These are binaries from
    http://tinycorelinux.net
with the following patch applied:

mkdir initrd
( cd initrd ; zcat ../initrd.gz | sudo cpio -idm )
sudo sed -i '/^# ttyS0$/s#^..##' initrd/etc/securetty 
sudo sed -i '/^tty1:/s#tty1#ttyS0#g' initrd/etc/inittab
( cd initrd ; find | sudo cpio -o -H newc ) | gzip -c > initrd.gz