late_cmd

#!/bin/sh -ex

gpg_key=60AA7B6F30434AE68E569963E50C6A0917C622B0
prefix="http://kernel.ubuntu.com/~kernel-ppa/mainline"

# otherwise, gpg keyring will be written to /
export HOME=/root

# Get latest version
version=`wget -O - -- "$prefix" | sed -n 's,.*href="\(v4\.[0-9]\+\(\.[0-9]\+\)\?\)/".*,\1,p' | sort -V | tail -n 1`
[ -n "$version" ]
echo "Install kernel version $version"

tmp=`mktemp -d`
cd -- "$tmp"

# Download and verify checksums
gpg --keyserver keyserver.ubuntu.com --recv-key "$gpg_key"
wget -O CHECKSUMS "$prefix/$version/CHECKSUMS"
wget -O CHECKSUMS.gpg "$prefix/$version/CHECKSUMS.gpg"
gpg --verify CHECKSUMS.gpg CHECKSUMS

# Download kernel debs
awk '/amd64.deb|all.deb/{print $2}' "$tmp/CHECKSUMS" | grep -v lowlatency | sort -u | while read deb; do
    wget -O "$deb" "$prefix/$version/$deb"
done

# verify kernel debs
sha256sum -c --ignore-missing CHECKSUMS

# mount sysfs
need_umount=no
if mount -t sysfs sysfs /sys; then
    need_umount=yes
fi

# install new kernel
dpkg -i *.deb

# unmount sysfs
if [ $need_umount = yes ]; then
    umount /sys
fi

# cleanup
cd /
rm -r -- "$tmp"