kerndev-create-foreign

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

# TODO: Duplicates kerndev-create, lots of copy-pasta, de-duplicate!!

[[ -z "$1" ]] && fatal missing arch.

target_arch=$1
shift

case $target_arch in
	"arm")
		debootstrap_arch="armhf"
		binfmt_sig=":arm:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\
\x00\x02\x00\x28\x00:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\
\xff\xfe\xff\xff\xff:/usr/bin/qemu-arm-static:"
	;;
	"aarch64")
		debootstrap_arch="arm64"
		binfmt_sig=":aarch64:M::\x7fELF\x02\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\
\x00\x02\x00\xb7:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\
\xff\xfe\xff\xff:/usr/bin/qemu-aarch64-static:"
	;;
	 *)
		fatal Unknown arch $target_arch.
	 ;;
esac

rootfs="rootfs_${target_arch}.img"
binfmt_path="/proc/sys/fs/binfmt_misc"
chroot_path="/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin"

# Functions.

function cleanup()
{
	[[ -f $binfmt_path/$target_arch ]] && echo -1 > $binfmt_path/$target_arch
	rm -f /mnt/usr/bin/qemu-$target_arch-static
	unmount
}

# Sanity checks.
check_exists debootstrap qemu-system-$target_arch qemu-$target_arch-static
[[ ! -d $binfmt_path ]] && fatal "binfmt not available."

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

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

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

unmount

mkdir -p $KERNDEV_PATH

push_kerndev

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

mount_image $rootfs
trap cleanup EXIT

if [[ -z "$USE_EXISTING_IMAGE" ]]; then
	echo "Downloading and installing first stage rootfs into image..."

	debootstrap --arch=$debootstrap_arch --variant=minbase --foreign  \
		--include=$DEBIAN_PACKAGES $DEBIAN_VERSION /mnt $DEBIAN_MIRROR \
		>/dev/null
fi

echo Enabling binfmt for chroot...
cp $(which qemu-${target_arch}-static) /mnt/usr/bin/
echo "$binfmt_sig" > $binfmt_path/register

if [[ -z "$USE_EXISTING_IMAGE" ]]; then
	echo Entering chroot, downloading and installing second stage rootfs into image...
	chroot /mnt /debootstrap/debootstrap --second-stage >/dev/null
fi

echo Running pre-chroot tasks...
cp $chroot_script_path /mnt/chroot.sh
# Copy ssh keys + config.
cp -R /home/$SUDO_USER/.ssh /mnt/

# Git + qemu/arm don't play nice, so clone oh-my-zsh here.
rm -rf /mnt/oh-my-zsh && mkdir /mnt/oh-my-zsh
git clone --depth=1 https://github.com/robbyrussell/oh-my-zsh.git /mnt/oh-my-zsh &>/dev/null

echo Running chroot-ed rootfs image config script...
arch-chroot /mnt /chroot.sh $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

if [[ -n "$ACCESS_CHROOT" ]]; then
	echo Entering chroot shell...
	arch-chroot /mnt env -i TERM=ansi PATH=$chroot_path /bin/bash
	echo ...chroot shell done!
fi

echo Building linux...
# Install separately so we can update user on progress separately + not write
# root owned files!
NO_DONE=y DONT_INSTALL=y sudo -E -u $SUDO_USER kerndev-build $target_arch

echo Installing modules into image...
NO_DONE=y source kerndev-install $target_arch

pop

# Pass ownership back to the user.
give_back $KERNDEV_PATH

say_done