yashsingh1/xdaforums huggingface dataset:
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
Just got a new A20 on a deal - after I get it rooted I'll see what I can do about getting TWRP on it like I did for the Unihertz Atom here:

https://xdaforums.com/android/development/twrp-modded-to-unihertz-atom-t3885793

Hopefully the same operation will let me create a usable TWRP for it.
[Samsung Galaxy A20 Guides, News, & Discussion] TheSnizz:
Welcome aboard dude :good:
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
Welcome
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
Thanks. I've got the A205G/DS version which I believe is the International version so I've got the OEM unlock turned on the the developer options. In the directions on page 1 here you have:

14. Hold power and vol+ to enter recovery mode.

15. select bootloader

17. Press power key to unlock bootloader.

In recovery mode I only see reboot to bootloader which just puts me in download mode. ???

Can't seem to find a country version for the U.S. - but as someone else mentioned in this thread I've got TPA/TPA in the 'Service provider software ver.' so I'm downloading a Panama version. If that is a problem for local use can you just change the CSC code? Also noticed Chainfire has a A20 boot and recovery available at https://desktop.firmware.mobi/ although it's for a PPR1.180610.011.A205GUBS1ASE1 so not sure if that's going to be useful for much.

Been out of modding a while but I'll be getting on this one. Sure wish I could pull the bootloader off this phone somehow without needing to download a ROM that seems close but may not be exact. I've been considering getting an Octopus box for Samsung. Got at least 6 hours to go on the stock rom download since it seems most places need $$ and membership now to get any reasonable speed in a download. Not even sure I've got the right one - seems it is the previous version date wise but I'm guessing with the patched Odin I can flash it.
[Samsung Galaxy A20 Guides, News, & Discussion] TheSnizz:
Should just download it from samfirm.

I got my TPA version downloaded in 10 minutes

https://xdaforums.com/galaxy-tab-s/general/tool-samfirm-samsung-firmware-t2988647
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
Thanks, Yes that is awesome - going way faster and also now am getting the correct version. :good:
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
Question about flashing the Magisk modded boot image onto the phone. Should the modded boot.img be incorporated back into the large (roughly 3GB) AP file to be flashed along with the BL, CSC , CP and so on files (in their related Odin slots) or do you flash only that boot image with Odin into the AP slot and of course the BL CSC CP and so on in their appropriate slots? I understand that if you flash only the boot image you may find your partition size will shrink in size.
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
I only flashed the boot image
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
Odin : FAIL! Now at a screen says at top custom binary (boot) blocked by OEM something - can't read it as camera is in way . Says error has occurred while updating the device software. Use emergency recovery function in the Smart Switch PC software. Can't turn phone off or get it to do anything.

---------- Post added at 03:36 PM ---------- Previous post was at 03:31 PM ----------

I still am not sure if the bootloader was unlocked - I asked earlier about it but OEM unlock is on but did not understand your directions as below:

13. Turn phone off

14. Hold power and vol+ to enter recovery mode.

15. select bootloader

17. Press power key to unlock bootloader.

doesn't compute ;)

---------- Post added at 03:44 PM ---------- Previous post was at 03:36 PM ----------

Darn! Smart switch is asking for an emergency recovery code. also not seeing my device in the list. I'm just staring at a bright turquoise screen and since I can't pull the battery (at least not easily ) this totally SUCKS!

---------- Post added at 03:45 PM ---------- Previous post was at 03:44 PM ----------

It's also saying Unsupported device - WTF?

---------- Post added at 03:52 PM ---------- Previous post was at 03:45 PM ----------

OK sheer PANIC has subsided as I managed to reflash it to stock with Odin. Back to square one. I think I need to understand the question above about the bootloader being unlocked. Can you please elaborate on that physwizz.

---------- Post added at 03:55 PM ---------- Previous post was at 03:52 PM ----------

Interesting that after that mess I've got all the apps back (just a couple I put on it before flashing). I did use Smart switch to backup things to the SD card.
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
Even the OEM in developer is still showing unlocked.
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
From the official Magisk directions regarding unlocking bootloader:

Allow bootloader unlocking in Developer options → OEM unlocking

Power off your device. Press Bixby + Volume Down and plug in your device to a PC to boot into download mode

Long press volume up to unlock the bootloader. This will wipe your data and automatically reboot.

