U-Boot port is based on sources forked from GRUB-0.97 by Sun in 2004,
which can be found here:
http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/grub/grub-0.97/stage2/zfs-include/zfs.h
Released by Sun for GRUB under the license:
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
GRUB official releases include ZFS in version:
ftp://alpha.gnu.org/gnu/grub/grub-1.99~rc1.tar.gz
And patched against GRUB Bazaar repository for ashift fixes (4KB HDDs)
more conveniently found at github:
e7b6ef3ac3
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Masahiro Yamada