IntelFspPkg/FspSecCore/Ia32/FspHelper.asm

   1 ;; @file
   2 ;  Provide FSP helper function.
   3 ;
   4 ; Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
   5 ; SPDX-License-Identifier: BSD-2-Clause-Patent
   6 ;;
   7
   8     .586p
   9     .model  flat,C
  10     .code
  11
  12 ;
  13 ; FspInfoHeaderRelativeOff is patched during build process and initialized to offset of the  AsmGetFspBaseAddress
  14 ; from the FSP Info header.
  15 ;
  16 FspInfoHeaderRelativeOff    PROC      NEAR    PUBLIC
  17    ;
  18    ; This value will be pached by the build script
  19    ;
  20    DD    012345678h
  21 FspInfoHeaderRelativeOff    ENDP
  22
  23 ;
  24 ; Returns FSP Base Address.
  25 ;
  26 ; This function gets the FSP Info Header using relative addressing and returns the FSP Base from the header structure
  27 ;
  28 AsmGetFspBaseAddress        PROC      NEAR    PUBLIC
  29    mov   eax, AsmGetFspBaseAddress
  30    sub   eax, dword ptr [FspInfoHeaderRelativeOff]
  31    add   eax, 01Ch
  32    mov   eax, dword ptr [eax]
  33    ret
  34 AsmGetFspBaseAddress        ENDP
  35
  36 ;
  37 ; No stack counter part of AsmGetFspBaseAddress. Return address is in edi.
  38 ;
  39 AsmGetFspBaseAddressNoStack    PROC      NEAR    PUBLIC
  40    mov   eax, AsmGetFspBaseAddress
  41    sub   eax, dword ptr [FspInfoHeaderRelativeOff]
  42    add   eax, 01Ch
  43    mov   eax, dword ptr [eax]
  44    jmp   edi
  45 AsmGetFspBaseAddressNoStack    ENDP
  46
  47 ;
  48 ; Returns FSP Info Header.
  49 ;
  50 ; This function gets the FSP Info Header using relative addressing and returns it
  51 ;
  52 AsmGetFspInfoHeader         PROC      NEAR    PUBLIC
  53    mov   eax, AsmGetFspBaseAddress
  54    sub   eax, dword ptr [FspInfoHeaderRelativeOff]
  55    ret
  56 AsmGetFspInfoHeader         ENDP
  57
  58 ;
  59 ; No stack counter part of AsmGetFspInfoHeader. Return address is in edi.
  60 ;
  61 AsmGetFspInfoHeaderNoStack         PROC      NEAR    PUBLIC
  62    mov   eax, AsmGetFspBaseAddress
  63    sub   eax, dword ptr [FspInfoHeaderRelativeOff]
  64    jmp   edi
  65 AsmGetFspInfoHeaderNoStack         ENDP
  66
  67      END