Leaf boot loop after deleting a system app

[frankbonatelli]

Good day all.
As title states the leaf is in boot loop after deleting a system app. I was rooted via Magisk patching of the boot.img from decrypted 3.2 update file.
Was able to enter fastboot via CLI and all was great till i removed one to many system applications.

Now I am in perpetual boot loop.

SO my question for those that are in the know is
How the heck one enters fastboot mode or recovery while the device is in continuous boot loop?

I do have the case with page buttons and i have tried a ton of combinations
I've seen a violet led light up
I've seen a pale blue LED lite up
and I am fairly certain the device shuts down after 10 seconds of long press.
Im at a lose for ideas, I am certian itll be a simple combo of steps. Ive dug around this great resource of a site but as yet nothing clear on the actual steps needed for entering recover or fastboot.
Any assistance would be much apreciated.

[Renate]

Did you have ADB enabled before? Is it enabled now?

[frankbonatelli]

Sure did
Is it enabled now? Wont really know till i can enter one of the three ways to interact with the device. Used adb to boot into recovery and into fastboot directly. However I am now not able to reach android "desktop can we say that?" SO i am left with the elusive key press combo to get into the device and effect change

[Renate]

If you deleted (or disabled) an "app" there is no reason that that should interfere with the underlying Linux system. There might be a problem if ADB is a late start from Android.

Have you really checked if you have ADB while the boot animation is playing?
More specifically, does your desktop "bong" when you plug/unplug the USB cable?
Do you remember what you killed? Was it UiSystem or something?

Do you have a copy of the Magisk'ed boot image on your desktop?
Can you pull one from recovery? Can you get to recovery? Fastboot?

Of course this can be fixed, it's just a question of how much effort is required.

[frankbonatelli]

Great questions,
As a seasoned emagineer of android devices I have a fair understanding of how it all goes together. I foolishly deleted the store application which after reboot put the device into boot loop. It will in fact interact with my laptop, ie windows system sees new hardware and assigns the appropriate drivers to the device. If left plugged into laptop it will bong (as you all aptly labeled it)on and off or plugged in device recognized then unplugged again.
Yes I have both the pulled boot image and the patched image which functioned as expected.

If I could find a key combination that allows entrance to either recovery or fastboot for the boox leaf I'm fair certain I will have a functional reader once again.

On a side note I have also tried with Ubuntu 22.04 laptop as well as my Debian desktop.
All with similar results. If i could just figure out the correct long press / plug it in prosses to enter fastboot....
Thanks for the input. All words are apreciated.

[Renate]

Well, what's it presenting as? ADB? MTP? Fastboot? EDL?
Find it in Device Manager or in Linux lsusb -v
We need VID/PID. Better yet, a listing of the USB interfaces.
You could be simply missing a Home application.
If you can get ADB you can install any launcher.

[frankbonatelli]

WOW sorry for such a long Hiatus!
Life got in the way of living around here, All the usual health issues one could expect came at us all at once........
!! Apologies to all!!
So if anyone is still interested in "assisting fools who take one step too far when tinkering....

I am currently trouble shooting from windows laptop (Linux system currently in the dustbin, don't ask...). From all of the web info I can gather up the Leaf is sitting in 05c6 / 900e and if I understand information posted else were this is not EDL mode.
As a recap
I uninstalled a system app and it bootlooped.
I have been able to enter adb but it is not a full adb so can not flash firmware and such
I cannot reach the device with adb commands while in recovery mode eve though enumusb.exe /l /v05c6 returns a result while in recovery mode
05C6:900E 628aced9 2022-09-25 17:11 Qualcomm HS-USB Diagnostics 900E (COM3)
I can from here enter fastboot mode (its labeled bootloader in recovery) and still see same results via enumusb.exe

And that's where things sit for now.
If I could understand how to get to EDL from fastboot i could push forward just a little more.
Any thoughts from the learned minds out there will be greatly apreciated.

[Renate]

I don't know much about 900e, but I should.
I've never gotten it to go from 900e to 9008.
I don't know much about fastbootd (in recovery, vs. normal fastboot).

But I do already have a custom recovery for (original) Leaf (not Leaf2).
I PM-ed you a link.
You should first try if this works:

C:\>fastboot boot frank-rec.img

It should get you a white screen and you should have rooted ADB.
If that doesn't work you can try flashing it, but that opens another can of worms.

Originally Posted by frankbonatelli

though enumusb.exe /l /v05c6 returns a result while in recovery mode

Oh, my enumusb.exe? That shows history, what has ever happened.
You want to use usblog.exe to see what is now present.

[frankbonatelli]

Originally Posted by Renate

I don't know much about 900e, but I should.
But I do already have a custom recovery for (original) Leaf (not Leaf2).
I PM-ed you a link.

SO thankful for this kindness! I will test today and report back.

Originally Posted by Renate

Oh, my enumusb.exe? That shows history, what has ever happened.
You want to use usblog.exe to see what is now present.

All your tinker tools are extremely useful. This makes more sense to me now i am able to see changes live.

Just one other query if I may. With zadig-2.7.exe what driver substitution works best? I've tried them all but not certain if there is a version more suited to the task.

[Renate]

Originally Posted by frankbonatelli

With zadig-2.7.exe what driver substitution works best?

The default is WinUSB. You want that for EDL when using either my EDL client or the Python EDL client.

The game plan is to get recovery working then you can do an update which will fix whatever problem that you had. Your data should all be safe.

[frankbonatelli]

excellent Thanks.
Just sitting down to a little tinkering.

[frankbonatelli]

Well looks like Im now dead in the water!

Was not able to fastboot boot the recovery img file so went to fastboot flash....img then fastboot reboot to recovery and it Reboots to the expected white screen (i assume that this is the custom recovery). Now it is no longer recognized by windows 11 laptop or windows 10 desktops. I have used both computers to interact with my boox leaf ereader before fastboot flashing the custom recovery image so i am certain the cable in use and ports are all good.

unplug from desktop and it still boots and hangs at the onyx logo. Also it is worth noting that usbLoger immediately shows the device if i re-plug the reader into the computer.
i can still manually get the device to boot to the custom recovery (white screen as expected) but windows will not recognize.

Any one out there have further thoughts on this? Not at all concerned about the any personal data just would like to learn the proper path to successfully bootup again.

[Renate]

When you get the white screen recovery does Windows "bong" when you plug/unplug the USB cable?

[frankbonatelli]

Originally Posted by Renate

When you get the white screen recovery does Windows "bong" when you plug/unplug the USB cable?

No it is not announcing hardware discovery. no Bong as you say.

[Renate]

Originally Posted by frankbonatelli

No it is not announcing hardware discovery. no Bong as you say.

Oops, I screwed up.
Load another recovery from that same link that I gave you.
MD5 = 41f826ff80e0cc4ff9936edf33e735ed
You should have ADB now?