32-bit ARM Driver Signing: A Forgotten Niche?

With the recent Authenticode apocalypse, it’s no longer possible to code sign Windows 7 and 8.1 drivers yourself; instead you have to go through Microsoft’s hardware portal in one way or another, whether it’s WHQL via HCK or Win10 attestation or otherwise. There seem to be workable avenues for drivers on Windows 7 and 8.1 for x86 and amd64. But it seems that Windows 8.1 on arm32 has been left out in the cold? There’s no Windows 10 arm32 platform available for attestation or certification, which means the hardware platform won’t provide signatures there. And Authenticode has now expired, so Authenticode can’t be used to sign Windows 8.1 arm32 drivers. That’s an unfortunate gap…

Anyone else run into this issue and have a good solution? Alternatively, is there a strong argument for dropping the platform?

Great observation. Win8.1 on 32-bit ARM is definitely a forgotten platform. Wow…. I was not aware that any commercial products actually shipped on this platform (outside of phone/mobile). There were some ARM-based development boards that ran IOT, but… support for those seemed to have been dropped pretty quickly.

I’m not aware of any way to sign drivers for this platform today. I’m not even sure what the “official” MSFT guidance would be… though I do know that the whole IoT Core vs IoT Enterprise is (thankfully) being merged into one (named, cleverly, IoT Enterprise) with a single LTSC being maintained, and everyone on Core is being told to go to this new Enterprise channel.

There’s an opportunity here for me to hold forth at great length about the horrible lost opportunity that is Windows Embedded which begat IoT and, in general, Windows on ARM. Oh, how the mighty have fallen! Never mind.

Awesome question, thank you.

Peter

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@“Peter_Viscarola_(OSR)” said:
Great observation. Win8.1 on 32-bit ARM is definitely a forgotten platform. Wow…. I was not aware that any commercial products actually shipped on this platform (outside of phone/mobile). There were some ARM-based development boards that ran IOT, but… support for those seemed to have been dropped pretty quickly.

As of today these Windows 10 IoT Core ARM32 platforms are listed at Microsoft as supported

  1. DragonBoard 410c
  2. Raspberry Pi 2/3
    with last update in year 2018 for pre-built images.

For Windows 10 IoT Enterprise ARM32 only Qualcomm seems to be listed now.

You’re right. Windows 10 still supports ARM32. And MSDN even mentions that attestation signing and such is available for it. But when you actually try to acquire a signature, there’s only x86, x64, and arm64, with no arm32 options in sight. (And trying to grab a signature for the wrong architecture properly returns errors.)

Is this an oversight on Microsoft’s part?

@zx2c4 said:
You’re right. Windows 10 still supports ARM32. And trying to grab a signature for the wrong architecture properly returns errors.)

Is this an oversight on Microsoft’s part?
Maybe so, or maybe it is intentional. I can think of a certain partnership may be a requirement now for Windows 10 IoT ARM32 architecture. E.g. if you have a Dragonboard to experiment with, and think of making a product based on it, then you might need to engage relationship with Qualcomm and they would sign your driver through their channel.

If you look at here, no ARM32 platform as well, only ARM64.
https://docs.microsoft.com/en-us/windows-hardware/test/hlk/testref/e1c0c2dd-cd25-4f60-a4bc-c8544d481225