Intel deactivated Legacy Mode = Bios = CRM on the NUC UEFI and I cant get the iso to boot on the Intel NUC
I have very good news for you. But first, what model NUC are you running? - I'm running the NUC6AYH. The "Visual Bios" is a thing of beauty.
For me, holding down F2 while it boots gets you into it. There, you can enable "legacy boot" to exist along with uefi, or in fact make it an old school "Legacy only" box. Very flexible.
I'd be very surprised that you can't do the same, unless perhaps some prior owner locked you out?
I'm a linux noob and from what it seems every linux distribution is like you download the right iso, clean the usb
drive and for example run etcher and patch the iso onto it.
Now this however works with Kubuntu which I just tested and some other Linux distributions but not with
tiny core. The nuc tells me there's no boot device.
That's right. Although us gray-beards do a DD. As it stands, the current TinyCorePure64 iso is not even recognized as a boot device for uefi-ONLY boxes.
It is NOT a 3rd party burner issue. There is something in the 64-bit iso that makes it different than most when it comes to uefi-only. Even though it may be following technical standards, the real-world hardware disagrees. I'm researching that myself.
So the first solution is to get into your Visual Bios and enable Legacy boot options. Visual Bios makes this so easy and simple to see. A far cry from the older bios menus that's for sure!
Your second option, is to utilize a chain-boot process.
The VENTOY usb stick maker, usually designed to make booting multiple iso's a breeze, can obviously be used with only a single one if you want. There is a Windows version, and Linux version (which is a script). GPL.
Ventoy solves TWO problems: It will be recognized by uefi-only hardware as a valid boot device. And, if your box is locked into Secure-Boot and you can't change that, you can register the VENTOY keys with Secure Boot and proceed.
All that you need on the VENtoy boot stick, is the TinyCorePure64 iso, which it will chain load and you operate on TC grub menus (if you want) like usual when it gets to that point.
Ventoy and other multibooters are discussed in other threads.
It seems I'm missing the right partition after flashing the usb which seems to be some kind of efi partiton.
VENtoy takes care of that. I still can't figure out why the release iso doesn't boot on uefi-only. Maybe testing on an actual uefi-only machine would help. But there may be a technical or other forward-looking reason as to why it won't.
Nevertheless, with TinyCore being a toolkit rather than a "distro", there are many ways to accomplish things.
So hope this helps. The easiest thing to do is figure out why you cannot enable legacy mode in Visual Bios. Out of the box, you should be able to do so. If someone has tweaked the bios prior to you, well, that's a variable I can't touch from this distance.
VENtoy can be used to overcome this obstacle if it comes to that.
Just know that TinyCore does not agree with everyone. If you are looking for a hands-off experience, well you may become frustrated. If you are the type who likes to turn wrenches, which means more than just following a checklist, then TC might be for you.