BaseOS

BaseOS is a small, fast operating system for Anbernic RG XX handhelds. It handles the hardware and starts your choice of frontend: NextUI, Slot, spruceOS, or your own. It has no menu of its own.

Installation guide

Startup time

These times include kernel loading but not frontend loading.

v1.4.0 also loads NextUI about 0.7 seconds faster and Slot about 0.3 seconds faster.

Features

• Display, sound, controls, Wi-Fi, HDMI, LEDs and deep sleep support.
• A small system with minimal background activity.
• Automatic expansion to use the full SD card on first boot.
• Updates by copying one file to your card. Games, saves and settings stay put.
• SSH/SFTP over Wi-Fi and adb over USB, enabled by default.
• USB storage mode to access your card from a computer.
• Optional startup sound: put startup_sound.wav at the root of TF1's BASEOS partition. Use a short WAV clip; other formats are not supported.

Installation and updates

For a fresh install, download your model's BaseOS release, unzip its .img.zip and flash the .img to TF1. Flashing erases the card. Then add a frontend using TF1's visible BASEOS volume or a separate TF2 card. Do not reformat TF1 after flashing BaseOS. A usable TF2 card takes priority.

Use one frontend per card. FAT32 works with all three frontends; NextUI also supports exFAT on TF2. Follow the installation guide for one-card or two-card setup.

To update BaseOS, copy your model's .bosupd to the root of your frontend card and restart. Keep power connected during the v1.4.0 update's one-time startup optimisation, and let it finish without switching off. From v1.5.2, the new boot method installs at any battery level. It takes a few seconds on the first start after the update, while the screen shows "SPEEDING UP BOOT".

If startup looks wrong, check baseos-boot.log at the root of the card. It says which startup ran and why.

Frontends

• NextUI: official v6.15.0 and later support H700 natively. Extract the -base.zip or -all.zip archive and copy its contents to your frontend card's root. Keep MinUI.zip zipped. BaseOS installs it automatically. You don't need a separate H700 fork or the stock-OS dmenu.bin setup. NextUI installation guide.
• Slot: extract its H700 release and copy the contents of slot-<version> to the card root, including the complete System/ folder. Put unzipped games in Games/GB/, Games/GBC/ or Games/GBA/, and optional BIOS files in BIOS/. Update by replacing System/ with the folder from the new release. Slot guide. For RetroAchievements, cheats and a few extra goodies, try my Slot fork.
• spruceOS: extract the full release archive and copy all contents, including hidden folders, to the card root. The card should then contain spruce/scripts/runtime.sh. The spruceOS Installer can set up a separate TF2 card; skip its TF1 image step if BaseOS is already installed. spruceOS installation guide.
• Your own frontend: add System/launch_frontend.sh or a glibc AArch64 binary at System/frontend. The binary takes priority. Scripts run through /bin/sh. Both run from the card root and need no executable bit.

Settings

Edit baseos.conf at the root of TF1's visible partition, then restart. Settings stay on TF1 even when your frontend is on TF2, and they survive OS updates.

hostname=my-handheld
mdns=true

• hostname: your device's network name. Defaults to its model ID, such as rg34xxsp. Use 1–63 letters, digits or hyphens, with no hyphen at either end.
• mdns: connect using <hostname>.local over Wi-Fi. Enabled by default. Set false to disable it.
• ssh_password: set your SSH password. Defaults to root if omitted or empty. baseos.conf holds it as plain text, so don't reuse an important password. Write it without quotes. BaseOS trims surrounding spaces.
• headphone_pop_fix: set true to try the headphone exit-pop fix. It is off by default because it can use more battery while awake. The speaker pop fix is always enabled. See audio support.

Omitted settings use their defaults. Lines starting with # are comments, but a # within an SSH password is part of the password.

USB access

For adb, connect a data-capable USB-C cable before powering on. If adb stops working after unplugging it, restart with the cable connected.

For USB storage, hold MENU while connecting the cable. If the handheld doesn't start automatically, hold Power for 3–4 seconds. Release Power when it starts, but keep holding MENU until you see "USB STORAGE: EJECT BEFORE RESTART".

Eject the drive on your computer before restarting the handheld. Restart without holding MENU to return to normal.

Supported devices

• Anbernic RG28XX
• Anbernic RG34XX
• Anbernic RG34XX SP
• Anbernic RG35XX Plus and RG35XX 2024
• Anbernic RG35XX H
• Anbernic RG35XX Pro
• Anbernic RG35XX SP
• Anbernic RG40XX H
• Anbernic RG40XX V
• Anbernic RG CubeXX
• Anbernic RG SP

How it works

BaseOS uses Anbernic's bootloader, kernel and hardware drivers for H700 handhelds, with a minimal BusyBox-based system in place of the stock Ubuntu userland. From version 1.3.0, BaseOS stores the kernel in compressed form to reduce loading work. The kernel itself is unchanged.

Build instructions and technical documentation are in CONTRIBUTING.md.