I can connect to TWRP (3.2.3-0) with adb but fastboot devices does not list any and fastboot continue (while my phone is booted into TWRP) only prints:

$ fastboot continue
< waiting for any device >

I can rule out a driver problem since I have used fastboot successfully with the same combination of phone, cable and PC.

New contributor
Micha Wiedenmann is a new contributor to this site. Take care in asking for clarification, commenting, and answering. Check out our Code of Conduct.

You are confused about fastboot. It is not another adb. There is no fastboot server (in TWRP) which accepts connections. Rather it is a step/mode in the boot process of Android. Think of it as GRUB. You need to reboot your phone while the fastboot command is waiting for your device.

New contributor
Micha Wiedenmann is a new contributor to this site. Take care in asking for clarification, commenting, and answering. Check out our Code of Conduct.

ADB and fastboot are two different protocols. Android Debugging Bridge works in ROM or in Recovery mode, when adbd (adb daemon) is running on phone.

Fastboot is one of the most commonly used Firmware Update Protocols. It works in bootloader mode which is also called download mode or emergency download mode (EDL) by some vendors. Some devices have both modes where EDL provides more primary access as compared to fastboot. Some OEM's use different tools for firmware flashing such as ODIN, nvFlash, QPST/QFIL etc.

Bootloader mode is usually accessible by rebooting in bootloader mode from recovery or ROM, or by pressing Vol+ key when device is booting. Similarly EDL is accessible using different combinations of Vol+, Vol- and Power key.

Bootloader is one of the very first pieces of software that is loaded in booting process. GRUB is the most common one used on Linux PCs. On Android embedded devices, the most commonly used bootloader by SOC vendors is ABOOT. To know further about bootloaders, boot process and what we can do in adb/fastboot mode, have a look at given links:

Your Answer

Micha Wiedenmann is a new contributor. Be nice, and check out our Code of Conduct.
 
discard

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Not the answer you're looking for? Browse other questions tagged or ask your own question.