kerndev-create

#!/bin/bash
set -e; set -o pipefail; source kerndev-shared.sh

# If an argument is provided, it specifies a cross-compile target architecture.
target_arch=${1:-"x86_64"}

case $target_arch in
	"arm")
		exec kerndev-create-foreign arm $@
		exit $?
		;;
	"aarch64")
		exec kerndev-create-foreign aarch64 $@
		exit $?
		;;
	"x86_64")
		;;
	 *)
		 fatal Unknown arch $1.
		 ;;
esac

# Sanity checks.
[[ ! -f "/etc/arch-release" ]] && \
	fatal This script is designed for arch linux only, sorry!

check_exists kerndev-create.chroot.sh kerndev-build kerndev-install pacstrap \
	    truncate mkfs.ext4 arch-chroot

[[ -n $USE_EXISTING_IMAGE ]] && [[ ! -f $KERNDEV_PATH/rootfs.img ]] && \
	fatal "can't find existing rootfs image"

chroot_script_path=$(which kerndev-create.chroot.sh)

# So many commands need sudo, so just force the issue.
elevate $@

# We want access to the underlying user.
[[ -z "$SUDO_USER" ]] && fatal please run this using sudo!

# If this fails due to being unable to unmount /mnt, mount below will fail so we
# can get away with ||true here.
unmount

mkdir -p $KERNDEV_PATH

push_kerndev

if [[ -z "$USE_EXISTING_IMAGE" ]]; then
	echo Creating and formatting rootfs image file...
	rm -f rootfs.img
	truncate -s $IMAGE_SIZE rootfs.img
	mkfs.ext4 -q rootfs.img
else
	echo Using existing rootfs...
fi

mount_image rootfs.img
trap "umount /mnt" EXIT

if [[ -z "$USE_EXISTING_IMAGE" ]]; then
	echo Downloading and installing rootfs into image...
	pacstrap /mnt base base-devel &>/dev/null
fi

echo Running chroot-ed rootfs image config script...
cp $chroot_script_path /mnt/chroot.sh
# Copy ssh keys + config.
cp -R /home/$SUDO_USER/.ssh /mnt/
arch-chroot /mnt /chroot.sh $SUDO_USER $(id -u $SUDO_USER) $ROOT_PASSWORD
rm /mnt/chroot.sh
# arch-chroot mounts the system's /etc/resolv.conf, so do this outside the
# chroot.
cat >/mnt/etc/resolv.conf <<EOF
nameserver 8.8.8.8
nameserver 8.8.4.4
EOF

echo ...chroot-ed script complete!

if [[ -z "$USE_EXISTING_IMAGE" ]] && [[ -n "$ENABLE_GCOV" ]]; then
    echo Generating gcov script...

	# Create 'cov' tool to check coverage for a specific file in the kernel tree.
	cov_path=/mnt/usr/bin/cov

	cat >$cov_path <<-EOF
		#!/bin/bash

		[[ -z "\$1" ]] && echo "usage: \$(basename \$0) [relative path to source file]" >&2 && exit 1

		# ref: https://goo.gl/rnd6yo
		args=\${@:1:-1}
		f=\${@: -1}

		local_linux=/home/$SUDO_USER/linux/

		pushd \$local_linux >/dev/null
		sudo gcov \$args -o /sys/kernel/debug/gcov/$LINUX_DEV_PATH/\$(dirname \$f) \$local_linux/\$f
		sudo chown $SUDO_USER *.gcov
		popd >/dev/null
	EOF
	chmod +x $cov_path
	give_back $cov_path

	pop
fi

if [[ -n "$ACCESS_CHROOT" ]]; then
	echo Entering chroot shell...
	arch-chroot /mnt
	echo ...chroot shell done!
fi

# We don't need /mnt any more.
unmount
trap - EXIT

if [[ -n "$KERNEL_BUILD_ON_CREATE" ]]; then
	echo Building linux...
	# Install separately so we can update user on progress separately, also this
	# means we can run as the user and thus not write root owned files!
	NO_DONE=y DONT_INSTALL=y sudo -E -u $SUDO_USER kerndev-build

	echo Installing modules into image...
	NO_DONE=y kerndev-install
fi

pop

# Pass ownership back to the user.
# Executing this outside of the chroot probably means uids need to be
# synced. TODO: Fix.
give_back $KERNDEV_PATH

say_done