OvmfPkg/XenResetVector/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 ; Copyright (c) 2019, Citrix Systems, Inc.
   7 ;
   8 ; SPDX-License-Identifier: BSD-2-Clause-Patent
   9 ;
  10 ;------------------------------------------------------------------------------
  11
  12 BITS    16
  13
  14 ALIGN   16
  15
  16 ;
  17 ; Pad the image size to 4k when page tables are in VTF0
  18 ;
  19 ; If the VTF0 image has page tables built in, then we need to make
  20 ; sure the end of VTF0 is 4k above where the page tables end.
  21 ;
  22 ; This is required so the page tables will be 4k aligned when VTF0 is
  23 ; located just below 0x100000000 (4GB) in the firmware device.
  24 ;
  25 %ifdef ALIGN_TOP_TO_4K_FOR_PAGING
  26     TIMES (0x1000 - ($ - EndOfPageTables) - (fourGigabytes - xenPVHEntryPoint)) DB 0
  27 %endif
  28
  29 BITS    32
  30 xenPVHEntryPoint:
  31 ;
  32 ; Entry point to use when running as a Xen PVH guest. (0xffffffd0)
  33 ;
  34 ; Description of the expected state of the machine when this entry point is
  35 ; used can be found at:
  36 ; https://xenbits.xenproject.org/docs/unstable/misc/pvh.html
  37 ;
  38     jmp     xenPVHMain
  39
  40 BITS    16
  41 ALIGN   16
  42
  43 applicationProcessorEntryPoint:
  44 ;
  45 ; Application Processors entry point
  46 ;
  47 ; GenFv generates code aligned on a 4k boundary which will jump to this
  48 ; location.  (0xffffffe0)  This allows the Local APIC Startup IPI to be
  49 ; used to wake up the application processors.
  50 ;
  51     jmp     EarlyApInitReal16
  52
  53 ALIGN   8
  54
  55     DD      0
  56
  57 ;
  58 ; The VTF signature
  59 ;
  60 ; VTF-0 means that the VTF (Volume Top File) code does not require
  61 ; any fixups.
  62 ;
  63 vtfSignature:
  64     DB      'V', 'T', 'F', 0
  65
  66 ALIGN   16
  67
  68 resetVector:
  69 ;
  70 ; Reset Vector
  71 ;
  72 ; This is where the processor will begin execution
  73 ;
  74     jmp     EarlyBspInitReal16
  75
  76 ALIGN   16
  77
  78 fourGigabytes:
  79