MemoryAllocationLib.c

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#include <PiPei.h>
 
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/PrePiLib.h>
#include <Library/DebugLib.h>
 
STATIC
VOID *
EFIAPI
InternalAllocatePages (
  IN UINTN            Pages,
  IN EFI_MEMORY_TYPE  MemoryType
  )
{
  EFI_PEI_HOB_POINTERS  Hob;
  EFI_PHYSICAL_ADDRESS  NewTop;
 
  Hob.Raw = GetHobList ();
 
  NewTop  = Hob.HandoffInformationTable->EfiFreeMemoryTop & ~(EFI_PHYSICAL_ADDRESS)EFI_PAGE_MASK;
  NewTop -= Pages * EFI_PAGE_SIZE;
 
  //
  // Verify that there is sufficient memory to satisfy the allocation
  //
  if (NewTop < (Hob.HandoffInformationTable->EfiFreeMemoryBottom + sizeof (EFI_HOB_MEMORY_ALLOCATION))) {
    return NULL;
  }
 
  //
  // Update the PHIT to reflect the memory usage
  //
  Hob.HandoffInformationTable->EfiFreeMemoryTop = NewTop;
 
  //
  // Create a memory allocation HOB.
  //
  BuildMemoryAllocationHob (
    Hob.HandoffInformationTable->EfiFreeMemoryTop,
    Pages * EFI_PAGE_SIZE,
    MemoryType
    );
 
  return (VOID *)(UINTN)Hob.HandoffInformationTable->EfiFreeMemoryTop;
}
 
VOID *
EFIAPI
AllocatePages (
  IN UINTN  Pages
  )
{
  return InternalAllocatePages (Pages, EfiBootServicesData);
}
 
VOID *
EFIAPI
AllocateRuntimePages (
  IN UINTN  Pages
  )
{
  return InternalAllocatePages (Pages, EfiRuntimeServicesData);
}
 
VOID *
EFIAPI
AllocateAlignedPages (
  IN UINTN  Pages,
  IN UINTN  Alignment
  )
{
  VOID   *Memory;
  UINTN  AlignmentMask;
 
  //
  // Alignment must be a power of two or zero.
  //
  ASSERT ((Alignment & (Alignment - 1)) == 0);
 
  if (Pages == 0) {
    return NULL;
  }
 
  //
  // Make sure that Pages plus EFI_SIZE_TO_PAGES (Alignment) does not overflow.
  //
  ASSERT (Pages <= (MAX_ADDRESS - EFI_SIZE_TO_PAGES (Alignment)));
  //
  // We would rather waste some memory to save PEI code size.
  //
  Memory = (VOID *)(UINTN)AllocatePages (Pages + EFI_SIZE_TO_PAGES (Alignment));
  if (Alignment == 0) {
    AlignmentMask = Alignment;
  } else {
    AlignmentMask = Alignment - 1;
  }
 
  return (VOID *)(UINTN)(((UINTN)Memory + AlignmentMask) & ~AlignmentMask);
}
 
VOID
EFIAPI
FreePages (
  IN VOID   *Buffer,
  IN UINTN  Pages
  )
{
  // For now, we do not support the ability to free pages in the PrePei Memory Allocator.
  // The allocated memory is lost.
}
 
VOID *
EFIAPI
AllocatePool (
  IN UINTN  AllocationSize
  )
{
  EFI_HOB_MEMORY_POOL  *Hob;
 
  Hob = GetHobList ();
 
  //
  // Verify that there is sufficient memory to satisfy the allocation
  //
  if (AllocationSize > 0x10000) {
    // Please call AllocatePages for big allocations
    return 0;
  } else {
    Hob = (EFI_HOB_MEMORY_POOL *)CreateHob (
                                   EFI_HOB_TYPE_MEMORY_POOL,
                                   (UINT16)(sizeof (EFI_HOB_MEMORY_POOL) +
                                            AllocationSize)
                                   );
    return (VOID *)(Hob + 1);
  }
}
 
VOID *
EFIAPI
AllocateZeroPool (
  IN UINTN  AllocationSize
  )
{
  VOID  *Buffer;
 
  Buffer = AllocatePool (AllocationSize);
  if (Buffer == NULL) {
    return NULL;
  }
 
  ZeroMem (Buffer, AllocationSize);
 
  return Buffer;
}
 
VOID
EFIAPI
FreePool (
  IN VOID  *Buffer
  )
{
  // Not implemented yet
}