memory.c

#include <efi.h>
#include <memory.h>
#include <util.h>

#define MEMMAP_BUFFER_SIZE 128 // Arbitrary size
static struct EFI_MEMORY_DESCRIPTOR memmap_buffer[MEMMAP_BUFFER_SIZE];

void exit_boot_services(EFI_HANDLE ImageHandle) {
  EFI_STATUS status;

  UINTN mmap_size = MEMMAP_BUFFER_SIZE * sizeof(struct EFI_MEMORY_DESCRIPTOR);
  UINTN map_key;
  UINTN descriptor_size;
  UINT32 descriptor_version;
  status = SystemTable->BootServices->GetMemoryMap(
      &mmap_size, memmap_buffer, &map_key, &descriptor_size, &descriptor_version);
  assert(status, L"BootServices#GetMemoryMap error");

  status = SystemTable->BootServices->ExitBootServices(ImageHandle, map_key);
  assert(status, L"BootServices#ExitBootServices");
}