Booteable USB for Legacy and UEFI

[sudodus]

If you want to boot both UEFI or Legacy on different computers, you will need the bios-grub unformatted partition. I don't see anything in the link you posted that discusses booting in Legacy mode.

Thanks for the heads up.

Please specify which link and where we should expect details about the bios_grub partition.

[yancek]

Please specify which link and where we should expect details about the bios_grub partition.

The link I was referring to was posted by the OP in post 6 and was what the OP used to attempt to create a bootable USB to boot UEFI and Legacy. Reviewing that link shows nothing about installing in Legacy mode but only UEFI. To boot also in Legacy mode, a bios_grub partition is also needed, both an EFI partition and an unformatted 1-2MB bios_grub partition, then installing Grub using the grub-install method described in post 5 modified to meet the OP's situation.

[sudodus]

Thanks @yancek

[yancek]

No problem.