ar71xx: add support for Cisco's MR18

This patch adds support for Cisco's MR18.
Detailed instructions for the flashing the device can
be found in the OpenWrt forum thread:
<https://forum.openwrt.org/viewtopic.php?id=59248>

Signed-off-by: Chris R Blake <chrisrblake93@gmail.com>

SVN-Revision: 47878

1 files changed, 137 insertions, 0 deletions

diff --git a/target/linux/ar71xx/base-files/lib/upgrade/merakinand.sh b/target/linux/ar71xx/base-files/lib/upgrade/merakinand.sh
new file mode 100644
index 0000000..fe78e9f
--- /dev/null
+++ b/target/linux/ar71xx/base-files/lib/upgrade/merakinand.sh
@@ -0,0 +1,137 @@
+#!/bin/sh
+#
+# Copyright (C) 2015 Chris Blake <chrisrblake93@gmail.com>
+#
+# Custom upgrade script for Meraki NAND devices (ex. MR18)
+# Based on dir825.sh and stock nand functions
+#
+. /lib/ar71xx.sh
+. /lib/functions.sh
+. /lib/upgrade/nand.sh
+
+get_magic_at() {
+	local mtddev=$1
+	local pos=$2
+	dd bs=1 count=2 skip=$pos if=$mtddev 2>/dev/null | hexdump -v -n 4 -e '1/1 "%02x"'
+}
+
+mr18_is_caldata_valid() {
+	local mtddev=$1
+	local magic
+
+	magic=$(get_magic_at $mtddev 4096)
+	[ "$magic" != "0202" ] && return 0
+
+	magic=$(get_magic_at $mtddev 20480)
+	[ "$magic" != "0202" ] && return 0
+
+	magic=$(get_magic_at $mtddev 36864)
+	[ "$magic" != "0202" ] && return 0
+
+	return 1
+}
+
+merakinand_copy_caldata() {
+	local cal_src=$1
+	local cal_dst=$2
+	local ubidev=$( nand_find_ubi $CI_UBIPART )
+	local board_name="$(cat /tmp/sysinfo/board_name)"
+	local rootfs_size="$(ubinfo /dev/ubi0 -N rootfs_data | grep "Size" | awk '{ print $6 }')"
+
+	# Setup partitions using board name, in case of future platforms
+	case "$board_name" in
+	"mr18")
+		# Src is MTD
+		mtd_src=$(find_mtd_chardev $cal_src)
+		[ -n "$mtd_src" ] || {
+			echo "no mtd device found for partition $cal_src"
+			exit 1
+		}
+
+		# Dest is UBI
+		# TODO: possibly add create (hard to do when rootfs_data is expanded & mounted)
+		# Would need to be done from ramdisk
+		mtd_dst="$(nand_find_volume $ubidev $cal_dst)"
+		[ -n "$mtd_dst" ] || {
+			echo "no ubi device found for partition $cal_dst"
+			exit 1
+		}
+
+		mr18_is_caldata_valid "$mtd_src" && {
+			echo "no valid calibration data found in $cal_src"
+			exit 1
+		}
+
+		mr18_is_caldata_valid "/dev/$mtd_dst" && {
+			echo "Copying calibration data from $cal_src to $cal_dst..."
+			dd if="$mtd_src" of=/tmp/caldata.tmp 2>/dev/null
+			ubiupdatevol "/dev/$mtd_dst" /tmp/caldata.tmp
+			rm /tmp/caldata.tmp
+			sync
+		}
+		return 0
+		;;
+	*)
+		echo "Unsupported device $board_name";
+		return 1
+		;;
+	esac
+}
+
+merakinand_do_kernel_check() {
+	local board_name="$1"
+	local tar_file="$2"
+	local image_magic_word=`(tar xf $tar_file sysupgrade-$board_name/kernel -O 2>/dev/null | dd bs=1 count=4 skip=0 2>/dev/null | hexdump -v -n 4 -e '1/1 "%02x"')`
+
+	# What is our kernel magic string?
+	case "$board_name" in
+	"mr18")
+		[ "$image_magic_word" == "8e73ed8a" ] && {
+			echo "pass" && return 0
+		}
+		;;
+	esac
+
+	exit 1
+}
+
+merakinand_do_platform_check() {
+	local board_name="$1"
+	local tar_file="$2"
+	local control_length=`(tar xf $tar_file sysupgrade-$board_name/CONTROL -O | wc -c) 2> /dev/null`
+	local file_type="$(identify_tar $2 sysupgrade-$board_name/root)"
+	local kernel_magic="$(merakinand_do_kernel_check $1 $2)"
+
+	case "$board_name" in
+	"mr18")
+		[ "$control_length" = 0 -o "$file_type" != "squashfs" -o "$kernel_magic" != "pass" ] && {
+			echo "Invalid sysupgrade file for $board_name"
+			return 1
+		}
+		;;
+	*)
+		echo "Unsupported device $board_name";
+		return 1
+		;;
+	esac
+
+	return 0
+}
+
+merakinand_do_upgrade() {
+	local tar_file="$1"
+	local board_name="$(cat /tmp/sysinfo/board_name)"
+
+	# Do we need to do any platform tweaks?
+	case "$board_name" in
+	"mr18")
+		# Check and create UBI caldata if it's invalid
+		merakinand_copy_caldata "odm-caldata" "caldata"
+		nand_do_upgrade $1
+		;;
+	*)
+		echo "Unsupported device $board_name";
+		exit 1
+		;;
+	esac
+}