UefiCpuPkg/ResetVector/Vtf0/Ia16/ResetVectorVtf0.asm

   1 ;------------------------------------------------------------------------------
   2 ; @file
   3 ; First code executed by processor after resetting.
   4 ;
   5 ; Copyright (c) 2008 - 2014, Intel Corporation. All rights reserved.<BR>
   6 ; SPDX-License-Identifier: BSD-2-Clause-Patent
   7 ;
   8 ;------------------------------------------------------------------------------
   9
  10 BITS    16
  11
  12 ALIGN   16
  13
  14 ;
  15 ; Pad the image size to 4k when page tables are in VTF0
  16 ;
  17 ; If the VTF0 image has page tables built in, then we need to make
  18 ; sure the end of VTF0 is 4k above where the page tables end.
  19 ;
  20 ; This is required so the page tables will be 4k aligned when VTF0 is
  21 ; located just below 0x100000000 (4GB) in the firmware device.
  22 ;
  23 %ifdef ALIGN_TOP_TO_4K_FOR_PAGING
  24     TIMES (0x1000 - ($ - EndOfPageTables) - 0x20) DB 0
  25 %endif
  26
  27 applicationProcessorEntryPoint:
  28 ;
  29 ; Application Processors entry point
  30 ;
  31 ; GenFv generates code aligned on a 4k boundary which will jump to this
  32 ; location.  (0xffffffe0)  This allows the Local APIC Startup IPI to be
  33 ; used to wake up the application processors.
  34 ;
  35     jmp     EarlyApInitReal16
  36
  37 ALIGN   8
  38
  39     DD      0
  40
  41 ;
  42 ; The VTF signature
  43 ;
  44 ; VTF-0 means that the VTF (Volume Top File) code does not require
  45 ; any fixups.
  46 ;
  47 vtfSignature:
  48     DB      'V', 'T', 'F', 0
  49
  50 ALIGN   16
  51
  52 resetVector:
  53 ;
  54 ; Reset Vector
  55 ;
  56 ; This is where the processor will begin execution
  57 ;
  58     nop
  59     nop
  60     jmp     EarlyBspInitReal16
  61
  62 ALIGN   16
  63
  64 fourGigabytes:
  65