iPXE
Functions | Variables
smbios.c File Reference

System Management BIOS. More...

#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <ipxe/uaccess.h>
#include <ipxe/smbios.h>

Go to the source code of this file.

Functions

 FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
 
static uint8_t smbios_checksum (userptr_t start, size_t offset, size_t len)
 Calculate SMBIOS entry point structure checksum. More...
 
int find_smbios_entry (userptr_t start, size_t len, struct smbios_entry *entry)
 Scan for SMBIOS 32-bit entry point structure. More...
 
int find_smbios3_entry (userptr_t start, size_t len, struct smbios3_entry *entry)
 Scan for SMBIOS 64-bit entry point structure. More...
 
static size_t find_strings_terminator (size_t offset)
 Find SMBIOS strings terminator. More...
 
int find_smbios_structure (unsigned int type, unsigned int instance, struct smbios_structure *structure)
 Find specific structure type within SMBIOS. More...
 
int read_smbios_structure (struct smbios_structure *structure, void *data, size_t len)
 Copy SMBIOS structure. More...
 
int read_smbios_string (struct smbios_structure *structure, unsigned int index, void *data, size_t len)
 Find indexed string within SMBIOS structure. More...
 
int smbios_version (void)
 Get SMBIOS version. More...
 
void smbios_clear (void)
 Clear SMBIOS entry point descriptor. More...
 

Variables

static struct smbios smbios
 SMBIOS entry point descriptor. More...
 

Detailed Description

System Management BIOS.

Definition in file smbios.c.

Function Documentation

◆ FILE_LICENCE()

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL  )

◆ smbios_checksum()

static uint8_t smbios_checksum ( userptr_t  start,
size_t  offset,
size_t  len 
)
static

Calculate SMBIOS entry point structure checksum.

Parameters
startStart address of region
offsetOffset of SMBIOS entry point structure
lenLength of entry point structure
Return values
sumByte checksum

Definition at line 52 of file smbios.c.

52  {
53  size_t end = ( offset + len );
54  uint8_t sum;
55  uint8_t byte;
56 
57  for ( sum = 0 ; offset < end ; offset++ ) {
58  copy_from_user ( &byte, start, offset, sizeof ( byte ) );
59  sum += byte;
60  }
61  return sum;
62 }
static __always_inline void copy_from_user(void *dest, userptr_t src, off_t src_off, size_t len)
Copy data from user buffer.
Definition: uaccess.h:411
uint32_t start
Starting offset.
Definition: netvsc.h:12
unsigned char uint8_t
Definition: stdint.h:10
unsigned char byte
Definition: smc9000.h:38
uint32_t end
Ending offset.
Definition: netvsc.h:18
uint16_t offset
Offset to command line.
Definition: bzimage.h:8
uint32_t len
Length.
Definition: ena.h:14

References copy_from_user(), end, len, offset, and start.

Referenced by find_smbios3_entry(), and find_smbios_entry().

◆ find_smbios_entry()

int find_smbios_entry ( userptr_t  start,
size_t  len,
struct smbios_entry entry 
)

Scan for SMBIOS 32-bit entry point structure.

Parameters
startStart address of region to scan
lenLength of region to scan
entrySMBIOS entry point structure to fill in
Return values
rcReturn status code

Definition at line 72 of file smbios.c.

