Le 21/02/2022 à 10:11, David Ventura a écrit :
I'm not sure how to do that; running grub-install with either a file or a loop device as target gets ignored and instead targets my primary disk: $ grub-install -vvv /dev/loop13 grub-install: info: executing modprobe efivars 2>/dev/null. grub-install: info: Looking for /sys/firmware/efi ... grub-install: info: ...found. Installing for x86_64-efi platform.
The target device is ignored because grub-install detects an EFI platform and defaults to install for EFI boot. You must force BIOS platform with --target=i386-pc.
On top of that, I'm building a franken-disk that can boot both in BIOS/GPT and UEFI/GPT with a bios boot partition and Grub in the ESP. I'm not sure if grub-install would be confused by this, or just work. Do you have any suggestions for this?
I observed that some BIOS platforms won't boot if the boot flag is not set on a partition entry of the MBR ; conversely, some UEFI platforms won't boot if the boot flag is set on the GPT partition entry of the MBR. Workaround : create a hybrid/DOS MBR or set the boot flag on an empty partition entry of the MBR.
