MdeModulePkg/Core/DxeIplPeim/Ia32/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 //
  21 // Include common header file for this module.
  22 //
  23 #include "CommonHeader.h"
  24
  25 #include "DxeIpl.h"
  26
  27 EFI_STATUS
  28 EFIAPI
  29 PeiImageRead (
  30   IN     VOID    *FileHandle,
  31   IN     UINTN   FileOffset,
  32   IN OUT UINTN   *ReadSize,
  33   OUT    VOID    *Buffer
  34   )
  35 /*++
  36
  37 Routine Description:
  38
  39   Support routine for the PE/COFF Loader that reads a buffer from a PE/COFF file
  40
  41 Arguments:
  42
  43   FileHandle - The handle to the PE/COFF file
  44
  45   FileOffset - The offset, in bytes, into the file to read
  46
  47   ReadSize   - The number of bytes to read from the file starting at FileOffset
  48
  49   Buffer     - A pointer to the buffer to read the data into.
  50
  51 Returns:
  52
  53   EFI_SUCCESS - ReadSize bytes of data were read into Buffer from the PE/COFF file starting at FileOffset
  54
  55 --*/
  56 {
  57   UINT8 *Destination32;
  58   UINT8 *Source32;
  59   UINTN  Length;
  60
  61
  62   Destination32 = Buffer;
  63   Source32      = (UINT8 *) ((UINTN) FileHandle + FileOffset);
  64
  65   //
  66   // This function assumes 32-bit alignment to increase performance
  67   //
  68 //  ASSERT (ALIGN_POINTER (Destination32, sizeof (UINT32)) == Destination32);
  69 //  ASSERT (ALIGN_POINTER (Source32, sizeof (UINT32)) == Source32);
  70
  71   Length = *ReadSize;
  72   while (Length--) {
  73     *(Destination32++) = *(Source32++);
  74   }
  75
  76   return EFI_SUCCESS;
  77 }
  78
  79 EFI_STATUS
  80 GetImageReadFunction (
  81   IN      PE_COFF_LOADER_IMAGE_CONTEXT  *ImageContext
  82   )
  83 /*++
  84
  85 Routine Description:
  86   Support routine to return the PE32 Image Reader.
  87   If the PeiImageRead() function is less than a page
  88   in legnth. If the function is more than a page the DXE IPL will crash!!!!
  89
  90 Arguments:
  91   ImageContext  - The context of the image being loaded
  92
  93 Returns:
  94   EFI_SUCCESS - If Image function location is found
  95
  96 --*/
  97 {
  98   VOID        *MemoryBuffer;
  99
 100   if (gInMemory) {
 101     ImageContext->ImageRead = PeiImageRead;
 102     return EFI_SUCCESS;
 103   }
 104
 105   //
 106   // BugBug; This code assumes PeiImageRead() is less than a page in size!
 107   //  Allocate a page so we can shaddow the read function from FLASH into
 108   //  memory to increase performance.
 109   //
 110
 111   MemoryBuffer = AllocateCopyPool (0x400, (VOID *)(UINTN) PeiImageRead);
 112   ASSERT (MemoryBuffer != NULL);
 113
 114   ImageContext->ImageRead = (PE_COFF_LOADER_READ_FILE) (UINTN) MemoryBuffer;
 115
 116   return EFI_SUCCESS;
 117 }