73  {
74  static size_t offset = 0; /* Avoid repeated attempts to locate SMBIOS */
75  uint8_t sum;
76 
77  /* Try to find SMBIOS */
78  for ( ; ( offset + sizeof ( *entry ) ) <= len ; offset += 0x10 ) {
79 
80  /* Read start of header and verify signature */
81  copy_from_user ( entry, start, offset, sizeof ( *entry ) );
82  if ( entry->signature != SMBIOS_SIGNATURE )
83  continue;
84 
85  /* Verify checksum */
86  if ( ( sum = smbios_checksum ( start, offset,
87  entry->len ) ) != 0 ) {
88  DBG ( "SMBIOS at %08lx has bad checksum %02x\n",
89  user_to_phys ( start, offset ), sum );
90  continue;
91  }
92 
93  /* Fill result structure */
94  DBG ( "Found SMBIOS v%d.%d entry point at %08lx\n",
95  entry->major, entry->minor,
96  user_to_phys ( start, offset ) );
97  return 0;
98  }
99 
100  DBG ( "No SMBIOS found\n" );
101  return -ENODEV;
102 }
uint32_t signature
Signature.
Definition: smbios.h:55
#define SMBIOS_SIGNATURE
Signature for 32-bit SMBIOS entry point.
Definition: smbios.h:36
static __always_inline void copy_from_user(void *dest, userptr_t src, off_t src_off, size_t len)
Copy data from user buffer.
Definition: uaccess.h:411
unsigned long user_to_phys(userptr_t userptr, off_t offset)
Convert user pointer to physical address.
uint32_t start
Starting offset.
Definition: netvsc.h:12
#define ENODEV
No such device.
Definition: errno.h:509
unsigned char uint8_t
Definition: stdint.h:10
uint8_t minor
Minor version.
Definition: smbios.h:63
static uint8_t smbios_checksum(userptr_t start, size_t offset, size_t len)
Calculate SMBIOS entry point structure checksum.
Definition: smbios.c:52
uint8_t len
Length.
Definition: smbios.h:59
uint16_t offset
Offset to command line.
Definition: bzimage.h:8
#define DBG(...)
Print a debugging message.
Definition: compiler.h:498
uint8_t major
Major version.
Definition: smbios.h:61
uint32_t len
Length.
Definition: ena.h:14

References copy_from_user(), DBG, ENODEV, len, smbios_entry::len, smbios_entry::major, smbios_entry::minor, offset, smbios_entry::signature, smbios_checksum(), SMBIOS_SIGNATURE, start, and user_to_phys().

Referenced by bios_find_smbios2().

◆ find_smbios3_entry()

int find_smbios3_entry ( userptr_t  start,
size_t  len,
struct smbios3_entry entry 
)

Scan for SMBIOS 64-bit entry point structure.

Parameters
startStart address of region to scan
lenLength of region to scan
entrySMBIOS entry point structure to fill in
Return values
rcReturn status code

Definition at line 112 of file smbios.c.

113  {
114  static size_t offset = 0; /* Avoid repeated attempts to locate SMBIOS */
115  uint8_t sum;
116 
117  /* Try to find SMBIOS */
118  for ( ; ( offset + sizeof ( *entry ) ) <= len ; offset += 0x10 ) {
119 
120  /* Read start of header and verify signature */
121  copy_from_user ( entry, start, offset, sizeof ( *entry ) );
122  if ( entry->signature != SMBIOS3_SIGNATURE )
123  continue;
124 
125  /* Verify checksum */
126  if ( ( sum = smbios_checksum ( start, offset,
127  entry->len ) ) != 0 ) {
128  DBG ( "SMBIOS3 at %08lx has bad checksum %02x\n",
129  user_to_phys ( start, offset ), sum );
130  continue;
131  }
132 
133  /* Fill result structure */
134  DBG ( "Found SMBIOS3 v%d.%d entry point at %08lx\n",
135  entry->major, entry->minor,
136  user_to_phys ( start, offset ) );
137  return 0;
138  }
139 
140  DBG ( "No SMBIOS3 found\n" );
141  return -ENODEV;
142 }
static __always_inline void copy_from_user(void *dest, userptr_t src, off_t src_off, size_t len)
Copy data from user buffer.
Definition: uaccess.h:411
unsigned long user_to_phys(userptr_t userptr, off_t offset)
Convert user pointer to physical address.
#define SMBIOS3_SIGNATURE
Signature for 64-bit SMBIOS entry point.
Definition: smbios.h:40
uint32_t start
Starting offset.
Definition: netvsc.h:12
uint8_t len
Length.
Definition: smbios.h:102
uint32_t signature
Signature.
Definition: smbios.h:96
#define ENODEV
No such device.
Definition: errno.h:509
unsigned char uint8_t
Definition: stdint.h:10
uint8_t minor
Minor version.
Definition: smbios.h:106
static uint8_t smbios_checksum(userptr_t start, size_t offset, size_t len)
Calculate SMBIOS entry point structure checksum.
Definition: smbios.c:52
uint16_t offset
Offset to command line.
Definition: bzimage.h:8
#define DBG(...)
Print a debugging message.
Definition: compiler.h:498
uint32_t len
Length.
Definition: ena.h:14
uint8_t major
Major version.
Definition: smbios.h:104

References copy_from_user(), DBG, ENODEV, len, smbios3_entry::len, smbios3_entry::major, smbios3_entry::minor, offset, smbios3_entry::signature, SMBIOS3_SIGNATURE, smbios_checksum(), start, and user_to_phys().

