How to manually install or update your OS on your BraX3

[plamen]

This guide will walk you through the process of **manually installing or updating the OS on your BraX3 device. While this is considered an advanced modification, we’re sharing a simple how-to guide which can be used by a wider audience to achieve their goal.

DISCLAIMER: Manually flashing or updating the OS may brick your device, rendering it unusable. By proceeding, you accept full responsibility for any risks involved, including potential data loss or hardware malfunction.

There are 2 ways to manually install and update your OS on the BraX3:

• Via fastboot
• Via spflash tool

Regardless of which way you choose, you need to ensure the following:

• Your BraX3 is charged to at least 35%
• (Windows only) You have installed the latest MediaTek USB driver (Windows driver)
• You have a USB cable that can establish a reliable connection to the device
• You downloaded the latest OS package installer, depending on the OS you want to install

Install via fastboot

Before you start, you need to ensure the following:

• Your BraX3 has an unlocked bootloader (see how to unlock your BraX3 bootloader)
• Android Platform Tools downloaded and extracted to your Desktop folder.

So let’s dive into the steps:

1. Download the latest OS installation package
2. Unarchive the installation package file
3. Copy all the Disc Image Files and .bin file from the installation package folder (see step 2) and paste them in the platform-tools folder (where your Android Platform Tools have been saved).
4. Copy the flash.sh file and paste it in the platform-tools folder (where your Android Platform Tools have been saved).

For Windows users: Edit the flash.sh file and remove #!/bin/bash comment, as well as any other comments in the file (comments start with “#”). Save the file after you’re done. At the end, rename the file to flash.bat so it changes its type to Windows Batch File.

Tip: In case you’re updating your OS and don’t want to wipe your user data, remove the command fastboot format userdata from your flash.bat or flash.sh file. That way your user data, including your installed apps, files, images, etc. will be preserved.

5. Connect your BraX3 to your PC by using a reliable USB data cable.
6. Pres Allow when you’re prompted to Allow USB debugging.
7. Open the Command Prompt (press Win + R, type cmd, and hit Enter) for Windows or Open your Terminal for Linux.
8. Navigate to the Platform Tools folder using the following commands:

For Windows:

---

cd C:\Users\[Your Username]\Desktop\platform-tools-latest-windows\platform-tools

Tip: You can get the path to your folder by clicking on the navigation bar in your file explorer.

For Linux:

---

cd ~\Desktop\platform-tools_r34.0.4-windows\platform-tools

9. Type adb devices and press enter.

If successful, you should see an identifier of your connected device, with the word “device” os its right.

10. Type adb reboot bootloader and press enter. The phone will now reboot into fastboot mode (when you’re in fastboot, you will see the “Brax” logo and a text “FASTBOOT MODE” at the bottom left of your screen.
11. On your PC, open your platform-tools folder and double click the flash.bat file (for windows) or flash.sh file (for linux)
12. The installation of the OS will now commence. You will see the installation progress on your terminal. Once completed, unplug your device from the USB and hold the power button.

Congratulations – Your OS is now installed/updated!

Common Issues When Installing the OS via Fastboot (and How to Fix Them)

If you’re running into problems while installing the OS on your BraX3, you’re not alone. Here are the most common issues users encounter — and how to solve them quickly.

1. Device Not Detected by ADB or Fastboot

Problem:
Running adb devices or fastboot devices returns nothing, or just says “unauthorized”.

Fix:

• Make sure USB debugging is enabled on your BraX3.
• Tap Allow when prompted with “Allow USB debugging”.
• Reconnect the USB cable and try a different port (preferably USB 2.0).
• Use a data-capable cable, not just a charging cable.
• Try restarting both your phone and PC.
• Reinstall or update the MediaTek USB drivers.

2. “Command not found” or Unrecognized Command in Command Prompt

Problem:
Commands like adb or fastboot aren’t recognized in Command Prompt.

Fix:

• Make sure you’re in the correct folder: the one that contains adb.exe and fastboot.exe.
• Use the cd command exactly as shown in the guide, and verify the path.
• Alternatively, drag the platform-tools folder into your Command Prompt window to autofill the path.
• Use .\adb or .\fastboot if Windows doesn’t recognize the command alone.

3. Nothing Happens When Running flash.bat (Windows only)

Problem:
You double-click the flash.bat file but the installer doesn’t run or closes immediately.

