, find_smbios, linux_find_smbios );