123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323 |
- /*
- * 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 <string.h>
- #include <stdio.h>
- #include <errno.h>
- #include <gpxe/uaccess.h>
- #include <gpxe/uuid.h>
- #include <realmode.h>
- #include <pnpbios.h>
- #include <smbios.h>
-
- /** @file
- *
- * System Management BIOS
- *
- */
-
- /** Signature for SMBIOS entry point */
- #define SMBIOS_SIGNATURE \
- ( ( '_' << 0 ) + ( 'S' << 8 ) + ( 'M' << 16 ) + ( '_' << 24 ) )
-
- /**
- * SMBIOS entry point
- *
- * This is the single table which describes the list of SMBIOS
- * structures. It is located by scanning through the BIOS segment.
- */
- struct smbios_entry {
- /** Signature
- *
- * Must be equal to SMBIOS_SIGNATURE
- */
- uint32_t signature;
- /** Checksum */
- uint8_t checksum;
- /** Length */
- uint8_t length;
- /** Major version */
- uint8_t major;
- /** Minor version */
- uint8_t minor;
- /** Maximum structure size */
- uint16_t max;
- /** Entry point revision */
- uint8_t revision;
- /** Formatted area */
- uint8_t formatted[5];
- /** DMI Signature */
- uint8_t dmi_signature[5];
- /** DMI checksum */
- uint8_t dmi_checksum;
- /** Structure table length */
- uint16_t smbios_length;
- /** Structure table address */
- physaddr_t smbios_address;
- /** Number of SMBIOS structures */
- uint16_t smbios_count;
- /** BCD revision */
- uint8_t bcd_revision;
- } __attribute__ (( packed ));
-
- /**
- * SMBIOS entry point descriptor
- *
- * This contains the information from the SMBIOS entry point that we
- * care about.
- */
- struct smbios {
- /** Start of SMBIOS structures */
- userptr_t address;
- /** Length of SMBIOS structures */
- size_t length;
- /** Number of SMBIOS structures */
- unsigned int count;
- };
-
- /**
- * SMBIOS strings descriptor
- *
- * This is returned as part of the search for an SMBIOS structure, and
- * contains the information needed for extracting the strings within
- * the "unformatted" portion of the structure.
- */
- struct smbios_strings {
- /** Start of strings data */
- userptr_t data;
- /** Length of strings data */
- size_t length;
- };
-
- /**
- * Find SMBIOS
- *
- * @ret smbios SMBIOS entry point descriptor, or NULL if not found
- */
- static struct smbios * find_smbios ( void ) {
- static struct smbios smbios = {
- .address = UNULL,
- };
- union {
- struct smbios_entry entry;
- uint8_t bytes[256]; /* 256 is maximum length possible */
- } u;
- unsigned int offset;
- size_t len;
- unsigned int i;
- uint8_t sum;
-
- /* Return cached result if available */
- if ( smbios.address != UNULL )
- return &smbios;
-
- /* Try to find SMBIOS */
- for ( offset = 0 ; offset < 0x10000 ; offset += 0x10 ) {
-
- /* Read start of header and verify signature */
- copy_from_real ( &u.entry, BIOS_SEG, offset,
- sizeof ( u.entry ));
- if ( u.entry.signature != SMBIOS_SIGNATURE )
- continue;
-
- /* Read whole header and verify checksum */
- len = u.entry.length;
- copy_from_real ( &u.bytes, BIOS_SEG, offset, len );
- for ( i = 0 , sum = 0 ; i < len ; i++ ) {
- sum += u.bytes[i];
- }
- if ( sum != 0 ) {
- DBG ( "SMBIOS at %04x:%04x has bad checksum %02x\n",
- BIOS_SEG, offset, sum );
- continue;
- }
-
- /* Fill result structure */
- DBG ( "Found SMBIOS entry point at %04x:%04x\n",
- BIOS_SEG, offset );
- smbios.address = phys_to_user ( u.entry.smbios_address );
- smbios.length = u.entry.smbios_length;
- smbios.count = u.entry.smbios_count;
- return &smbios;
- }
-
- DBG ( "No SMBIOS found\n" );
- return NULL;
- }
-
- /**
- * Find SMBIOS strings terminator
- *
- * @v smbios SMBIOS entry point descriptor
- * @v offset Offset to start of strings
- * @ret offset Offset to strings terminator, or 0 if not found
- */
- static size_t find_strings_terminator ( struct smbios *smbios,
- size_t offset ) {
- size_t max_offset = ( smbios->length - 2 );
- uint16_t nulnul;
-
- for ( ; offset <= max_offset ; offset++ ) {
- copy_from_user ( &nulnul, smbios->address, offset, 2 );