Referenced by bios_find_smbios3().

◆ find_strings_terminator()

static size_t find_strings_terminator ( size_t  offset)
static

Find SMBIOS strings terminator.

Parameters
offsetOffset to start of strings
Return values
offsetOffset to strings terminator, or 0 if not found

Definition at line 150 of file smbios.c.

150  {
151  size_t max_offset = ( smbios.len - 2 );
152  uint16_t nulnul;
153 
154  for ( ; offset <= max_offset ; offset++ ) {
155  copy_from_user ( &nulnul, smbios.address, offset, 2 );
156  if ( nulnul == 0 )
157  return ( offset + 1 );
158  }
159  return 0;
160 }
unsigned short uint16_t
Definition: stdint.h:11
static __always_inline void copy_from_user(void *dest, userptr_t src, off_t src_off, size_t len)
Copy data from user buffer.
Definition: uaccess.h:411
size_t len
Length of SMBIOS structures.
Definition: smbios.h:212
SMBIOS entry point descriptor.
Definition: smbios.h:208
userptr_t address
Start of SMBIOS structures.
Definition: smbios.h:210
uint16_t offset
Offset to command line.
Definition: bzimage.h:8

References smbios::address, copy_from_user(), smbios::len, and offset.

Referenced by find_smbios_structure().

◆ find_smbios_structure()

int find_smbios_structure ( unsigned int  type,
unsigned int  instance,
struct smbios_structure structure 
)

Find specific structure type within SMBIOS.

Parameters
typeStructure type to search for
instanceInstance of this type of structure
structureSMBIOS structure descriptor to fill in
Return values
rcReturn status code

Definition at line 170 of file smbios.c.

171  {
172  unsigned int count = 0;
173  size_t offset = 0;
174  size_t strings_offset;
175  size_t terminator_offset;
176  int rc;
177 
178  /* Find SMBIOS */
179  if ( ( smbios.address == UNULL ) &&
180  ( ( rc = find_smbios ( &smbios ) ) != 0 ) )
181  return rc;
182  assert ( smbios.address != UNULL );
183 
184  /* Scan through list of structures */
185  while ( ( ( offset + sizeof ( structure->header ) ) < smbios.len ) &&
186  ( ( smbios.count == 0 ) || ( count < smbios.count ) ) ) {
187 
188  /* Read next SMBIOS structure header */
189  copy_from_user ( &structure->header, smbios.address, offset,
190  sizeof ( structure->header ) );
191 
192  /* Determine start and extent of strings block */
193  strings_offset = ( offset + structure->header.len );
194  if ( strings_offset > smbios.len ) {
195  DBG ( "SMBIOS structure at offset %zx with length "
196  "%x extends beyond SMBIOS\n", offset,
197  structure->header.len );
198  return -ENOENT;
199  }
200  terminator_offset = find_strings_terminator ( strings_offset );
201  if ( ! terminator_offset ) {
202  DBG ( "SMBIOS structure at offset %zx has "
203  "unterminated strings section\n", offset );
204  return -ENOENT;
205  }
206  structure->strings_len = ( terminator_offset - strings_offset);
207 
208  DBG ( "SMBIOS structure at offset %zx has type %d, length %x, "
209  "strings length %zx\n", offset, structure->header.type,
210  structure->header.len, structure->strings_len );
211 
212  /* Stop if we have reached an end-of-table marker */
213  if ( ( smbios.count == 0 ) &&
214  ( structure->header.type == SMBIOS_TYPE_END ) )
215  break;
216 
217  /* If this is the structure we want, return */
218  if ( ( structure->header.type == type ) &&
219  ( instance-- == 0 ) ) {
220  structure->offset = offset;
221  return 0;
222  }
223 
224  /* Move to next SMBIOS structure */
225  offset = ( terminator_offset + 1 );
226  count++;
227  }
228 
229  DBG ( "SMBIOS structure type %d not found\n", type );
230  return -ENOENT;
231 }
size_t strings_len
Length of strings section.
Definition: smbios.h:136
struct arbelprm_rc_send_wqe rc
Definition: arbel.h:14
unsigned int count
Number of SMBIOS structures.
Definition: smbios.h:214
#define SMBIOS_TYPE_END
SMBIOS end of table type.
Definition: smbios.h:200
uint32_t type
Operating system type.
Definition: ena.h:12
static __always_inline void copy_from_user(void *dest, userptr_t src, off_t src_off, size_t len)
Copy data from user buffer.
Definition: uaccess.h:411
size_t len
Length of SMBIOS structures.
Definition: smbios.h:212
#define ENOENT
No such file or directory.
Definition: errno.h:514
SMBIOS entry point descriptor.
Definition: smbios.h:208
struct smbios_header header
Copy of SMBIOS structure header.
Definition: smbios.h:132
int find_smbios(struct smbios *smbios)
uint8_t len
Length.
Definition: smbios.h:124
assert((readw(&hdr->flags) &(GTF_reading|GTF_writing))==0)
uint16_t count
Number of entries.
Definition: ena.h:22
uint8_t type
Type.
Definition: smbios.h:122
#define UNULL
Equivalent of NULL for user pointers.
Definition: uaccess.h:42
userptr_t address
Start of SMBIOS structures.
Definition: smbios.h:210
uint16_t offset
Offset to command line.
Definition: bzimage.h:8
#define DBG(...)
Print a debugging message.
Definition: compiler.h:498
static size_t find_strings_terminator(size_t offset)
Find SMBIOS strings terminator.
Definition: smbios.c:150
size_t offset
Offset of structure within SMBIOS.
Definition: smbios.h:134

