Samsung Galaxy Tab A7 10.4 2020 (Wi-Fi) flashing help needed

[make-nz]

@globetrotterdk

recovery-e looks like it is Windows software, so I am assuming that using TWRP is the way to go… It looks like TWRP is an Android install

TWRP recovery is the Swiss Army Knife for all custum ROMs.
The /e recovery is tailored towards /e so it has the greater compatibility with /e OTA updates, or maybe even some customisation /e depends on.

(Personally, I always start with a TWRP and the ROM on a SD card, if the device has a SD)

[piero]

@globetrotterdk

should run the following command:

$ heimdall flash --RECOVERY recovery.img --no-reboot

don’t forget VBmeta

$ heimdall flash --VBMETA vbmeta.img --RECOVERY recovery.img --no-reboot

.
.
.

@make-nz

Personally, I always start with a TWRP and the ROM on a SD card

it is also my prefered way

[globetrotterdk]

Thanks for that. Where is this TWRP that needs to be installed on the Galaxy Tab A7, and do I use heimdall to get this on the A7? As far as I can see there is a different TWRP for each device, and there doesn’t appear to be an official version of TWRP Recovery for the Samsung Galaxy Tab A7 10.4 WiFi SM-T500…

[piero]

So take the “recovery-e” that is recommanded…

[globetrotterdk]

Yes, I have thought of that, but I have not been able to find a link for that either.

[piero]

2) Download a custom recovery manager .img

On your PC,

@piero

see details for “recovery-e”

for officially supported devices only, you will find the recovery-e aside to the official build at https://doc.e.foundation/devices
for some recent unofficial devices, you will find some .IMG into the recovery compatible and sideloadable unofficial build install .ZIP , extract it from the .ZIP

you will find vbmeta.img and recovery.img into the .ZIP

[globetrotterdk]

I am unable to get to that point. I have run into problems with “Enable Developer Options by pressing the Build Number option in the Settings app within the About menu. From within the Developer options menu, enable OEM unlock” instruction. No problems with enabling USB debugging. However, the OEM unlock option only appears from time to time. Not sure why.

[aibd]

Have you got the tablet online ? Some suggestions and links to mysterious locking in this recent thread

Easy-installer error (Samsung Galaxy S9+ with Android 10)

The Download mode screen shows OEM LOCK: ON While this remains you cannot install any Custom ROM. Maybe after a Factory reset you did not re-enable USB debugging ? The Easy Installer log looks OK; things progress OK, until wait-download.sh cannot complete. (As said already bootloader / Download mode is locked.) There are a few words on the subject here Know your hardware – Samsung # OEM unlock. This is a generic page for USB debugging https://doc.e.foundation/pages/enable-usb-debugging. A…

[globetrotterdk]

Thanks. Yes, I can confirm that it is necessary to have an Internet connection before the OEM unlock setting is active.

[globetrotterdk]

OK, I shutdown the tablet and then booted as instructed. Working from the correct directory, I got the following message:

$ heimdall flash --VBMETA vbmeta.img --RECOVERY recovery.img --no-reboot
Heimdall v1.4.2

Copyright (c) 2010-2017 Benjamin Dobell, Glass Echidna
http://www.glassechidna.com.au/

This software is provided free of charge. Copying and redistribution is
encouraged.

If you appreciate this software and you would like to support future
development please consider donating:
http://www.glassechidna.com.au/donate/

Initialising connection...
Detecting device...
Claiming interface...
Setting up interface...

Initialising protocol...
ERROR: Failed to send handshake!ERROR: Protocol initialisation failed!

$ heimdall print-pit
Heimdall v1.4.2

Copyright (c) 2010-2017 Benjamin Dobell, Glass Echidna
http://www.glassechidna.com.au/

This software is provided free of charge. Copying and redistribution is
encouraged.

If you appreciate this software and you would like to support future
development please consider donating:
http://www.glassechidna.com.au/donate/

Initialising connection...
Detecting device...
Claiming interface...
Setting up interface...

Initialising protocol...
ERROR: Failed to send handshake!ERROR: Protocol initialisation failed!

Releasing device interface...