Fix:

• Double-check that you followed step 4 correctly:
  • Removed the #!/bin/bash line and other comments starting with #.
  • Saved the file as flash.bat, not flash.sh or flash.bat.txt.
• Right-click the file and select “Run as Administrator”.
• Ensure all the Disc Image Files were correctly copied into the platform-tools folder.

4. Installation Fails or Freezes Midway

Problem:
The flashing process starts but fails midway, or appears to freeze with no progress.

Fix:

• Confirm that all required files were copied into the platform-tools folder (not just flash.bat).
• Try using a different USB cable and/or port.
• Do not use USB hubs or adapters; plug directly into your computer.
• Restart the process and make sure the device is in Fastboot mode (you should see “FASTBOOT MODE” at the bottom left).

5. Device Boots to Old OS After Flashing

Problem:
After the flash completes, the device boots into the old operating system or doesn’t reflect changes.

Fix:

• Make sure the flashing process actually completed without errors.
• Try manually rebooting into recovery and wiping cache/factory resetting.
• If in doubt, re-run the process from the beginning and double-check that you are using the latest OS package.

6. Stuck in Fastboot Mode After Flashing

Problem:
Your BraX3 doesn’t boot into the system and stays on the Fastboot screen.

Fix:

• After the flashing completes, disconnect USB and hold the power button for 10–15 seconds until it reboots.

Install via spflash

Installing via spflash holds some advantages over installing via fastboot, mainly the possibility to not erase userdata, possible since the bootloader can be locked when using spflash.

Before you start, you need to ensure the following:

• You’ve installed the spflash tool (by MediaTek). Link here.

How to install the OS on Windows

1. Open the SPFlashToolV6 application located in the folder where your spflash is downloaded
2. Add the Download-XML file, by pressing on the choose button (next to Download-XML), and selecting the flash.xml typically located in the download_agent folder in the OS installation package you’ve downloaded.
   
   

3. Next step provides several options, which will determine whether your user data will get deleted or not.
   Option 1: Select Download only and deselect user data. By choosing this option, you will keep the userdata already stored on the device. Please note that some OS versions do not allow the Download only option, as they require a firmware update, which will lead to erasing user data. If a firmware upgrade is required, select Firmware upgrade from the dropdown and press Download. Once ready, you can then select Download from the dropdown and continue with the next steps.
   
   

Option 2: Select Format All + Download. By choosing this option, you will reformat the device while installing the latest version. Note that deselecting userdata will not be an option when Format All + Download is selected. Note that if you select Format All + Download, you will also wipe the device’s IMEI and serial number. Make sure you take a note of those before you start the installation process, as you may need to insert them later on in order to receive mobile connectivity from your telco operator.

4. Press download.

5. Turn your BraX3 device off.

6. Plug in your BraX3 device via USB cable. Once plugged, the process of flashing the OS will start. The process usually takes 2-3 minutes. When completed, you will see an indication that the process has finished successfully.
   

   

Congratulations – Your OS is now installed/updated!

You can now reboot your phone and enjoy the version you’ve installed.

How to install the OS on Windows

Instructions coming soon!

[LostEther]

are we sure there is no incidence of the old driver? I m asking this about the popup of “please remove origin USB driver”

and reboot bootloader
instead of
adb reboot bootloader

For the test units, we don’t have any line in the mentioned file

@plamen

fastboot format userdata

We should also add a line to reassure average user who never did this before, that they can do it just after having unlocked the bootloader and where they have stayed into fastboot mode.

The process still erased my data.
content of the flash.bat

fastboot flash connsys_bt_a connsys_bt.img
fastboot flash dpm_a dpm.img
fastboot flash gz_a gz.img
fastboot flash lk_a lk.img
fastboot flash logo_a logo.img
fastboot flash mcf_ota_a mcf_ota.img
fastboot flash mcupm_a mcupm.img
fastboot flash md1img_a md1img.img
fastboot flash pi_img_a pi_img.img
fastboot flash scp_a scp.img
fastboot flash spmfw_a spmfw.img
fastboot flash sspm_a sspm.img
fastboot flash tee_a tee.img
fastboot flash vcp_a vcp.img
fastboot flash boot boot.img
fastboot flash dtbo dtbo.img
fastboot flash init_boot_a init_boot.img
fastboot flash vbmeta vbmeta.img
fastboot flash vbmeta_system vbmeta_system.img
fastboot flash vbmeta_vendor vbmeta_vendor.img
fastboot flash vendor_boot vendor_boot.img
fastboot flash super super.img

flash.txt (752 Bytes)