References smbios::address, assert(), copy_from_user(), count, smbios::count, DBG, ENOENT, find_smbios(), find_strings_terminator(), smbios_structure::header, smbios_header::len, smbios::len, offset, smbios_structure::offset, rc, SMBIOS_TYPE_END, smbios_structure::strings_len, type, smbios_header::type, and UNULL.

Referenced by smbios_fetch(), and smsc95xx_vm3_fetch_mac().

◆ read_smbios_structure()

int read_smbios_structure ( struct smbios_structure structure,
void *  data,
size_t  len 
)

Copy SMBIOS structure.

Parameters
structureSMBIOS structure descriptor
dataBuffer to hold SMBIOS structure
lenLength of buffer
Return values
rcReturn status code

Definition at line 241 of file smbios.c.

242  {
243 
244  assert ( smbios.address != UNULL );
245 
246  if ( len > structure->header.len )
247  len = structure->header.len;
248  copy_from_user ( data, smbios.address, structure->offset, len );
249  return 0;
250 }
static __always_inline void copy_from_user(void *dest, userptr_t src, off_t src_off, size_t len)
Copy data from user buffer.
Definition: uaccess.h:411
SMBIOS entry point descriptor.
Definition: smbios.h:208
struct smbios_header header
Copy of SMBIOS structure header.
Definition: smbios.h:132
uint8_t len
Length.
Definition: smbios.h:124
assert((readw(&hdr->flags) &(GTF_reading|GTF_writing))==0)
#define UNULL
Equivalent of NULL for user pointers.
Definition: uaccess.h:42
userptr_t address
Start of SMBIOS structures.
Definition: smbios.h:210
uint8_t data[48]
Additional event data.
Definition: ena.h:22
uint32_t len
Length.
Definition: ena.h:14
size_t offset
Offset of structure within SMBIOS.
Definition: smbios.h:134

References smbios::address, assert(), copy_from_user(), data, smbios_structure::header, len, smbios_header::len, smbios_structure::offset, and UNULL.

Referenced by smbios_fetch(), and smsc95xx_vm3_fetch_mac().

◆ read_smbios_string()

int read_smbios_string ( struct smbios_structure structure,
unsigned int  index,
void *  data,
size_t  len 
)

Find indexed string within SMBIOS structure.

Parameters
structureSMBIOS structure descriptor
indexString index
dataBuffer for string
lenLength of string buffer
Return values
rcLength of string, or negative error

Definition at line 261 of file smbios.c.

