Android isn't "just Linux". It's a heavily modified kernel, it's often an even closed source bootloader in many cases and it's completely untrue for userspace, where it incorporates stuff from other OSs (BSDs, etc.). There are huge amounts of blobs.
Yes, there technically is a Linux kernel, but if it's "just Linux" then macOS is "just FreeBSD", because grep -V tells you so, because it has dtrace, because you run (ran?) Docker with effectively FreeBSD's bhyve, etc.
If you wanna spin it even further neither are Safari and Chrome or any other Webkit browsers just Konqueror because they took the layout engine code from KDE (KHTML).
And you can totally install Debian and even OpenBSD, etc. on a Steam Deck and at least the advertisement seems to indicate it won't be all that different for the VR headset.
The problem is that you're talking about the Linux desktop ecosystem whereas the op could be talking about the kernel. Both are just Linux (and the fact we've not evolved our nomenclature to differentiate the two is surprising). Also, fwiw, the android kernel is no longer heavily modified. Most of the custom stuff has been upstreamed.
I'd just like to interject for a moment. What you're refering to as Linux, is in fact, GNU/Linux, or as I've recently taken to calling it, GNU plus Linux. Linux is not an operating system unto itself, but rather another free component of a fully functioning GNU system made useful by the GNU corelibs, shell utilities and vital system components comprising a full OS as defined by POSIX.
Many computer users run a modified version of the GNU system every day, without realizing it. Through a peculiar turn of events, the version of GNU which is widely used today is often called Linux, and many of its users are not aware that it is basically the GNU system, developed by the GNU Project.
There really is a Linux, and these people are using it, but it is just a part of the system they use. Linux is the kernel: the program in the system that allocates the machine's resources to the other programs that you run. The kernel is an essential part of an operating system, but useless by itself; it can only function in the context of a complete operating system. Linux is normally used in combination with the GNU operating system: the whole system is basically GNU with Linux added, or GNU/Linux. All the so-called Linux distributions are really distributions of GNU/Linux!
that doesn't in any way mean you can install an alternate OS. But i get your point that at least you can run Arch stuff. Isnt Arch ARM support unofficial? (its been ages since i tried) You dont hear of people running it on RPis for example
Well. It doesn't say in any docs or specs, but for what it's worth, Valve's hardware has always been open like that. You're free to install windows on your steam deck, for example.
Valve sponsored asahi linux which was a herculean exercise in running another OS on locked down hardware. They've also sponsored wine and fex. It would be a sudden, steep, and unexpected departure for them to go from being leaders in cross platform OS/hardware support to locking down their own hardware platform. It's just not in their nature. They know their nature is good and they know we know it. That's called trust.
They're being a little vague about it but this collaboration to improve Arch's build service/infrastructure is being done in part to faciliate support of multiple architectures.
iirc it was in Tested coverage that Valve said the hardware supports other OSes. It'd be out of character for Valve not to allow for this.
If it's anything like the Deck, then the version of SteamOS on it won't be locked down in any way whatsoever. You can install Windows or any other distro you want on the Deck with 0 issues (other than regular ones you'd experience anyways on any regular computer, nothing to do with Valve locking anything down).
The steam deck was not arm. Unlike the steam machine page, the steam frame page does not insinuate you can put a custom OS on it. On top of custom drivers which are not necessarily upstreamed, qualcomm socs always require closed source userspace daemons which are coupled to the kernel.
Valve have been working with Linaro to develop FOSS drivers for the Adreno 750. This is necessary, given how heavily Valve leans on having integrations with Mesa whereas Qualcomm's drivers are designed for an Android environment.
I don't see why they wouldn't unlock the bootloader, it wouldn't be the first Qualcomm-based product to allow it and in press interviews they have pressed, quite hard, that the Frame is still a PC.
