Linux works on desktops because the companies making desktop hardware put somewhere between “some” and “massive” effort into making mainline Linux work. It’s not that difficult for motherboards (most of the work is done for motherboard manufacturers already) but for anything from CPUs to disk drives, manufacturers write Linux code and submit it back upstream. Without companies wanting to make Linux work on PC, it simply wouldn’t. Of course there are plenty of volunteer and hobbyist programmers who also contribute, as well as people paid by the various free software funds, but they generally do smaller stuff rather than complete device support. It also helps that computers have standardised ways of booting and identifying what hardware is present.

On ARM, companies like Qualcomm take the inverse approach. They take Linux, make some modifications (usually ones that will never be accepted upstream because of code quality or style concerns), build binary drivers for that specific version of Linux, and then hand that entire thing to companies like Google and Samsung. These vendors have no interest in upstreaming code and make a lot of money selling ongoing maintenance for old, customised kernels.

Booting ARM devices is also a pain. Instead of BIOS/UEFI, every vendor has their own boot method, usually involving a modified version of u-boot that’s customised to do whatever weird shit the vendor needs.

Even if you get Linux to boot, you’ll probably struggle with basic features like “not burning through the battery in ten minutes” without vendor code or binaries.

There are projects to bring normal Linux to phones. Ubuntu Touch is actually quite usable, Plasma Mobile works on a few devices, and postmarketOS has a surprising range of working hardware. One big challenge is support for hardware accelerated wifi, and the latter is doing quite well for that.

Still, despite all the hard work, some stuff like binary drivers just won’t make it into the kernel without major effort for every model of SoC. For Android phones, the custom upstream kernel can form a good basis, but someone needs to go through the code and make it Linux compatible. WiFi and Bluetooth can usually be hacked together but someone needs to do it. Cell modems are even worse, so calling and texting are even less likely to work.

Basically, there’s no commercial interest, the hardware works very differently, and it’s a lot of work. It can be done if someone is passionate enough about Linux on their device but only for one or a few related models in that case.

Locked bootloaders can prevent that. Or proprietary hardware drivers can make it unworkable.

I guess I’m going to be that guy today. Android is Linux, and it’s installed on a lot of mobile devices already.

Android is Linux

There’s been multiple attempts Ubuntu and Plasma both have projects, Ultimately a lot of compatibility issues seem to hamper uptake, components like cameras and such can be hit or miss.

The processors and peripherals aren’t as uniform as they are on computers. Each SoC has a different set of components, which need drivers and custom set-up mechanics and they’re often only shared between the chip designer and phone manufacturers. A lot of complicated reverse engineering is needed. And that’s often not worth it as there are many different phones on the market and they’re short-lived devices. So we end up in the current situation where we don’t have the operating system foundation / drivers available to the community to build upon.

There is Linux on phones. A modified Linux kernel runs on every Android device. Just the userland is an entirely different one. And Linux isn’t there yet with the desktop and apps. A lot of features are missing, power saving, delivering messages while sleeping and doing background tasks while saving power in the pocket… It’s kind of a chicken and egg dilemma. We’d need some popular Linux phone so people are motivated to tackle the remaining software issues for a mobile ecosystem. And we won’t get one unless there is some good software so it can be marketed.

Android OS runs a modified version of the Linux kernel.

Nothing prevents you drom installing a linux os on an android phone, provided someone made a rom for your device. It’s just not very useable due to proprietary drivers. Ubuntu touch exists for example, but on most phones you can’t even use the cellular antenna iirc

Nothing really. Someone else already wrote that Android is technically Linux. But you can also get “regular” Linux on mobile devices, it’s just a matter of using a distribution with mobile-friendly UI as well as getting driver support for the phone’s hardware. Ubuntu touch exists for example, but only works on a limited number of devices and even on supported devices it’s not really suitable for the average user yet.

Pratically no universal way of making Linux boot with ARM processors.

Much more closed source drivers (than x86 ecosystem).

In practice? Constantly changing hardware with soc vendors that publish nothing and device manufacturers that (have to) keep pushing out new models on a short cycle. Plus many of them have extra shenanigans to keep the bootloader locked so you can’t install a recovery (presuming you had a working one) so you could replace the os. There are some rare exceptions, but the hardware is rare and tedious and not many people can or will work on installable Linux on them.

If you just want to run some Linux userland, there’s ways to do that on top of android, though. Want to get to a Linux like system or run a program? Might be as close as installing a terminal or running adb shell.

You can install Linux on rooted phones using Linux Deploy, or you can install Linux-in-an-app such as Userland or Termux if you don’t have root.