On 02/02/2024 01:46, Dmitry wrote:
3. Now I want to boot using that Flash. 1. ESP is a partition that stores GRUB Binary. /boot/EFI/Name/grub64.eif
On a *removable* drive EFI/Boot/bootx64.efi (that is actually /usr/lib/shim/shimx64.efi.signed that loads grubx64.efi) may allow to boot without modification of boot entries in NVRAM. Likely it is implementation-dependent whether a drive with GPT partition table is considered as a removable. For regular (internal) drives UEFI requires GPT. I do not suggest you to use msdos partition table that might be suitable for live media, not for installation with multiple partitions including Linux native file systems.
3. At the system partition there is a /boot/grub/grub.cfg
There are 2 grub.cfg: for ESP and for /boot