I of course don't have the Bixby button on this phone but I would assume going into download mode the normal way on this phone works. However long pressing volume up seems to do nothing - doesn't wipe data and doesn't reboot.

---------- Post added at 04:29 PM ---------- Previous post was at 04:03 PM ----------

Is my problem related to this - From a Galaxy S9 message thread: "The reason why your "OEM unlock" switch was already toggled was because, even after the data wipe, it doesn't reset. Your device stays OEM unlocked, but isn't RMM unlocked until the 7 day timer has passed -- so your bootloader stays locked until the RMM timer passes."

---------- Post added at 05:29 PM ---------- Previous post was at 04:29 PM ----------

Tried another approach - following Magisk directions to patch the entrie AP file - which it did successfully. Then tried to flash that and the BL, CSC and CP files. Odin got stuck and about 98% on the Recovery file. OEM something blocking it again. Vaultkeeper? Not sure where to go from here.
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
Now it seems VBMETA.img is being blocked by OEM when flashing with Odin. Beginning to think this is a lost cause. Can't see working on TWRP until I get rooted. Can't figure out what I'm missing here - been out of XDA for a while but I have looked through a ton of message threads on Magisk and don't seem to be finding a solution. Tried different versions of it including latest beta but still no cigar.
[Samsung Galaxy A20 Guides, News, & Discussion] shumway66:
Rooting A20

Guide To Root Samsung Galaxy A20 Without PC

First Of All Download >> Magisk Manager

Now Paste Magisk Manager Zip File In Your >> Internal Storage

Rename The File >> Update.Zip

Now Turn Of Your Smartphone

Now Boot Your Samsung Galaxy A20 In >> TWRP Recovery Mode

Guide To Boot Samsung Galaxy A20 In Recovery Mode You Have To Press Volume Up + Power Botton Together Turn On >> TWRP Recovery Mode

Now You Will See Many Option

Then Tap On >> Install

Root Process

Then Find >> Update.Zip You Will Paste In Internal Storage Earlier

Root Process

Then >> Flash Update.Zip

Root Process

Now Flashing Your Samsung Galaxy A20

After That Choose >> Wipe Cashe

Root Process

Then >> Swipe To Wipe

Now Reboot >> Your Samsung Galaxy A20, Your Smartphone Successfully Rooted

in this thread also posted twrp in twrp section

hope it helps
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
That would be great if anyone had made a version of TWRP for the A20 but it seems no one has done so yet. I was planning on trying to create a TWRP for this phone once I got it rooted but haven't been able to achieve root yet. I created a working TWRP for the Unihertz Atom through a lot of work so I was hoping to use the same methods for this phone but not going to happen unless I can get root. If you know of a TWRP for this phone please do let us know.
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
Since I haven't used Magisk for a while before trying on this phone I'd like to ask if this is normal. I don't seem to be able to install the Magisk Zip file from Magisk manager - all it does is download it. Looks like this:
[Samsung Galaxy A20 Guides, News, & Discussion] shumway66:
https://xdaforums.com/showpost.php?p=80098545&postcount=20 this help at all
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
As I said there is NO TWRP image available for this phone. And currently something on my phone is preventing installing anything with Odin other than the completely stock ROM files. I've installed TWRP on over 40 phones so I don't really need help with how to do that. Just this phone is being a PITA.
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
Did you patch the boot.img with magisk?
[Samsung Galaxy A20 Guides, News, & Discussion] shumway66:
i forget to put that in my directions sorry was in a rush when posted it:D
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
Yes I patched it and followed the exact directions for Magisk. I've used Magisk before on other phones with success. My A20 has the June 1st update on it. I think there is a newer July and possibly August update too but is it possible the June 1 update has some new anti-rooting junk in it?
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
do you get the warning screens when you reboot? if not then the bootloader is still locked.

12. Backup data. It will be wiped.

13. Turn phone offoffshore

14. Hold power and vol+ to enter recovery mode.

15. select bootloader

17. Press power key to unlock bootloader.

18. Reboot and reactivate developer options. Don't enter too much data at this stage as you will lose it again later.

at step 15, use the volume keys to select and power to choose. There should be a message on the screen about unlocking the bootloader at step 17.

