routin_64

    OpenVMS usage:procedure
    type:         procedure value
    access:       call without stack unwinding
    mechanism:    by 32- or 64-bit reference
    Routine to be executed while the process is in executive mode.
    The routin_64 argument is the 32- or 64-bit address of this
    routine.

 arglst_64

    OpenVMS usage:arg_list
    type:         quadword (unsigned)
    access:       read only
    mechanism:    by 32- or 64-bit reference
    Argument list to be passed to the routine specified by the
    routin_64 argument. The arglst_64 argument is the 32- or 64-bit
    address of this argument list.

    If the arglst value is nonzero and is not accessible as an
    address or if the routine is inaccessible, the service returns
    SS$_ACCVIO.

    Alpha and Integrity server systems require a pointer to a valid
    argument list or a value of 0 in the arglst_64 argument. This
    means that the arglst_64 argument, if nonzero, must contain
    an accessible virtual address for an argument list, the first
    quadword of which must be a number between 0 and 255 specifying
    the number of quadwords that follow it on the list.