build_kernels.sh

#!/bin/bash

if [ ! -d /home/runner/work ]; then NTHREADS=$(nproc); else NTHREADS=$(($(nproc)*4)); fi

if [ -z "$1" ]; then
kernels=$(ls -d ./kernels/* | sed 's#./kernels/##g')
else
kernels="$1"
fi

for kernel in $kernels; do
	echo "Building kernel $kernel"
	KCONFIG_NOTIMESTAMP=1 KBUILD_BUILD_TIMESTAMP='' KBUILD_BUILD_USER=chronos KBUILD_BUILD_HOST=localhost make -C "./kernels/$kernel" -j"$NTHREADS" O=out || { echo "Kernel build failed"; exit 1; }
	rm -f "./kernels/$kernel/out/source"
	if [ -f /persist/keys/brunch.priv ] && [ -f /persist/keys/brunch.pem ]; then
		echo "Signing kernel $kernel"
		mv "./kernels/$kernel/out/arch/x86/boot/bzImage" "./kernels/$kernel/out/arch/x86/boot/bzImage.unsigned" || { echo "Kernel signing failed"; exit 1; }
		sbsign --key /persist/keys/brunch.priv --cert /persist/keys/brunch.pem "./kernels/$kernel/out/arch/x86/boot/bzImage.unsigned" --output "./kernels/$kernel/out/arch/x86/boot/bzImage" || { echo "Kernel signing failed"; exit 1; }
	fi
	echo "Including kernel $kernel headers"
	srctree="./kernels/$kernel"
	objtree="./kernels/$kernel/out"
	SRCARCH="x86"
	KCONFIG_CONFIG="$objtree/.config"
	destdir="$srctree/headers"
	mkdir -p "${destdir}"
	(
		cd "${srctree}"
		echo Makefile
		find "arch/${SRCARCH}" -maxdepth 1 -name 'Makefile*'
		find include scripts -type f -o -type l
		find "arch/${SRCARCH}" -name Kbuild.platforms -o -name Platform
		find "arch/${SRCARCH}" -name include -o -name scripts -type d
	) | tar -c -f - -C "${srctree}" -T - | tar -xf - -C "${destdir}"
	{
		cd "${objtree}"
		if grep -q "^CONFIG_OBJTOOL=y" include/config/auto.conf; then
			echo tools/objtool/objtool
		fi
		find "arch/${SRCARCH}/include" Module.symvers include scripts -type f
		if grep -q "^CONFIG_GCC_PLUGINS=y" include/config/auto.conf; then
			find scripts/gcc-plugins -name '*.so'
		fi
	} | tar -c -f - -C "${objtree}" -T - | tar -xf - -C "${destdir}"
	cp "${KCONFIG_CONFIG}" "${destdir}/.config"
done