u-boot:

setenv kernel netbsd-SUNXI.ub
setenv bootargs root=ld0a
setenv kernel_addr 0x46000000
setenv dtb_addr 0x48000000
fatload mmc 0 ${kernel_addr} ${kernel}
fatload mmc 0 ${dtb_addr} ${fdtfile}
fdt addr ${dtb_addr}
bootm ${kernel_addr} - ${fdt_addr_r}

XXX (should work):

mmc dev 0
setenv kernel netbsd-SUNXI.ub
setenv bootargs root=ld0a
fatload mmc 0:1 0x46000000 ${kernel}
fatload mmc 0:1 0x48000000 ${fdtfile}
bootm 0x46000000 - 0x48000000


partitions:

# disklabel -i ld0
partition>f
Filesystem type [unused]: 4.2BSD
Start offset ('x' to start after partition 'x') [0c, 0s, 0M]: a
Partition size ('$' for all remaining) [0c, 0s, 0M]: 4096M
 f:   8388608   3270016     4.2BSD      0     0     0  # (Cyl.   1596*-   5692*)
partition>g
Filesystem type [unused]: 4.2BSD
Start offset ('x' to start after partition 'x') [0c, 0s, 0M]: f
Partition size ('$' for all remaining) [0c, 0s, 0M]: 1024M
 g:   2097152  11658624     4.2BSD      0     0     0  # (Cyl.   5692*-   6716*)
partition>h
Filesystem type [unused]: cgd
Start offset ('x' to start after partition 'x') [0c, 0s, 0M]: g
Partition size ('$' for all remaining) [0c, 0s, 0M]: $
 h:   1809024  13755776        cgd                     # (Cyl.   6716*-   7599)
partition>W
Label disk [n]?y
Label written
partition>Q

# newfs /dev/rld0f
[...]
# newfs /dev/rld0g
[...]
# mount -o async /dev/rld0f /mnt
# cp -a /usr/* /mnt
# service cron stop
# service syslogd stop
# rm -rf /usr/*
# umount /mnt
# mount /dev/ld0f /usr
# mkdir /home
# mount /dev/ld0g /home
[...add /usr entry in fstab...]
[...add /usr in critical_filesystems_local in rc.conf...]
[...edit /etc/ifconfig.emac0 ...]
[...edit /etc/mygate ...]
[...edit /etc/resolv.conf ...]
[...edit /etc/resolvconf.conf ...]