Flashing CFW
on xaga
and unbrick it
Note
LineageOS for xaga
already ships with the engineering preloader image. This page is for information only.
Getting Started
As we have seen in the past "begonia
CFW Megathread", MTK devices are pretty easy to brick. All it takes is one wrong move and you are FUCKED!.
The same concept of a brick also applies to xaga
devices "Example of what a brick looks like".
Note
If you are already in this state and have not flashed the engineering preloader image, the only way out is to visit an authorised Xiaomi Center.
So what do we do to avoid a brick?
It's not that easy to avoid bricking these devices. Just follow the instructions and don't do anything stupid.
However, by flashing the engineering preloader
image, you can save yourself a lot of headaches.
Why do we need to flash the engineering preloader
image and how it works?
Usually, MTK devices follow this boot pattern:
`Boot ROM` -> `preloader` -> `Little Kernel (lk)` -> `kernel`
With MIUI preloader
, nothing unsual happens, however, after flashing the engineering preloader
image, (with ever boot) the preloader
exposes an insecure VCOM
port with SLA
(Serial Link Authentication) and DAA
(Download Agent Authentication) checks disabled, allowing you to flash images with SP Flash tool V6
without worrying about having an authorised Mi account.
If you use the MIUI preloader
image, the only "download" mode you can access in case of a brick is Boot ROM
(which is burnt into the SoC). This requires an authorised Mi account to access and write partitions from it.
There is currently no way to bypass these checks on xaga
, as Boot ROM
has a bunch of checks to prevent unauthorised attacks.
Can I revert to the MIUI preloader
image?
Of course, at your own risk :P.
Flashing process
- Download the correct
preloader
image:
Link | Sha1sum |
---|---|
HyperOS Based ROMs (preloader_aristotle ) |
d9399d4faeea64cf82b2675aa6b26bd8cbd75e36 |
MIUI Based ROMs (preloader_xaga ) |
4a7486c4c954aedca2e585ac92e5bd640bfa6bee |
- Reboot your device into fastboot mode by holding down the appropriate key combination.
- Open a
ADB & Fastboot tools
window on your PC and flash thepreloader
image you downloaded before.
# Mention the path of the image before running the commands
# Ex: fastboot flash preloader1 /home/itsvixano/xaga/preloader_xaga.bin
$ fastboot flash preloader1 <preloader_xaga>.bin
$ fastboot flash preloader2 <preloader_xaga>.bin
- Reboot your device by holding the
Power
button. - You are good to go :D
How to unbrick (with the engineering preloader
image)
So you have managed to brick your device and you have previously flashed the engineering preloader
image? You can easily restore it by following these simple steps:
Warning
Avoid using the Firmware Upgrade
option, it will lock the bootloader.
Never use the Format all + Download
option, it will ERASE the whole device UFS (including IMEIs, mac addresses, and more).
Always make a backup of your partitions
- Download the Fastboot ROM of your choice.
- Download the custom
xaga_MT6895_Android_scatter.xml
file. - Extract the Fastboot ROM and replace the file
images/MT6895_Android_scatter.xml
withxaga_MT6895_Android_scatter.xml
. - Turn off your device.
- Open
SP Flash tool V6
. - Load the MIUI Fastboot ROM of your choice by pressing the
Download XML
button and selecting theimages/download_agent/flash.xml
file. - Press the
Download
button. - Connect the device to your PC (if it doesn't detect, press and hold the
Power
button for 8-10 seconds). - The flash process should start.
You can get the latest SP Flash tool V6
from here and the latest xaga
Fastboot ROMs from here: (make sure you choose the right MIUI / HyperOS Fastboot ROM for your device :D).
Version | Download |
---|---|
HyperOS | xmfirmwareupdater.com |
MIUI | xmfirmwareupdater.com |