Microsoft finally releases a direct-download Windows 11 on Arm ISO

Microsoft is making ISO images of Windows 11 on Arm available at last, years after the hardware architecture made its debut. The ISO is for the current release, Windows 11 24H2, and is an indicator the Windows-maker is taking the platform seriously. This is important, as Microsoft wants customers to take its Copilot+ PCs …

[BobbyTables]

Don't get me wrong, I like arm. I'm typing this on an Arm powered laptop, but it has a seriously long way to go before it supplants x86. In fact I don't think it ever will until the hardware stops being such a wild west of incompatibility.

The biggest problem is a lack of standardisation. On the PC you can download an iso, throw it on bootable media and be fairly confident it will work. Not so on arm. There's no bios/uefi equivalent to manage startup, nor is there an equivalent of the CPUID instruction, so the OS cannot see what hardware is available and configure itself to suit. This means a separate build is needed for every single individual device you want to support. Not only that, a lot of arm devices are locked down to keep you from even being able to boot an operating system the manufacturer doesn't also conveniently produce! Look up Linux for the arm powered chromebooks. It's a mess and must be a pain for maintainers.

I don't know what devices that ISO is targetting, but I'm willing to bet they're all pretty microsofty. It's not going to work on a chromebook even if they had the exact same CPU.

It's a bit like the 1980s when there were multiple competing incompatible home computers. The PC won out for a few reasons but by far the biggest one was that it essentially became an open standard and anyone could build one, and was free to run anything that boots. The Amiga, Atari ST and Mac all shared a 68000 CPU, but good luck getting AmigaOS to work on a ST! (Yeah, the ST and Amiga could run Mac as virtual machines, but that's an entirely different topic!). "ARM" just doesn't tell you much about any piece of hardware, whereas x86 essentially became synonymous with PC compatible.

To be a real contender for replacing x86, Arm needs that. It needs some form of standardised bootloader, and some form of standardised hardware reporting. I don't see that happening though while its not in the commercial interests of Microsoft, Google and Apple!

[Ubercorn]

Arm SystemReady

Arm has produced the SystemReady certification, since 2020 - see https://www.arm.com/architecture/system-architectures/systemready-certification-program - which guarantees boot compatibility. I'm guessing the Arm64 ISO will boot on anything which is certified. Partners (includes Qualcomm) are listed here: https://www.arm.com/architecture/system-architectures/systemready-certification-program/partners

[BobbyTables]

Re: Arm SystemReady

A small step in the right direction, however its not going to be enough. It might catch on in the server world where smaller players are the norm, interop is everything, and all the customers are technically literate, but the purveyors of consumer devices will never adopt it unless forced kicking and screaming. It is not in their interests.

This sentence is the problem: "The program provides a balanced approach to standards; too much standardization might restrict partner innovation and too little can result in high software maintenance costs for supporting fragmented products.

Unless forced, there won't be any standardisation at all.

If I'm wrong, and any of the three giants start being more cooperative, it would be Microsoft. They are used to existing on an open platform and aren't reliant on sales from their "Store". They are also less into tweaking their own hardware far from off the shelf designs and are more comfortable to let hardware made by other companies run their stuff. Apple would never dream of adopting it and have so much money and political clout they could sue arm out of relevance in a single suit (like they did to HTC) and Google are cut from the same cloth. They both want their walled garden (or mostly walled) and to take a cut of all sales on the stores they control. And that's your "innovation" for you.

So the catch-22 will carry on. No open hardware means nobody makes OSs for it, and no OSs mean nobody makes hardware to run them on. Yes, I say that with a little hypocrisy since I am using Linux on a Chromebook, but boy was it a challenge to get usable and I have a single distro choice! It just isn't good enough and unless something changes I'm going back to x86 on my next laptop despite the advantages ARM has. It's just too much of a pain in the backside unless you're happy with Apple's prices or Google's spying and forced cloud.

[dharmOS]

Re: Arm SystemReady

Apple is a founding member of ARM, so unlikely to sue them (well, unless you eat your own children),

[Nelbert Noggins]

Re: Arm SystemReady

Considering one part of Apple spent the best part of 7 years (2011-2018) burning cash to sue Samsung over mobiles while another part of Apple relied on Samsung as a component supplier and the only supplier for some of the chips in the iPhones they made at that time, I’m not sure unlikely is the word I’d choose.

From the outside looking in, it would seem like an odd thing to do, but it wouldn’t be the first time Apple poured money into their army of lawyers for something that may look unlikely.

[katrinab]

I think it was Compaq reverse engineering the IBM BIOS that made x86 the standard rather than Intel?

[Gene Cash]

I think it was the fact that Compaq wasn't instantly sued out of existence that made x86 the standard, and the fact that there was an IBM open spec for the bus. That allowed the flood of clone machines to start.

[Jason Bloomberg]

I had, maybe still have, some IBM ring binders which seemed to contain absolutely everything you would need to clone an original 'PC', was high quality and detailed documentation as I recall.

[david 12]

There was also an army of 'DOS Compatible" machines that would run text-mode DOS applications (and actually, DOS graphic-mode applications, but no native programs used DOS graphic mode).

[collinsl]

Yes - the problem being it was all © IBM and therefore Compaq couldn't use any of it when reverse-engineering the BIOS. They intentionally set up a "clean room" team who had never read the IBM documentation before, presented them with the results of each bit of BIOS code, and told them to "write some code which produces this result".

This, meticulously documented, was their main way of preventing IBM from alleging copyright infringement and suing the doublet and hose off of them.