On 04/05/2023 at 16:21, Peter Ehlert wrote:"Install the GRUB boot loader" menu ... 6 itemsEnter device manually/dev/sda (usb-SanDisk .../dev/sdb (ata-WL4000G .../dev/sdc (ata-WDC_WD300.../dev/sdd (ata-WDC_WD300.../dev/sde (ata-SanDisk_SDSSDA240G_162248447811)I selected /dev/sde and pressed the Continue buttonthen the GUI progress bar Installing GRUB and I see Running"grub-install /dev/sdd" ...in this case sdd was the install location, sde is the drive that has abios_grub flagged partitionOK, I think I managed to reproduce the issue and it shares the rootcause with another bug I am currently chasing (GRUB is not installed atall). Some logic in grub-installer seems to be flawed but I still needto understand the original intent before I can submit a patch for both bugs.Meanwhile, a workaround is to enter the boot device manually.
setting up BIOS to boot from a drive that does not have a bios_grubflagged partition results in:"GPT-formatted disk.Legacy boot not supported. Press any key to reboot."If this is a message from the BIOS, then it is flawed. A compliantBIOS should not care about the partition table, even less the presenceof any kind of partition. All a BIOS should care about is the presenceof the "boot signature" 0x55, 0xAA at the end of the boot sector.Yes, that is from the BIOS(...)root@z820-3:~# grub-install /dev/sda && update-grubInstalling for i386-pc platform.grub-install: warning: this GPT partition label contains no BIOS BootPartition; embedding won't be possible.grub-install: error: embedding is not possible, but this is required forcross-disk install.This failure has nothing to do with the above. You are trying to installGRUB on a GPT disk which is not the one containing /boot ("cross-disk"),and this requires a BIOS boot partition.