Patching the Linux Kernel to install the Xin-Mo Dual Arcade driver on a Raspberry Pi
These are instruction for Raspbian on the Raspberry Pi. I also have instructions for Ubuntu.
The Xin-Mo Dual Arcade is a USB interface for up to two arcade joysticks and 22 buttons. It’s a cool little device if you want to build an arcade controller for your computer or Raspberry Pi. You can get one from Ultracabs.
Unfortunately there is a bug in the Xin-Mo Dual Arcade: the values it sends for the up and left positions of the joysticks are out of range with the values it announces it would send, and Linux therefore ignores these values (it’s its right). Therefore the joystick do nothing in the up and left position.
I wrote a driver to fix that problem, as a patch to the Linux Kernel. A few people asked me for help on how to install it, hence this article.
Cliché Disclaimer: Use these instructions at your own risks. Backup your computer before you start. I am not responsible for any data loss or fried computers caused by following these instructions.
Raspbian
I used NOOBS 1.2.1 and selected Raspbian. Everything here happens in the terminal, make sure you’re logged in as an administrator (typically user pi). If a command that starts with sudo asks for your password (not normally the case on Raspbian), use the password for that administrator user. These instructions were derived from the RPi Kernel Compilation page on the Embedded Linux Wiki.
Observing the problem
First we’re going to install evtest, a tool to test the joystick:
sudo apt-get update
sudo apt-get install evtest
To try it out, connect your joystick and run the program:
evtest
It will list devices and ask you to select your joystick. Find the line that says Xin-Mo Xin-Mo Dual Arcade, type the number next to /dev/input/event (4 in this example) and Enter.
No device specified, trying to scan all of /dev/input/event*
Not running as root, no devices may be available.
Available devices:
/dev/input/event4: Xin-Mo Xin-Mo Dual Arcade
Select the device event number [0-5]: 4
Now when you move the joysticks and press buttons, it will print lines like these (for a button):
Event: time 1378629038.490828, type 4 (EV_MSC), code 4 (MSC_SCAN), value 90001
Event: time 1378629038.490828, type 1 (EV_KEY), code 288 (BTN_TRIGGER), value 1
Event: time 1378629038.490828, -------------- SYN_REPORT ------------
Event: time 1378629038.618674, type 4 (EV_MSC), code 4 (MSC_SCAN), value 90001
Event: time 1378629038.618674, type 1 (EV_KEY), code 288 (BTN_TRIGGER), value 0
Event: time 1378629038.618674, -------------- SYN_REPORT ------------
or these (for a joystick):
Event: time 1378629075.546079, type 3 (EV_ABS), code 1 (ABS_Y), value 1
Event: time 1378629075.546079, -------------- SYN_REPORT ------------
Event: time 1378629075.740176, type 3 (EV_ABS), code 1 (ABS_Y), value 0
Event: time 1378629075.740176, -------------- SYN_REPORT ------------
and nothing when you move the joysticks up or left.
Fixing the problem
Downloading the sources
First we need to install the programs needed to build the kernel:
sudo apt-get update
sudo apt-get -y dist-upgrade
sudo apt-get -y install gcc make ncurses-dev
Then we can download the source code for the kernel. We’re going to use a ‘tarball’, the rpi-3.6.y one, as proposed at the very end of the Get the kernel source section:
wget 'https://github.com/raspberrypi/linux/archive/rpi-3.6.y.tar.gz'
Extract the sources:
tar xpfvz rpi-3.6.y.tar.gz
You can now find the sources in the linux-rpi-3.6.y directory.
Applying the patch
linux-rpi-3.6.y is the directory where the source code was extracted. Enter it:
cd linux-rpi-3.6.y
Then download the patch using wget:
wget 'https://ithink.ch/blog/files/xin-mo/0001-hid-Add-new-driver-for-non-compliant-Xin-Mo-devices.patch'
and apply it:
patch -p1 < 0001-hid-Add-new-driver-for-non-compliant-Xin-Mo-devices.patch
It should display something like this:
patching file drivers/hid/Kconfig
Hunk #1 succeeded at 670 with fuzz 2 (offset -73 lines).
patching file drivers/hid/Makefile
Hunk #1 succeeded at 86 (offset -24 lines).
patching file drivers/hid/hid-core.c
Hunk #1 succeeded at 1689 (offset -47 lines).
patching file drivers/hid/hid-ids.h
Hunk #1 succeeded at 808 (offset -79 lines).
patching file drivers/hid/hid-xinmo.c
Building the kernel
First, make sure the build directory is clean:
make mrproper
Then copy the current kernel configuration from your Raspberry Pi:
zcat /proc/config.gz > .config
We need to make the configuration up to date. This step might ask a lot of questions about whether to support some new features. We are going to take the default answer every time except for our Xin-Mo Dual Arcade driver. We want to make sure it’s enabled, since that’s the one we’re going through all this trouble for.
