Ölbaum’s Delirium

These are instruction for Ubuntu. I also have instructions for the Raspberry Pi.

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.

Ubuntu

I used Ubuntu 13.04, but it should be the same for the other affected versions (12.04, 12.10). Everything here happens in the terminal, make sure you’re logged in as an administrator (typically the user you created when you installed Ubuntu). Whenever a command that starts with sudo asks for your password, use the password for that administrator user. These instructions were derived from the BuildYourOwnKernel page on the Ubuntu 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 kernel¹:

sudo apt-get build-dep linux-image-$(uname -r)

Then we can download the source code for the kernel:

apt-get source linux-image-$(uname -r)

It will download and extract the following files to the current directory (the numbers can vary):

linux-3.8.0
linux_3.8.0-30.44.diff.gz
linux_3.8.0-30.44.dsc
linux_3.8.0.orig.tar.gz

Applying the patch

linux-3.8.0 is the directory where the source code was extracted. Enter it:

cd linux-3.8.0

Before we start, we need to install a tool called fakeroot²:

sudo apt-get install fakeroot

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 697 with fuzz 2 (offset -46 lines).
patching file drivers/hid/Makefile
Hunk #1 succeeded at 108 (offset -2 lines).
patching file drivers/hid/hid-core.c
Hunk #1 succeeded at 1738 (offset 2 lines).
patching file drivers/hid/hid-ids.h
Hunk #1 succeeded at 849 (offset -38 lines).
patching file drivers/hid/hid-xinmo.c

Building the kernel

Run the following commands to start the build:

fakeroot debian/rules clean
fakeroot debian/rules binary-headers binary-generic

After a short while, it should pause to ask you about enabling a new driver:

Xin-Mo non-fully compliant devices (HID_XINMO) [N/m/?] (NEW)

That’s the one we’re going through all this trouble for, so tell it to install the module by typing m and Enter.

Then the actual compilation will begin. It will take a while.

Installing the new kernel

Exit the linux-3.8.0 directory:

cd ..

Four debian packages were created (again, the numbers will vary):

linux-headers-3.8.0-30_3.8.0-30.44_all.deb
linux-headers-3.8.0-30-generic_3.8.0-30.44_amd64.deb
linux-image-3.8.0-30-generic_3.8.0-30.44_amd64.deb
linux-image-extra-3.8.0-30-generic_3.8.0-30.44_amd64.deb

Install them one by one:

sudo dpkg -i linux-headers-3.8.0-30_3.8.0-30.44_all.deb
sudo dpkg -i linux-headers-3.8.0-30-generic_3.8.0-30.44_amd64.deb
sudo dpkg -i linux-image-3.8.0-30-generic_3.8.0-30.44_amd64.deb
sudo dpkg -i linux-image-extra-3.8.0-30-generic_3.8.0-30.44_amd64.deb

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.