Mine was also June upgrade
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
No option I can see to unlock bootloader. Only reference to bootloader says 'reboot to bootloader' which puts you into download mode. picture of my recovery screen:

The second I use the power button when highlighting 'reboot to bootloader' it goes blank and in a couple seconds comes up to an aqua color screen that says 'Downloading'. From there I can flash stock boot or the whole firmware package okay but any Magisk modded boot produces a "FAIL".
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
I think I mentioned I also let Magisk modify the entire AP file and have then flashed that along with all the other files (BL, CSC and CP) which also fails. I thought today it might be failing because I didn't have a SIM in the phone but tried with a SIM in it and it still fails. New SIM but not active.
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
This will not work because there is currently no twrp available for the A20.
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
You unlock bootloader from the aqua screen
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
A couple other notes. I've only had the phone two days. Bought it from a guy who said he never used it and it appeared new in box with everything and I had to go through usual first time setup. Date was way off - at least a couple months ago if I recall. First time I looked at and turned on 'developer options' I did not see any option to OEM unlock bootloader. Later I changed the date to the correct date and time. Then I believe is when I noticed the option to OEM unlock the bootloader in developer options so I turned the slider on. Now if this phone has that 7 day RMM thing on it would it be possible the 'unlock bootloader' won't show up in the Recovery for another 5 days or so?

---------- Post added at 04:11 PM ---------- Previous post was at 03:57 PM ----------

Tried setting date 10 days forward. Still fails. Tiny red print at top of download screen says something regarding boot image flash fails due to OEM lock? the word lock is partly blocked by the front camera but I believe that is what it says. So apparently something still needs to be done to unlock the bootloader even though it shows it is allowed in the developer options.

---------- Post added at 04:14 PM ---------- Previous post was at 04:11 PM ----------

I have tried pushing the power key on the download screen even though there is nothing there about unlocking. It seems to do nothing. I'll try again but I'm sure I've done that several tries. Thanks for your suggestions.

---------- Post added at 04:19 PM ---------- Previous post was at 04:14 PM ----------

Held down power key on download screen about 10 seconds. Tried Odin flash again. Fail.. says again at top Odin flash (boot) blocked by OEM lock
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
Picture of Download screen before flash (no text at top about fail)

Second picture shows the failure text.
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
Press power button on aqua screen
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
Thanks for hanging in there with me on this but as I said I've done that. I tried pressing it for about 2 seconds. On another try I tried holding it about 10 seconds. Still each attempt to flash fails. Tried turning off OEM unlock. reboot. flash fails. Turn OEM back on. reboot to recovery > then Download. Flash fails. I think I've tried about a hundred variations by now but always the flash fails. Have tried multiple redo's of Magisk patch of boot, patch of entire AP file etc. There must be some detail I'm missing or I've got a weird phone. As a last resort I may try a totally different A20 stock ROM from another region. Pain to download though...
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
You can't do anything with Odin until the bootloader is unlocked. Did you have to do a first time setup again with entering data etc.

Do you get the warning screens?

What is your model number?
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
A205G/DS (dual sim) - had TPA (Panama) so I downloaded the ROM when I got in trouble a while back (see Panic message earlier in this thread) and flashed that with Odin. No problems flashing stock ROM with Odin. Just now did a complete factory reset and wipe and had to start over. Unfortunately now I see NO OEM unlock in the developer options again. Set date 10 days forward, rebooted and still no OEM unlock option. Going backwards here .... At least Smart Switch makes it easy to get settings / apps back in place.

All model info shown in screenshot:
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
The 205U won't unlock either.
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
Set date to August 2nd. Did a Factory wipe / reset again. Went through setup again. turned on automatic time and then turned on Wifi. Now as the date is August 20th I have the OEM unlock option again in Developer settings and it is on. So it would appear it has that RMM thing such that it needs to have a week or so before OEM unlock shows up in developer settings. Haven't tried any more Odin flashes yet but will see soon about that.
[Samsung Galaxy A20 Guides, News, & Discussion] TheSnizz:
Have you tried setting the clock ahead to see if the oem unlock option becomes available?
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
SOS - same old flash fails.

