On 01/04/2018 10:26 AM, Christopher Ursich wrote:
Hi, all. First-timer here.
I am setting up a new Raspberry Pi 3. When I review the AltArch pages, I see that most of the RPi3 coverage is categorized under Arm32, including
https://wiki.centos.org/SpecialInterestGroup/AltArch/Arm32/RaspberryPi3
I'm under the impression that the RPi3 is actually a AArch64 system. I'm not sure whether I should use
http://mirror.centos.org/altarch/7/isos/armhfp/CentOS-Userland-7-armv7hl-Min...
versus
http://mirror.centos.org/altarch/7/isos/aarch64/CentOS-7-aarch64-rootfs-7.4....
Can a more-experienced person clarify this for me?
The aarch64 build we produce was aimed at server systems like Cavium's ThunderX initially. There are some limitations with the aarch64 distribution kernel (currently based on RH's kernel-alt 4.11) which make it terrible to run on the rpi.
1. It's set up for 64k pagesize. This, combined with some CMA math in the kernel means that you'll take a pretty severe memory hit when running the CentOS aarch64 build on the rpi. In some cases this memory hit consumes nearly all of the available ram.
2. The distro is built to expect ACPI. While you can disable it and it'll work okay, it generates quite a number of errors in the logs.
In short, the rpi currently works better (by default) as a 32bit setup and we want users to have a better experience.