How To Guide Samsung Galaxy Tab A8 2021 (SM-X200 + SM-X205) Android 13 Treble flash Guide

[Vinpinto]

Your warranty will be void after any of these procedures.

* I am not responsible for the outcome for using any of this information, e.g. bricked devices, dead devices, boot loops
* do some research regarding flashing, custom ROM and unlocking bootloaders
* you chose to make these modifications under your own responsibility.

The following guide is for flashing any Treble Project compatible ROM (GSI) on the Samsung Galaxy Tab A8 2021 (SM-X200 + SM-X205)​

What's working on android 12 / 12.1 ROMs :

• Everything

What's working on android 13 ROMs :

• Everything

There are two ways of flashing GSI, generic system images, for treble compatible devices:

• ROM flash from fastboot mode.
• Dynamic System Updates (DSU) loading

Prerequisites:​

• First you should check if your device is treble compatible, this has been already checked by me. Here's the app link for checking it if you make sure yourself
• Then you should unlock your bootloader and flash TWRP, here's the link for it
• Enable ADB over USB.
• Wipe the Data Partition from TWRP
• You can root with Magisk if you like.

Option 1 ROM flash from fastboot mode:​

This is my preferred mode

Instructions:

• Turn off the device and Hold Power & Vol Up buttons during restart to enter TWRP recovery
• Format data from TWRP and wipe all partitions
• Navigate to reboot and select Fastboot mode
• Download a GSI image, including LineageOS, Google Android, AOSP, or any other custom GSI Treble compatible ROM for AB partition scheme.
• fastboot flash system system.img
• also a fastboot -w after flashing for additional wiping wouldn't hurt
• IMPORTANT: remember to always only flash *.img files, never flash zip, img.xz, img.tar, gz, or img.tar.zx files, look for the tools for unzipping these file formats and always extract just the system.img file for these procedures. NEVER flash the vbmeta.img this can brick your device
• if by any case it wont boot, just flash the stock recovery back again

Option 2 Dynamic System Updates (DSU) loading:​

Instructions:

Enable the DSU feature flag​

Before using DSU, ensure the corresponding feature flag is enabled. You can enable the flag using one of the following methods:

• On a device with a userdebug Android build: You can enable the feature in Settings > System > Developer options > Feature flags > settings_dynamic_system.
• On other devices: Use the following adb command:
  adb shell setprop persist.sys.fflag.override.settings_dynamic_system true

Launch DSU​

After the feature is enabled, launch DSU using the adb tool.

1. Download a GSI image, including LineageOS, Google Android, or any other custom GSI Treble compatible ROM for AB partition scheme.
   Note: If you build your own GSI from source, or if you download a GSI from another image server, your GSI might not be unsparsed. Use the following command inside your build tree to convert the image to an unsparsed image: simg2img system.img system_raw.img
2. gzip the GSIand then Push the GSI to the device:
   • gzip -c system_raw.img > system_raw.gz
   • adb push system_raw.gz /storage/emulated/0/Download/
3. Launch DSU using adb.
   adb shell am start-activity \
   -n com.android.dynsystem/com.android.dynsystem.VerificationActivity \
   -a android.os.image.action.START_INSTALL \
   -d file:///storage/emulated/0/Download/system_raw.gz \
   --el KEY_SYSTEM_SIZE $(du -b *.img|cut -f1) \
   --el KEY_USERDATA_SIZE 8589934592

The KEY_SYSTEM_SIZE should be for the uncompressed image file, otherwise it will fail
IMPORTANT: remember to always only flash *.img files, never flash zip, img.xz, img.tar, gz, or img.tar.zx files, look for the tools to uncompressed these file formats and always extract always the system.img file for these procedures. NEVER flash the vbmeta.img this can brick your device

Boot into the GSI​

Figure 1. A persistent notification that you can use to control DSU.
After DSU installs the GSI, a DSU menu appears as a persistent notification inside the system notification drawer (see figure 1).

At this point, you can do one of the following:

• Boot into the GSI by tapping Restart.
• Clean up the GSI by tapping Discard.

Switch back to the device's original system image​

After you are done testing your app using the GSI, you can perform a cold reboot to boot the system back into its original system image.

When setting the next reboot to use a GSI, you can have the GSI stay installed through multiple boot cycles (until discarded) by enabling sticky mode, or have it used for only one boot cycle by disabling sticky mode.

The following command enables sticky mode:


adb shell gsi_tool enable

The following commands disable sticky mode:


adb shell gsi_tool disable
adb shell gsi_tool enable -s
adb shell gsi_tool disable

Install GSIs using DSU and the DSU Loader​

Android 11 introduced the DSU Loader, a tool available in the device's developer options that lets you download, install, and manage GSIs entirely through the system's UI.

To install a GSI using the DSU Loader, follow these steps on a device running Android 11 or higher:

1. Enable developer options on your device.
2. Open your device's Settings app, then tap Developer options > DSU Loader.
3. Choose the GSI that you want to install on your device.
   
   
4. Agree to the GSI terms and conditions.
   After you agree to the terms and conditions, the GSI that you selected starts downloading. You can check the status of the download through the DSU notification.
5. After the download has finished, tap Restart to boot the GSI.
   
