A custom operating system for the TrimUI Brick / Hammer, written from scratch. No inherited code — one launcher, one libretro game frontend, one small system daemon, all built for exactly this device. Faster and lighter than what came before, and fully self-sufficient: kUI runs the whole show, from the boot chain to the pixels.
- Fast. Boot adds ~1.2 s over the kernel to a fully-dressed carousel; navigation, settings, and overlays are instant. 18–24 MB of RAM across two processes — the whole OS is a few megabytes on the card.
- One of everything. One settings surface (the Control Panel), one config file, one LED editor, one save-state universe per game. Nothing duplicated, nothing to hunt for.
- Yours. Theme colors drive the entire chrome. Artbook carousel. The Dude keeps your streaks honest. Your saves, states, art, and history are read in place and carried forward.
Launcher
- Three views — Carousel (full-art), Covers (list + boxart), or Lists (text only), switchable any time.
- Artbook carousel with per-system art, tinted to your theme.
- Pins, Collections, Recents, per-list cursor memory, and launch-origin memory (you return to where you launched from).
- Game Switcher — SELECT from anywhere: your recent games as a carousel of last-session screenshots.
- The Dude — kUI's built-in gamification companion: XP and levels, session / daily / weekly quests, achievements, play streaks, and retro trivia.
Game frontend (native libretro host)
- Broad system support — GB/GBC/GBA, SNES, Genesis / SMS / Game Gear, TurboGrafx-16 (+CD) / SuperGrafx, Lynx, NeoGeo Pocket, WonderSwan, Virtual Boy, Amiga (+CD32), DOS, and more.
- 8 save-state slots with PNG previews, plus auto-resume into the slot you were using.
- Bezels (console-shaped / CRT), five scaling modes, screen effects (scanlines, LCD grid), and GLSL shaders.
- Cheats, per-game control remapping, turbo, fast-forward, multi-disc, screenshots.
- RetroAchievements built on the official rcheevos library: session announce, unlock toasts, badge art, in-game achievement browser, plus an offline queue and bulk pre-fetch. Softcore today (hardcore pending upstream approval).
Control Panel — every setting and tool in one place
- Appearance — theme colors (live preview), fonts, backgrounds.
- Display — brightness, color temperature, contrast, saturation, white point + RGB gains.
- Connectivity — real WiFi and Bluetooth pages (scan / connect / pair / forget).
- LED Control — per-light profiles across every hardware effect, including a Gaming profile applied while a game runs.
- System — volume, power profile, FN-switch behavior, time zone, date & time, developer (SSH), NTP.
- Tools — Scraper & Patcher (artwork + metadata), Collections manager, Boot Logo picker, Themes, Battery graph, Game tracker, Core Options, Input tester, Files, and PakDek.
- Updater — over-the-air updates from the device with a live progress bar; no reinstall, no data loss.
Under the hood
- kuid — a ~1.8 MB system daemon owning battery, LEDs, and radios.
- kUI-owned boot chain — the device boots straight into kUI; clean shutdown via a direct PMIC sequence.
- Pak-compatible — SD layout, env vars,
launch.sh, and lifecycle hooks are honored, so existing paks run. Zero paks shipped, none required.
| Category | Systems |
|---|---|
| Consoles | Channel F, Atari 2600, Odyssey 2, Intellivision, ColecoVision, Vectrex, SG-1000, NES, Master System, Atari 7800, TurboGrafx-16, SuperGrafx, Genesis, SNES, Neo Geo, GX4000, 3DO, Amiga CD32, Jaguar, Neo Geo CD, Virtual Boy |
| Add-ons | FDS, TurboGrafx-CD, Sega CD, 32X, Jaguar CD |
| Handhelds | Game Boy, Lynx, Game Gear, Supervision, Mega Duck, GBC, NGP/NGPC, WonderSwan/Color, Pokémon Mini, GBA |
| Computers | ZX Spectrum, Atari 800/XL/XE/5200, C64, C128, VIC-20, PET, Plus/4, CPC, MSX, Amiga |
| Other | fake08, Uzebox, Doom, Arcade |
| Via PakDek | N64, DreamCast, PSP, DS, Saturn, ScummVM, PICO-8, and more |
- Format the SD card as FAT32 (MBR)
- Copy all contents to the SD card root
- Copy ROMs into the matching
Roms/folders - Copy BIOS files into the matching
Bios/folders - Insert the SD card and power on
Your games, saves, states, box art, collections, and play history stay exactly where they are — kUI reads them in place.
All in-game shortcuts are rebindable in Control Panel → Core Options. Defaults:
In-game
| Shortcut | Action |
|---|---|
| MENU | Pause / in-game menu |
| MENU + R1 | Save state |
| MENU + L1 | Load state |
| MENU + START | Save & quit (into the switcher) |
| MENU + SELECT | Game switcher |
| MENU + B | Reset |
| MENU + X | Screenshot |
| F1 | Turbo (all held buttons) |
| F2 | Fast-forward (toggle) |
Launcher
| Shortcut | Action |
|---|---|
| A | Open / launch (auto-resumes your slot) |
| B | Back |
| X | Pin |
| Y, Y | Wipe saves (press twice to confirm) |
| MENU | Quick menu / Control Panel |
| SELECT | Game switcher |
| L1 / R1 | Jump platform |
| L / R | Jump page |
| POWER | Sleep |
The Brick/Hammer has no analog sticks, so fast-forward lives on the F2 front button (not R3), and Turbo on F1.
Cross-compiled to aarch64-unknown-linux-gnu with kUI's own
aarch64-kui-linux-gnu toolchain (glibc 2.28; place it in toolchain/):
nix-shell --run 'cargo build --release --target aarch64-unknown-linux-gnu'
scripts/package.sh # assembles the release zipBuilds are deterministic.
- kUI by ArjunKdaf
- Artbook Next artwork by Anthony Caccese
- Overlay bezels by Shin (KrutzOtrem) (MIT)
- rcheevos (RetroAchievements) — MIT, vendored
- Libretro cores by their respective authors
❤️ Libretro — none of this would be possible without the incredible work of the libretro team and the core developers who keep retro gaming alive. Thank you. ❤️
GPL-3.0 — see LICENSE. The Dude, the scraper, and the design are original works by ArjunKdaf; rcheevos is vendored under its MIT license.