---------- Post added at 09:05 PM ---------- Previous post was at 09:04 PM ----------

See my previous post - basically what I did and now OEM unlock appears and I have it on. But nothing appears in the Recovery or Download for unlocking. Seems weird that OEM unlock is on and says bootloader can be unlocked in developer but flashing any non stock stuff fails with Odin.
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
I think I found the problem.

1 turn off phone

2 hold both volume Keys at once

3 plug in power cable attached to pc to enter unlock screen

4 use vol+ to select yes

5 press power key

Sorry ???
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
YES! That is how to unlock the bootoader. Actually maybe should go like this:

14. HOLD both volume up and down keys and plug in cable to PC - (not this: Hold power and vol+ to enter recovery mode.)

14a. Then hold long press Volume UP

14b Press Volume UP on next screen

Not done yet but I think I'm on my way to root. :good:
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
Yes. Have already made the changes.

I had that originally but changed it because I thought I made a mistake when I couldn't get back in to the unlock screen after because it is no longer accessible.

Happy rooting.
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
ROOTED! Yeah! and again thanks for sticking with me on this. Like I mentioned I've been out of this for a while and I'm not sure if this phone is unique in the button presses to get to that unlock screen or if I have just forgotten. Last Samsung I rooted was the Note 4 so it's been a while since I've done much with Samsungs. Tried rooting the VZ version of Note 5 but no one was ever able to get it rooted once it had the newer OS on it. I'll see what I can do with TWRP for this phone. Looks like the Galaxy A8 has the same chipset so probably will start looking at that TWRP. Cheers!

:good::good::good:
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
We could use you here.

https://xdaforums.com/android/help/twrp-samsung-galaxy-a20-custom-recovery-t3955271
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
One other note you may want to add for those who can't see the OEM unlock in developer options. Booting the phone after a factory reset I would advise to turn off Wifi in the initial setup and turn off autoupdate Time in the date and time section of the General Management. Then set the date back 3 or 4 weeks. Then turn on developer options. You won't see OEM unlock anywhere if your phone is like mine. Then reboot, turn on Wifi and autoupdate time. After that is done you should be able to see the OEM unlock in developer options.

---------- Post added at 01:48 PM ---------- Previous post was at 01:47 PM ----------

I'm starting to look into TWRP for this phone and will post any info in the other thread here: https://xdaforums.com/android/help/twrp-samsung-galaxy-a20-custom-recovery-t3955271
[Samsung Galaxy A20 Guides, News, & Discussion] blu3i:
This worked perfectly for me on an a20e SM-A202F
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
congratulations
[Samsung Galaxy A20 Guides, News, & Discussion] TBM 13:
Nice thread!

It's something new to me that OEM unlock isn't enough and you also have to unlock the bootloader (yeah, i come from an old device, the J2 Prime).
[Samsung Galaxy A20 Guides, News, & Discussion] franco44313:
When i trie to patch the boot image say this in the log file. please help :( i have the galaxy a205g

- Device platform: arm64-v8a

- Existing zip found

- Copying image to cache

1022+1 records in

1022+1 records out

1047368 bytes (1022.8KB) copied, 0.008158 seconds, 122.4MB/s

- Unpacking boot image

Parsing boot image: [/data/user_de/0/com.Ad.iqri.j7l.e.zG/install/boot.img]

PXA_BOOT_HDR

HEADER_VER [0]

KERNEL_SZ [29705896]

RAMDISK_SZ [301990144]

SECOND_SZ [1110030]

EXTRA_SZ [16777224]

RECOV_DTBO_SZ [0]

DTB [0]

PAGESIZE [112756306]

NAME [19A003#]

CMDLINE [linux=permissive �]

CHECKSUM [949f3a03d588d6]

Segmentation fault

- Checking ramdisk status

- Stook boot image detected

- Patching ramdisk

Add entry [init] (0750)

Patch with flag KEEPVERITY=[false]

KEEPFORCEENCRYPT=[false]

Create directory [.backup] (0000)

Add entry [.backup/.magisk] (0000)

