You can it create with debootstrap and copy it to the sdcard…see link to my wiki. Deboostrap can be used from any ubuntu/debian system.
I can look if i still have an archive from other board that you can simply unpack.
There is a ubuntu jammy for arm64.
After unpacking install kernel and change uEnv.txt point to your kernel file
You will need a serial uart adapter to bootup system and configure network stack.
I don’t have a serial uart adapter
Time to get one 
if anything is not working you can look whats the problem. Else you are blind till your network stack works and you can login via ssh. I zhe moment board hangs at bootup or you have a problem in your network config you are unable to fix it.
Would building this version work?
do you really want an outdated system?
No, but is there an out dated source?
official repo uses kernel 4.19 (afaik never updated to include security fixes)…we have now 6.1…there are 3 years between.
i guess ubuntu image created by the repo is old too…my debbootstrap is already ubuntu 22.04
so unpack and flash the image from uboot github-releases (bpi-r64-sdmmc.img.gz), sync and re-read the sdcard (pluging out and in again). you will see 2 partitions: BPI_BOOT and BPI-ROOT
unpack the debootstrap-archive to the BPI-ROOT-partition (root-rights required)
then get kernel-package from my kernel-repo (6.1-main for r64), here you have 2 folders inside: BPI-BOOT and BPI-ROOT…unpack their content to the right partition (itb to BPI-BOOT and lib/modules to your ubuntu rootfs).
then you have to create an uEnv.txt pointing fit-var to your itb-filename
e.g.
fit=bpi-r64.itb
if this all is done you can try booting the board with the card and debug-uart to see if all gets up or you hang somewhere uboot or similar…it is possible that ssh-server is not installed and you get IP-address from your current router…need to configure it to fixed IP
Frank was pointing to my R64 script. But now I only maintain this one:
This will create a bootable SD card with up to date Linux kernel in just a few minutes. It runs Archlinux. It is almost the same as Ubuntu, except the package manager (apt) is different and the packages are much newer. Not standard packages one builds from the AUR with simple tools.
Best thing i like about Archlinux is rolling updates. Never need to upgrade to another version of OS anymore.
The Linux kernel is pre-built, so no need to figure out how to build one.
Ah ok! I will try that as well if Frank’s solution doesn’t work.
Would that bootstrap work? It says bpi-r2_bionic, also flashing bpi-r64_sdmmc.img.gz to the sd card doesn´t do anything. After flashing the sd card remains empty, what am I doing wrong?
For rootfs use arm64 yammy. Wiki example is for r2 (armhf and bionic)
Have you unpacked the s img an re-read partition table.
By openning the zip file and examining it or flashing it to the sd card?
Unpacking sd img and flash to card,then unpack the ubuntu rootfs to BPI-ROOT partition. And then you need kernel+modules as described above
You need to:
xz -dcv ~/Downloads/bpir64-sdmmc.img.xz | sudo dd of=/dev/sda
or
gunzip -c ~/Downloads/bpir64-sdmmc.img.gz | sudo dd of=/dev/sda
To unpack and flash it to the card in one go. Make sure you enter the correct /dev/sdX. And then
sync
To make sure cache is emptied and the write is finished.
If you want to see the result, you could open the program disks in debian/ubuntu/arch.
is there a way to see the progress? I tried pv after installing it but pv is not working if I write in like this: gunzip pv -c ~/Downloads/bpi-r64_sdmmc.img.gz | sudo dd of=/dev/sdb
Add status=progress to the arguments of dd.
But anyway, as Frank suggested, it might be easier to use the ready made script. It also writes to the card for you. Just follow the readme.
Is that the script you mention in post #17?
Correct. On github you can read the readme:
I would suggest to post any questions about it in the topic from post #17
Edit: Posted the question in the thread from post#17.
How would I find the Arch equivalent of a Ubuntu package?