It's doable from the BMC (as of 2.0.5, but there a...
# │firmware-dev
c
It's doable from the BMC (as of 2.0.5, but there are some fixes on master that make it a little easier). You can also access the eMMC with (something like):
tpi advanced -n 1234 msd
+
modprobe rockusb
+
mkdir /tmp/mnt && mount -t ext4 /dev/sda2 /tmp/mnt