PS C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools> ./flash.bat

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash connsys_bt_a connsys_bt.img
Warning: skip copying connsys_bt_a image avb footer (connsys_bt_a partition size: 0, connsys_bt_a image size: 4287216).
Sending ‘connsys_bt_a’ (4186 KB) OKAY [ 0.126s]
Writing ‘connsys_bt_a’ OKAY [ 0.100s]
Finished. Total time: 0.251s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash dpm_a dpm.img
Warning: skip copying dpm_a image avb footer (dpm_a partition size: 0, dpm_a image size: 148288).
Sending ‘dpm_a’ (144 KB) OKAY [ 0.005s]
Writing ‘dpm_a’ OKAY [ 0.005s]
Finished. Total time: 0.030s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash gz_a gz.img
Warning: skip copying gz_a image avb footer (gz_a partition size: 0, gz_a image size: 3120128).
Sending ‘gz_a’ (3047 KB) OKAY [ 0.090s]
Writing ‘gz_a’ OKAY [ 0.071s]
Finished. Total time: 0.185s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash lk_a lk.img
Sending ‘lk_a’ (2497 KB) OKAY [ 0.077s]
Writing ‘lk_a’ OKAY [ 0.065s]
Finished. Total time: 0.168s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash logo_a logo.img
Warning: skip copying logo_a image avb footer (logo_a partition size: 0, logo_a image size: 3450064).
Sending ‘logo_a’ (3369 KB) OKAY [ 0.089s]
Writing ‘logo_a’ OKAY [ 0.079s]
Finished. Total time: 0.193s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash mcf_ota_a mcf_ota.img
Warning: skip copying mcf_ota_a image avb footer (mcf_ota_a partition size: 0, mcf_ota_a image size: 29999104).
Sending ‘mcf_ota_a’ (29296 KB) OKAY [ 0.875s]
Writing ‘mcf_ota_a’ OKAY [ 0.695s]
Finished. Total time: 1.596s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash mcupm_a mcupm.img
Warning: skip copying mcupm_a image avb footer (mcupm_a partition size: 0, mcupm_a image size: 129920).
Sending ‘mcupm_a’ (126 KB) OKAY [ 0.005s]
Writing ‘mcupm_a’ OKAY [ 0.004s]
Finished. Total time: 0.035s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash md1img_a md1img.img
Sending ‘md1img_a’ (70377 KB) OKAY [ 2.183s]
Writing ‘md1img_a’ OKAY [ 1.646s]
Finished. Total time: 4.194s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash pi_img_a pi_img.img
Warning: skip copying pi_img_a image avb footer (pi_img_a partition size: 0, pi_img_a image size: 31232).
Sending ‘pi_img_a’ (30 KB) OKAY [ 0.002s]
Writing ‘pi_img_a’ OKAY [ 0.002s]
Finished. Total time: 0.026s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash scp_a scp.img
Warning: skip copying scp_a image avb footer (scp_a partition size: 0, scp_a image size: 2773792).
Sending ‘scp_a’ (2708 KB) OKAY [ 0.071s]
Writing ‘scp_a’ OKAY [ 0.069s]
Finished. Total time: 0.159s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash spmfw_a spmfw.img
Warning: skip copying spmfw_a image avb footer (spmfw_a partition size: 0, spmfw_a image size: 15344).
Sending ‘spmfw_a’ (14 KB) OKAY [ 0.002s]
Writing ‘spmfw_a’ OKAY [ 0.002s]
Finished. Total time: 0.021s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash sspm_a sspm.img
Warning: skip copying sspm_a image avb footer (sspm_a partition size: 0, sspm_a image size: 754016).
Sending ‘sspm_a’ (736 KB) OKAY [ 0.020s]
Writing ‘sspm_a’ OKAY [ 0.018s]
Finished. Total time: 0.057s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash tee_a tee.img
Warning: skip copying tee_a image avb footer (tee_a partition size: 0, tee_a image size: 908240).
Sending ‘tee_a’ (886 KB) OKAY [ 0.033s]
Writing ‘tee_a’ OKAY [ 0.022s]
Finished. Total time: 0.082s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash vcp_a vcp.img
Warning: skip copying vcp_a image avb footer (vcp_a partition size: 0, vcp_a image size: 1384288).
Sending ‘vcp_a’ (1351 KB) OKAY [ 0.034s]
Writing ‘vcp_a’ OKAY [ 0.032s]
Finished. Total time: 0.087s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash boot boot.img
Sending ‘boot_a’ (65536 KB) OKAY [ 1.948s]
Writing ‘boot_a’ OKAY [ 1.541s]
Finished. Total time: 3.506s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash dtbo dtbo.img
Sending ‘dtbo_a’ (8192 KB) OKAY [ 0.203s]
Writing ‘dtbo_a’ OKAY [ 0.195s]
Finished. Total time: 0.416s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash init_boot_a init_boot.img
Warning: skip copying init_boot_a image avb footer (init_boot_a partition size: 0, init_boot_a image size: 8388608).
Sending ‘init_boot_a’ (8192 KB) OKAY [ 0.214s]
Writing ‘init_boot_a’ OKAY [ 0.190s]
Finished. Total time: 0.430s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash vbmeta vbmeta.img
Sending ‘vbmeta_a’ (8 KB) OKAY [ 0.001s]
Writing ‘vbmeta_a’ OKAY [ 0.001s]
Finished. Total time: 0.018s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash vbmeta_system vbmeta_system.img
Sending ‘vbmeta_system_a’ (4 KB) OKAY [ 0.001s]
Writing ‘vbmeta_system_a’ OKAY [ 0.001s]
Finished. Total time: 0.019s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash vbmeta_vendor vbmeta_vendor.img
Sending ‘vbmeta_vendor_a’ (4 KB) OKAY [ 0.001s]
Writing ‘vbmeta_vendor_a’ OKAY [ 0.001s]
Finished. Total time: 0.018s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash vendor_boot vendor_boot.img
Sending ‘vendor_boot_a’ (65536 KB) OKAY [ 2.069s]
Writing ‘vendor_boot_a’ OKAY [ 1.546s]
Finished. Total time: 3.951s

