What is needed for a Custom Rom friendly Android device?

In a few days (Oct 5) Google is expected to announce their next iteration of developer friendly phones, the Pixel and the Pixel XL. This is significant because it suggests they are not using their old brand (Nexus) anymore and instead trying to aim for the mainstream, to compete against Apple's iPhone and Samsung's Galaxies.

It is also significant for the android enthusiast, as the Nexus and hopefully the new Pixel phones have always been developer friendly, AOSP, bootloader unlockable and easy to develop for. These features have been getting rarer and rarer recently in other phones. Here is a rundown of what these features mean for those not in the know.

Bootloader Unlockable

When the bootloader is locked, you can't flash custom roms on your phone. While not something most people really care about, custom roms allow one to change the look of the phone and add extra features.


While the Z3 Compact can be bootloader unlocked it would result in a loss of DRM keys, reducing camera quality and preventing the use of some features.

Usually it is quite easy to unlock the bootloader, whether the manufacturer provides a way (Google Nexus, Sony, Motorola) or custom developers develop one. However a phone can be shipped with a bootloader that cannot be unlocked.

Fortunately in Australia this is not a problem, as unlockable bootloaders are decided by the carriers and here where the market is more competitive none of the carriers do it. In the United States the carriers lock the bootloaders permanently so that phones cannot be used past their planned obsolescence.


A common acronym in Android development, the Android Open Source Project is the base android rom that Google develops. It is the choice for enthusiasts as it is the lightest, fastest and most stable (up for opinion) software available on Android. Manufacturers will put their own software layer on top which can slow the phone down. This varies between different manufacturers, from the very heavy and slow Touchwiz by Samsung to the almost indistinguishable and fast skin by Motorola. Because of this, custom rom developers usually try to bring AOSP to phones.

Developer Friendly Manufacturer

Even if bootloaders are unlocked, developers cannot develop custom roms without good support and documentation.

Some of the most popular AOSP custom roms are Cyanogenmod, Paranoid Android, and Omnirom. Unfortunately of recent days only Cyanogenmod has a wide reach across many types of phones while the others exist only on developer friendly phones.

Current Situation


One of the last Samsung devices that is developer friendly, the Galaxy Note 4 has a Qualcomm processor and unlocked bootloader.

Once upon a time, the largest android manufacturer, Samsung was reasonably developer friendly with phones up until the Galaxy S6 which used their proprietary Exynos processors.

The developer friendly manufacturers Sony and Motorola provide easy ways to unlock their bootloaders and provide kernel sources. However they do not sell phones at large enough volumes to have a strong custom developer community.

A lot of phones have lost their custom developers to the Nexus phones, their open source and easily unlocked bootloaders have made many developers jump ship.


One of the android community darlings, the Nexus 5 had flagship specs at a really low price.

The Nexus devices of every year were the reference Android device, running the AOSP rom. There is some worry about the new Pixel brand phones as now they may not be AOSP anymore.

Interestingly enough, new manufacturers like Oneplus, Oppo and Nextbit have attracted developers by providing good developer support alongside cheaper phones.

BY Dennis Nguyen

Melbourne University Electrical Engineering Club


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