aarch64 kernel on Raspberry Pi 4 - instructions

[esotericnonsense]

Hi all,

I put together an AUR package to build the standard config with minimal tweaks for aarch64.

https://git.sr.ht/~esotericnonsense/lin ... i4-aarch64

I've also put together a blog post explaining how to use it

https://esotericnonsense.com/blog/rpi-chroot.html

It's likely that some of the steps in that guide can be skipped - it may be possible to just boot the aarch64 image directly with some tweaks - but I haven't tried it because I'm using my rpi as a desktop and only have the one.

Cheers!

~ esotericnonsense / Daniel Edgecumbe

[graysky]

viewtopic.php?f=67&t=14096

[esotericnonsense]

Thanks for the link! I realised independently that you could just use the aarch64 mainline image and replace the kernel + install those packages.

The problem was that initially I was trying to build the kernel on the rpi itself via cross-compilation to aarch64, similar to the old Arch guide of making the 32-64 transition.

However, because alarm doesn't have multilib repos (at least, not that I know of) I broke the system halfway through once 32bit glibc was gone. Hence the way in which I arrived at my system being this roundabout 32 to 64 conversion.

If you use another machine then indeed you can just start out by compiling the kernel and using the aarch64 userland to begin with which is far simpler indeed.

[moonman]

I didn't actually uyse generic aarch64 to create the rootfs.
pacstrap + chroot is more efficient and cleaner.

[lvml]

For those who have not compared the 32bit and 64bit modes on the Pi 4 themselves yet, can you describe in a few words what benefits one might expect from the 64bit mode?

For x86_64 CPUs, almost everyone today knows about the richer instruction set, more registers, and the larger usable address space.

But is there a tangible benefit feature/performance wise also from the ARM v8 instruction set?

[vap0rtranz]

$this->bbcode_second_pass_quote('lvml', 'o')r those who have not compared the 32bit and 64bit modes on the Pi 4 themselves yet, can you describe in a few words what benefits one might expect from the 64bit mode?

[WebReflection]

AFAIK Linux 5.5 brought in support for the Raspberry Pi 4, and I wonder if any of this is needed anymore or if it's planned to provide an aarch64 version of ArchLinux ARM for the Pi 4 (IIRC Manjaro has been there for few months now).

Does anyone have any clue what's the current path forward regarding Pi4?

Thanks in advance for any sort of hint/link/insight

$this->bbcode_second_pass_quote('', '
')AFAIK Linux 5.5 brought in support for the Raspberry Pi 4, and I wonder if any of this is needed anymore or if it's planned to provide an aarch64 version of ArchLinux ARM for the Pi 4 (IIRC Manjaro has been there for few months now).

[WebReflection]

Thanks to sum it up, and yes, most posts around this look like misleading indeed, but it's also easy to misunderstand these summaries:
https://www.cnx-software.com/2020/01/27 ... itectures/

Although, pointing at a link that's about rpi-zero can also create great confusion, don't you think?

Anyway, my question was rather related to the fact there are ways to have aarch64 ArchLinuxARM working on the Pi4, and seeing how many moving parts there are around this, I was hoping for some better information (which you actually provided).

Looking forward to the day rpi3 and rpi4 can both run on 64bit, but I guess, at this point, that day is at least few months further away.

[WebReflection]

FWIW, also another reason to ask for aarch64
https://hackaday.com/2020/01/28/raspber ... s-64-bits/