sunxi: ensure NanoPi R1 has unique MAC address

Ensure the MAC address for all NanoPi R1 boards is assigned uniquely for
each board.

The vendor ships the device in two variants; one with and one without
eMMC; but both without static mac-addresses.
In order to assign both board types unique MAC addresses, fall back on
the same method used for the NanoPi R2S and R4S in case the EEPROM
chip is not present by generating the board MAC from the SD card CID.

[0] https://wiki.friendlyelec.com/wiki/index.php/NanoPi_R1#Hardware_Spec

Similar too and based on:

commit b5675f500d ("rockchip: ensure NanoPi R4S has unique MAC address")

Co-authored-by: David Bauer <mail@david-bauer.net>
Signed-off-by: Jan-Niklas Burfeind <git@aiyionpri.me>

package/base-files/files/lib/functions/system.sh

@@ -204,6 +204,14 @@ macaddr_add() {
 	echo $oui:$nic
 }
 
+macaddr_generate_from_mmc_cid() {
+	local mmc_dev=$1
+
+	local sd_hash=$(sha256sum /sys/class/block/$mmc_dev/device/cid)
+	local mac_base=$(macaddr_canonicalize "$(echo "${sd_hash}" | dd bs=1 count=12 2>/dev/null)")
+	echo "$(macaddr_unsetbit_mc "$(macaddr_setbit_la "${mac_base}")")"
+}
+
 macaddr_geteui() {
 	local mac=$1
 	local sep=$2