Working on building my own custom retro gaming device, and GitHub actions was a blocker due to size, so I remembered I Do have a Linux device!
Basically starting from scratch, but it's been interesting and fun to say the least!
Long time lurker, first time poster with an actual project to share. I'm building Octane — an open source retro gaming handheld platform from scratch. Here's the full breakdown.
The brain: Radxa Cubie A7S
Allwinner A733, 6GB LPDDR5, WiFi 6, USB-C DisplayPort Alt Mode, ~$50. It's the only SBC at this price point that hits everything simultaneously: DPI GPIO lines for a direct-connect screen, USB-C DP Alt Mode for dock output, and a PCIe FFC expansion port that's become the key to the whole WiFi architecture.
The OS: OctaneOS
A custom Batocera Linux fork with Allwinner A733 support built from the ground up. Zero upstream Batocera A733 support exists — everything below the emulation layer (kernel, device tree, display driver) is being written specifically for this hardware. Kernel is Linux 5.15 from Radxa's Allwinner AIOT BSP.
Three play modes baked into the OS:
- Handheld — DPI screen direct via LCD0 GPIO
- Wired docked — USB-C DisplayPort Alt Mode, one cable does everything
- Wireless streaming — MT7921K M.2 on the PCIe FFC port as a dedicated private AP radio, streams to a Raspberry Pi Zero 2W in the dock
The dual WiFi architecture:
This is the part I'm most proud of figuring out. The onboard FCU760K handles home network internet as wlan0. The MT7921K M.2 card on the PCIe FFC expansion port runs as wlan1 — a completely independent radio on an independent bus, acting as a private AP for the streaming session. Two fully isolated radios, no interference, no shared bandwidth. Intel AX210 was ruled out because LAR enforcement blocks 5GHz AP mode on Linux.
The dock:
Raspberry Pi Zero 2W as the dock chip. Outputs HDMI, Component (Y/Pb/Pr), and Composite simultaneously — all three live with no selector switch. Plug in your CRT, your PVM, and your modern TV at the same time and they all get a signal. No commercial handheld at any price does this. Composite is native on the Pi Zero 2W — single solder point. Component via a small DAC board.
The CI pipeline:
Full Buildroot compile on GitHub Actions. The build spans multiple sessions over weeks of active development on an A733 target that didn't exist before this project. A checkpoint-failure cache technique keeps build artifacts alive across runs so nothing gets thrown away between sessions. Hat tip to suckbluefrog from Batocera-Multilib for pre-packaged dl cache tarballs for ecwolf and same-cdi — those two packages would have been a permanent CI blocker otherwise.
Where it stands:
Build environment up, A733 target defined, CI running. Hardware not yet in hand — building the software stack before the board arrives. Very much in progress and building in public from day one.
Everything is open source — spec, OctaneOS source, wiring diagrams, STL files, all of it.
*Disclosure: OctaneOS is developed with Claude Code assistance per community rules. The architecture decisions, hardware research, and project direction are mine — Claude Code handles build system execution and file-level work.*
Links:
- GitHub: github.com/GameOctane/OctaneOS
- Full build system writeup: gameoctane.com/how-octaneos-is-built-the-architecture-behind-the-software
- Project intro: gameoctane.com/introducing-a-new-open-source-handheld-octane
Happy to go deep on the A733 bring-up, the dual-radio architecture, the PCIe FFC expansion, or anything else. This community has been a huge reference — glad to finally have something to contribute back...and learn more than I ever realized was possible.