C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>fastboot flash super super.img
Sending sparse ‘super’ 1/14 (131068 KB) OKAY [ 3.742s]
Writing ‘super’ OKAY [ 3.080s]
Sending sparse ‘super’ 2/14 (131068 KB) OKAY [ 3.966s]
Writing ‘super’ OKAY [ 3.081s]
Sending sparse ‘super’ 3/14 (131068 KB) OKAY [ 3.790s]
Writing ‘super’ OKAY [ 3.076s]
Sending sparse ‘super’ 4/14 (131068 KB) OKAY [ 3.773s]
Writing ‘super’ OKAY [ 3.082s]
Sending sparse ‘super’ 5/14 (131068 KB) OKAY [ 3.741s]
Writing ‘super’ OKAY [ 3.071s]
Sending sparse ‘super’ 6/14 (131068 KB) OKAY [ 3.767s]
Writing ‘super’ OKAY [ 3.138s]
Sending sparse ‘super’ 7/14 (131068 KB) OKAY [ 3.958s]
Writing ‘super’ OKAY [ 3.076s]
Sending sparse ‘super’ 8/14 (131068 KB) OKAY [ 3.731s]
Writing ‘super’ OKAY [ 3.083s]
Sending sparse ‘super’ 9/14 (131068 KB) OKAY [ 3.740s]
Writing ‘super’ OKAY [ 3.072s]
Sending sparse ‘super’ 10/14 (131068 KB) OKAY [ 3.870s]
Writing ‘super’ OKAY [ 3.081s]
Sending sparse ‘super’ 11/14 (117520 KB) OKAY [ 3.469s]
Writing ‘super’ OKAY [ 2.808s]
Sending sparse ‘super’ 12/14 (131068 KB) OKAY [ 3.836s]
Writing ‘super’ OKAY [ 3.075s]
Sending sparse ‘super’ 13/14 (116980 KB) OKAY [ 3.387s]
Writing ‘super’ OKAY [ 2.780s]
Sending sparse ‘super’ 14/14 (114392 KB) OKAY [ 3.229s]
Writing ‘super’ OKAY [ 2.699s]
Finished. Total time: 94.365s
PS C:\Users\user\Downloads\platform-tools-latest-windows\platform-tools>

results-problem-erasing-user-data.txt (9.1 KB)

[guardian241]

Flashed update successfully
Did not wipe user data
Wifi now working as expected
Hotspot is also working
Also in step 10, when in fastboot it displays Android logo not Brax

[plamen]

are we sure there is no incidence of the old driver? I m asking this about the popup of “please remove origin USB driver”

Not sure what USB driver you’ve installed. Make sure you have the latest one from the source I shared. if you’ve installed other USB drivers before (e.g. if you’ve done this for qualcomm/tensor device for example), it might be best to remove it and install the mediatek.

and reboot bootloader
instead of
adb reboot bootloader

I corrected the type with adb reboot bootloader. Good catch.

