Clockwork Tech is a company that sells the GameShell, a handheld game console kit. One of the modules in the GameShell kit is a compute board based on the AllWinner R16, also known as A33, or sun8i in some codebases. Presumably, Clockwork Tech could release upgraded compute modules for the GameShell in the future, so we've named this layer "meta-clockwork" to encompass BSPs for all Linux compatible boards from this company.
Currently, the only board is known as cpi3. I have no idea what happened to cpi1 and cpi2. I assume the Pi in the name is meant to remind you of the RaspberryPi, a similar and much more popular development board.
- Building u-boot and SPL from source, no copying binaries from the clockwork images!
- Patched mainline Linux 5.4 kernel from meta-sunxi, includes Lima drivers
- Mesa 19.1.6, also with Lima, from Yocto core
- Broadcom wifi firmware configuration
- DRAM clock can probably be increased, but the current setting is a safe default.
- No HDMI output. Need to combine the -hdmi dts and configure wayland for a second output. Note: supposedly this only works on the CPI rev 3.1 boards due to a PCB error.
- Distro layer not yet public, but it does boot to weston and run an app.
Skip this is you're already familiar with Yocto Linux.
Yocto Linux is a system of build scripts and recipes for building bespoke Linux images. A Yocto environment is composed of several layers, generally including the "core" layer, named "meta", along with a BSP (Board Support Package) for the target system, and a distro layer that defines all of the libraries and applications that will be included in the image. Yocto includes a reference distro called Poky and BSPs for a small number of common systems, such as x86_64.
- Yocto core "meta"
- meta-sunxi
Start with Setting Up to Use The Yocto Project.
git clone -b zeus git://git.yoctoproject.org/poky
cd poky
git clone -b zeus https://github.com/linux-sunxi/meta-sunxi
git clone -b zeus https://github.com/JeremyGrosser/meta-clockwork
source oe-init-build-env
<edit conf/bblayers.conf to add meta-sunxi and meta-clockwork>
<edit conf/local.conf change MACHINE to clockwork-cpi3>
bitbake core-image-minimal
This will take a while. Depending on your hardware configuration, it may take several hours. Only changed recipes and their dependencies are built, so subsequent runs should be faster.
If all went well, you should now have some files in tmp-glibc/deploy/images/clockwork-cpi3/
Insert a microSD card and dd the
core-image-minimal-clockwork-cpi3.wks file to it. If you don't know
how to do this, read this guide.
Put the microSD card in your cpi3 board and hold the power button for 10 seconds, or until the display turns on. If it worked, you should see a bunch of penguins and eventually a login prompt. If nothing happens, try poking the reset button next to the GPIO connector.
You may have noticed that you cannot type with a D-Pad. You could try to come up with some obscene combination of USB adapters to get a keyboard attached to your GameShell, but a serial console is much more usable. If you connect the GPIO cable (the rainbow octopus thing) that came with your GameShell to a 3.3V USB-Serial adapter, you can use a terminal emulator to poke at it. Use of a serial console is outside the scope of this README but the pinout you'll need is included below.
From the schematic, this is connector J46 in the DEBUG block on page 8.
From left to right, with the cpi3's flat-flex display connector on the left)
1 Blue Not Connected
2 Green TX
3 Yellow RX
4 White GND
The blue wire is 5V output. DO NOT FEED 5V INTO THIS PIN. Configure your serial terminal for 115200 baud, 8n1.
If you want your GameShell to do more than boot to a shell, you're going to
need a more complete Yocto distro to install some software with some graphics
or something. I'm currently working on this, but it's not ready yet. In the
meantime, you can bitbake core-image-sato for a desktop-like experience.