MdePkg/Library/DxeServicesLib/Allocate.c

   1 /** @file
   2   DxeServicesLib memory allocation routines
   3
   4   Copyright (c) 2018, Linaro, Ltd. All rights reserved.<BR>
   5
   6   This program and the accompanying materials are licensed and made available
   7   under the terms and conditions of the BSD License which accompanies this
   8   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 #include <PiDxe.h>
  17 #include <Library/UefiBootServicesTableLib.h>
  18 #include <Library/DxeServicesLib.h>
  19
  20 /**
  21   Allocates one or more 4KB pages of a given type from a memory region that is
  22   accessible to PEI.
  23
  24   Allocates the number of 4KB pages of type 'MemoryType' and returns a
  25   pointer to the allocated buffer.  The buffer returned is aligned on a 4KB
  26   boundary.  If Pages is 0, then NULL is returned.  If there is not enough
  27   memory remaining to satisfy the request, then NULL is returned.
  28
  29   @param[in]  MemoryType            The memory type to allocate
  30   @param[in]  Pages                 The number of 4 KB pages to allocate.
  31
  32   @return A pointer to the allocated buffer or NULL if allocation fails.
  33
  34 **/
  35 VOID *
  36 EFIAPI
  37 AllocatePeiAccessiblePages (
  38   IN EFI_MEMORY_TYPE  MemoryType,
  39   IN UINTN            Pages
  40   )
  41 {
  42   EFI_STATUS                  Status;
  43   EFI_PHYSICAL_ADDRESS        Memory;
  44
  45   if (Pages == 0) {
  46     return NULL;
  47   }
  48
  49   Status = gBS->AllocatePages (AllocateAnyPages, MemoryType, Pages, &Memory);
  50   if (EFI_ERROR (Status)) {
  51     return NULL;
  52   }
  53   return (VOID *)(UINTN)Memory;
  54 }