#!/bin/sh

set -eu

destdir="$(readlink -e "$1")"

kver=$(rpm --root "${destdir}" -q --qf '%{VERSION}-%{RELEASE}.%{ARCH}' kernel)
printf 'Building initramfs image for kernel %s\n' "${kver}"

cd "${destdir}"
mkdir -p boot dev proc sys tmp
mountpoint -q dev || mount -o bind /dev dev
mountpoint -q proc || mount -t proc proc proc
mountpoint -q sys || mount -t sysfs sysfs sys
mountpoint -q tmp || mount -t tmpfs tmpfs tmp

echo 'Copying kernel image to /boot/ ...' >&2
cp -a "${destdir}"/lib/modules/"${kver}"/vmlinuz \
    "${destdir}"/boot/
echo 'Running depmod ...' >&2
chroot "${destdir}" depmod -a "${kver}"
echo 'Building initramfs image ...' 2>&1
chroot "${destdir}" dracut \
    --no-hostonly \
    --modules 'nbd udev-rules dracut-systemd shutdown' \
    --drivers 'genet nbd squashfs' \
    --force-drivers 'bcm2835_wdt i2c_bcm2835 i2c_mux_pinctrl rtc_pcf85063' \
    --force \
    /boot/initramfs.img \
    "${kver}"
echo 'Fixing boot file pemissions ...' 2>&1
find "${destdir}"/boot \
    -type d -exec chmod a+rx {} + \
    -or \
    -type f -exec chmod a+r {} +

umount tmp sys proc dev