Right, I figured it out in the end from the online documentation provided by a competing vendor of embedded ARM-modules. :-p
So for reference, you can format a partition as JFFS2 using "flash_eraseall -j <device>
Use "cat /proc/mtd
" to figure out which partition you want to format.
E.g. for the module I was using, the UserFS was supposed to be on mtd4, so I did:
flash_eraseall -j /dev/mtd4
The partition can then be mounted, e.g.: mount /dev/mtdblock4 /mnt -t jffs2
The boot-scripts can do this automagically for you, if you uncomment the corresponding shell-magic in /etc/init.d/S05userfs.sh
But of course you can also add the partition to /etc/fstab
, or provide you own boot-script for mounting and other things...
Alternatively, you can create a JFFS2 image on a separate computer using the MTD utilities:
mkfs.jffs2 -r <file system dir> -e <erase block size> -o <output file>
Then you can for instance export the image via NFS and flash it using:
update_flash -v <image> <partition number>
Hope this will be of use to others who get lost in the docs trying to figure this out...