Hello,

I saw that we can get ramdisk image from tarballs.openstack.org[1] in
ironic doc[2].

I would like to ask whether all the above are of amd64 architecture.
Where can I download the ramdisk image of aarch64 architecture？

When I built aarch64 image locally, It's always failed.

```shell
# export ARCH=aarch64
# ironic-python-agent-builder fedora
...
mount: /tmp/tmp.1yEQhatS1X/mnt: wrong fs type, bad option, bad
superblock on /dev/mapper/loop0p5, missing codepage or helper program,
or other error.

# ironic-python-agent-builder centos
...
2023-02-12 14:15:02.361 | dib-run-parts Running
/tmp/in_target.d/pre-install.d/01-00-centos-python3
2023-02-12 14:15:05.204 | CentOS Linux 8 - AppStream
    17  B/s |  38  B     00:02
2023-02-12 14:15:05.209 | Error: Failed to download metadata for repo
'appstream': Cannot prepare internal mirrorlist: No URLs in mirrorlist


# ironic-python-agent-builder ubuntu
...
2023-02-12 14:15:31.623 | Fetching Base Image
2023-02-12 14:15:31.657 |   % Total    % Received % Xferd  Average
Speed   Time    Time     Time  Current
2023-02-12 14:15:31.657 |                                  Dload
Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
2023-02-12 14:15:32.388 | Server copy has not changed. Using locally
cached https://cloud-images.ubuntu.com/focal/current/SHA256SUMS
2023-02-12 14:15:32.422 |   % Total    % Received % Xferd  Average
Speed   Time    Time     Time  Current
2023-02-12 14:15:32.422 |                                  Dload
Upload   Total   Spent    Left  Speed
100   286  100   286    0     0    418      0 --:--:-- --:--:-- --:--:--   418
2023-02-12 14:15:33.110 | Server returned an unexpected response code. [404]
```

[1]: https://tarballs.opendev.org/openstack/ironic-python-agent/dib/files/
[2]: https://docs.openstack.org/ironic/latest/install/deploy-ramdisk.html