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   SPDX-License-Identifier: BSD-2-Clause-Patent
   7
   8 **/
   9
  10 #include <PiDxe.h>
  11 #include <Library/UefiBootServicesTableLib.h>
  12 #include <Library/DxeServicesLib.h>
  13
  14 /**
  15   Allocates one or more 4KB pages of a given type from a memory region that is
  16   accessible to PEI.
  17
  18   Allocates the number of 4KB pages of type 'MemoryType' and returns a
  19   pointer to the allocated buffer.  The buffer returned is aligned on a 4KB
  20   boundary.  If Pages is 0, then NULL is returned.  If there is not enough
  21   memory remaining to satisfy the request, then NULL is returned.
  22
  23   @param[in]  MemoryType            The memory type to allocate
  24   @param[in]  Pages                 The number of 4 KB pages to allocate.
  25
  26   @return A pointer to the allocated buffer or NULL if allocation fails.
  27
  28 **/
  29 VOID *
  30 EFIAPI
  31 AllocatePeiAccessiblePages (
  32   IN EFI_MEMORY_TYPE  MemoryType,
  33   IN UINTN            Pages
  34   )
  35 {
  36   EFI_STATUS                  Status;
  37   EFI_PHYSICAL_ADDRESS        Memory;
  38
  39   if (Pages == 0) {
  40     return NULL;
  41   }
  42
  43   Status = gBS->AllocatePages (AllocateAnyPages, MemoryType, Pages, &Memory);
  44   if (EFI_ERROR (Status)) {
  45     return NULL;
  46   }
  47   return (VOID *)(UINTN)Memory;
  48 }