smbios_settings.c

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/*
 * Copyright (C) 2008 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 <string.h>
#include <errno.h>
#include <gpxe/settings.h>
#include <gpxe/init.h>
#include <gpxe/uuid.h>
#include <gpxe/smbios.h>

/** SMBIOS settings tag magic number */
#define SMBIOS_TAG_MAGIC 0x5B /* "SmBios" */

/**
 * Construct SMBIOS empty tag
 *
 * @ret tag             SMBIOS setting tag
 */
#define SMBIOS_EMPTY_TAG ( SMBIOS_TAG_MAGIC << 24 )

/**
 * Construct SMBIOS raw-data tag
 *
 * @v _type             SMBIOS structure type number
 * @v _structure        SMBIOS structure data type
 * @v _field            Field within SMBIOS structure data type
 * @ret tag             SMBIOS setting tag
 */
#define SMBIOS_RAW_TAG( _type, _structure, _field )             \
        ( ( SMBIOS_TAG_MAGIC << 24 ) |                          \
          ( (_type) << 16 ) |                                   \
          ( offsetof ( _structure, _field ) << 8 ) |            \
          ( sizeof ( ( ( _structure * ) 0 )->_field ) ) )

/**
 * Construct SMBIOS string tag
 *
 * @v _type             SMBIOS structure type number
 * @v _structure        SMBIOS structure data type
 * @v _field            Field within SMBIOS structure data type
 * @ret tag             SMBIOS setting tag
 */
#define SMBIOS_STRING_TAG( _type, _structure, _field )          \
        ( ( SMBIOS_TAG_MAGIC << 24 ) |                          \
          ( (_type) << 16 ) |                                   \
          ( offsetof ( _structure, _field ) << 8 ) )

/**
 * Fetch value of SMBIOS setting
 *
 * @v settings          Settings block, or NULL to search all blocks
 * @v setting           Setting to fetch
 * @v data              Buffer to fill with setting data
 * @v len               Length of buffer
 * @ret len             Length of setting data, or negative error
 */
static int smbios_fetch ( struct settings *settings __unused,
                          struct setting *setting,
                          void *data, size_t len ) {
        struct smbios_structure structure;
        unsigned int tag_magic;
        unsigned int tag_type;
        unsigned int tag_offset;
        unsigned int tag_len;
        int rc;

        /* Split tag into type, offset and length */
        tag_magic = ( setting->tag >> 24 );
        tag_type = ( ( setting->tag >> 16 ) & 0xff );
        tag_offset = ( ( setting->tag >> 8 ) & 0xff );
        tag_len = ( setting->tag & 0xff );
        if ( tag_magic != SMBIOS_TAG_MAGIC )
                return -ENOENT;

        /* Find SMBIOS structure */
        if ( ( rc = find_smbios_structure ( tag_type, &structure ) ) != 0 )
                return rc;

        {
                uint8_t buf[structure.header.len];

                /* Read SMBIOS structure */
                if ( ( rc = read_smbios_structure ( &structure, buf,
                                                    sizeof ( buf ) ) ) != 0 )
                        return rc;

                if ( tag_len == 0 ) {
                        /* String */
                        return read_smbios_string ( &structure,
                                                    buf[tag_offset],
                                                    data, len );
                } else {
                        /* Raw data */
                        if ( len > tag_len )
                                len = tag_len;
                        memcpy ( data, &buf[tag_offset], len );
                        return tag_len;
                }
        }
}

/** SMBIOS settings operations */
static struct settings_operations smbios_settings_operations = {
        .fetch = smbios_fetch,
};

/** SMBIOS settings */
static struct settings smbios_settings = {
        .refcnt = NULL,
        .name = "smbios",
        .tag_magic = SMBIOS_EMPTY_TAG,
        .siblings = LIST_HEAD_INIT ( smbios_settings.siblings ),
        .children = LIST_HEAD_INIT ( smbios_settings.children ),
        .op = &smbios_settings_operations,
};

/** Initialise SMBIOS settings */
static void smbios_init ( void ) {
        int rc;

        if ( ( rc = register_settings ( &smbios_settings, NULL ) ) != 0 ) {
                DBG ( "SMBIOS could not register settings: %s\n",
                      strerror ( rc ) );
                return;
        }
}

/** SMBIOS settings initialiser */
struct init_fn smbios_init_fn __init_fn ( INIT_NORMAL ) = {
        .initialise = smbios_init,
};

/** UUID setting obtained via SMBIOS */
struct setting uuid_setting __setting = {
        .name = "uuid",
        .description = "UUID",
        .tag = SMBIOS_RAW_TAG ( SMBIOS_TYPE_SYSTEM_INFORMATION,
                                struct smbios_system_information, uuid ),
        .type = &setting_type_uuid,
};

/** Other SMBIOS named settings */
struct setting smbios_named_settings[] __setting = {
        {
                .name = "manufacturer",
                .description = "Manufacturer",
                .tag = SMBIOS_STRING_TAG ( SMBIOS_TYPE_SYSTEM_INFORMATION,
                                           struct smbios_system_information,
                                           manufacturer ),
                .type = &setting_type_string,
        },
        {
                .name = "product",
                .description = "Product name",
                .tag = SMBIOS_STRING_TAG ( SMBIOS_TYPE_SYSTEM_INFORMATION,
                                           struct smbios_system_information,
                                           product ),
                .type = &setting_type_string,
        },
        {
                .name = "serial",
                .description = "Serial number",
                .tag = SMBIOS_STRING_TAG ( SMBIOS_TYPE_SYSTEM_INFORMATION,
                                           struct smbios_system_information,
                                           serial ),
                .type = &setting_type_string,
        },
        {
                .name = "asset",
                .description = "Asset tag",
                .tag = SMBIOS_STRING_TAG ( SMBIOS_TYPE_ENCLOSURE_INFORMATION,
                                           struct smbios_enclosure_information,
                                           asset_tag ),
                .type = &setting_type_string,
        },
};