Matthew Green has committed a tiny change to <sys/lkm.h>
    to fix LKM's on the NetBSD/sparc64 port.  To take advantage of this,
    you will need to rebuild your kernel and modload(1) with the fixed
    <sys/lkm.h>.  Trying to load a LKM on an old kernel will cause
    a panic, and using an old modload(1) will return ENOTTY (Inappropriate
    ioctl for device).
    
    Update: This has been pulled into the netbsd-1-5 branch, so it will
    be available in NetBSD 1.5.1.