Make it easy to drop components

[cgwalters]

For Fedora bootc and derivatives the default is that we install+update both BIOS + EFI.

Let's add a UX that allows dropping out components from the update payload...and in theory perhaps also uninstall the relevant packages if they exist.

rpm -e grub2-pc grub2-pc-modules
bootupctl backend regenerate-update-metadata

or so?

Related to this, for "from scratch" builds we should handle the case where BIOS doesn't exist.

[HuijingHei]

Is this meant to remove file /usr/lib/bootupd/updates/BIOS.json (for example)? To uninstall related packages, only get grub2-tools in json file that is not we want to remove, maybe should specify grub2-pc grub2-pc-modules or let user run rpm -e.

# cat /usr/lib/bootupd/updates/BIOS.json | jq
{
  "timestamp": "2025-08-07T18:40:56Z",
  "version": "grub2-tools-1:2.12-40.fc43.x86_64",
  "versions": [
    {
      "name": "grub2",
      "rpm_evr": "1:2.12-40.fc43"
    }
  ]
}

How about bootupctl backend remove-update-metadata --component BIOS ? And we only want this to run on x86_64 that has both BIOS + EFI, is this right?

[cgwalters]

Is this meant to remove file /usr/lib/bootupd/updates/BIOS.json (for example)?

Yes exactly!

How about bootupctl backend remove-update-metadata --component BIOS ? And we only want this to run on x86_64 that has both BIOS + EFI, is this right?

So far the backend verb has been a hidden thing but I think if we're giving users something to invoke it should be a properly documented thing (which relates to more of this code) it should probably just be a bootupctl remove-component BIOS or so/