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 ; This program and the accompanying materials
   7 ; are licensed and made available under the terms and conditions of the BSD License
   8 ; which accompanies this distribution.  The full text of the license may be found at
   9 ; http://opensource.org/licenses/bsd-license.php
  10 ;
  11 ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12 ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13 ;
  14 ;------------------------------------------------------------------------------
  15
  16 BITS    16
  17
  18 ALIGN   16
  19
  20 ;
  21 ; Pad the image size to 4k when page tables are in VTF0
  22 ;
  23 ; If the VTF0 image has page tables built in, then we need to make
  24 ; sure the end of VTF0 is 4k above where the page tables end.
  25 ;
  26 ; This is required so the page tables will be 4k aligned when VTF0 is
  27 ; located just below 0x100000000 (4GB) in the firmware device.
  28 ;
  29 %ifdef ALIGN_TOP_TO_4K_FOR_PAGING
  30     TIMES (0x1000 - ($ - EndOfPageTables) - 0x20) DB 0
  31 %endif
  32
  33 applicationProcessorEntryPoint:
  34 ;
  35 ; Application Processors entry point
  36 ;
  37 ; GenFv generates code aligned on a 4k boundary which will jump to this
  38 ; location.  (0xffffffe0)  This allows the Local APIC Startup IPI to be
  39 ; used to wake up the application processors.
  40 ;
  41     jmp     EarlyApInitReal16
  42
  43 ALIGN   8
  44
  45     DD      0
  46
  47 ;
  48 ; The VTF signature
  49 ;
  50 ; VTF-0 means that the VTF (Volume Top File) code does not require
  51 ; any fixups.
  52 ;
  53 vtfSignature:
  54     DB      'V', 'T', 'F', 0
  55
  56 ALIGN   16
  57
  58 resetVector:
  59 ;
  60 ; Reset Vector
  61 ;
  62 ; This is where the processor will begin execution
  63 ;
  64     nop
  65     nop
  66     jmp     EarlyBspInitReal16
  67
  68 ALIGN   16
  69
  70 fourGigabytes:
  71