replace
TARGETS = KERNEL IMAGE [...]
with
MDTARGETS = KERNEL IMAGE FILENAME [...]
If FILENAME is "-", use "netbsd.${KERNEL}" as the target filename
The rest:
Update for new MDTARGETS syntax. In some cases, the kernel
name from the "old" method will be used to override the default.
This was tested using a custom INSTALL kernel. The current one is >4Mb
which the cats firmware can't currently boot. We need to decide what
needs to be removed from INSTALL.