> Why don't you use the normal setup? Spend a lot of time on research, it would be nice to finish.
I made experiments with a FlashDrive, and create GPT there, if I want to use standard Debian Image how I should partition that flash drive (MBR, GPT)? > Do you need a special configuration here or is the default just fine? Need just working one. But I am confusing about how GRUB would get a plenty of things related to filesystem, kernel location and so on. > If you create a separate boot partition (do you really need it?), it must be mounted at /boot. Here where the mess starts. How GRUB and Kernel would get information about all this mounting points during the Boot.