fastboot - bootloader mode FAILED (remote: 'unknown command')

[defcondoc]

I know this has probably been posted before, butI couldn't find any answers in the posts I found.

The phone has OEM Unlocking turned on in Dev options.

I tried switching off and restarting and then switching back on.

fastboot devices is recognized but all of the fastboot commands I have tried except "help" return the Error - FAILED (remote: 'unknown command')

Why would this be?

It works with 3 other phones we have here to unlock the bootloader. I don't think Ive encountered this before.

Is it possible it could require some unlock key?

Is is a 2022 no name chinese brand.

Any advice is greatly appreciated!

Thank you!

 

[simplepinoi177]

do you run it in PowerShell or CMD?
PowerShell sometimes needs extra in the sytnax or it gets the "command" confused or calls it incorrect...

 

[xXx yYy]

fastboot devices is recognized but all of the fastboot commands I have tried except "help" return the Error - FAILED (remote: 'unknown command')

Why would this be?

Answer is simple: Either device isn't booted into Fastboot ( Bootloader ) mode or Fastboot commands aren't supported at all.

FYI:

simply checks whether your device has been detected and recognized by your computer or not.

 

[defcondoc]

do you run it in PowerShell or CMD?
PowerShell sometimes needs extra in the sytnax or it gets the "command" confused or calls it incorrect...

CMD
I do know what you mean when using powershell, however I haven't used that in a while.

IMO - I think it has to do with phone. I've done enough of these to know its probably the phone, but apparently not enough to know how to fix this one

Thank you!

 

[defcondoc]

Answer is simple: Either device isn't booted into Fastboot ( Bootloader ) mode or Fastboot commands aren't supported at all.

FYI:

simply checks whether your device has been detected and recognized by your computer or not.

OK. Its booted into the Bootloader. It reads the device and serial.
Why would fastboot commands not be supported? Could the developer lock those out?

Thank you!

 

[simplepinoi177]

OK. Its booted into the Bootloader. It reads the device and serial.
Why would fastboot commands not be supported? Could the developer lock those out?

Thank you!

does anything come up if you do fastboot getvar all?

 

[defcondoc]

does anything come up if you do fastboot getvar all?

Yes. all the usual phone info.

 

[defcondoc]

We have another phone here that is much older with OEM Unlocking Checked ON and can't unlock the bootloader either. It is a brand new UMX Tracfone with android 8 on it.

I'm my experience, the OEM Unlock feature is either grayed out or not available at all if the phone wasn't meant to have the bootloader unlocked.

So why have the option to unlock it, if fastboot commands won't let you unlock?

 

[simplepinoi177]

I'm wondering if you're platform-tools isn't up to date or your usb (cord or port) is doing something "funky"....

 

[defcondoc]

I'm wondering if you're platform-tools isn't up to date or your usb (cord or port) is doing something "funky"....

I've checked over the most obvious stuff. I've tried two other computers as well. We don't have these problems with other phones.

Also, on the second older Tracfone. The command

fastboot flashing unlock

is accepted but it just hangs and nothing completes. I have to unplug the device and replug to access the bootloader again from CMD

I think maybe these phones need an unlock key or special file or possibly a different fastboot unlock command? I'm clueless as to why these two phones won't let me unlock the bootloader when the option to unlock is turned on.

 

[defcondoc]

Because these are some off brand chinese phones. Do they typically lock these types of phones down more often, disabling fastboot commands? Does anyone have experience with these types of phones that don't have access to fastboot commands? Are we wasting our time with these? Should I be asking in a different thread? Maybe a developer section?

 

[simplepinoi177]

Yes. all the usual phone info.

I asked because, if fastboot devices was the only thing that worked, then that just states the device is connected; whereas the getvar all proves it can actually at least read the data from the device -- doesn't prove it can write or execute other commands.

Because these are some off brand chinese phones. Do they typically lock these types of phones down more often, disabling fastboot commands? Does anyone have experience with these types of phones that don't have access to fastboot commands? Are we wasting our time with these? Should I be asking in a different thread? Maybe a developer section?

After a small bit of research, it does look like vendor's/manufacturer's can limit or restrict specific/certain fastboot commands...

 

[defcondoc]

I asked because, if fastboot devices was the only thing that worked, then that just states the device is connected; whereas the getvar all proves it can actually at least read the data from the device -- doesn't prove it can write or execute other commands.


After a small bit of research, it does look like vendor's/manufacturer's can limit or restrict specific/certain fastboot commands...

Thanks. Yes, I seemed to have found the same info. However, it seems some are able to bypass in EDL mode. I'm not sure what that involves. It would nice to be able to delete the current rom and flash something else in EDL mode. Do you know if its possible to delete partitions in EDL mode and flash generic partitions from a another phone that has the same processor?

Or maybe we only need to target the boot.IMG. I can get into EDL mode but the software is requiring a firehose MBN file. I have tried generic and ones with the processor but have had no luck so I cannot get access to the partitions.

 

[simplepinoi177]

Thanks. Yes, I seemed to have found the same info. However, it seems some are able to bypass in EDL mode. I'm not sure what that involves. It would nice to be able to delete the current rom and flash something else in EDL mode. Do you know if its possible to delete partitions in EDL mode and flash generic partitions from a another phone that has the same processor?

Or maybe we only need to target the boot.IMG. I can get into EDL mode but the software is requiring a firehose MBN file. I have tried generic and ones with the processor but have had no luck so I cannot get access to the partitions.

Unfortunately, I know absolutely minimal concerning EDL mode. And because I am completely unfamiliar with the device make & model that you are attempting this with, even moreso I wouldn't even know where to begin with modifying partitions or the requirements of "firehose MBN file" and the such...

Hopefully you figure something out! Good luck to you!