Dear Jorgen Lundman,
Sorry if I am posting some kind of FAQ here,
I recently picked up a Cubox (arm) which uses uboot. Added ZFS to Linux and made it have a ZFS root filesystem. The only drawback is the small boot partition of ext2/fat to read uImage and initrd.
So I am curious about adding ZFS support to uboot. Looking at the sources http://git.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=tree in particular, the ext2 work, I see it was once imported from GRUB.
Comparing that with https://github.com/pendor/grub-zfs/tree/master/grub-core/fs/zfs which is a fork for ZFS support to GRUB.
At first glance, it would suggest that it should be feasible to add ZFS to uboot. But since I only have 'usage-level knowledge' of both boot systems, I am unaware of any show-stoppers.
Oh please study this and submit a patch, I believe at least Pavel (CCed) would be glad to see it in :-)
Perhaps memory/object-size is an issue? The ext2 code is some ~1100 lines in uboot, but ZFS is 2700 lines in GRUB. Or any of a thousand other issues I am unaware about.
Well the porting might be quite a long run indeed, but basic booting from this should not be that hard. Besides the code would be fairy separate, so it should be OK.
Anyone already attempted such a project? Any resources available for such porting? Will I even be able to run my own version of uboot on the Cubox?
I don't know, sorry.
Lund
Best regards, Marek Vasut