I got a similar screen as the picture in the post that was linked to. OEM lock was listed as on, despite while in settings OEM unlock was on.

Wondering how to solve this…

[aibd]

Any other clues on your Download mode screen ? Do you see Prenormal ? What is the history of the tablet, have you been using it “normally” for a while before attempting /e/OS install ?

[globetrotterdk]

The tablet was expressly purchased for this purpose. It arrived from an eBay seller two days ago and was listed as “new - other”. There was no box, power supply, etc. however it does appear to be new.

Nothing with Prenormal. The current binary is listed as “Samsung Official”.

[aibd]

@globetrotterdk

OEM lock was listed as on, despite while in settings OEM unlock was on.

Different generations of Samsung may behave slightly differently … but it is a regular thing that a Samsung may not fully unlock until Remote Monitoring decides the device is in normal use. In recent generation devices it is recorded that Prenormal is not displayed but is active.

Another move is to check for updates in the Samsung UI, this will trigger a connection to RMM… many other things that might happen listed in Know your hardware - Samsung Troubleshooting section. The possible need for Samsung account on the device to satisfy RMM is also mentioned; but such account must be removed after unlock is indicated and before flashing a custom ROM.

[piero]

i read Heimdall is not working on some recent devices.
try Odin3 windows or Odin4 Linux… to flash the custom-recovery on the tablet…

[globetrotterdk]

OK, so what I have been able to find out is that while Odin4 and Samloader (both are apparently needed) are official Samsung tools, neither has been released by Samsung. Rather, there are just copies floating around on the Internet.

As I am looking for a system that not only is de-Googled, but also provides added security when I am on the Internet, using these tools are a step too far. Which is unfortunate, as I am no closer to a tablet that is de-Googled, as well as takes reasonable security measures to address current and future threats on the Internet. That doesn’t mean that /e/ OS doesn’t provide that, it means that I am not going to do things that could potentially compromise those key goals to find out if /e/ OS provides those things…

[make-nz]

@globetrotterdk

just copies floating around on the Internet.

It can seem that way and some sites and links are doggy. That said I use the very same ODIN3 since ~2016 — on a Win notebook, just for AOSP, ROMs… related stuff.
You can look at ODIN a bit like Thunar, Dolphin… but build for Android file operations.
It may not be everbodies cup of tea to use Win, but I have flashed first on a Android 1.6 on Sony-Ericson and later on, I started with ODIN on Samsung Galaxy S2 — and would not do any Samsung flashing without ODIN (as of today ~240 phones) as it has not filed me ever.
I do server admin work, bash scripts, php… but ODIN just has that place in my workflow.

[globetrotterdk]

No problem with the software itself. At the very least however, I would expect the /e/os community to link to reputable download sites for the software. Leaving people interested in /e/os to the vagaries of any random, dodgy site does not promote the image of a company concerned about security.

[aibd]

@globetrotterdk

OEM lock was listed as on, despite while in settings OEM unlock was on.
Wondering how to solve this…

There are very specific Preinstall instructions involving download and tar of vbmeta.img to deal with this. Copy of link in your OP.

• https://wiki.lineageos.org/devices/gta4lwifi/install/#pre-install-instructions

[make-nz]

@aibd

There are very specific Preinstall instructions

@aibd did you read them? To me they are not making much sense, as they mix Win/Linux, doing VBMETA twice, but no recovery…

I do not have the device, to test for myself, but I don't think this is right:

• Check the box labeled next to the button labeled “AP”, and then click the “AP” button.
• In the menu that pops up, select the newly created custom VBMeta .tar file.
• Power off the device, and again boot it into download mode:
• With USB plugged in, hold Volume up + Volume Down + Power.
• Check in the top left of the Odin window that you see a valid device, it will show up as something like COM0.

check

Tip: The COM port, or the number succeeding COM, may be any valid number.

• Click “Start”. A transfer bar will appear on the device showing the VBMeta image being flashed.

I normaly do this in Odin:

|AP| recovery.tar.md5|
|USERDATA| vbmeta.tar.md5|

[piero]

The first times i saw instructions for vbmeta (about s10 series) using odin it was in BL