#!/usr/bin/bash
#
# Teach kernel-install about the C630's device tree.
#
# The C630's UEFI hands Linux no device tree, so GRUB has to load one. Fedora's
# BLS snippets have a `devicetree` key for exactly this, but nothing in the
# stock toolchain populates it — which means a plain `dnf update kernel` would
# otherwise produce an unbootable entry. This hook runs after 20-grub.install
# and patches the entry it just wrote.

set -eu

COMMAND="${1:?}"
KERNEL_VERSION="${2:?}"

DTB_REL="@DEVICE_DTB@"
BOOT_ROOT="${KERNEL_INSTALL_BOOT_ROOT:-/boot}"
ENTRIES_DIR="${BOOT_ROOT}/loader/entries"

case "$COMMAND" in
add)
    dtb_path="/dtb-${KERNEL_VERSION}/${DTB_REL}"
    if [ ! -e "${BOOT_ROOT}${dtb_path}" ]; then
        echo "95-c630-devicetree: ${BOOT_ROOT}${dtb_path} is missing;" \
             "leaving boot entries alone rather than writing a bad one" >&2
        exit 0
    fi

    shopt -s nullglob
    for entry in "${ENTRIES_DIR}"/*-"${KERNEL_VERSION}".conf; do
        # Drop any stale devicetree line, then append the current one. Doing it
        # in that order makes the hook idempotent across re-installs.
        tmp="${entry}.c630.$$"
        grep -v '^devicetree[[:space:]]' "$entry" > "$tmp"
        printf 'devicetree %s\n' "$dtb_path" >> "$tmp"
        mv -f "$tmp" "$entry"
        echo "95-c630-devicetree: set devicetree ${dtb_path} in ${entry}"
    done
    ;;
remove)
    # The build writes its own bootstrap entry under a fixed name, which
    # kernel-install would not otherwise clean up when the kernel goes away.
    rm -f "${ENTRIES_DIR}/c630-${KERNEL_VERSION}.conf"
    ;;
esac

exit 0