[Pkg-raspi-maintainers] Bug#865069: uncompress kernel images

[Martin Schitter]

Package: raspi3-firmware
Version: 1.20170317-4

the raspi3-firmware kernel postinstall hook should take care of 
uncompressing kernel moved to /boot/firmware. raspberry firmware can 
only handle uncompressed images (otherwise the board will hang and only 
show the rainbow screen).

debians official arm64 kernel packages utilize uncompressed kernel 
images, but cross compiled custom kernels (e.g. by using 'make 
ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- deb-pkg') will pack 
compressed ones in the linux-image*_arm64.debs by default.

'scripts/extract-vmlinux', provided by the linux kernel source code, 
could be used to decompress all kinds of kernel images.