RT5350 "3G" Router Firmware

Projects / Original post date:01/22/2015

This is a bit out of date and probably no longer needed.

I bought one of those 3G routers for $9 from China with free shipping. Same as the one talked about in detail here:http://my-embedded.blogspot.ca/2013/12/mini-4g-router-rt5350f.html except it has 32MB of SDRAM and a different firmware load that have only 10 commands when you telnet into it.This project is how to generate a custom firmware for it.Files are at https://github.com/FPGA-Computer/RT5350.git

Firmware: OpenWrt "Barrier Breaker" r35407/LuCI Trunk (svn-r9946) Kernel version: 3.7.5snapshot images are not built by default (fixed) https://dev.openwrt.org/ticket/18712

I google and played around with several precompiled firmware images for it, but I wasn't happy with any of them. They all seem to be missing a package or two as the router has only 4MB of SPI FLASH.

Here is a firmware builder for this router. https://code.google.com/p/rcc/source/browse/trunk/projects/rt5350_mini_router/OpenWrt-ImageBuilder-ramips_rt305x-for-linux-x86_64.tar.bz2

Basically this is the final pass for the OpenWRT building process when everything including all the packages have been precompiled. The scripts loads up the packages specified and compress a firmware image for it.

There are a few things that wasn't mentioned: The commands inside the scripts were compiled for x64 only, so you need to run that on x64 Linux. (I ran bodhi-3.0.0-rc2 (Ubuntu) in VirtualBox on my windows machine as it is the only x64 box I have. I had to replace the command line parameter (in text) from 16M to 32M inside vmlinux with a hex editor. The file was hardcoded for 16MB of SDRAM and it ignores the u-boot arguments. The directory path is "build_dir/target-mipsel_r2_uClibc-0.9.33.2/linux-ramips_rt305x/" Thankfully the build scripts compresses the file from scratch (as evidenced from the file date), so I don't have to figure out what to modify.

I didn't have much luck making a new entry as there is some dependency on the directory structures, so I simply modified one of the entries in the build script: "image_builder_rt5350.sh" located at the root of the package. This builds a wifi router with luci web interface and has opkg and USB mass storage support. The original factory firmware is more slick than that. I wish I had a backup :(

mini_luci_web_wifi)
    PACKAGES="opkg $LUCI $MASS_STORAGE $WIFI"
#   PACKAGES="$LUCI $DEFAULT_EXCLUDED $WIFI"
;;

To compile for it, I simply type in ./image_builder_rt5350.sh mini_luci_web_wifi

There will be a wall of scrolling text for a minute and the script spits out the compiled image at bin/ramips/mini_luci_web_wifi.bin The default ip address can be changed by editing the line containing the following line in build_dir/target-mipsel_r2_uClibc-0.9.33.2/root-ramips/etc/config /network : option ipaddr '192.168.100.1'

There are not much of space left on the SPI FLASH after the packages. If you need more file space, you can mount Rootfs on External USB Storage. The packages required are in this firmware.

OpenWRT Documentation: http://wiki.openwrt.org/doc/start
OpenWRT page: http://wiki.openwrt.org/toh/unbranded/a5-v11