#!/bin/bash

set +o posix
shopt -s extglob

# Kernel Module experimentation copy tool.
# Purpose: To facilitate testing of the included Kernel modules
# list by utilising an x86 Slackware machine to re-process
# the Slackware AArch64 Installer.
# This method offers a faster alternative to rebuilding the Installer
# repeatedly.
#
# mozes@slackware.com
# 02-Jan-2024

# This assumes a number of things - don't run this without setting things up!

# Mount your Slackware AArch64 Installer SD card at /mnt/floppy:
SLKINSTSDCARD=/mnt/floppy/
TMP=/tmp/slkinst-modify
SLKA64K=/devel/armedslack/slackwareaarch64-current/source/k-wip/
KMODSLIMMER=${SLKA64K}/scripts/slim-kmods-initrd

KMODINCLUDELIST=${SLKA64K}/sources/kmod-dirlist
#KMODINCLUDELIST=${SLKA64K}/sources/kmod-dirlist-PREV

mountpoint -q ${SLKINSTSDCARD} || exit 1

# Path to the new Kernel package:
# We'll extract all Kernel modules from here, then
# copy those listed in in ${KMODINCLUDELIST} into the
# Slackware Installer file system:
KERNPKG=/devel/armedslack/tmp/6.6/a/kernel_armv8-6.6.8_armv8-aarch64-1.txz

rm -rf $TMP
mkdir -p $TMP/{tree,tmp}

# Unpack the Kernel modules package into a temp space:
tar xf $KERNPKG -C $TMP/tmp/ || exit 1
# Determine the Kernel version:
KVER=$( echo $TMP/tmp/lib/modules/* | sed 's/.*\///' )
echo "Handling Kernel version: $KVER"

# Unpack the Slackware Installer into the temporary space:
pushd $TMP/tree || exit 1
xzcat $SLKINSTSDCARD/initrd-armv8.img | cpio -di || exit 1
# Clean out the Kernel modules:
rm -rf lib/modules
mkdir -vpm755 lib/modules/$KVER/kernel

# Copy the indexes, etc. (everything other than the Kernel modules and the build/source symlinks):
#cp -fa ${TMP}/tmp/lib/modules/${KVER}/!(build|kernel|source) lib/modules/${KVER}/
cp -fav ${TMP}/tmp/lib/modules/${KVER}/modules.{order,builtin*} lib/modules/${KVER}/

# Copy the listed Kernel modules into the Slackware Installer tree from
# the temporary location into which they were unpacked:
# Enter the temp area:
cd $TMP/tmp/lib/modules/${KVER}/kernel || exit 1
grep -Ev '^#|^$' ${KMODINCLUDELIST} | tar --wildcards -pvvcf - -T- | tar -C${TMP}/tree/lib/modules/${KVER}/kernel/ -pxf -
# Slim them down:
cd ${TMP}/tree/lib/modules/${KVER}/kernel/
echo "Slimming..."
. ${KMODSLIMMER}
# Depmod:
cd ${TMP}/tree
echo "Depmod..."
depmod -b . -a $KVER
# Repack:
echo "Repacking.."
find . | cpio -o -H newc | xz --threads $(( $(nproc) -1 )) -vze9f -C crc32 > $SLKINSTSDCARD/initrd-armv8.img
sync
du -sh ${TMP}/tree/lib/modules

echo "now umount the SD card"