OW2 Project

A step by step guide for building an OpenWRT firmware, installing and configuring it for TP-LINK MR3020 or MR3040 devices

Our objective is to obtain fully configured small device based on TP-LINK MR3020 or MR3040 router hardware with OpenWRT as firmware. It can be used for:

• Compact router with 3G/4G modem support
• Video surveillance (by USB web cam) device with ethernet, wifi or 3G/4G connectivity
• Remote, internet control of lighting, heating, automating etc. (need hardware hacks and additional components)
• Remote measure of temperature, air humidity, pressure and/or some other sensor reading (again need hw works)
• A lot of other things that can be powered by 400 MHz MCU and linux inside

Below are steps to build and configure OpenWRT:

0. If you start from scratch, first you need to install all required packets on your host. Check http://wiki.openwrt.org/doc/howto/buildroot.exigence for prerequisites for your exact system. Below is Ubuntu-1404LTS-64bit example:

sudo apt-get install git-core build-essential subversion libncurses5-dev zlib1g-dev gawk intltool gcc-multilib flex libssl-dev

1. Download the latest OpenWRT repo snapshot and all feeds by following commands:

git clone git://git.openwrt.org/openwrt.git
cd openwrt
./scripts/feeds update -a
./scripts/feeds install -a

2. Perform make menuconfig and go to "Target Profile" in the main menu. Select "TP-LINK TL-MR3020" or "-3040", according to your hardware. Exit by pressing ESC ESC two time and confirm saving the config.

3. Perform make defconfig (that creates general configuration of the build system including a check of dependencies and prerequisites for your selected system

4. Now you can already build your system with default settings/environment (it can take from 1 to 3 hours depend on your host performance, internet connection speed and other factors...

time make

5. make menuconfig and select:

• Base System -> block-mount (*)
• Boot Loaders -> uboot ( ) <-- remove selection
• Kernel Modules -> Filesystems -> kmod-fs-ext4 (*)
• Kernel Modules -> USB Support -> kmod-usb-storage-extras (*), kmod-usb-uhci (*)

Also you can select a lot of additional items depend of what you need for your exact system. Below are some examples:

• Kernel Modules -> USB Support -> kmod-usb-serial -> (M) <-- for 3G modems and other usb to serial converters
• Kernel Modules -> USB Support -> kmod-usb-serial-option -> (M) <-- for 3G modems
• Kernel Modules -> I2C support -> (M) <-- if you need i2c support - put (M) on required items
• Kernel Modules -> W1 support -> (M) <-- if you need 1-wire support - put (M) on required items
• Kernel Modules -> Video support -> (M) <-- if you need webcam support - put (M) on required items
• Multimedia -> mjpg-streamer (M)
• Multimedia -> motion (M)
• Network -> File Transfer -> curl (M)
• Network -> File Transfer -> wget (M)
• Network -> IP Addresses and Names -> ddns-scripts (M)
• Network -> Web Servers/Proxies -> lighttpd (M) -> lighttpd-mod-* (M) <-- put (M) on all lighttpd modules that you need
• Network -> wpad (*) if you need full IEEE 802.1x Authenticator/Supplicant for enterprise Wi-Fi networks, otherwise select wpad-mini (*)
• Utilities -> mc (M)
• Utilities -> comgt (M) <-- for 3G modems
• Utilities -> digitemp (M) (? - no in latest OpenWRT, need to check ?)
• Utilities -> haserl (M)
• Utilities -> oww (M) (? - no in latest OpenWRT, need to check ?)
• Utilities -> usb-modeswitch (M) <-- for 3G modems

time make V=s > build.log 2>errors.log it will create also build log and errors log in corresponding files

6. (optional) Create file ~openwrt/files/etc/config/fstab and ...(will be updated soon)... in order to have overlay filesystem (pivot overlay) on USB flash drive

7. time make V=s > build.log 2>errors.log it will create also build log and errors log in corresponding files If build process aborts with error (of course not related with unavailable downloads) - sometimes it helps full rebuild: make dirclean and then make again

8. After the build process completed successfully - you can install OpenWrt "*-squashfs-factory.bin" firmware from ~/youpathtoprojects/OW2/openwrt/bin/ar71xx/ using manufacturer's WebGUI like a regular firmware update. Wait for the progress bar to finish twice (the device will reset itself in the process).
   If your device is already on OpenWrt - just copy the firmware .bin file to /tmp and perform mtd -r write /tmp/your_firmware_file.bin firmware

9. Connect ethernet directly to you device and perform telnet 192.168.1.1. After that use passwd command to set a password to be able to connect through ssh and to copy files by using scp

10. Copy all files from files/ directory to corresponding places on your device. Check all shell scripts have execution permission, perform chmod +x scriptname if not. Enable init script by /etc/init.d/button_slider enable. If your device is MR3040 v1 (without slider) - need to correct the script in /etc/init.d/ with only one option and also no need to copy to /etc/hotplug.d/button

11. Copy all packages from ~/youpathtoprojects/OW2/openwrt/bin/ar71xx/packages to ext4-formatted USB flash, insert it to your device, mount it and install all package you need by opkg update; opkg install thepackageswhatyouneed (remember to check free space on device's flash or use overlay filesystem on USB flash as in step #6). The file /etc/opkg.conf should be corrected properly to point to your USB flash.

12. for 3G/4G usb modem support need to install the following: opkg install comgt usb-modeswitch kmod-usb-serial-option (don't forget to update package list for opkg first: opkg update

13. to be continued...