- if ( nulnul == 0 )
- return ( offset + 1 );
- }
- return 0;
- }
-
- /**
- * Find specific structure type within SMBIOS
- *
- * @v type Structure type to search for
- * @v structure Buffer to fill in with structure
- * @v length Length of buffer
- * @v strings Strings descriptor to fill in, or NULL
- * @ret rc Return status code
- */
- int find_smbios_structure ( unsigned int type, void *structure,
- size_t length, struct smbios_strings *strings ) {
- struct smbios *smbios;
- struct smbios_header header;
- struct smbios_strings temp_strings;
- unsigned int count = 0;
- size_t offset = 0;
- size_t strings_offset;
- size_t terminator_offset;
-
- /* Locate SMBIOS entry point */
- if ( ! ( smbios = find_smbios() ) )
- return -ENOENT;
-
- /* Ensure that we have a usable strings descriptor buffer */
- if ( ! strings )
- strings = &temp_strings;
-
- /* Scan through list of structures */
- while ( ( ( offset + sizeof ( header ) ) < smbios->length ) &&
- ( count < smbios->count ) ) {
-
- /* Read next SMBIOS structure header */
- copy_from_user ( &header, smbios->address, offset,
- sizeof ( header ) );
-
- /* Determine start and extent of strings block */
- strings_offset = ( offset + header.length );
- if ( strings_offset > smbios->length ) {
- DBG ( "SMBIOS structure at offset %zx with length "
- "%x extends beyond SMBIOS\n", offset,
- header.length );
- return -ENOENT;
- }
- terminator_offset =
- find_strings_terminator ( smbios, strings_offset );
- if ( ! terminator_offset ) {
- DBG ( "SMBIOS structure at offset %zx has "
- "unterminated strings section\n", offset );
- return -ENOENT;
- }
- strings->data = userptr_add ( smbios->address,
- strings_offset );
- strings->length = ( terminator_offset - strings_offset );
-
- DBG ( "SMBIOS structure at offset %zx has type %d, "
- "length %x, strings length %zx\n",
- offset, header.type, header.length, strings->length );
-
- /* If this is the structure we want, return */
- if ( header.type == type ) {
- if ( length > header.length )
- length = header.length;
- copy_from_user ( structure, smbios->address,
- offset, length );
- return 0;
- }
-
- /* Move to next SMBIOS structure */
- offset = ( terminator_offset + 1 );
- count++;
- }
-
- DBG ( "SMBIOS structure type %d not found\n", type );
- return -ENOENT;
- }
-
- /**
- * Find indexed string within SMBIOS structure
- *
- * @v strings SMBIOS strings descriptor
- * @v index String index
- * @v buffer Buffer for string
- * @v length Length of string buffer
- * @ret rc Return status code
- */
- int find_smbios_string ( struct smbios_strings *strings, unsigned int index,
- char *buffer, size_t length ) {
- size_t offset = 0;
- size_t string_len;
-
- /* Zero buffer. This ensures that a valid NUL terminator is
- * always present (unless length==0).
- */
- memset ( buffer, 0, length );
-
- /* String numbers start at 1 (0 is used to indicate "no string") */
- if ( ! index )
- return 0;
-
- while ( offset < strings->length ) {
- /* Get string length. This is known safe, since the
- * smbios_strings struct is constructed so as to
- * always end on a string boundary.
- */
- string_len = strlen_user ( strings->data, offset );
- if ( --index == 0 ) {
- /* Copy string, truncating as necessary. */
- if ( string_len >= length )
- string_len = ( length - 1 );
- copy_from_user ( buffer, strings->data,
- offset, string_len );
- return 0;
- }
- offset += ( string_len + 1 );
- }
-
- DBG ( "SMBIOS string index %d not found\n", index );
- return -ENOENT;
- }
-
- /**
- * Get UUID from SMBIOS
- *
- * @v uuid UUID to fill in
- * @ret rc Return status code
- */
- int smbios_get_uuid ( union uuid *uuid ) {
- struct smbios_system_information sysinfo;
- int rc;
-
- if ( ( rc = find_smbios_structure ( SMBIOS_TYPE_SYSTEM_INFORMATION,
- &sysinfo, sizeof ( sysinfo ),
- NULL ) ) != 0 )
- return rc;
-
- memcpy ( uuid, sysinfo.uuid, sizeof ( *uuid ) );
- DBG ( "SMBIOS found UUID %s\n", uuid_ntoa ( uuid ) );
-
- return 0;
- }
|