/*
* 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 <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 "
"%zx 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 %zx, 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;
}
/**
* Find SMBIOS serial number
*
*/
int dump_smbios_info ( void ) {
struct smbios_system_information sysinfo;
struct smbios_strings strings;
char buf[64];
int rc;
if ( ( rc = find_smbios_structure ( SMBIOS_TYPE_SYSTEM_INFORMATION,
&sysinfo, sizeof ( sysinfo ),
&strings ) ) != 0 )
return rc;
DBG_HD ( &sysinfo, sizeof ( sysinfo ) );
if ( ( rc = find_smbios_string ( &strings, sysinfo.manufacturer,
buf, sizeof ( buf ) ) ) != 0 )
return rc;
DBG ( "Manufacturer: \"%s\"\n", buf );
if ( ( rc = find_smbios_string ( &strings, sysinfo.product,
buf, sizeof ( buf ) ) ) != 0 )
return rc;
DBG ( "Product: \"%s\"\n", buf );
DBG ( "UUID:\n" );
DBG_HD ( &sysinfo.uuid, sizeof ( sysinfo.uuid ) );
return 0;
}
