I enable developer mode in the phone, usb debugging and smart bootloader. I do where successfully boot to bootloader such that I see Android mascot with the text Downloading... target Do not turn off!! but I cannot get any ID from fastboot devices

root@masi:/home/masi# fastboot devices
root@masi:/home/masi# adb reboot bootloader
* daemon not running. starting it now on port 5037 *
* daemon started successfully *
root@masi:/home/masi# fastboot devices
root@masi:/home/masi# fastboot devices

I have successfully completed the stages before in Windows 10, but Ubuntu 16.04 and Debian 8.x cause problems.

Phone: Samsung Galaxy S4 gt-i9506
OS: CyanogenMod Temasek february/2016
Recovery: TWRP 2.8.x

PC: Asus Zenbook UX303UA
OS: Debian 8.5

  • 1
    You expect fastboot to work in Download Mode? O_o On Samsung phones you're supposed to load stuff via Odin.
    – Andy Yan
    Commented Sep 2, 2016 at 8:51
  • Sure, but what if you don't have TWRP installed yet (coming from stock)?
    – Andy Yan
    Commented Sep 2, 2016 at 11:18
  • 2
    I don't really get your last comment. Recovery is supposed to be overwriting - the new version overwrites the old. Also, my previous comments are focused on the fastboot aspect of your question where there's no need to take TWRP's capability to update recovery into question.
    – Andy Yan
    Commented Sep 2, 2016 at 14:27

2 Answers 2


The part of the Android bootloader that usually features the fastboot server is called aboot.

As explained in this article, the standard aboot derives from the Little Kernel (LK) project. Almost any phone manufacturer then customized it and created its own bootloader. Follows an excerpt from the abovementioned article:

All Bootloaders I've checked (including Samsung's and Amazon's) seem to derive from LK (in fact printing out the "welcome to lk\n\n" from its kmain), though Amazon's take steps to disable fastboot, as does Samsung, which then uses their own custom App, called Odin.

In short, there's no way to use fastboot with Samsung devices. Only Odin is recognized (by the Loke component).

  • @Masi If I understood correctly (which I somehow doubt), your goal was to update from TWRP 2.8.x to 3.0.2. On Windows, this can be accomplished by booting the phone in Download mode and then using Odin to flash the recovery file, in the form of a .tar.md5 file. On Linux, you can search for the Heimdall software, which does pretty much the same as Odin. P.S.: despite the wording used in the section I quoted, and whether the Android bootloader may or may not derive from Little Kernel, the fact is that Samsung removed fastboot support, and there is nothing we can do to fix it.
    – Grimoire
    Commented Sep 2, 2016 at 12:35
  • @Masi Do not mistake recovery for bootloader/fastboot. You flash a recovery into the recovery partition of your device within bootloader/fastboot. "Only Odin/Heimdall" stands correct.
    – Andy Yan
    Commented Sep 2, 2016 at 14:29
  • Then, it must be that I inserted a new recovery inside odin/heimdall. Commented Sep 2, 2016 at 14:50

I could not find an answer for this. However, I found a differential solution. Boot to recevory mode (mine TWRP 2.8.x), and flash the new recovery mode (TWRP 3.0.2) in Odin/Heimdall. This way, I could complete my target.

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