EdkModulePkg/Core/DxeIplX64Peim/x64/ImageRead.c

   1 /*++
   2
   3 Copyright (c) 2006, Intel Corporation
   4 All rights reserved. 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 Module Name:
  13
  14   ImageRead.c
  15
  16 Abstract:
  17
  18 --*/
  19
  20 #include <DxeIpl.h>
  21
  22 EFI_STATUS
  23 EFIAPI
  24 PeiImageRead (
  25   IN     VOID    *FileHandle,
  26   IN     UINTN   FileOffset,
  27   IN OUT UINTN   *ReadSize,
  28   OUT    VOID    *Buffer
  29   )
  30 /*++
  31
  32 Routine Description:
  33
  34   Support routine for the PE/COFF Loader that reads a buffer from a PE/COFF file
  35
  36 Arguments:
  37
  38   FileHandle - The handle to the PE/COFF file
  39
  40   FileOffset - The offset, in bytes, into the file to read
  41
  42   ReadSize   - The number of bytes to read from the file starting at FileOffset
  43
  44   Buffer     - A pointer to the buffer to read the data into.
  45
  46 Returns:
  47
  48   EFI_SUCCESS - ReadSize bytes of data were read into Buffer from the PE/COFF file starting at FileOffset
  49
  50 --*/
  51 {
  52   CHAR8 *Destination8;
  53   CHAR8 *Source8;
  54   UINTN Length;
  55
  56   Destination8  = Buffer;
  57   Source8       = (CHAR8 *) ((UINTN) FileHandle + FileOffset);
  58   Length        = *ReadSize;
  59   while (Length--) {
  60     *(Destination8++) = *(Source8++);
  61   }
  62
  63   return EFI_SUCCESS;
  64 }
  65
  66 EFI_STATUS
  67 GetImageReadFunction (
  68   IN      PE_COFF_LOADER_IMAGE_CONTEXT  *ImageContext
  69   )
  70 /*++
  71
  72 Routine Description:
  73
  74   Support routine to return the PE32 Image Reader.
  75   If the PeiImageRead() function is less than a page
  76   in legnth. If the function is more than a page the DXE IPL will crash!!!!
  77
  78 Arguments:
  79   ImageContext  - The context of the image being loaded
  80
  81 Returns:
  82
  83   EFI_SUCCESS - If Image function location is found
  84
  85 --*/
  86 {
  87   VOID        *MemoryBuffer;
  88
  89   if (gInMemory) {
  90     ImageContext->ImageRead = PeiImageRead;
  91     return EFI_SUCCESS;
  92   }
  93
  94   //
  95   // BugBug; This code assumes PeiImageRead() is less than a page in size!
  96   //  Allocate a page so we can shaddow the read function from FLASH into
  97   //  memory to increase performance.
  98   //
  99
 100   MemoryBuffer = AllocateCopyPool (0x400, (VOID *)(UINTN) PeiImageRead);
 101   ASSERT (MemoryBuffer != NULL);
 102
 103   ImageContext->ImageRead = (PE_COFF_LOADER_READ_FILE) (UINTN) MemoryBuffer;
 104
 105   return EFI_SUCCESS;
 106 }