Real Android 2.0 (AOSP Eclair) running bare-metal on the New Nintendo 3DS XL.

This is not an emulator and not a Horizon app. Luma3DS chainloads a Linux kernel, and Android's own init, Dalvik, SurfaceFlinger and stock apps run on top of it. The Android UI is on the bottom (touch) screen. The top screen shows the kernel console.

The kernel, ARM9 firmware and FIRM loader come from the linux-3ds project. Everything Android-side is AOSP Eclair, ported and patched for the console.

Current release: Alpha 1. Settings > About phone > Build number reads Android3DS Alpha 1 (a1). It boots, joins Wi-Fi, browses the web, and makes calls and sends texts over Wi-Fi. It is still an alpha: expect slow spots and the occasional crash.

• No sleep mode. The console never suspends. Power it off when you are done.
• No cellular radio. The 3DS has none. "Mobile data" here means 3DSTelco over Wi-Fi (see below).
• Wi-Fi limits. 5 GHz, WPA3-only and enterprise (802.1X) networks are not supported.
• Android 2.0 apps only (API level 5). There is no Google Play / Market.
• Single screen. No 3D, and no dual-screen apps: the top screen is console only.
• The SD card stays mounted. There is no USB storage mode and no unmount button. Power off before you take the card out.

You need:

• a Nintendo 3DS with Luma3DS custom firmware installed;
• an SD card with a few hundred MB free;
• a 2.4 GHz Wi-Fi network, for anything online.

Steps:

1. Download android3ds_a1.zip from the Releases page, or build it yourself (see Building). The release zip is ready to use: it already has the firmware the console needs, so you can skip the Firmware section.
2. Extract it to the root of the SD card. Its linux/ and luma/payloads/ folders merge with what is already there. Do not delete your existing luma/ folder.
3. Put the card back. Hold D-pad DOWN while you press POWER. Luma3DS starts luma/payloads/down_firm_linux_loader.firm, which boots Android3DS.
4. To go back to the normal 3DS system, power off (hold START) and turn the console on without holding anything.

To update, extract the newer release zip over the old one the same way.

1. Open Settings (from the app drawer on the home screen).
2. Tap Wi-Fi settings.
3. Tick Wi-Fi to turn the radio on. Wait a few seconds for the network list.
4. Tap your network. Type the password with the on-screen keyboard, then tap Connect.
5. The network shows Connected. It is remembered and rejoins on the next boot.

Tips:

• Only 2.4 GHz networks show up. If your router combines both bands under one name, the 3DS uses the 2.4 GHz side.
• For a hidden network, use Add Wi-Fi network at the bottom of the list.
• If the list stays empty, untick Wi-Fi, wait a moment, and tick it again.
• The 3DS's Wi-Fi MAC address is in Settings > About phone > Status, and also under START (Menu) > Advanced on the Wi-Fi screen.

The 3DS has no cellular modem. In Android3DS, "mobile data" is 3DSTelco. It gives the console a phone number, and carries its calls and texts over Wi-Fi through an HTTPS server. The built-in server is https://3dstelco.divergen.io. You can point the 3DS at your own server instead.

1. Connect to Wi-Fi first (above). Mobile Data refuses to turn on without it.
2. Note the 3DS's Wi-Fi MAC address from Settings > About phone > Status.
3. On the 3DSTelco website, register that MAC address. The site gives you a one-time provisioning code.
4. On the 3DS, open Settings > 3DSTelco Mobile Data.
5. Optional: tap 3DSTelco HTTPS endpoint only if you use a different server. It must be an https:// address. Changing it clears the old number, so enroll again afterwards.
6. Tick Enable Mobile Data.
7. Tap Enroll this 3DS, type the code, and tap OK. Dashes and spaces are ignored, and the code is never saved.
8. After a few seconds, Phone number shows your number and Service status reads Online over Wi-Fi.

Then:

• Calls: open the Phone dialer. Calls use the speaker.
• Texts: use Messaging.
• Who you can reach:
  • other 3DS consoles have 3- or 4-digit numbers;
  • web accounts have 10-digit numbers;
  • texts can also go to 6-digit service numbers.
• Missed calls and voicemail show in the dialer's Recents. Voicemail is downloaded once, then plays offline.

If Service status says the call audio relay is offline, texts still work, but calls will have no audio until the server's relay is back.

1. Open Settings > Wireless ADB and tick Enable wireless ADB.

2. The screen shows the connection address. From a PC on the same network, run:

   adb connect <address>:5555

This is a root shell for anyone on your network. Turn it off when you are not using it.

Open Settings > About phone and tap Firmware version three times quickly.

The build runs on Linux or WSL2 (Ubuntu). The large source trees must live on a Linux filesystem: the kernel tree does not survive a Windows checkout. The scripts default to ~/android3ds, so clone there (or set ANDROID3DS_ROOT):

git clone https://github.com/Octoblimp/Android-Eclair-3DS.git ~/android3ds

This repository carries the port's own code and the vendored trees (WebKit, ICU, ...). The Linux kernel, the linux-3ds firmware and loader, Buildroot and the AOSP projects it modifies come from upstream, plus the changes in patches/. This fetches each one at the exact upstream commit and applies its patch:

scripts/fetch_third_party.sh

The kernel patch comes with the .config the release was built with (patches/linux.config), which the script installs.

Building from a fresh clone has not been tested end to end yet. Expect to adapt paths and packages on your machine.

