Install MT7601U WiFi adapter driver for OpenELEC (Raspberry Pi)

GUIDE.md

I bought (a few) Wireless-N WiFi adapters from Ebay to enable WiFi on my OpenELEC-featured Raspberry Pi. I was hoping it would work out-of-the-box, but that wasn't true. Some attempts such as modprobe rt2x00usb did not work as expected because it's a totally different chipset.

The output of lsusb:

...
Bus 001 Device 004: ID 148f:7601 Ralink Technology, Corp.
...

This guide shows you how to cross compile the driver and integrate it in an existing OpenELEC installation. It works under Ubuntu 14.04 for OpenELEC nightly with kernel version 3.15. Common build tools are assumed, plus squashfs-tools). I'm not a pro in building modules, but this has worked for me.

• Install the dependencies: apt-get install build-essential squashfs-tools git
• Download the the driver source from here (version v3.0.0.4 from 9/13/2013) and unzip it.
• Apply this patch, for kernel 3.13+. Can be done manually.
• Note your OpenELEC kernel version, via SSH uname -a.
• Clone the Raspberry Pi tools repository: git clone https://github.com/raspberrypi/tools.
• Clone the OpenELEC repository: git clone https://github.com/OpenELEC/OpenELEC.tv.
• Download the approriate kernel version from here, and unzip it.
  • Apply the patch to KERNEL_ROOT: patch -p1 < OPENELEC_ROOT/projects/RPi/patches/linux/linux-01-RPi_support.patch. Make sure you have changed directory to the KERNEL_ROOT folder.
  • Copy OPENELEC_ROOT/project/RPi/config/linux.arm.conf to KERNEL_ROOT/.config
• Add RPI_TOOLS_ROOT/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin to your PATH. The compile tools should be available for running.
• Compile kernel modules: make modules.
• Change DRIVER_ROOT/Makefile to look as below (around line 198). Replace the LINUX_ROOT with your path.

ifeq ($(PLATFORM),PC)
# Linux 2.6
LINUX_SRC = LINUX_ROOT
# Linux 2.4 Change to your local setting
#LINUX_SRC = /usr/src/linux-2.4
LINUX_SRC_MODULE = LINUX_ROOT/kernel/drivers/net/wireless/
CROSS_COMPILE = arm-linux-gnueabihf-
ARCH=arm
export ARCH
export CROSS_COMPILE
endif

• Run make, which should result in a kernel object DRIVER_ROOT/os/linux/mt7601Usta.ko
• Take the SYSTEM image file from your SD card, and mount it with sudo mount -t squashfs SYSTEM TMPDIR.
• Since the file system is read-only, rsync (as root) the contents to another dir sudo rsync -avp TMPDIR TMPDIR2.
• Create directories for the following operations (as root) if needed. Replace x.x.x with the kernel version.
  • Copy DRIVER_ROOT/os/linux/mt7601Usta.ko to TMPDIR2/lib/modules/x.x.x/kernel/drivers/net/wireless
  • Copy DRIVER_ROOT/RT2870STA.dat to TMPDIR2/etc/Wireless/RT2870STA/RT2870STA.dat
  • In TMPDIR2, run depmod -a -b . x.x.x
• Repack the filesystem (as root) with sudo mksquashfs TMPDIR2 SYSTEM -noappend -comp gzip.
• Run chown USER:USER SYSTEM so you can access the file.
• Copy the new SYSTEM image to your SD card and boot OpenELEC.

Your WiFi should be ready to use! In case of problems, SSH into the system, and view the output of dmesg. Note that auto-update will probably overwrite your custom SYSTEM image, but chances are the driver will still work.

Someone is working on a Linux 3.19+ module that should be integrated into the Linux Repository someday. His repository can be found at https://github.com/kuba-moo/mt7601u.