adb-reboot

Reboot the device normally

$ adb reboot

$ adb reboot bootloader

$ adb reboot recovery

$ adb reboot fastboot

adb reboot [bootloader | recovery | sideload | fastboot | <reason>]

bootloader
    Reboots the device directly into the bootloader (also known as fastboot) mode. This mode is typically used for flashing firmware, unlocking the bootloader, or interacting with the device at a low level.

recovery
    Reboots the device into the recovery mode. Recovery mode allows users to perform system updates, factory resets, clear cache partitions, or flash custom ROMs.

sideload
    Reboots the device into recovery mode and automatically prepares it to receive an update package via ADB sideload. This is commonly used for installing official OTA updates or custom ROMs.

fastboot
    An alias for bootloader. Reboots the device into the fastboot mode.


    Allows specifying a custom reboot reason string. This is less commonly used by end-users and more for system-level debugging or specific device implementations.

adb reboot is an Android Debug Bridge command used to restart a connected Android device. It's part of the adb utility, which provides a versatile command-line tool for communication between a computer and an Android-powered device. This command is frequently used by developers, system administrators, and advanced users to quickly restart a device without needing to manually interact with the device's power button.

It's particularly useful when debugging applications, flashing custom ROMs, or performing system-level operations. The command supports various reboot modes, allowing the user to specify whether the device should reboot into the normal system, bootloader, recovery, or sideload mode. This granular control makes it an indispensable tool for device management and development workflows.

Caveats:
Requires Android SDK Platform-Tools to be installed on the host computer.
USB debugging must be enabled on the Android device.
The device must be connected to the computer via USB and authorized for debugging.
Firewall rules or USB driver issues can prevent a successful connection.
Using adb reboot with no arguments performs a normal system reboot.

Before using adb reboot, ensure that the Android SDK Platform-Tools are installed on your computer and that USB debugging is enabled on your Android device. You also need to authorize the connection on your device when prompted.

Beyond general restarts, adb reboot is crucial for:
Flashing custom ROMs or recoveries: By rebooting into bootloader or recovery mode.
Applying OTA updates: Using sideload mode.
Debugging boot issues: Restarting the device to observe boot logs.

The Android Debug Bridge (ADB) has been an integral part of the Android SDK since its early days, evolving alongside the Android operating system. The reboot command has been a core functionality, providing developers with a consistent way to restart devices during development and testing cycles. Its functionality has remained largely stable, with occasional additions of specific reboot modes like sideload to support new device functionalities and development workflows.

adb(1), adb devices(1), adb shell(1), adb install(1), fastboot(1)