grub-bios-setup

Set up a device to use GRUB with a BIOS configuration. You should use grub-install instead of grub-bios-setup in most cases. More information: https://manned.org/grub-bios-setup.8.

grub-bios-setup /dev/sdX

grub-bios-setup --force /dev/sdX

grub-bios-setup --directory=/boot/grub /dev/sdX