VDDAllocMem

VDDAllocMem allocates memory at a given virtual address.

BOOL
  VDDAllocMem(
    IN HANDLE  hVdd,
    IN PVOID  Address,
    IN DWORD  Size
    );

hVdd: Identifies the VDD.
Address: Specifies the address between 640K and 1MB where memory will be allocated.
Size: Specifies the number of bytes of memory to allocate.

VDDAllocMem returns TRUE if successful. If the function fails then FALSE is returned and an error is logged.

The extended error codes are:

Value	Meaning
ERROR_OUTOFMEMORY	Indicates insufficient memory error.
ERROR_INVALID_ADDRESS	Identifies invalid address error.

VDDs must use this function instead of VirtualAlloc (see the Win32 SDK) to allocate memory.

Address is page-aligned downwards, and Size is stretched upward to be page-aligned.

Address is relative to DOS 0:0. GetVDMPointer should not be called on this address before calling VDDAllocMem.

This address is the same as that provided by the hook handler for memory-mapped I/O.