On 13.06.2022 22:48, Simon Becherer wrote:
ok, i may have understand if gpt i must have a pbr ?partition? where "core.img" is inside.
PBR == Partition Boot Record
i checked at the moment "gparted" (only reduce and then make new partiton (without writing)) to check the filsystem dialog. but i did not find a filesystem called "pbr" (even if pbr will not be a real filesystem partition)
As you are apparently banned by Google: https://en.wikipedia.org/wiki/BIOS_boot_partition
so if i make space by reducing my existing partitions, how do i tell the system where to put the pbr partition?
simoN
When booting in UEFI mode the UEFI starts an EFI program , which name/path is stored in UEFIs NVRAM from the ESP as bootloader. When grub is installed , this should be either shim.efi ( with secure boot) or the efi incarnation of grub.
Then there is the restriction that BIOS ( and CSM ) usually doesn't support NVME protocol but only SATA protocol.
So you can't boot a NVME disk with CSM unless the rare case that the nvme disk provides an BIOS extension PROM with NVME driver.
And there is the Windows only restriction that the Windows bootloader only supports either legacy boot with MBR partition scheme or UEFI boot with GPT scheme