EmulatorPkg/Sec/X64/SwitchRam.asm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>
   4 ; Portitions copyright (c) 2011, Apple Inc. All rights reserved.
   5 ; SPDX-License-Identifier: BSD-2-Clause-Patent
   6 ;
   7 ;------------------------------------------------------------------------------
   8
   9 EXTERN CopyMem:PROC
  10 EXTERN ZeroMem:PROC
  11
  12     .code
  13
  14 ;------------------------------------------------------------------------------
  15 ;  EFI_STATUS
  16 ;  EFIAPI
  17 ;  SecTemporaryRamSupport (
  18 ;    IN CONST EFI_PEI_SERVICES   **PeiServices,         // %rcx
  19 ;    IN EFI_PHYSICAL_ADDRESS     TemporaryMemoryBase,   // %rdx
  20 ;    IN EFI_PHYSICAL_ADDRESS     PermanentMemoryBase,   // %r8
  21 ;    IN UINTN                    CopySize               // %r9
  22 ;    )
  23 ;------------------------------------------------------------------------------
  24 SecTemporaryRamSupport PROC
  25   ; Adjust callers %rbp to account for stack move
  26   sub     rbp, rdx      ; Calc offset of %rbp in Temp Memory
  27   add     rbp, r8       ; add in permanent base to offset
  28
  29   push    rbp           ; stack frame is for the debugger
  30   mov     rbp, rsp
  31
  32   push    rdx           ; Save TemporaryMemoryBase
  33   push    r8            ; Save PermanentMemoryBase
  34   push    r9            ; Save CopySize
  35
  36   ;
  37   ; Copy all of temp RAM to permanent memory, including stack
  38   ;
  39   ; CopyMem (PermanentMemoryBase, TemporaryMemoryBase, CopySize);
  40   ;          %rcx,                %rdx,                %r8
  41   mov     rcx, r8       ; Shift arguments
  42   mov     r8, r9
  43   sub     rsp, 028h     ; Allocate register spill area & 16-byte align stack
  44   call    CopyMem
  45   ; Temp mem stack now copied to permanent location. %esp still in temp memory
  46   add     rsp, 028h
  47
  48   pop     r9            ; CopySize (old stack)
  49   pop     r8            ; PermanentMemoryBase (old stack)
  50   pop     rdx           ; TemporaryMemoryBase (old stack)
  51
  52   mov     rcx, rsp      ; Move to new stack
  53   sub     rcx, rdx      ; Calc offset of stack in Temp Memory
  54   add     rcx, r8       ; Calc PermanentMemoryBase address
  55   mov     rsp, rcx      ; Update stack
  56   ; Stack now points to permanent memory
  57
  58   ; ZeroMem (TemporaryMemoryBase /* rcx */, CopySize /* rdx */);
  59   mov     rcx, rdx
  60   mov     rdx, r9
  61   sub     rsp, 028h     ; Allocate register spill area & 16-byte align stack
  62   call    ZeroMem
  63   add     rsp, 028h
  64
  65   ; This data comes off the NEW stack
  66   pop     rbp
  67   ret
  68 SecTemporaryRamSupport ENDP
  69
  70   END