We should also add a line to reassure average user who never did this before, that they can do it just after having unlocked the bootloader and where they have stayed into fastboot mode.

I’ve never heard of flashing the OS via fastboot without unlocking the bootloader. That will be possible with spflash, but not sure about fastboot with locked bootloader.

For the test units, we don’t have any line in the mentioned file

@plamen

fastboot format userdata

Yes, the latest install package I shared doesn’t include it. But it will be included in installation packages for production version builds.

The process still erased my data.

That’s quite stange. Will test additionally to see if I find a pattern.

[herbert]

out of curiosity: did you run the steps for unlocking bootloader or just flash the update without?

[FrostDaemon]

@herbert

ut of curiosity: did you run the steps for unlocking bootloader or just flash the update without

I did not go through those steps as the test phones are already unlocked. I assume that is in there because they intend on giving the option to relock the bootloader, and that the release units will have it locked.

[FrostDaemon]

Installed on the newest release of Ubuntu,no drivers needed.

Did not go through unlocking the bootloader since it is already unlocked.

It did not wipe Any data.

Everything updated perfect.

[LostEther]

beta5 did not erase my date but there was nothing much to erase compare to before so…
going through beta6 now

[LostEther]

@plamen

Before you start, you need to ensure the following:

• You’ve installed the spflash tool (by MediaTek). Link here.

install would not be the right word since there is not installation for us, just to run the executables… It might confuse people

[LostEther]

@plamen

Add the Download-XML file, by pressing on the choose button (next to Download-XML), and selecting the scatter.xml typically located in the download_agent folder in the OS installation package you’ve downloaded.

you meant the flash.xml according to your screenshot right?

[plamen]

you’re right. I just corrected it.

[LostEther]

We are not supposed to be in fastboot mode or anything according to the chat, so I let on the homescreen and … nothing for 2 minutes then this message appears. And yes the phone is recognized and adb too

[plamen]

It gives the message but the installation should be successful. Not sure why the error is present in this built. Check the OS version when you reboot - should be the latest.

[guardian241]

Running the Seedvault backup before installing latest update had me wondering what would happen if I tried to restore the Seedvault backup from my Pixel with the latest version of iode. Anyone try it or have any guesses before I try it tonight?

[herbert]

May be helpful for someone else: on openSUSE (linux) with Gnome desktop I had to run SPflash6.sh with sudo -E SPFlashToolV6.sh to be able to have easy access to the restricted ports and still be able to start the UI

[LostEther]

Okey so new addendum to the help page.

Apparently after flash of beta6 the OEM lock engaged itself again within dev options even if it has not been resetting itself.

For coming to that conclusion I have been giving this by the terminal

FAILED (remote: ‘No support by lock control’)

So I tried the unlocking of bootloader first which gave me in turn this:

FAILED (remote: 'Prohibit unlock operation
')
fastboot: error: Command failed

so I have checked the environment variables of the bootloader with
./fastboot.exe getvar all
checked the line

(bootloader) unlocked: no

So came back in the system, found the toggle.
reactivated the toggle
unlock the bootloader with the 2 commands back in fastboot
flashed the beta7 again with success
rebooted it.

Bad surprise: it erased my data… again. At least I am used to do a full backup of seedvault plus separate backups of my encrypted conversations by now.
So I’m in the process to retransfer the seedbackup folder and my backup folder right now.

I have already tried to join my wpa2 ddwrt wifi with no success … again.
I will check again with after the restoration of the backups.

And by the way, wifi on OWRT router image with wpa2-PSK on CCMP is working fine. Only the ddwrt implementation is not working on this phone.

All that to say we should add a few more troubleshooting commands which I used to the wiki.

[guardian241]

Successfully flashed beta 8 via SPFlash
All apps and user data retained
OTA uptate installed successfully

[guardian241]

Successfully updated via OTA to 6.3-20250428-brax3

[nolan]

I couldn’t get into fastboot mode no matter how i tried, my phone is now in a boot loop.

“adb reboot bootloader” and Power + Vol- both didn’t work.

EDIT : nevermind, I did Power + Vol+ and selected fastboot mode, my bad