debian-cd-clone/tools/make-firmware-image

#!/bin/sh

# Work out which firmware files to include in the image
# Several steps:
#
# 1. Look for firmware packages just like a regular debian-cd build with
#    non-free enabled would do (see NONFREE_COMPONENTS variable for details)
# 2. Add them into the firmware temp tree
# 3. Make images (tar.gz, zip) of that tree

set -e

export MIRROR=$1
export CODENAME=$2
TMPDIR=$3
export LC_ALL=C

if [ "$MIRROR"x = ""x ] || \
	[ "$CODENAME"x = ""x ] || \
	[ "$TMPDIR"x = ""x ] ; then
	echo "$0: Need parameters"
	exit 1
fi

rm -rf $TMPDIR/firmware
mkdir -p $TMPDIR/firmware

# Debian 12+ official images use main and non-free-firmware, Debian 11
# sticks to the three historical components:
case $CODENAME in
	bullseye)
		export FIRMWARE_COMPONENTS="main contrib non-free"
		;;
	*)
		# FIXME: drop non-free when we no longer need it
		export FIRMWARE_COMPONENTS="main non-free non-free-firmware"
		;;
esac

# This tool requires environment variables (exported earlier) and two
# parameters; the second one has a special value for us to use:
FILES=$($BASEDIR/tools/generate_firmware_task '*' --list-filenames)
for FILE in $FILES; do
	cp ${MIRROR}/${FILE} $TMPDIR/firmware
done

cd $TMPDIR/firmware
tar czf ../firmware.tar.gz .
zip -9rq ../firmware.zip .
cd ..
find firmware | cpio --quiet -o -H newc | pigz -9nm > firmware.cpio.gz
ls -l $PWD/firmware.cpio.gz $PWD/firmware.tar.gz $PWD/firmware.zip

sha256sum firmware.* > SHA256SUMS
sha512sum firmware.* > SHA512SUMS