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      1 /*	$NetBSD: smbios.c,v 1.1.1.3 2021/09/30 18:50:09 jmcneill Exp $	*/
      2 
      3 /*++
      4 
      5 Copyright (c) 2000  Intel Corporation
      6 
      7 Module Name:
      8 
      9     Smbios.c
     10 
     11 Abstract:
     12 
     13     Lib fucntions for SMBIOS. Used to get system serial number and GUID
     14 
     15 Revision History
     16 
     17 --*/
     18 
     19 #include "lib.h"
     20 
     21 /*
     22  * We convert 32 bit values to pointers. In 64 bit mode the compiler will issue a
     23  * warning stating that the value is too small for the pointer:
     24  * "warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]"
     25  * we can safely ignore them here.
     26  */
     27 #ifdef __GNUC__
     28 #pragma GCC diagnostic ignored "-Wint-to-pointer-cast"
     29 #endif
     30 
     31 EFI_STATUS
     32 LibGetSmbiosSystemGuidAndSerialNumber (
     33     IN  EFI_GUID    *SystemGuid,
     34     OUT CHAR8       **SystemSerialNumber
     35     )
     36 {
     37     EFI_STATUS                  Status;
     38     SMBIOS_STRUCTURE_TABLE      *SmbiosTable;
     39     SMBIOS_STRUCTURE_POINTER    Smbios;
     40     SMBIOS_STRUCTURE_POINTER    SmbiosEnd;
     41     UINT16                      Index;
     42 
     43     Status = LibGetSystemConfigurationTable(&SMBIOSTableGuid, (VOID**)&SmbiosTable);
     44     if (EFI_ERROR(Status)) {
     45         return EFI_NOT_FOUND;
     46     }
     47 
     48     Smbios.Hdr = (SMBIOS_HEADER *)SmbiosTable->TableAddress;
     49     SmbiosEnd.Raw = (UINT8 *)((UINTN)SmbiosTable->TableAddress + SmbiosTable->TableLength);
     50     for (Index = 0; Index < SmbiosTable->TableLength ; Index++) {
     51         if (Smbios.Hdr->Type == 1) {
     52             if (Smbios.Hdr->Length < 0x19) {
     53                 //
     54                 // Older version did not support Guid and Serial number
     55                 //
     56                 continue;
     57             }
     58 
     59             //
     60             // SMBIOS tables are byte packed so we need to do a byte copy to
     61             //  prevend alignment faults on IA-64.
     62 
     63             CopyMem (SystemGuid, &Smbios.Type1->Uuid, sizeof(EFI_GUID));
     64             *SystemSerialNumber = LibGetSmbiosString(&Smbios, Smbios.Type1->SerialNumber);
     65             return EFI_SUCCESS;
     66         }
     67 
     68         //
     69         // Make Smbios point to the next record
     70         //
     71         LibGetSmbiosString (&Smbios, -1);
     72 
     73         if (Smbios.Raw >= SmbiosEnd.Raw) {
     74             //
     75             // SMBIOS 2.1 incorrectly stated the length of SmbiosTable as 0x1e.
     76             //  given this we must double check against the lenght of
     77             /// the structure. My home PC has this bug.ruthard
     78             //
     79             return EFI_SUCCESS;
     80         }
     81     }
     82 
     83     return EFI_SUCCESS;
     84 }
     85 
     86 CHAR8*
     87 LibGetSmbiosString (
     88     IN  SMBIOS_STRUCTURE_POINTER    *Smbios,
     89     IN  UINT16                      StringNumber
     90     )
     91 /*++
     92 
     93     Return SMBIOS string given the string number.
     94 
     95     Arguments:
     96         Smbios - Pointer to SMBIOS structure
     97         StringNumber - String number to return. -1 is used to skip all strings and
     98             point to the next SMBIOS structure.
     99 
    100     Returns:
    101         Pointer to string, or pointer to next SMBIOS strcuture if StringNumber == -1
    102 --*/
    103 {
    104     UINT16  Index;
    105     CHAR8   *String;
    106 
    107     //
    108     // Skip over formatted section
    109     //
    110     String = (CHAR8 *)(Smbios->Raw + Smbios->Hdr->Length);
    111 
    112     //
    113     // Look through unformated section
    114     //
    115     for (Index = 1; Index <= StringNumber; Index++) {
    116         if (StringNumber == Index) {
    117             return String;
    118         }
    119 
    120         //
    121         // Skip string
    122         //
    123         for (; *String != 0; String++);
    124         String++;
    125 
    126         if (*String == 0) {
    127             //
    128             // If double NULL then we are done.
    129             //  Retrun pointer to next structure in Smbios.
    130             //  if you pass in a -1 you will always get here
    131             //
    132             Smbios->Raw = (UINT8 *)++String;
    133             return NULL;
    134         }
    135     }
    136     return NULL;
    137 }
    138