diff --git a/target/linux/rockchip/armv8/base-files/etc/board.d/02_network b/target/linux/rockchip/armv8/base-files/etc/board.d/02_network
index 267cf2ddc..9cdcae422 100755
--- a/target/linux/rockchip/armv8/base-files/etc/board.d/02_network
+++ b/target/linux/rockchip/armv8/base-files/etc/board.d/02_network
@@ -39,9 +39,7 @@ rockchip_setup_interfaces()
 
 generate_mac_from_mmc_cid()
 {
-	local mmc_dev=$1
-
-	local sd_hash=$(sha256sum /sys/class/block/$mmc_dev/device/cid)
+	local sd_hash=$(sha256sum /sys/class/block/mmcblk*/device/cid | head -n 1)
 	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}")")"
 }
@@ -58,7 +56,7 @@ nanopi_r4s_get_mac()
 			address=$(macaddr_setbit_la "$address")
 		fi
 	else
-		address=$(generate_mac_from_mmc_cid mmcblk1)
+		address=$(generate_mac_from_mmc_cid)
 		if [ "$interface" = "lan" ]; then
 			address=$(macaddr_add "$address" 1)
 		fi
@@ -84,7 +82,7 @@ rockchip_setup_macs()
 	friendlyarm,nanopi-r2s|\
 	friendlyarm,nanopi-r5s|\
 	sharevdi,guangmiao-g4c)
-		wan_mac=$(generate_mac_from_mmc_cid mmcblk0)
+		wan_mac=$(generate_mac_from_mmc_cid)
 		lan_mac=$(macaddr_add "$wan_mac" +1)
 		;;
 	friendlyarm,nanopi-r4s|\