$ file kernelcache
kernelcache: data
$ img4tool -e kernelcache -m kernelcache.im4m -p kernelcache.im4p
img4tool version: 0.195-2f8d192d13741eabbec792ff0a017dfe2dbaf06c
Compiled with plist: NO
Extracted IM4P to kernelcache.im4p
Extracted IM4M to kernelcache.im4m
$ img4tool kernelcache.im4p -e -o kernelcache
img4tool version: 0.195-2f8d192d13741eabbec792ff0a017dfe2dbaf06c
Compiled with plist: NO
Compression detected, uncompressing (bvx2): ok
Extracted (and uncompressed bvx2) IM4P payload to kernelcache
$ file kernelcache
kernelcache: Mach-O 64-bit arm64e 0x00) filetype=12