--- title: Factory Reset category: Booting layout: default SPDX-License-Identifier: LGPL-2.1-or-later --- # Factory Reset In various scenarios it is important to be able to reset operating systems back into a "factory state", i.e. where all state, user data and configuration is reset so that it resembles the system state when it was originally shipped. systemd natively supports a concept of factory reset, that can both act as a specific implementation for UEFI based systems, as well as a series of hook points and a template for implementations on other systems. Factory reset always takes place during early boot, i.e. from a well-defined "clean" state. Factory reset operations may be requested from one boot to be executed on the next. Specifically, the following concepts are available: * The `factory-reset.target` unit may be used to request a factory reset operation and trigger a reboot in order to execute it. It by default executes three services: `systemd-factory-reset-request.service`, `systemd-tpm2-clear.service` and `systemd-factory-reset-reboot.service`. * The [`systemd-factory-reset-request.service`](https://www.freedesktop.org/software/systemd/man/latest/systemd-factory-reset-request.service.html) unit is typically invoked via `factory-reset.target`. It requests a factory reset operation for the next boot by setting the `FactoryResetRequest` EFI variable. The EFI variable contains information about the requesting OS, so that multi-boot scenarios are somewhat covered. * The [`systemd-tpm2-clear.service`](https://www.freedesktop.org/software/systemd/man/latest/systemd-tpm2-clear.service.html) unit can request a TPM2 clear operation from the firmware on the next boot. It is also invoked via `factory-reset.target`. UEFI firmwares that support TPMs will ask the user for confirmation and then reset the TPM, invalidating all prior keys associated with the security chip and generating a new seed key. * The [`systemd-factory-reset-reboot.service`](https://www.freedesktop.org/software/systemd/man/latest/systemd-factory-reset-reboot.service.html) unit automatically reboots the system as part of `factory-reset.target`. It is ordered after `systemd-tpm2-clear.service` and `systemd-factory-reset-request.service` in order to initiate the reboot that is supposed to execute the factory reset operations. * The `factory-reset-now.target` unit is started at boot whenever a factory reset is requested for the boot. A factory reset may be requested via a kernel command line option (`systemd.factory_reset=1`) or via the UEFI variable `FactoryResetRequest` (see above). The `systemd-factory-reset-generator` unit generator checks both these conditions and adds `factory-reset-now.target` to the boot transaction, already in the initial RAM disk (initrd). * The [`systemd-factory-reset-complete.service`](https://www.freedesktop.org/software/systemd/man/latest/systemd-factory-reset-complete.service.html) unit is invoked after `factory-reset-now.target` and marks the factory reset operation as complete. The boot process then may continue. * The [`systemd-repart`](https://www.freedesktop.org/software/systemd/man/latest/systemd-repart.html) tool can take the factory reset logic into account. Either on explicit request via the `--factory-reset=` logic, or automatically derived from the aforementioned kernel command line switch and EFI variable. When invoked for factory reset it will securely erase all partitions marked for that via the `FactoryReset=` setting in its partition definition files. Once that is complete it will execute the usual setup operation, i.e. format new partitions again. * The [`systemd-logind.service(8)`](https://www.freedesktop.org/software/systemd/man/latest/systemd-logind.service.html) unit supports automatically binding factory reset to special keypresses (typically long presses), see the [`logind.conf(5)`](https://www.freedesktop.org/software/systemd/man/latest/logind.conf.html) man page. * The [`systemd-factory-reset`](https://www.freedesktop.org/software/systemd/man/latest/systemd-factory-reset.html) tool can be used to query the current state of the factory request mechanism, i.e. whether a factory reset is currently being executed, or if one has been requested for the next boot. * The `/run/systemd/io.systemd.FactoryReset` Varlink service provides two IPC APIs for working with factory reset: it permits querying whether the local system supports requesting a factory reset by starting `factory-reset.target`. This may be used by UIs to hide or show in the UI an interface to request a factory reset. The Varlink IPC service also reports the current factory reset state, much like the `systemd-factory-reset` tool mentioned above. This may be used by various early boot services that potentially intent to reset system state during a factory reset operation. ## Exposure in the UI If a graphical UI shall expose a factory reset operation it should first check if requesting a factory reset is supported at all via the Varlink service mentioned above. Once a factory reset shall be executed it shall ask for activation of the `factory-reset.target` unit. Alternatively, `systemd-logind.service`'s hotkey support may be used, for example to request factory reset if the reboot button is pressed for a long time. ## Support for non-UEFI Systems The above is a relatively bespoke solution for EFI systems. It uses EFI variables as stateful memory to request the factory reset on the next boot. On non-EFI systems, a different mechanism should be devised. A service requesting the factory request can then be plugged into `factory-reset.target`. At boot the request should then be fed back to the booted kernel via the `systemd.factory_reset=1` kernel command line option, in order to execute the reset operation. ## Support for Resetting other Resources than Partitions + TPM By default a factory reset implemented with systemd's tools can reset/erase partitions (via `systemd-repart`, see above) and reset the TPM (via `systemd-tpm2-clear.service`, see above). In some cases other resources shall be reset/erased too. To support that, define your own service and plug it into `factory-reset-now.target`, ensuring it is ordered before that. ## Factory Reset via Boot Menu Factory reset can also be requested via the boot menu. A simple factory reset (that does not touch the TPM) at boot can be requested via a boot menu item containing the `systemd.factory_reset=1` kernel command line option. A more comprehensive factory reset operation (that also erases the TPM) can be requested by booting with `rd.systemd.unit=factory-reset.target`. Note that the latter will require one reboot (required since that's how TPM resets work), while the former will reset state and continue running without an additional reboot.