This article first appeared on https://screenontime.com/2021/09/05/what-is-a-gsi-on-android-and-how-to-flash-a-gsi/

WHAT IS A GSI AND HOW TO FLASH A GSI ON ANDROID?

A GSI (Generic System Image) is a pure, untouched implementation of Android with unmodified AOSP (Android Open Source Project) code. According to Google’s Android website, a GSI is designed to run on any Android device launched with Android 8.1 and higher. GSI became a thing as a part of Google’s project treble. What does GSI mean in a simple explanation? GSI simply means a generic system image built from the AOSP source. A GSI can run on any Android smartphone, no matter the chipset or manufacturer.

WHAT IS PROJECT TREBLE?

Project treble is the separation of Android-specific code and hardware-specific code. Android phones that launched with Android 8.1 Oreo implemented Google’s mandatory Android architecture change. This was a move taken to improve slow Android updates by manufacturers. Project treble has two major components – OS framework and Vendor.

The OS framework is Android itself; GSI and skinned Android system images from different manufacturers.
Vendors are device-specific low-level software. This low-level software consists of important device-specific drivers that help devices communicate with system images. With vendors, Android devices do not need kernel or firmware updates to boot generic system images.




HOW DOES A GSI WORK ON ANDROID?

Generic system image (GSI) is quite explanatory with its name. Generic system images are pure Android system images with no changes or alterations from the AOSP source itself. A GSI contains pure AOSP code. Since it is a generic system image, it can run on any Android device. A GSI runs on any Android device by communicating with the device vendor. Vendors provide system needed drivers for a GSI to communicate with device components, and once this is achieved, the device boots. However, sometimes, there are bugs when a GSI is booted.

HOW TO FLASH A GSI ON ANDROID

As explained earlier in this post, a GSI only needs your device-specific vendor to boot. We will be using an Android 12 GSI image for this tutorial. This tutorial is straightforward.

DISCLAIMER

You need to be calm and know what you are doing. Screenontime is not responsible if this turns out bad for your device. If you are not able to boot your device after flashing the GSI image, make sure you have your device system image to return your device to a working state. Also, be aware that you will lose your files on your device. Make sure you back up your Android device before you begin this procedure.

WHAT YOU NEED

An Android device with project treble support
Latest system files for your Android device (check your device manufacturer website)
An Unlocked Bootloader
A Windows PC/ Apple MacBook

DOWNLOAD LINKS

Device driver (this is not needed for MacBook users)
Platform tools
Android 12 GSI
If you are a OnePlus owner, you need VBMeta. You should follow this link to get it

COMMANDS IN BOOTLOADER

You should extract your device ‘boot.img’ from the system files you downloaded from your manufacturer’s website and execute the commands below

fastboot flash boot_a boot.img
fastboot flash boot_b boot.img

Flash your GSI


fastboot -w flash system <Your GSI.img>

You should disable verification


fastboot --disable-verity --disable-verification flash vbmeta vbmeta.img

Reboot

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let me act like i understand what i just read

SunshineHQ:
let me act like i understand what i just read

Haha, it is actually easy to those who like flashing roms.