IntelFspPkg/FspSecCore/Ia32/FspHelper.s

   1 #------------------------------------------------------------------------------
   2 #
   3 # Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
   4 # This program and the accompanying materials
   5 # are licensed and made available under the terms and conditions of the BSD License
   6 # which accompanies this distribution.  The full text of the license may be found at
   7 # http://opensource.org/licenses/bsd-license.php.
   8 #
   9 # THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 # WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11 #
  12 # Abstract:
  13 #
  14 #   Provide FSP helper function.
  15 #
  16 #------------------------------------------------------------------------------
  17
  18 #
  19 # FspInfoHeaderRelativeOff is patched during build process and initialized to offset of the  AsmGetFspBaseAddress
  20 # from the FSP Info header.
  21 #
  22 ASM_GLOBAL ASM_PFX(FspInfoHeaderRelativeOff)
  23 ASM_PFX(FspInfoHeaderRelativeOff):
  24    #
  25    # This value will be pached by the build script
  26    #
  27    .long    0x012345678
  28
  29 #
  30 # Returns FSP Base Address.
  31 #
  32 # This function gets the FSP Info Header using relative addressing and returns the FSP Base from the header structure
  33 #
  34 ASM_GLOBAL ASM_PFX(AsmGetFspBaseAddress)
  35 ASM_PFX(AsmGetFspBaseAddress):
  36    mov    $AsmGetFspBaseAddress, %eax
  37    sub    FspInfoHeaderRelativeOff, %eax
  38    add    $0x01C, %eax
  39    mov    (%eax), %eax
  40    ret
  41
  42 #
  43 # No stack counter part of AsmGetFspBaseAddress. Return address is in edi.
  44 #
  45 ASM_GLOBAL ASM_PFX(AsmGetFspBaseAddressNoStack)
  46 ASM_PFX(AsmGetFspBaseAddressNoStack):
  47    mov    $AsmGetFspBaseAddress, %eax
  48    sub    FspInfoHeaderRelativeOff, %eax
  49    add    $0x01C, %eax
  50    mov    (%eax), %eax
  51    jmp    *%edi
  52
  53 #
  54 # Returns FSP Info Header.
  55 #
  56 # This function gets the FSP Info Header using relative addressing and returns it
  57 #
  58 ASM_GLOBAL ASM_PFX(AsmGetFspInfoHeader)
  59 ASM_PFX(AsmGetFspInfoHeader):
  60    mov    $AsmGetFspBaseAddress, %eax
  61    sub    FspInfoHeaderRelativeOff, %eax
  62    ret
  63
  64 #
  65 # No stack counter part of AsmGetFspInfoHeader. Return address is in edi.
  66 #
  67 ASM_GLOBAL ASM_PFX(AsmGetFspInfoHeaderNoStack)
  68 ASM_PFX(AsmGetFspInfoHeaderNoStack):
  69    mov    $AsmGetFspBaseAddress, %eax
  70    sub    FspInfoHeaderRelativeOff, %eax
  71    jmp    *%edi