cramfs partitions are essentially a modified zip type readonly image.
To update you need to offload the cramfs partition to a regular linux
system (like tar it, then untar it in a regular filesystem). Then you
can update it all you want. When finished you would have to:
mkcramfs /your-untar-point part.img
then write the part.img file back in place of the old one (carefully
not to trash it's neighbors).
Personally I'm just running mine on a 64mb flashcard and mounting
my partitions rw,noatime till my setup settles down.
- My opinions are my own, my employer doesn't own this account.