wt3020 upgrade to 16M and LEDE.txt

Prerequisites: 
	* Linux PC (tested with Ubuntu 16.04)
	* soldering iron
	* W25Q128FVSSIG (16MB Flash Chip)
	* CH341 based SPI to USB flash programmer
	* some thin wire or a SO-8 adapter
	* one nexx WT3020 router

1. Unsolder the 8MB Flash chip (SO-8)

2. Read flash chip with ch341prog (https://github.com/danielkucera/ch341prog)
	$ sudo ./ch341prog -r nexx.bin

3. Write flash chip to new W25Q128FVSSIG (16MB Flash)
	$ sudo ./ch341prog -w nexx.bin  
	(takes quite a while and will automatically verify)

4. Re-solder the new flash chip to the router
	maybe on top of pre-soldered pads to ease later unsoldering in case things go wrong

5. Boot up router with stock firmware on new chip

6. Install new Bootloader
	
	Downloading .bin directly to wt3020 will not work, therefore we download it on PC and http-transfer it to the router.
	
	On PC ($)
	get the breed bootloader:
	$ wget --no-check-certificate https://breed.hackpascal.net/breed-mt7620-reset1.bin 
	serve actual directory over http:
	$ python -m SimpleHTTPServer 8000	

	The file is also provided in this repository for your convenience
	Thanks to hackpascal for providing this on his website.

	Now connect to your router:
	$ telnet 192.168.8.1
		login: nexxadmin
		Password: y1n2inc.com0755
		this is the backdoor built into the original firmware
	
	transfer data to /tmp on the router:
		# cd /tmp
		# wget http://<your PC name or IP>:8000/breed-mt7620-reset1.bin
		check if stuff arrived
		# ls -l  

	now we are ready to flash the bootloader:
		
	# mtd_write unlock mtd0 
	
	power falure before completing the next two steps: brick - soldering - repeat
	
	# mtd_write erase mtd0 
	# mtd_write -r write breed-mt7620-reset1.bin mtd0 
	
	The last step takes a quite short amount of time, but freezes your telnet session which makes it seem to take forever. 
	If you do this over serial console, you will see it rebooting shortly after issuing the write command.
	
6. Building LEDE
	Choose a nice place for you build directory, needs ~14 GB - this is a full Linux build.
	See instructions here:
	https://lede-project.org/docs/guide-developer/quickstart-build-images
	
	Short instructions:
	
	$ sudo apt-get install subversion g++ zlib1g-dev build-essential git python
	$ sudo apt-get install libncurses5-dev gawk gettext unzip file libssl-dev wget

	Get the LEDE source code:

	$ git clone https://git.lede-project.org/source.git lede
	$ cd lede

	apply patch for the 16MB version (0001-WT3020-Add-support-for-16M-flash.patch) from this repo
		$ patch -p1 < file.patch
		or three way
		$ git am -3 < file.patch 

	$ ./scripts/feeds update -a
	$ ./scripts/feeds install -a

	$ make defconfig
	$ make menuconfig
	
	choose 
	Target System (MediaTek Ralink MIPS)
	Subtarget (MT7620 based boards)
	Target Profile (Nexx WT3020 (16MB))

	$ make	
	takes aeons to build. (went away during buid, future builds will much faster)
	
7. Install new FW to router
	login into web interface 192.168.8.1
		admin - admin
	go to: Advanced - System Settings - Upgrade firmware 
	select:
	<LEDE buid dir>/bin/targets/ramips/mt7620/lede-ramips-mt7620-wt3020-16M-squashfs-factory.bin
	- say goodbuye to the nexx-firmware.
	- Upgrade 
	
	- after reboot the wt3020 is accessible via 192.168.1.1 
	- maybe you have to change you ip manually or reboot
		
8. Using breed
	If you do not understand Chinese (the breed has a very nice (Chinese) web interface served on 192.168.1.1 if reboot got interrupted by serial console. or things went wrong)
	Install Chrome / Chromium and a translation plugin:
	https://github.com/szsoftware/breed-translator
	Still hoping for hackpascal to release the source ;)