   
6. When you want to switch back to your device's original system image, tap Restart from the DSU system notification.
   [IMG alt="DSU notification with an option that lets you reboot the device using the
   original system image"]https://developer.android.com/static/images/topic/dsu/restart-original-system-image.png[/IMG]

​

Thanks to Magendanz for the TWRP recovery​

 

[Vinpinto]

 

[isahzbxfviccq]

Does anyone know if selinux and encryption work with this gsi?

 

[WackyHacky1]

only issue is rainbow six mobile and pubg new state detect it as a emulator so how would we fix this?

 

[jeffbar2]

Twrp keeps saying entering fastboot but never does.
I think it was using older versions of adb and usb drivers

 

[lewmur]

Twrp keeps saying entering fastboot but never does.
I think it was using older versions of adb and usb drivers

When it says that, try checking "fastboot devices" from the PC. I think you'll find you are in fastboot mode.

 

[MarcusGuy1108]

Does this trip knox like on s22 etc, or does it go back to normal if you restore back to original and relock bootloader?

 

[lewmur]

Does this trip knox like on s22 etc, or does it go back to normal if you restore back to original and relock bootloader?

AFAIK, the knox bit is a physical "fuse" and once it is tripped, it will never restore back. But normally Sansung will still honor the warranty so long as you go back to a stock ROM and relock the bootloader. That will also re-enable OTA updates.

 

[MarcusGuy1108]

AFAIK, the knox bit is a physical "fuse" and once it is tripped, it will never restore back. But normally Sansung will still honor the warranty so long as you go back to a stock ROM and relock the bootloader. That will also re-enable OTA updates.

I see, just like the phones... damn samsung. Thank you very much for the quick response.

 

[lewmur]

I see, just like the phones... damn samsung. Thank you very much for the quick response.

It isn't just Samsung. Installing a custom ROM or rooting your device will void the warranty with all makers. But at least Samsung will still honor the warranty unless there is some indication that what you did caused the problem. Like bricking the device. But if it is really a hardware problem, they'll still fix it for free during the warranty period.

 

[MarcusGuy1108]

It isn't just Samsung. Installing a custom ROM or rooting your device will void the warranty with all makers. But at least Samsung will still honor the warranty unless there is some indication that what you did caused the problem. Like bricking the device. But if it is really a hardware problem, they'll still fix it for free during the warranty period.

I mean the knox warrantee bit

 

[lewmur]

I know what you meant. Yes, the warranty bit is blown. But as I said, Samsung will honor it anyway unless they feel something you did caused the problem. Of course, you will still have to reflash to a stock rom, relock the bootloader and factory reset before sending in for repair.

 

[MarcusGuy1108]

I know what you meant. Yes, the warranty bit is blown. But as I said, Samsung will honor it anyway unless they feel something you did caused the problem. Of course, you will still have to reflash to a stock rom, relock the bootloader and factory reset before sending in for repair.

Maybe I'll try it then. I like a lot about this tablet but god is it sluggish on OneUi. Games and all that work fine (even smooooth) but animations and stuff on OneUI are just.... wow

 

[lewmur]

Maybe I'll try it then. I like a lot about this tablet but god is it sluggish on OneUi. Games and all that work fine (even smooooth) but animations and stuff on OneUI are just.... wow

There is a fix for that. It has to do with using ADB to change the options for how to size the ramdisk to zero. You might try googling "Samsong One Ui laggy". Lineage doesn't have One Ui so it doesn't have the problem.

 

[kevinco1]

Maybe I'll try it then. I like a lot about this tablet but god is it sluggish on OneUi. Games and all that work fine (even smooooth) but animations and stuff on OneUI are just.... wow

This will fix your issue - https://www.androidpolice.com/samsung-ram-plus-phone-how-to-disable/

 

[MarcusGuy1108]

This will fix your issue - https://www.androidpolice.com/samsung-ram-plus-phone-how-to-disable/

Tried that - made a bit of difference but just gonna return the tablet.

 

[abagm]

if you still own it: maybe you're in the mood to take a look here:https://xdaforums.com/t/samsung-galaxy-one-ui-optimization-guide.4376755/

 

[kevinco1]

The SM-X200 is a budget device so if you've had a higher end Sam tab then yeah this will seem very slow

 

[ke4peo]

Hey all. I just recently bought a Tab A8 32GB and was looking for a way to load a ROM on it so I can use the SD Card as internal storage.

I found this guide, but I'm not seeing some of the steps it says to take on my device. I've enabled Developer Options, but I don't see the DSU/GSI stuff. Nor the 'feature flag' to turn that on.

I know back in the old days all you have to do way flash a recovery image and then you could load the ROM from recovery. Is that still the basic process? Can I flash TWRP and then flash the ROM, or is more detailed now than that?

 

[Vinpinto]

Hey all. I just recently bought a Tab A8 32GB and was looking for a way to load a ROM on it so I can use the SD Card as internal storage.

I found this guide, but I'm not seeing some of the steps it says to take on my device. I've enabled Developer Options, but I don't see the DSU/GSI stuff. Nor the 'feature flag' to turn that on.

I know back in the old days all you have to do way flash a recovery image and then you could load the ROM from recovery. Is that still the basic process? Can I flash TWRP and then flash the ROM, or is more detailed now than that?

The full process for flashing is in the first post, in case you don't have the DSU option