Dump cpio: [ramdisk.cpio]

- Repacking boot image

Parsing boot image: [/data/user_de/0/com.Ad.iqri.j7l.e.zG/install/boot.img]

PXA_BOOT_HDR

HEADER_VER [0]

KERNEL_SZ [29705896]

RAMDISK_SZ [301990144]

SECOND_SZ [1110030]

EXTRA_SZ [16777224]

RECOV_DTBO_SZ [0]

DTB [0]

PAGESIZE [112756306]

NAME [19A003#]

CMDLINE [linux=permissive �]

CHECKSUM [949f3a03d588d6]

Segmentation fault

! Unable to repack boot image!

! Installation failed
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
Try extracting the boot.img again

If that doesn't work try downloading the rom again. Make sure it's the correct one
[Samsung Galaxy A20 Guides, News, & Discussion] franco44313:
The same error :(
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
Strange ?
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
Send it to me and I'll try.
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
You will need to 7z it first and then tar it if you want to post it so I can try to patch it.
[Samsung Galaxy A20 Guides, News, & Discussion] tuxutku:
On linux you don't have to boot into windows virtual box or use windows.

9. Don't compress `boot.img`

10. install heimdall flash with `sudo apt install heimdall-flash`, if you want front-end install it with `sudo apt install heimdall-flash-frontend`

To flash:

1. Detect device with `heimdall detect`

2. Flash the `boot.img` with `heimdall flash --BOOT {location of the boot.img, you can also just drop the file into terminal and terminal should auto-fill it}` ex: `heimdall flash --BOOT '/home/utku/Programlar/ext/boot.img'`

P.S: an easy way to boot into download mode is `adb reboot bootloader`
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
Thanks for the Linux alternative. I'll add these lines to the instructions.
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
Try this.

Unzip it first

Extract the ing file and then continue
[Samsung Galaxy A20 Guides, News, & Discussion] shezzy83:
Does this root guide work for the Boost Mobile version of the Galaxy A20?
[Samsung Galaxy A20 Guides, News, & Discussion] droidzer1:
If you want to fix those boot warnings as mentioned above I've done the work of fixing up the param.tar file so all you have to do is flash this file with Odin to the 'BL' section in Odin, it will reboot to recovery, then reboot from there to system and you're done. Enjoy! param.tar attached:
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
Thanks for that.

I'll add this to the instructions.
[Samsung Galaxy A20 Guides, News, & Discussion] rezarac:
Managed to follow these instructions but had some edits to make:

Should be:

4. Rename AP_205xxxxxxxx.md5 to AP_205xxxxxxx.tar and extract using zarchiver

...

15. Follow the instructions to unlock (hold volume up and confirm)

...

18. Reboot and reactivate developer options. Enable USB debugging. Don't enter too much data at this stage as you will lose it again later.

...

19. Turn phone on in bootloader (download) mode (Hold power and vol+ to enter recovery mode then select bootloader mode)​

Anyway I got an error on screen when trying to flash the patched boot.img: "Only official released binaries are allowed to be flashed".

I fixed this by following these steps:

re-lock bootloader

install system update via settings (June security update) since this corresponded to the boot.img which I'd downloaded&patched

unlock bootloader

use heimdall (instead of Odin) to flash
[Samsung Galaxy A20 Guides, News, & Discussion] physwizz:
thanks. i will make the changes
[Samsung Galaxy A20 Guides, News, & Discussion] LeonardoGC:
Thanks physwizz for providing this procedure to root the phone.

I succesfully rooted my Galaxy A20.

Regards
[Samsung Galaxy A20 Guides, News, & Discussion] magnafunk:
How can I revert the param.tar changes? I did a full factory image restore with odin and still get the modified boot screens
[Samsung Galaxy A20 Guides, News, & Discussion] LeonardoGC:
Try this thread:

https://xdaforums.com/galaxy-a30/how-to/hide-bootloader-warning-unlocked-t3954589
[Samsung Galaxy A20 Guides, News, & Discussion] mrao:
Does this lose root upon normal reboot like the s10? Do you have to use Bitton combo during reboot to boot into rooted system..the s10 root method had that issue if I remember correctly