[1626176406] Upstream Reporter: Dusty Mabe
Upstream issue status: Closed
Upstream description:

I just pro-actively updated my `t4g.medium` AWS instance to `38.20230310.1.0` and it didn't come back. Upon inspecting the serial console I see:

```
error: ../../grub-core/loader/arm64/linux.c:58:invalid magic number.
error: ../../grub-core/loader/arm64/linux.c:278:you need to load the kernel
first.

Press any key to continue...
```

Pressing a key and selecting the older boot entry (thankfully I had console access) allowed me to re-connect with my system.

This system was provisioned a long time ago with `34.20210904.2.0` (`testing` stream; later moved over to the `next` stream to allow for earlier testing).

The problem here is that by default the bootloader on machines isn't updated so it keeps the one from when you first installed the machine. [bootupd](https://github.com/coreos/bootupd) was created to solve this problem, but is [still a work in progress](https://github.com/coreos/bootupd#status) so not widely used.

Here's what it shows on my system:

```
[core@dustymabe ~]$ sudo bootupctl status
Component EFI
Installed: grub2-efi-aa64-1:2.06-2.fc34.aarch64,shim-aa64-15.4-4.aarch64
Update: Available: grub2-efi-aa64-1:2.06-88.fc37.aarch64,shim-aa64-15.6-2.aarch64
No components are adoptable.
CoreOS aleph image ID: fedora-coreos-34.20210904.2.0-qemu.aarch64.qcow2
Boot method: EFI
```

After updating the bootloader...

```
[core@dustymabe ~]$ sudo bootupctl update
Updated EFI: grub2-efi-aa64-1:2.06-88.fc37.aarch64,shim-aa64-15.6-2.aarch64
```

I am able to boot the system:

```
[core@dustymabe ~]$ rpm-ostree status
State: idle
AutomaticUpdatesDriver: Zincati
DriverState: active; periodically polling for updates (last checked Wed 2023-03-15 19:38:43 UTC)
Deployments:
? fedora:fedora/aarch64/coreos/next
Version: 38.20230310.1.0 (2023-03-10T22:51:50Z)
Commit: b0fdf736cdbbd3971380d5549635e30155f07af6100925d987de623b4722637f
GPGSignature: Valid signature by 6A51BBABBA3D5467B6171221809A8D7CEB10B464

fedora:fedora/aarch64/coreos/next
Version: 37.20230303.1.0 (2023-03-06T18:55:26Z)
Commit: 0e785d34bddf7ff985fe49a4a9bdf2e88050c366f02b19f28df74b67fb3792ae
GPGSignature: Valid signature by ACB5EE4E831C74BB7C168D27F55AD3FB5323552A

```

This is most likely due to recent changes for aarch64 kernels around [EFI_ZBOOT](https://cateee.net/lkddb/web-lkddb/EFI_ZBOOT.html), which we also think is the root cause for https://github.com/coreos/fedora-coreos-tracker/issues/1430.