Run
make oldconfig
and when the following question pops up, type m and Enter:
Xin-Mo non-fully compliant devices (HID_XINMO) [N/m/y/?] (NEW)
For the other questions, if any, just type Enter to accept the default.
If you missed the Xin-Mo line or are not sure, you can use the menu config1 to make sure it is enabled. Type
make menuconfig
and navigate to Device Drivers -> HID support -> Special HID drivers -> Xin-Mo non-fully compliant devices and type m to enable it as a module. An <M> should be displayed next to the line:
<M> Xin-Mo non-fully compliant devices
Then select the Exit button until it asks if you want to save your nw configuration, and answer Yes.
When ready (ideally at the end of the evening), type
make ; make modules
Then the actual compilation will begin. It will go on for a long, long, long long, long, long time, so go to sleep.
Installing the new kernel
Copy the new kernel image to the boot partition, under a name different than the existing one:
sudo cp arch/arm/boot/Image /boot/kernel_new.img
Then enable it in the boot config by adding the following line to /boot/config.txt, or changing the kernel=kernel.img if it already exists:
kernel=kernel_new.img
You can do this using the nano text editor:
sudo nano /boot/config.txt
Type the kernel=kernel_new.img line on its own line or modify the existing one, then hit Control-O and the Enter to save, and Control-X to exit.
Now we need to install the modules:
mkdir ~/modules
export MODULES_TEMP=~/modules
make INSTALL_MOD_PATH=${MODULES_TEMP} modules_install
and put the files into place:
cd /lib
sudo cp -R ~/modules/lib/firmware/ .
sudo cp -R ~/modules/lib/modules/ .
Next the instructions recommend to “update your GPU firmware and libraries.” Since I didn’t spend a night recompiling the kernel to write this article, I cannot follow along as I write this, so if you started from a fresh and recent Raspbian installation, you can live dangerously and reboot (remember my disclaimer above, though). Otherwise, try and follow the instructions under Get the firmware.
And then reboot:
sudo reboot
Test the patch
Run evtest again, like above, and enjoy the result:
Event: time 1378634592.175998, type 3 (EV_ABS), code 1 (ABS_Y), value -1
Event: time 1378634592.175998, -------------- SYN_REPORT ------------
Event: time 1378634592.335920, type 3 (EV_ABS), code 1 (ABS_Y), value 0
Event: time 1378634592.335920, -------------- SYN_REPORT ------------
Event: time 1378634593.613888, type 3 (EV_ABS), code 0 (ABS_X), value -1
Event: time 1378634593.613888, -------------- SYN_REPORT ------------
Event: time 1378634593.809001, type 3 (EV_ABS), code 0 (ABS_X), value 0
Event: time 1378634593.809001, -------------- SYN_REPORT ------------
Event: time 1378634595.165686, type 3 (EV_ABS), code 3 (ABS_RX), value -1
Event: time 1378634595.165686, -------------- SYN_REPORT ------------
Event: time 1378634595.325688, type 3 (EV_ABS), code 3 (ABS_RX), value 0
Event: time 1378634595.325688, -------------- SYN_REPORT ------------
Event: time 1378634595.933826, type 3 (EV_ABS), code 2 (ABS_Z), value -1
Event: time 1378634595.933826, -------------- SYN_REPORT ------------
Event: time 1378634596.093610, type 3 (EV_ABS), code 2 (ABS_Z), value 0
Event: time 1378634596.093610, -------------- SYN_REPORT ------------
If these instructions helped you, I would appreciate it if you could send me a couple of pictures of your set-up so I can compile them on a web page. Drop me a note on Twitter.
1. Note: We installed the ncurses-dev package earlier required by menuconfig, but if you missed that step, you will get the following error:
*** Unable to find the ncurses libraries or the
*** required header files.
*** 'make menuconfig' requires the ncurses libraries.
***
*** Install ncurses (ncurses-devel) and try again.
***
In this case, run
sudo apt-get install ncurses-dev <a class="footnoteBack" href="#ref_1_250_menuconfig">↩</a>