Mailinglist Archive: opensuse-features (16 mails)

< Previous Next >
[openFATE 318252] 32-bit UEFI boot in 64-bit Distro
Feature changed by: Michael Chang (michael-chang)
Feature #318252, revision 14
Title: 32-bit UEFI boot in 64-bit Distro

openSUSE Distribution: Unconfirmed
Requester: Desirable

Requested by: David Poole (dspoole-novell)
Partner organization:

Allow for 64-bit versions of openSUSE to boot on to 32-bit UEFI
hardware and allow for installation.
Thus, hardware that supports only 32-bit UEFI and not legacy boot in
BIOS yet has 64-bit processors (typically Intel Atom) would let
openSUSE 64-bit install.

Use Case:
Some Ubuntu users have created a work-around to get their 64-bit kernel
version installed on Dell Venue/Toshiba Encore Mini-series tablets
using a custom 32-bit UEFI boot. This is not officially supported by
Ubuntu but there has been some interest in getting Linux onto the
sub-$200 tablet market.
However, because it is basically a hack to do so and only on specific
hardware, only the bravest Ubuntu users have accomplished this task.

Business case (Partner benefit): There is a surge of low-end tablets starting to appear on
the market. See the HP Stream 7 and 8 series, which start at $99 and
$149 respectively. These tablets are equipped with quad-core Intel Atom
Z3735G 1.83GHz 64-bit processors but are saddled with a 32-bit UEFI
BIOS that does not support Legacy BIOS boot. As such, it is currently
impossible to install openSUSE on this hardware since 32-bit legacy
versions of openSUSE only support Legacy BIOS booting and 64-bit
versions only support 64-bit UEFI booting. Since Linux kernel 3.14, the
ability to boot from 32-bit UEFI into a 64-bit kernel has been
By supporting a 32-bit UEFI boot and a 64-bit kernel, openSUSE could
open the door to installation on a new market of low-cost tablets and
thus introduce openSUSE as an alternative to Microsoft Windows 8.1 32-
bit which currently is the only option as an operating system.

#1: Martin Pluskal (pluskalm) (2014-12-22 21:46:09)
Well it is possible to build i586 iso image using kiwi that boots in
uefi on such platform (in my case I tried Prestigio MultiPad Visconte
Quad): # linux32 kiwi --target-arch i586 --build suse-13.2-JeOS --type
iso -d /root/kiwi ... resulting image boots fine from usb flash
attached to tablet.
It is also possible to boot current factory installer/live iso, all you
need is to copy grubia32.efi to image (efi boot partition on it_ and
then boot x86_64 kernel.
There are at least two things that should be done: 1) Build i586
opensuse/factory images with grub2-efi (I am not sure it is missing
currently). 2) Add 32 bit grub2 to x86_64 image.

#2: giuseppe rossi (hawake) (2015-01-20 12:27:52) (reply to #1)
Hi, "# linux32 kiwi --target-arch i586 --build suse-13.2-JeOS --type
iso -d /root/kiwi ... resulting image boots fine from usb flash
attached to tablet." So the resulting image should work with x64
hardware and 32 bit UEFI? For example on an Asus Transformer T100? The
strange thing is that GParted Live works flawlessy, you burn it on an
USB drive and it will boot graphically with any problem.
Bye hawake

#3: Thorsten Kukuk (kukuk) (2015-06-18 13:53:53) (reply to #1)
You don't need to create i586 images/builds. It is really enough to
include bootia32.efi on the x86-64 media and grub2-i386-efi.

#4: Michal Kubeček (mkubecek) (2015-07-16 09:35:59)
While grub2 bootloader can load current openSUSE kernel as it is, to be
able to access efivars (and EFI services) in a 64-bit system booted
from 32-bit UEFI, CONFIG_EFI_MIXED option needs to be be enabled.
Without it, we can't even run grub2-install and the bootloader must be
set up manually (and EFI loader put in exactly the path where UEFI
expects it - e.g. EFI/Microsoft/Boot/bootmgfw.efi in my case).
I'm going to suggest enabling this option in the opensuse-kernel
mailing list.

#5: Jean-Daniel Dodin (jdd) (2015-11-05 17:01:30)
it's needed for this computer:


#6: Michael Chang (michael-chang) (2016-02-25 05:05:23)
Here is a quick list from me as todo list. 1. grub2 need to package
grub2-i386-efi on x86_64 builds, currently it's missing. (grub2) 2.
grub2 need to package a default (versatile) grub.efi to be used in
installation media creation (grub2/kiwi) 3. No secure boot support, no
shim, so use that grub.efi as bootia32.efi in media (grub2) 4. Use
linux command on all grub.cfg in 32 bit as linuxefi won't be there for
kernel's uefi boot stub, in which I don't know about it has any mixed
arch support? (kernel) 6. The xen loader or xen uefi boot stub can
handle this mixed mode? (xen) 7. YaST2 bootloader need to provide a 32
bit options on this detected x86_64 cpu then we could handle the update

+ #7: Michael Chang (michael-chang) (2016-02-25 05:11:35) (reply to #6)
+ Good. The kernel question seems to be answer by Michal. But sadly,
+ still the linuxefi lacks 32 bit support and have to be patched.

openSUSE Feature:

< Previous Next >
This Thread