BeagleBone Notes

I bought the RTL8188cus/RTL8192cu-based WIFI adaptor from Adafruit and followed the Adafruit WIFI BeagleBone Tutorial.  I had a similar experience as almost everyone else: it didn't work.  After beating my head against the wall and trying many things here's what I found:

The mainlined kernel driver for the adaptor's chipset (aka rtlwifi) does not work well.

I was able to get it to work, but it was unreliable, especially when changing access points.

Connman, the connection manager used by Angstrom linux, only seems to want one network adaptor in use at a time.  It prefers Ethernet, so if you have an Ethernet cable plugged into your BeagleBone it will cause WIFI not to work.

The Realtek-supplied drivers work great.

Pre-requisites

These instructions are for Angstrom Linux, the distribution that ships with the BeagleBone.  Make sure you are running the latest system image on your BeagleBone. 

These instructions assume you are cross-compiling the driver on another machine (not the beaglebone) and they assume you have the BeagleBone 3.8 Linux kernel building in that environment.  Use these instructions if you want to compile on the BeagleBone.

Go to the directory you have the kernel and run this to ensure it's ready to build modules

make CROSS_COMPILE=arm-linux-gnueabi- ARCH=arm scripts prepare

Steps

Get a binary of the Realtek drivers

Install the driver

Configure your WIFI settings

1) Build the RTL8192 Driver

Note: You can get the pre-patched source code here and a pre-built binary of the driver here.  These may or may not work though, so I would recommend building it yourself.

Download the Unix/Linux driver from the Realtek web site - It will be called something like RTL8192xC_USB_linux_v3.4.4_4749.20121105.zip

Unzip the file and then unpack the driver source which is  driver/tl8188C_8192C_usb_linux_v3.4.4_4749.20121105.tar.gz in the zip file

cp rtl8188C_8192C_usb_linux_v3.4.4_4749.20121105.tar.gz ~/ tar xvfz rtl8188C_8192C_usb_linux_v3.4.4_4749.20121105.tar.gz cd rtl8188C_8192C_usb_linux_v3.4.4_4749.20121105

Download this patch to add BB config and to fix building on linux 3.8 into the driver directory and apply it

wget https://raw.github.com/cmicali/rtl8192cu_beaglebone/master/util/rtl-8192-beaglebone-linux-3.8.patch patch -p1 < rtl-8192-beaglebone-linux-3.8.patch

Build the driver - Replace your_kernel_dir with the root of your BeagleBone 3.8 kernel source (mine is ~/projects/beaglebone_kernel/kernel)

make KSRC=your_kernel_dir

2) Install the RTL8192 Driver

Copy the driver (8192cu.ko) to your beaglebone and then log into it (note: change BeagleBoneBlack2 to the IP/hostname of your beaglebone)

scp 8192cu.ko root@BeagleBoneBlack2:~/ ssh root@BeagleBoneBlack2

Install the driver

mv 8192cu.ko /lib/modules/$(uname -r) depmod -a cd /etc/modules-load.d echo "8192cu" >rtl8192cu-vendor.conf

Blacklist the old rtlwifi drivers 

cd /etc/modprobe.d echo "install rtl8192cu /bin/false" >wifi_blacklist.conf echo "install rtl8192c_common /bin/false" >>wifi_blacklist.conf echo "install rtlwifi /bin/false" >>wifi_blacklist.conf

3) Configure your Access Point

Edit /var/lib/connman/settings and enable WIFI

[global] OfflineMode=false [Wired] Enable=true Tethering=false [WiFi] Enable=true Tethering=false

Encrypt your passphrase

wpa_passphrase YourSSID YourPassphrase

Edit /var/lib/connman/wifi.config and set it to the following

[service_home] Type=wifi Name=YourSSID Passphrase=YourEncryptedPassphrase

Plug in your WIFI adaptor and reboot

shutdown -r 0

Closing Notes

These instructions assume you are using WPA security on your WIFI network

Connman appears to pick up changes to wifi.config almost immediately, so you can usually change WIFI AP/password without rebooting

Optional: I installed the latest version of connman(1.15) - I don't think it's required, but in case you want to install it this how I built it:

./configure --prefix=/usr --exec_prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin --libexecdir=/usr/libexec --datadir=/usr/share --sysconfdir=/etc --sharedstatedir=/com --localstatedir=/var --libdir=/usr/lib  --includedir=/usr/include --oldincludedir=/usr/include --infodir=/usr/share/info --mandir=/usr/share/man make make install 

Optional: I also installed the latest version of wpa_supplicant (1.1) - here is the config file i used. Also libnl3-dev needs to be installed to build it

Here are some simplified instructions for getting the BeagleBone 3.8 kernel built and installed.  Cross-compiling the kernel from another machine is a good idea - it's much faster than building on the BeagleBone.  I got a lot of this from from this great post and the very helpful README on the beaglebone kernel page.

Steps

Setup a working build environment

Download and configure the kernel source

Build the kernel

Deploy it to your BeagleBone

1) Build Environment

Get a working Ubuntu machine.  I use a physical Ubuntu 12.10 machine to build the kernel.  You can also run this in a VM (qemu, parallels, etc.)

Install the build tools

sudo apt-get install build-essential gcc-arm-linux-gnueabi git lzop u-boot-tools

2) Get the Kernel Source

Clone the BB git kernel repo

git clone git://github.com/beagleboard/kernel.git

Switch to the 3.8 branch

cd kernel git checkout origin/3.8 -b 3.8

Run patch.sh to fetch the kernel source and apply all of the BB patches. This will take a while.

./patch.sh

Download and copy the power management firmware to kernel/firmware

wget -O kernel/firmware/am335x-pm-firmware.bin http://bit.ly/11R6luL

Copy the default kernel config

cd kernel cp ../configs/beaglebone .config

optional:customize the kernel config

make ARCH=arm menuconfig

3) Build the Kernel

Build the kernel

make -j 4 CROSS_COMPILE=arm-linux-gnueabi- ARCH=arm uImage dtbs modules

4) Deploy the Kernel to your BeagleBone

Make a directory to stage all the files we need

mkdir dist mkdir dist/boot

Copy the kernel and the device tree files

cp arch/arm/boot/uImage dist/boot cp arch/arm/boot/dts/am335x-bone.dtb dist/boot cp arch/arm/boot/dts/am335x-boneblack.dtb dist/boot

Install the kernel modules to our dist directory

make -j 4 CROSS_COMPILE=arm-linux-gnueabi- ARCH=arm modules_install INSTALL_MOD_PATH=dist

Pack up the directory

cd dist tar cvzf kernel.tar.gz *

Deploy to your beaglebone (change BeagleBoneBlack2 to the hostname/IP of your beaglebone)

scp dist/kernel.tar.gz root@BeagleBoneBlack2:/home/root/kernel.tar.gz ssh root@BeagleBoneBlack2 'tar xovfz ~/kernel.tar.gz -C /; sync;'