Wednesday, April 27, 2016

[fedora-arm] Re: armhf dnf is not working on aarch64 kernel

>> >> > Hi all,
>> >> >
>> >> > I want to use the armhf fedora rootfs on the aarch64 bit kernel.
>> >>
>> >> You can't, it's not a use case we support.
>> >>
>> > Why not? All arm binaries can be runnable on aarch32 mode of aarch64
>> > kernel.
>> Not exactly actually, it's possible to have aarch64/ARMv8 CPUs that
>> don't have the 32 bit components.
>> >> > The question is 'how can I run 'dnf' command on armhf fedora with
>> >> > aarch64 kernel?'
>> >>
>> >> No, the ARMv7 and aarch64 ABI aren't compatible, the only way we
>> >> support ARMv7 on aarch64 is via virtualisation. We will not be
>> >> supporting this or a "multilib" usecase.
>> >
>> >
>> > The aarch64 kernel can execute both aarch64 and aarch32(fully compatible
>> > armv7) binaries. For example, the kernel of raspberry pi 3 is aarch64
>> > and
>> > fedora arm version can't run on rpi3. Even all binaries can run on it
>> > but
>> > only dnf command can't do that.
>> Actually that isn't entirely true. The kernel that's currently shipped
>> in raspbian for RPi3 is actually an ARMv7 kernel where the firmware
>> boots the ARM cores as v7 cores. The kernel code that's running there
>> is ARMv7 code not cortex-a53 code paths. That is a fairly special
>> usecase and you can actually do that on Fedora ARMv7 with a Fedora
>> ARMv7 kernel, not a aarch64 kernel.
> Ah. Sorry. It's not good example. Actually, rpi3 try to enable aarch64
> kernel but they can't di that lack of time.
> (
> Pine64 is also available cheap board which kernel is aarch64 version.
>> ARM multilib is something we explicitly decided not to support when we
>> were dealing with that. Multilib is a mess on x86, it's not a mess we
>> need on ARM.
> No. It's not multilib. I want to run _only_ armv7 binaries and libraries. I
> want to know why only 'dnf' is impossible do that.

Because we don't support it. For example the aarch64 kernels have a
64K page size, ARMv7 uses 4K. So you'd need a custom kernel before you
even start so you may as well do a custom image.
arm mailing list

No comments:

Post a Comment