How do I use an initramfs with l4linux? I tried using "l4x_rd=rom/initrd.cpio.gz" but it doesn't work. I see linux trying to use it:

INITRD: 15000000 - 15114e00
...
Unpacking initramfs...
INITRD: Freeing memory. 
...

But then I get
Failed to execute /init
Kernel panic - not syncing: No init found.  Try passing init= option to kernel. See Linux Documentation/init.txt for guidance.

I'm able to use the same initramfs file to boot normal linux kernel. I tried various combinations of cpio formats and compression but it doesn't seem to help. The only thing that works is compiling the initramfs into the kernel which I want to avoid.