Most of the devices out there has something called Engineering ROM, which sounds weird to the person in first time hearing it. This article explains what exactly it is being used for.
What is Engineering ROM?
When a device is being built in factory, it must be verified that it works properly before going out to the world. Or, if the device is broken and has to be repaired, and needs to be verified that it’s working before giving it to the owner, it also needs to be checked that it works. But, the factory of course can’t know without testing the device out. This is why Engineering ROM exist.
Engineering ROM is a set of software files that that are installed on smartphones by the manufacturer. This allows the developers to check and verify the device and confirm the repair of the device during the building process. It has testing software and apps inside of it. It’s used to test the whole hardware from the software so that phone can be checked properly before selling the device out to the world. Or, in such cases, like if the device’s some component got damaged and should be clarified which exactly component is broken, or writing software things over default ones, which normally stock software of the device doesn’t let you to do that.
What does an Engineering ROM look like?
It’s just pure android, without any modifications (like MIUI), that is light and only made for testing purposes in the device. The phone itself probably will never come with this ROM packed in, as it’s only used for testing purposes.
Here’s a Redmi Note 10 Pro 5G running Engineering ROM captured in factory, meanwhile being tested. Normal users probably have nothing to do with this ROM. Only the factory itself, or the phone repairmans use this ROM when repairing the device and has to verify that device does work intended.
Here’s all the apps that ROM contains, they are all mostly made to test the device’s hardware such as display, fingerprint sensor, camera, proximity sensor, Bluetooth, CPU’s parts like resistors, GPU, cellular (calling), camera, vibrator, speakers, and many more. Engineering ROM is mostly based on the Android version that the phone came out of the box. If the phone came to you with a higher version out of the box compared to the Engineering ROM, that means that phone is updated, which you can understand it that way as well.
As you can see in the picture above, the ROM contains apps that are testing purposes for the device’s hardware. The app there was being used to test such hardware like Wi-fi, Bluetooth and more. Not only the ROM is being used for only hardware, also being tested for hardware speed as well, like RAM working speed, storage speed, etc.
While these ROMs are only installed by the manufacturers for testing purposes, users can also have access to it and flash it at their own peril. You can find these ROMs on our Telegram channel. If you wish to make tests on your device but don’t want to bother with such immense actions, you can also do a minimal version of this with CIT feature that is present in most devices. You can learn more about it in our How to Use Hidden Hardware Test Menu (CIT) on Xiaomi Phones content.