I generate a ramdisk image using simple tools.
See below for sample script I use.
I run this from my images folder. You'll need to change the path to your ramfs files location to something appropriate for you to use.
genramfs.sh
#!/bin/sh
#Dangerous, but i'm lazy
rm tmpramfs.img OPENIPCAMramfs.img
mkdir /tmp/ramfs
dd if=/dev/zero of=tmpramfs.img bs=1k count=1024
mkfs.minix -c tmpramfs.img
mount -o loop -t minix tmpramfs.img /tmp/ramfs
# Change the folder below to the location you store your files and folders for the ramdisk
cp -av ../romdisknew/* /tmp/ramfs
umount /tmp/ramfs
gzip -v9 -c tmpramfs.img >OPENIPCAMramfs.img