The installation of OpenWrt is device specific. A detailed procedure should be found in the Table of Hardware. If your device is not listed, read on… Definitely have a look at the Flash Layout.

Warning! This section describes actions that might damage your device or firmware. Proceed with care!

If your attempt to install OpenWrt fails, generic.debrick could help you.

This HowTo is VERY generic. You cannot just use it, but you have to adapt values and other stuff to your hardware

Generally, you have three options:

• Option_1: install OpenWrt onto the router's non-volatile memory: this page
• Option_2: install OpenWrt into the RAM:
• Option_3: boot OpenWrt over the network: Netbooting is not supported by all bootloaders!

There are four ways to install OpenWrt on a device:

Open the WebGUI of the original firmware with your web browser and install the OpenWrt factory firmware image file using the "Firmware Upgrade" option.

NOTE: Sometimes the original or factory firmware will only allow you to flash your device with a specific firmware file. If that is the case, you will not be able to install OpenWrt using this method.

NOTE: If you got other than original firmware installed (e.g. dd-wrt), it is recommended or required to reflash original firmware and then proceed with installing OpenWRT.

Most, if not all bootloaders provide built-in functionality for this purpose. Some use a TFTP-client, others a TFTP-server, others a FTP-client and some even an FTP-server or web server.

Before proceeding you need to determine the following:

• the preset IP address of the bootloader (not necessarily the same as after the device has booted the original firmware!)
• which protocol
• whether the bootloader acts as client or as server
• the appropriate port number default ports
• the interface you need to connect to
• a user name and and login password (if necessary)
• the time window you have after starting the device to obtain a connection

Once you know all of the above parameters, you may proceed.

1. Install the appropriate software on your PC (i.e. if the bootloader uses an FTP-server, you need a FTP-client).
2. Read the appropriate manual page ie: tftp, tftpd, ftp, ncftp, ftpd, pure-ftpd, etc …
3. Configure a static IP address for your PC interface in the same IP address block as pre-configured in the bootloader.
4. Connect your PC to the device.
5. Power cycle the device.
6. Connect to the bootloader using the software you chose
7. Install the OpenWrt firmware file.
8. Do not overwrite or alter the bootloader until explicitly instructed to do so!

NOTES: Sometimes the bootloader prevents you from flashing a non-OEM firmware. If you have a short time window, the connection between your computer and device needs to be established quickly. To make this as quick possible, you can disable auto-negotiation on your NIC and/or disable media sensing.

• generic.flashing.tftp
• generic.flashing.ftp
• generic.flashing.xmodem

• generic.flashing.serial

• port.jtag

This step shows you howto upload a new ramdisk image to the device. The existing firmware on the flash remains unchanged! You require a working serial cable to do the ramdisk upload.

1. specifically select the RAMDISK option to make OpenWrt Buildroot create a ramdisk-image for you to upload
2. connect an ethernet cable between your computer and one of the LAN ports (doesn't matter which, just so long as it's not the WAN port) of the WNDR3700.
3. connect your serial cable to the header on the WNDR3700 and set your local terminal program (eg. minicom) to
   • 115200 bps 8N1
   • no software flow control
   • no hardware flow control.
4. set your computer's ethernet port to use the IP address 192.168.0.10/24
5. set up a TFTP server on your local computer to respond to requests on the 192.168.0.10 interface. Make sure that the ramdisk image (openwrt-ar71xx-uImage-lzma.bin) is in the directory used by the TFTP server.
6. Fix the header for the ramdisk image so that it's recognized by the u-Boot firmware. Use the wndr3700.c program that was posted by *aorlinsk* on the forums here http://aorlinsk2.free.fr/openwrt/wndr3700/ and run it from the TFTP server's data directory. I've also reproduced the code here just in case:

   • ./wndr3700 openwrt-ar71xx-uImage-lzma.bin openwrt-fixed.out

7. power up the board. When it gets to the message asking you to press any key to interrupt the normal bootup sequence, press a key on the serial console (or just hold down the enter key from first bootup until you get to a prompt):
8. enter the following into the serial console:

   setenv ipaddr 192.168.0.1
   setenv serverip 192.168.0.10
   setenv bootargs 'board=WNDR3700'
   tftpboot 80800000 openwrt-fixed.out
   bootm

   (if you forget the bootargs piece below, the board will boot and look normal, but it won't be able to bring up any of the network interfaces!)
9. The system should boot!

Concrete examples: wnr2000, …

Don't forget to consult the other Generic Basic Howtos for OpenWrt

This checklist cannot and does not completely cover all the ways you can install OpenWrt.