Next year might be “the year of desktop Linux” in perpetuity, but mobile operating systems aren’t waiting around. They represent the fastest-growing of the Linux kernel, powering the vast majority of mobile devices. But how can the same kernel work on the desktop and a mobile system? Android doesn’t make much of a desktop operating system after all. The basic rules stay the same, but there are significant differences between mobile and desktop operating systems.
What Is Mobile Linux?
Mobile Linux is any mobile operating system based on the Linux kernel, which was first created by Linux Torvalds in the 1990s. The kernel is the heart of the operating system: like the foundation of a building, it holds the rest of the computer system up and controls input and output operations.
Just like on the desktop, there is more than one Linux distro for mobile devices. Android is the most popular and best known, though it may have drifted away from the philosophical underpinnings of Linux. Android is the top mobile OS in terms of units sold worldwide, and it’s based on the Linux kernel. Google thoroughly developed the OS since that adaptation. The Linux philosophy is better maintained by Replicant, a FOSS fork of Android that emphasizes freedom and security.
Other Linux-based mobile operating systems also exist, and plenty more litter the open-source project graveyard. The most well-known distros include Linux kernel builds like PureOS, Ubuntu Touch (now community-supported by UBports), and postmarketOS, as well as Android ports like Replicant, LineageOS, and Plasma.
Of course, it should be noted that desktop Linux can be installed on nearly any mobile device. However, that’s not what we’re discussing here. We’ll be describing Linux distros built specifically for mobile devices.
Security and Permission Architecture
Mobile operating systems have different methods of ensuring user privacy. While most Linux-based mobile operating systems include some method for apps to communicate with one another, it’s rare for apps to have device access outside of their protected sandbox. Android includes fine-grained control over various device permissions, like writing to the local disk or communicating over your data connection.
Desktop operating systems rarely include this level of permission control, especially not with an easy-to-understand user interface attached. While desktop Linux does include the well-known Unix-style file permissions, the permission toggles are typically limited to read, write, and execute. Mobile OSes, on the other hand, offer dozens of permissions that can be requested from the user.
While each distro uses their own precise system, most mature operating systems provide a high degree of control over which app can do what. Apps are rarely permitted to control the device completely and are limited in what operations they can perform, even with permissions.
Users are also limited in what data they can edit, though those restrictions can be overturned after obtaining root access. Root access and administrator privileges, which is available by default on desktop, is significantly harder to access, requiring device modifications to obtain root privileges.
Hardware and Device Flexibility
In general, mobile operating systems do not need to be as flexible as desktop operating systems. While a desktop computer can have literally infinite input and output configurations, mobile devices typically adopt only a single configuration: the one they were shipped with.
As a result, the many software packages on Linux that exist to support a huge variety of input, output, and storage devices can be removed. Fewer file formats and connectivity standards are supported, and only strictly necessary input and output packages will be included with the device. The distro is built with only what is necessary for the integrated deployment, with little consideration given to users’ aftermarket connectivity options.
Wireless or USB-C cable display capabilities exist today on higher-end devices, but this has only become an expected feature in recent years. While mobile operating systems get more powerful with each release, in general, mobile OSes are less flexible than desktop OSes.
You might think we missed the most obvious difference – the look and feel of the devices – but that obvious difference doesn’t necessarily decide how the underlying operating system works. The real differences live beneath the surface of the OS.
Mobile Linux is heavily customized for the deployed use and device, while desktop Linux distros have more generic packages. Despite these differences, the security and freedom of open-source software are maintained in most Linux-based mobile operating systems, just like on desktop.
Image credit: Vinodh Moodley