script taken here: http://forum.tinycorelinux.net/index.php?topic=12300.0

cr_tc-initrd.sh

#!/bin/sh

# a quick & dirty script to create a TinyCore initrd (for Core >= 4.2)

H=$( pwd )

M=$( mount | grep iso9660 | head -1 | awk '{print $3}' )
[ -z "$M" ] && echo "can not find mounted CD-ROM" && exit 1

D=$( mktemp -d )
cd $D

[ ! -f ${M}/boot/core.gz ] && "can not find initrd file" && exit 2
zcat ${M}/boot/core.gz | sudo cpio -idum

[ ! -f ${M}/cde/copy2fs.lst ] && "can not find copy2fs.lst file" && exit 3
T=$( mktemp -d )
cat ${M}/cde/copy2fs.lst | while read F ; do
    sudo mount ${M}/cde/optional/${F} $T || ! echo "can not mount $F" || exit 4
    sudo cp -a $T/* .
    umount -d $T || ! echo "can not umount $F" || exit 5
done
sudo rm -rf $T

sed -i '$i for F in /usr/local/tce.installed/* ; do sudo $F ; done' \
    opt/bootsync.sh

sudo find . | sudo cpio -odum -H newc \
    | gzip > "${H}/tinycore_$( cat /usr/share/doc/tc/release.txt ).gz"

cd "$H"    
sudo rm -rf $D