262  {
263  size_t strings_start = ( structure->offset + structure->header.len );
264  size_t strings_end = ( strings_start + structure->strings_len );
265  size_t offset;
266  size_t string_len;
267 
268  assert ( smbios.address != UNULL );
269 
270  /* String numbers start at 1 (0 is used to indicate "no string") */
271  if ( ! index )
272  return -ENOENT;
273 
274  for ( offset = strings_start ; offset < strings_end ;
275  offset += ( string_len + 1 ) ) {
276  /* Get string length. This is known safe, since the
277  * smbios_strings struct is constructed so as to
278  * always end on a string boundary.
279  */
280  string_len = strlen_user ( smbios.address, offset );
281  if ( --index == 0 ) {
282  /* Copy string, truncating as necessary. */
283  if ( len > string_len )
284  len = string_len;
286  return string_len;
287  }
288  }
289 
290  DBG ( "SMBIOS string index %d not found\n", index );
291  return -ENOENT;
292 }
size_t strings_len
Length of strings section.
Definition: smbios.h:136
long index
Definition: bigint.h:61
static __always_inline void copy_from_user(void *dest, userptr_t src, off_t src_off, size_t len)
Copy data from user buffer.
Definition: uaccess.h:411
#define ENOENT
No such file or directory.
Definition: errno.h:514
SMBIOS entry point descriptor.
Definition: smbios.h:208
struct smbios_header header
Copy of SMBIOS structure header.
Definition: smbios.h:132
uint8_t len
Length.
Definition: smbios.h:124
assert((readw(&hdr->flags) &(GTF_reading|GTF_writing))==0)
size_t strlen_user(userptr_t userptr, off_t offset)
Find length of NUL-terminated string in user buffer.
#define UNULL
Equivalent of NULL for user pointers.
Definition: uaccess.h:42
userptr_t address
Start of SMBIOS structures.
Definition: smbios.h:210
uint8_t data[48]
Additional event data.
Definition: ena.h:22
uint16_t offset
Offset to command line.
Definition: bzimage.h:8
#define DBG(...)
Print a debugging message.
Definition: compiler.h:498
uint32_t len
Length.
Definition: ena.h:14
size_t offset
Offset of structure within SMBIOS.
Definition: smbios.h:134

References smbios::address, assert(), copy_from_user(), data, DBG, ENOENT, smbios_structure::header, index, len, smbios_header::len, offset, smbios_structure::offset, smbios_structure::strings_len, strlen_user(), and UNULL.

Referenced by smbios_fetch(), and smsc95xx_vm3_fetch_mac().

◆ smbios_version()

int smbios_version ( void  )

Get SMBIOS version.

Return values
versionVersion, or negative error

Definition at line 299 of file smbios.c.

299  {
300  int rc;
301 
302  /* Find SMBIOS */
303  if ( ( smbios.address == UNULL ) &&
304  ( ( rc = find_smbios ( &smbios ) ) != 0 ) )
305  return rc;
306  assert ( smbios.address != UNULL );
307 
308  return smbios.version;
309 }
struct arbelprm_rc_send_wqe rc
Definition: arbel.h:14
SMBIOS entry point descriptor.
Definition: smbios.h:208
int find_smbios(struct smbios *smbios)
uint16_t version
SMBIOS version.
Definition: smbios.h:216
assert((readw(&hdr->flags) &(GTF_reading|GTF_writing))==0)
#define UNULL
Equivalent of NULL for user pointers.
Definition: uaccess.h:42
userptr_t address
Start of SMBIOS structures.
Definition: smbios.h:210

References smbios::address, assert(), find_smbios(), rc, UNULL, and smbios::version.

Referenced by smbios_fetch().

◆ smbios_clear()

void smbios_clear ( void  )

Clear SMBIOS entry point descriptor.

Definition at line 315 of file smbios.c.

315  {
316 
317  /* Clear address */
318  smbios.address = UNULL;
319 }
SMBIOS entry point descriptor.
Definition: smbios.h:208
#define UNULL
Equivalent of NULL for user pointers.
Definition: uaccess.h:42
userptr_t address
Start of SMBIOS structures.
Definition: smbios.h:210

References smbios::address, and UNULL.

Variable Documentation

◆ smbios

struct smbios smbios
static
Initial value:
= {
.address = UNULL,
}
#define UNULL
Equivalent of NULL for user pointers.
Definition: uaccess.h:42

SMBIOS entry point descriptor.

Definition at line 40 of file smbios.c.