Rooting Sinty OS

Work in progress: not available in this Alpha

Bootloader unlock is designed but not yet implemented in the current Alpha. No device can be rooted today: there is no unlock switch in Settings, and the recovery unlock stops before it changes anything. The flow below describes the intended design, not a procedure that works on this release yet.

Rooting is strongly discouraged and voids support stability

Sinty OS is designed to run as a sealed, verified system. Rooting it, gaining full root and stepping outside that verified system, breaks the guarantees the OS is built on. A rooted system is no longer one whose behavior we can stand behind: updates, rollback, and the security model may not work as intended, and the stability of support no longer applies. Do not do this unless you fully understand and accept that you are on your own.

Why there is no root by default

On most systems you become root with sudo or a root password whenever you want. Sinty OS deliberately does not work that way. The point of the system is that what runs is exactly what was built and signed, and that nothing can quietly change it.

• The system is read-only and verified. The base is mounted read-only and checked by dm-verity, so it cannot be modified underneath you. There is nothing to “edit as root” in the normal sense.
• There is no always-on root and no root login. You do not log in as root, and there is no sudo or pkexec waiting to hand out privilege.
• Privileged actions are mediated. When something legitimately needs a privileged operation, it goes through a broker that asks for your explicit approval, rather than through a blanket root shell. See ush for how applications get what they need without root.

This is a feature, not a limitation. It is what lets the system promise that it is running exactly what was signed, and roll back safely when an update goes wrong.

What “rooting” means on Sinty OS

Because there is no supported way to simply “become root”, rooting means deliberately stepping outside the verified system: putting the device into an unverified, developer state so you can run a root shell and change things the sealed system would otherwise refuse.

That is a different machine from the one Sinty ships. Once you do it:

• The verification guarantee is gone. You can no longer trust that the system is exactly what was built and signed, which is the whole point of the design.
• Updates and rollback may not behave. The atomic update and automatic rollback rely on the system being sealed and verified; a modified system can break those paths.
• The security model is weakened. The brokered, no-blanket-root design is there to contain mistakes and attacks. A root shell removes that containment.
• Support stability no longer applies. Support assumes a stock, verified Sinty OS. A rooted device is outside that assumption.

How to unlock the device

When it ships, rooting will be a deliberate, physically present act, closer to unlocking an Android bootloader than to typing a password. The exact keys and prompts depend on your device, but the intended flow is:

1. Arm the unlock in settings. In the system settings, under the developer or advanced section, turn on “Allow bootloader unlock”. This asks for your PIN, so a locked device that is lost or stolen cannot be unlocked without you.
2. Reboot into recovery. Choose “Reboot into recovery” from settings, or hold the device’s recovery key combination as it powers on.
3. Choose to unlock. Recovery shows a screen explaining exactly what unlocking does, verification off, a full wipe, the effect on support. Select “Unlock bootloader”.
4. Confirm deliberately. A second screen requires an explicit, non-accidental action, such as holding a button for a few seconds or typing UNLOCK, so it cannot happen with a single stray tap.
5. The device wipes and unlocks. On confirmation the device erases all your data, flips a hardware-anchored lock bit to “unlocked”, and disables dm-verity enforcement. The wipe is immediate, done by discarding the encryption keys.
6. Reboot unlocked. The device restarts and, from now on, shows a persistent notice at every boot that it is unlocked. It is now root-capable: the read-only system can be remounted read-write and a root shell is available. Updates still work; being unlocked does not cut you off from them.

After that you have a modifiable system with root, and you own the consequences: the verification and immutability guarantees are gone, your data was wiped, and the device is no longer in the sealed state Sinty ships and supports.

Reach for the supported paths first

For almost everything people reach for root to do, there is a supported way that does not require it: install and run software through ush, develop with containers through dsh, and let the broker grant privileged actions one at a time. Reach for those first.