Sets the attribute (volatile or nonvolatile) associated with the specified handle. A nonvolatile memory handle and the contents of the expanded memory pages that are allocated to it are maintained across a warm boot operation (system restart using Ctrl-Alt-Del).
Call with:
AH = 52H
AL = 01H
BL = attribute
0 = volatile
1 = nonvolatile
DX = EMM handle
Returns:
If function successful
AH = 00H
If function unsuccessful
AH = error code
Note:
If the expanded memory hardware cannot support nonvolatile pages, this function returns an error.