Make Your Code Portable

The following are principles to make your code portable.

1) Use C instead of C++.

If you want your library more portable, please use C instead of C++.

2) Use C standard library.

Because EDK II supports C standard library, we just use it.

Please refer Use C Library in EDK II UEFI Driver. 

3) As far as possible, allocate memory space for a returned parameter before calling a public function.

For example,

EFI_STATUS
CompressData (
  IN UINT8 *Buffer,
  IN UINTN BufferSize,
  OUT UINT8 **Output,
  OUT UINTN *OutputSize
  );

This Compress function allocates memory space for the returned Output. The problem is that the memory management mechanisms are different in environments. In UEFI DXE environment, gBS->AllocatePool() supports the memory space allocation. In SMM mode, UEFI provides SmmAllocatePool(). In Windows KMDF, we should use WdfMemoryCreate to allocate memory space.

Therefore please rework the function as below otherwise we need to create many stubs to wrap the memory management functions for different environments.

EFI_STATUS
GetCompressedDataSize (
  IN UINT8 *Buffer,
  IN UINTN BufferSize,
  OUT UINTN *OutputSize
  );

EFI_STATUS
CompressData (
  IN UINT8 *Buffer,
  IN UINTN BufferSize,
  OUT UINT8 *Output,
  IN UINTN OutputSize
  );

4) The sizes of fields in C struct must be determined.

Don't use UINTN or ulong, the sizes are undetermined, in your struct. If you define struct in UEFI environment, please use UINT8, UINT16, UINT32, CHAR8, CHAR16 of which sizes are always same in IA32 and X64.

-Count