Copied an ISO file to a flash drive and wonderd why it doesn't boot...

Very common. Even some senior devs do that and come complaining that it isn't booting.

I use Etcher for my Raspberry Pi sd-boots. Works well.

etcher or Rufus is the way to go here 👍

@darxor what about dd or DiskDestroyer

@jbjjbjjbj these are great for command line, Etcher is great when you have a GUI up and running.

@sudorm-rf Never heard of it, always been a pretty big rofus fan.

I use Rufus because it works and it reminds me of Deponia :D

Hmm. I wonder if a CD will boot if it has a single data track with a /EFI directory (or even iso9660 format with an EFI directory).

The fact that CDs boot differently from every other medium is an interesting legacy carryover.

There are some Linux distros setup so their isos will boot if you simply use dd with a USB stick, but if you're stuck with one that doesn't, there's unetbootin.

sudo dd if=/some/path/to/iso.iso of=/dev/sdc bs=512

@djsumdog I think it somewhat depends on the mainboard.
I had laptops which only could bood from EFIs on a GPT FAT32 partition (old HP EliteBook), others only when on NTFS (GPT & MBR)...