[ramips] Add Netgear WNCE2001 (OF version)

Add Netgear WNCE2001.

This is a small RT3052 device with 4MB spi flash and 32MB ram.
2 built-in antennas, 1x fastE, no USB, reset & wps switch.
On my model the AP/RT switch is unpopulated, but I verified the gpio
mapping for it.
The stock firmware is running an unprotected tftpd which allows you
to read any file from the filesystem.
Serial port is present on testpads (See image on the wiki page).
There are more testpads below the shield near the SoC, which
may have JTAG.

Slight annoyance: The bootloader is checksumming kernel&rootfs, but
can be tricked by zeroing checksum and length fields in the checksum
partition, see
target/linux/ramips/base-files/lib/preinit/04_disable_wnce2001_flash_checksumming

The manufacturer image is very similar to the DAP one, so I slightly
modified mkdapimg to support generating it.

The resulting
openwrt-ramips-rt305x-wnce2001-squashfs-factory-(worldwide|northamerica).bin
can be used to flash from stock to OpenWRT using the stock firmware
upgrade function, without using the serial port.

http://www.netgear.com/landing/wnce2001.aspx
http://wiki.openwrt.org/toh/netgear/wnce2001

Signed-off-by: Tobias Diedrich <ranma+openwrt@tdiedrich.de>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@36289 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 43 insertions, 0 deletions

diff --git a/target/linux/ramips/base-files/lib/preinit/04_disable_wnce2001_flash_checksumming b/target/linux/ramips/base-files/lib/preinit/04_disable_wnce2001_flash_checksumming
new file mode 100644
index 000000000..67a1746f1
--- /dev/null
+++ b/target/linux/ramips/base-files/lib/preinit/04_disable_wnce2001_flash_checksumming
@@ -0,0 +1,43 @@
+#!/bin/sh
+
+# Netgear WNCE2001 has does a checksum check on boot and goes into recovery
+# tftp mode when the check fails.  Initializing the JFFS2 partition triggers
+# this, so we make sure to zero checksum and size to be checksummed before
+# that happens, so this needs to run very early during boot.
+
+do_wnce2001_checksumming_disable() {
+	. /lib/ramips.sh
+
+	local board=$(ramips_board_name)
+
+	case "$board" in
+	wnce2001)
+		echo "Board is WNCE2001, updating checksum partition..."
+		local zeroes=/dev/zero
+		local tmpfile=/tmp/wnce2001_checksum
+		local partname=checksum
+		local mtd=$(find_mtd_part $partname)
+		dd if=$mtd of=$tmpfile bs=80 count=1 2>/dev/null
+		signature=$(dd if=$tmpfile bs=1 skip=24 count=20 2>/dev/null)
+		checksum=$(dd if=$tmpfile bs=1 count=4 2>/dev/null | hexdump -v -n 4 -e '1/1 "%02x"')
+		if [ "$signature" != "RT3052-AP-WNCE2001-3" ]; then
+			echo "Signature of checksum partition is wrong, bailing."
+			return 0
+		fi
+		if [ "$checksum" != "00000000" ]; then
+			echo "Checksum is set, zeroing."
+			# zero out checksum
+			dd if=$zeroes of=$tmpfile conv=notrunc bs=1 seek=0 count=4 2>/dev/null
+			# zero out bytecount to be checksummed
+			dd if=$zeroes of=$tmpfile conv=notrunc bs=1 seek=60 count=4 2>/dev/null
+			mtd write $tmpfile $partname
+		else
+			echo "Checksum is already zero, nothing to do."
+		fi
+	;;
+	esac
+
+	return 0
+}
+
+boot_hook_add preinit_main do_wnce2001_checksumming_disable