By enabling developer mode and running "sudo crossystem dev_boot_usb=1 dev_boot_signed_only=0" to allow booting alternative images. Then you can boot USB based images and they don't have to be signed.
chromebooks can boot from other sources in developer mode, pressing ctrl + u on startup brings up a generic SeaBIOS when certain flags are enabled from crosh
“The Depthboot base distros all allow image/iso/rootfs sharing, but only in an unmodified form. The Depthboot script customizes some internal distro behavior (for example it adds our eupnea packages) and thereby creates modified images. To allow modified images to be shared, all trademarked content would have to be removed, i.e. all Distro logos.”
They add some of their own sauce to each of the distros. (This you're allowed to do (and do very easily because it's free (as in freedom) software). What you're not allowed do is build an ISO of the result and distribute and still call it Arch or Pop!_OS or whatever (because … drumroll … it isn't any more). You can't expect Distro makers to be getting user support requests from users from custom versions of their distros that a 3rd-party made.
All this is obvious and perfectly reasonable when you think about it. And without free software it'd be difficult for a non mega-corp to create and maintain a project like this. So what you see as user hostile is actually users being allowed an able to try shiny new software on their proprietary hardware/software combo.
Their FAQ has a "why is distributing our images illegal" section.
Not sure why that would mean hating users, distributing modified software while keeping their trademarks is always a no-no, at least with Linux it's possible to just rebrand (which these guys don't want to do).
I guess they could ask to merge their stuff upstream and get away from these roundabout ways.
- Archlinux has clear trademark policies that allows you to distribute derived product as long as it is not done with a commercial intent.
- Ubuntu policies mention asking them for permission, I guess Eupnea just didn't bother.
- Debian trademark policy do not mention derived work, my wild guess is it would be allowed as they say you can use their trademark to promote debian and distributing a lightly modified version that works on more devices looks to me like promoting debian work. In doubt I would still ask.
- Pop!OS do not have a public trademark policy, so Eupnea would have to ask.
- Fedora trademark says you can do it if you are using their secondary mark: Fedora Remix. And they facilitiates this with the existence of 3 packages generic-logos, generic-release, and generic-release-notes that need to replace fedora-logos, fedora-release, and fedora-release-notes packages in your distro (you can also do your own derivatives). Not a huge deal.
So basically Eupnea is lying. They just don't want to bother. In 1 or 2 cases, it is clear that it can distribute it as is, in 2 cases it needs to ask permission before arguing it is or not possible and in the last case they can distribute it as is but need to advertise it differently (fedora remix instead of fedora and replacing 3 packages).