The console needs some of Nintendo's firmware, which is not in this repository. The release zip already includes it. Only builders need to dump their own. Everything goes into third_party/buildroot/board/nintendo3ds/rootfs_overlay/usr/lib/firmware/:

Wi-Fi firmware. The 3DS Wi-Fi chip (an Atheros AR6014) boots from four blobs inside the NWM system module, title 0004013000002D02. Dump it with GodMode9:

1. Start GodMode9. In the usual Luma3DS setup, hold START while powering on.

2. Open [1:] SYSNAND CTRNAND > title > 00040130 > 00002d02 > content.

3. Press A on the .app file there (its name depends on your system version, for example 0000001e.app). Choose NCCH image options... > Extract .code, or Decrypt file (SD output). Menu wording varies a little between GodMode9 versions. GodMode9 writes the result to gm9/out/ on the SD card.

4. Copy that file to the build machine and run:

   scripts/extract_n3ds_firmware.py path/to/the/file

The script takes a decrypted .app, or its .code (compressed or not). It finds the four blobs through the module's own pointer table and checks each one by SHA-256 against the firmware this port was tested with (NWM v11264). Nothing is written unless all four match. Then it puts them into the overlay.

DSP firmware (optional). dspfirm.cdc is the 3DS DSP firmware. If you followed the usual Luma3DS setup guide, you already have it at sd:/3ds/dspfirm.cdc. Otherwise run DSP1 once on the console to create it. Android3DS plays sound through CSND, not the DSP. Without this file the kernel just logs "audio unavailable" for the DSP driver. To include it anyway:

scripts/extract_n3ds_firmware.py path/to/the/file --dsp path/to/dspfirm.cdc

Regulatory database. regulatory.db and regulatory.db.p7s come from wireless-regdb. On Ubuntu, install the wireless-regdb package and copy both files from /lib/firmware/.

The release gate (scripts/verify_release_artifacts.sh) refuses a build without the Wi-Fi blobs, and says which file is missing.

Setup:

1. Toolchain: Bootlin armv6-eabihf--glibc--stable-2025.08-1 (toolchains.bootlin.com), extracted to toolchain/ in the checkout.

2. The bare-metal ARM9/ARM11 firmware uses the distribution's gcc-arm-none-eabi package.

3. Several tests run ARM binaries under a static qemu-arm-static, kept in toolchain/qemu/.

4. Machine-specific settings go in ~/.config/android3ds/env. This file is plain shell assignments and is never committed. See scripts/a3ds_env.sh for the variables:

   # Optional: a second checkout that holds sdcard/ (for example on a Windows drive).
   ANDROID3DS_WIN="/mnt/c/path/to/Android3DS"
   # Optional: only for unattended runs where sudo must not prompt.
   ANDROID3DS_SUDO_PASSWORD=...

A release is assembled like this. The build scripts for each component (kernel, framework jars, apps, native stack) are in scripts/.

scripts/sync_android_to_sdcard.sh   # stage /system, /etc, /usr into sdcard/
scripts/build_dexpreopt_qemu.sh     # pre-optimise the framework jars
scripts/prebake_all_app_odex.sh     # pre-optimise the apps
scripts/sync_android_to_sdcard.sh   # stage again with the optimised files
scripts/verify_release_artifacts.sh # release gate: refuses stale or wrong artifacts
scripts/build_sdcard_zip.sh         # pack sdcard/ into sdcard.zip

After any framework jar change, re-run the two pre-optimise steps. Otherwise the system stalls at boot rebuilding them on the console.

docs/BUILD.md has the original boot-chain recipe and the build environment gotchas.

content/      Android-side sources: Settings additions, the stock-app overlays (Phone, Mms, ...), extra apps
native/       native daemons and tools
hal/          hardware HALs (lights, sensors, copybit, input)
scripts/      build, deploy and test scripts, and the release gates
patches/      changes to the upstream trees (kernel, linux-3ds, Buildroot, AOSP), with MANIFEST.tsv
third_party/  upstream sources: vendored here (WebKit, ICU, ...) or fetched by fetch_third_party.sh
sdcard/       build output, the SD card tree the release zip is packed from (only templates are tracked)
tools/        PC-side 3DSTelco diagnostics
docs/         scope, build notes, and research (PICA200 GPU, cameras, 3DSTelco protocol)

patches/ holds plain text diffs. Binary files they leave out are listed in patches/BINARIES.tsv. Some are Nintendo firmware (see Firmware). The rest are build outputs and media that the build scripts regenerate, and that the release zip also carries.

• linux-3ds: the Linux kernel, arm9linuxfw and firm_linux_loader this port boots on.
• The Android Open Source Project: Android 2.0 Eclair.
• Luma3DS: the custom firmware that chainloads it.
• libn3ds and GBATEK, for the 3DS hardware details.
• Bootlin: the cross toolchain.

Android3DS's own code is under the Apache License 2.0, like AOSP itself, except where a file says otherwise. Third-party code keeps its upstream license, and each patch in patches/ carries the license of the project it changes. The Linux kernel and its patch are GPL-2.0. See NOTICE.

This repository contains no Nintendo firmware and no system-module dumps.

Android3DS is not affiliated with or endorsed by Nintendo or Google. Android is a trademark of Google LLC. Nintendo 3DS is a trademark of Nintendo. Use at your own risk.