I want to dual boot my computer. It has an EFI, not a traditional BIOS. It has two drives. I want to install Gentoo Linux on the first NVMe SSD (according to the EFI firmware). I currently have Windows 10 installed on the main drive (second NVMe SSD, according to firmware). I have my second SSD as the default boot drive (physical location to logical numbering of drive was an afterthought) with the whole drive used for the OS. After erasing what used to be my data drive, I am now ready to install my distro.
Since I want to leave the default boot drive setting on the firmware the same, I have a few choices to make as far as partitioning the new drive:
- Omit any boot partition and use the EFI partition of the main drive. Only issue is it would need to be resized, which would require the moving of around 800GiB of data over by around 412 MiB, creating a significant amount of wear on the drive.
- Create a FAT32 partition at the beginning of the new drive, setting the
bootflags with parted.
- Create a FAT32 partition at the beginning of the new drive, without adding any flags to the partition.
For the latter two options, I would use the FAT32 partition to store my kernel(s) and use a relatively lightweight boot-loader like rEFInd on the first drive (by default Windows 10 will only create an insufficient 100MiB partition for use for EFI, leaving little room for kernels).
Since I would prefer not to use the first option, my question essentially boils down to the following: Would setting (or not setting) the flags on the secondary drive (as in #2) mess with booting either OS? Would the EFI firmware be able to run a kernel (or GRUB2) from the secondary drive after loading the boot menu (rEFInd) from the main drive? The kernel will be executed directly by the firmware. It will have a .EFI file extension.