Establishes a correspondence between pages (maps) in the virtual
    address space of the process and physical pages occupied by a
    global section.

    Format

      SYS$MGBLSC  inadr ,[retadr] ,[acmode] ,[flags] ,gsdnam ,[ident]

                  ,[relpag]

    C Prototype

      int sys$mgblsc  (struct _va_range *inadr, struct _va_range

                      *retadr, unsigned int acmode, unsigned int

                      flags, void *gsdnam, struct _secid *ident,

                      unsigned int relpag);