[GTALUG] distro support for 32-bit UEFI

[Lennart Sorensen]

On Thu, Nov 19, 2015 at 03:22:09AM -0500, D. Hugh Redelmeier wrote:
> I have a couple of devices with 64-bit Atom CPUs, built to be cheap
> Windows devices, that have 32-bit UEFI firmware.  With no
> old-fashioned BIOS or emulation thereof.  This seems to be intentional
> crippling by Intel: they only provide power management firmware in
> 32-bit mode.

Actually I believe it is Microsoft's fault.  Windows UEFI support requires
the firmware to be the same as the OS bit size wise, and windows 64bit
is bigger than 32bit and needs a bit more resources, and apparent;y
a lot of these small amchines can't really handle 64bit.  And besides
they want you to buy a real big machine instead to get all that stuff.
Also connected standby initially was only avaialble in the 32bit version
of windows and was supposedly a required feature for some of these small
machines (not sure if microsoft insisted they support it or the vendors
actually wanted it).

Linux doesn't care if UEFI is 32 or 64bit under a 32 or 64bit kernel.
It just deals.

> The devices I have are an Asus TF100 "convertible" (tablet with detachable 
> keyboard) and a Dell Venue 8 Pro.
> 
> The Intel / Microsoft idea seemed to be: build very inexpensive devices
> to compete with ARM / Android.  But be careful to limit the damage to
> the market for full-fledged Windows systems.  It worked to some extent.
> 
> The Hugh idea was: cheap computers that should run Linux!  Close, but
> no cigar yet.
> 
> What I want is a 64-bit distro that can boot from 32-bit UEFI.  That
> could be managed but it doesn't seem to be available now.  (The 64-bit
> Linux kernel knows how to call 32-bit UEFI functions.  This feature is
> not always enabled.)

Debian certainly can do that.

> Almost as good would be a 32-bit distro that can boot from UEFI.
> After all, these cheap boxes are limited to 2G of RAM anyway
> (crippled: see above).
> 
> Scott informed me that 32-bit Debian Jessie (8.0) does support UEFI.
> Wonderful!  But I'm chicken: there is no 32-bit UEFI live image and I
> don't want to install without trying.  After all, there may well be
> unsupported bits on these screwy devices.  (Sadly Linux distros seem
> to be weak on touch, one of the strengths of these little devices.)

I believe the only debian image with 32bit UEFI support is the multiarch
netinstall image.  I used it on some wacky intel development board for
an embedded atom which only had 32bit UEFI.  I installed 64bit debian
with the 32bit UEFI boot.

> These cheap devices come with very little "disk".  Mine each have 32G;
> some have 16G; a few have more.  That's not really enough space for
> both Linux and Windows.
> 
> I have a netbook built in the same style, but with 64-bit UEFI.  I've
> found 32G quite reasonable for Fedora Linux.
> 
> <https://wiki.debian.org/UEFI>
> 
> Another bit of news from Scott: the next generation of Atoms, or at
> least some of them, drop support for virtualization!  What jerks.

-- 
Len Sorensen