#!/usr/bin/ksh93

#

# Build Debian RT kernel from source,

# and retain the kernel build including source and *.o

# files so we can build custom kernel modules from

# that

#

compound bconfig=(

	# config

	typeset kernel_maj_min='5.10'

	# calculated values

	typeset kernel_build_path

)

function build_debian_kernel_from_src

{

	set -o xtrace

	set -o errexit

	set -o nounset

	integer res

	integer num_cpus=$(getconf '_NPROCESSORS_CONF')

	tar xf "/usr/src/linux-source-${bconfig.kernel_maj_min}.tar.xz"

	cd "linux-source-${bconfig.kernel_maj_min}"

	unxz <"/usr/src/linux-patch-${bconfig.kernel_maj_min}-rt.patch.xz" | patch -p1

	cp "/usr/src/linux-config-${bconfig.kernel_maj_min}/config.amd64_rt_amd64.xz" .

	unxz 'config.amd64_rt_amd64.xz'

	# copy config and make kernel build accept it without

	# jumping to the $ make menu # menu

	cp 'config.amd64_rt_amd64' '.config'

	make oldconfig <'/dev/null'

	# show any modifications $ make oldconfig # did to the kernel config

	print '--------------------------------------'

	diff -u 'config.amd64_rt_amd64' '.config' || true

	print '--------------------------------------'

	make clean

	time nice -n 19 make -j$((num_cpus*2)) deb-pkg 2>&1 | tee -a buildlog.log

	(( res=$? ))

	printf '#### Finished, return code = %d\n' res

	if (( res == 0 )) ; then

		# remember the path to the kernel build, but only if we were successful

		bconfig.kernel_build_path="$PWD"

	fi

	return $res

}

function build_simatic_kernel_modules

{

	set -o xtrace

	set -o errexit

	set -o nounset