Changes the access mode of the calling process to kernel mode.
    This service allows a process to change its access mode to
    kernel, execute a specified routine, and then return to the
    access mode in effect before the call was issued.

    Format

      SYS$CMKRNL  routin ,[arglst]

    C Prototype

      int sys$cmkrnl  (int (*routin)(__unknown_params), unsigned int

                      *arglst);