[source] oxnas: add method to extract mac_adr from legacy cmdline

[LEDE Commits]

dangole pushed a commit to source.git, branch master:
https://git.lede-project.org/9c69ba83e2d0c19959fed81cf4fa038fde3e518d

commit 9c69ba83e2d0c19959fed81cf4fa038fde3e518d
Author: Daniel Golle <daniel at makrotopia.org>
AuthorDate: Sun Sep 4 03:34:19 2016 +0200

    oxnas: add method to extract mac_adr from legacy cmdline
    
    Signed-off-by: Daniel Golle <daniel at makrotopia.org>
---
 .../linux/oxnas/base-files/etc/board.d/02_network  | 10 +++++++++
 target/linux/oxnas/base-files/lib/oxnas.sh         | 24 ++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/target/linux/oxnas/base-files/etc/board.d/02_network b/target/linux/oxnas/base-files/etc/board.d/02_network
index a025027..d4010e8 100755
--- a/target/linux/oxnas/base-files/etc/board.d/02_network
+++ b/target/linux/oxnas/base-files/etc/board.d/02_network
@@ -2,10 +2,20 @@
 
 . /lib/functions/uci-defaults.sh
 . /lib/functions/system.sh
+. /lib/oxnas.sh
 
 board_config_update
 
+lan_mac=""
+
+case "$(oxnas_board_name)" in
+	kd20)
+		lan_mac="$(legacy_boot_mac_adr)"
+		;;
+esac
+
 ucidef_set_interface_lan "eth0" "dhcp"
+[ -n "$lan_mac" ] && ucidef_set_interface_macaddr lan "$lan_mac"
 
 board_config_flush
 
diff --git a/target/linux/oxnas/base-files/lib/oxnas.sh b/target/linux/oxnas/base-files/lib/oxnas.sh
index 991f927..b0d79ea 100755
--- a/target/linux/oxnas/base-files/lib/oxnas.sh
+++ b/target/linux/oxnas/base-files/lib/oxnas.sh
@@ -6,6 +6,30 @@
 OXNAS_BOARD_NAME=
 OXNAS_MODEL=
 
+bootloader_cmdline_var() {
+	local param
+	local pval
+	for arg in $(cat /proc/device-tree/chosen/bootloader-args); do
+		param="$(echo $arg | cut -d'=' -f 1)"
+		pval="$(echo $arg | cut -d'=' -f 2-)"
+
+		if [ "$param" = "$1" ]; then
+			echo "$pval"
+		fi
+	done
+}
+
+legacy_boot_mac_adr() {
+	local macstr
+	local oIFS
+	macstr="$(bootloader_cmdline_var mac_adr)"
+	oIFS="$IFS"
+	IFS=","
+	set -- $macstr
+	printf "%02x:%02x:%02x:%02x:%02x:%02x" $1 $2 $3 $4 $5 $6
+	IFS="$oIFS"
+}
+
 oxnas_board_detect() {
 	local machine
 	local name