lib/smbios.c

   1 /*++
   2
   3 Copyright (c) 2000  Intel Corporation
   4
   5 Module Name:
   6
   7     Smbios.c
   8
   9 Abstract:
  10
  11     Lib fucntions for SMBIOS. Used to get system serial number and GUID
  12
  13 Revision History
  14
  15 --*/
  16
  17 #include "lib.h"
  18
  19 /*
  20  * We convert 32 bit values to pointers. In 64 bit mode the compiler will issue a
  21  * warning stating that the value is too small for the pointer:
  22  * "warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]"
  23  * we can safely ignore them here.
  24  */
  25 #ifdef __GNUC__
  26 #pragma GCC diagnostic ignored "-Wint-to-pointer-cast"
  27 #endif
  28
  29 EFI_STATUS
  30 LibGetSmbiosSystemGuidAndSerialNumber (
  31     IN  EFI_GUID    *SystemGuid,
  32     OUT CHAR8       **SystemSerialNumber
  33     )
  34 {
  35     EFI_STATUS                  Status;
  36     SMBIOS_STRUCTURE_TABLE      *SmbiosTable;
  37     SMBIOS_STRUCTURE_POINTER    Smbios;
  38     SMBIOS_STRUCTURE_POINTER    SmbiosEnd;
  39     UINT16                      Index;
  40
  41     Status = LibGetSystemConfigurationTable(&SMBIOSTableGuid, (VOID**)&SmbiosTable);
  42     if (EFI_ERROR(Status)) {
  43         return EFI_NOT_FOUND;
  44     }
  45
  46     Smbios.Hdr = (SMBIOS_HEADER *)SmbiosTable->TableAddress;
  47     SmbiosEnd.Raw = (UINT8 *)(SmbiosTable->TableAddress + SmbiosTable->TableLength);
  48     for (Index = 0; Index < SmbiosTable->TableLength ; Index++) {
  49         if (Smbios.Hdr->Type == 1) {
  50             if (Smbios.Hdr->Length < 0x19) {
  51                 //
  52                 // Older version did not support Guid and Serial number
  53                 //
  54                 continue;
  55             }
  56
  57             //
  58             // SMBIOS tables are byte packed so we need to do a byte copy to
  59             //  prevend alignment faults on IA-64.
  60
  61             CopyMem (SystemGuid, &Smbios.Type1->Uuid, sizeof(EFI_GUID));
  62             *SystemSerialNumber = LibGetSmbiosString(&Smbios, Smbios.Type1->SerialNumber);
  63             return EFI_SUCCESS;
  64         }
  65
  66         //
  67         // Make Smbios point to the next record
  68         //
  69         LibGetSmbiosString (&Smbios, -1);
  70
  71         if (Smbios.Raw >= SmbiosEnd.Raw) {
  72             //
  73             // SMBIOS 2.1 incorrectly stated the length of SmbiosTable as 0x1e.
  74             //  given this we must double check against the lenght of
  75             /// the structure. My home PC has this bug.ruthard
  76             //
  77             return EFI_SUCCESS;
  78         }
  79     }
  80
  81     return EFI_SUCCESS;
  82 }
  83
  84 CHAR8*
  85 LibGetSmbiosString (
  86     IN  SMBIOS_STRUCTURE_POINTER    *Smbios,
  87     IN  UINT16                      StringNumber
  88     )
  89 /*++
  90
  91     Return SMBIOS string given the string number.
  92
  93     Arguments:
  94         Smbios - Pointer to SMBIOS structure
  95         StringNumber - String number to return. -1 is used to skip all strings and
  96             point to the next SMBIOS structure.
  97
  98     Returns:
  99         Pointer to string, or pointer to next SMBIOS strcuture if StringNumber == -1
 100 --*/
 101 {
 102     UINT16  Index;
 103     CHAR8   *String;
 104
 105     //
 106     // Skip over formatted section
 107     //
 108     String = (CHAR8 *)(Smbios->Raw + Smbios->Hdr->Length);
 109
 110     //
 111     // Look through unformated section
 112     //
 113     for (Index = 1; Index <= StringNumber; Index++) {
 114         if (StringNumber == Index) {
 115             return String;
 116         }
 117
 118         //
 119         // Skip string
 120         //
 121         for (; *String != 0; String++);
 122         String++;
 123
 124         if (*String == 0) {
 125             //
 126             // If double NULL then we are done.
 127             //  Retrun pointer to next structure in Smbios.
 128             //  if you pass in a -1 you will always get here
 129             //
 130             Smbios->Raw = (UINT8 *)++String;
 131             return NULL;
 132         }
 133     }
 134     return NULL;
 135 }