sudo gdisk /dev/sdc

Command (? for help): r
Recovery/transformation command (? for help): h
Type from one to three GPT partition numbers, separated by spaces, to be added to the hybrid MBR, in sequence: 1 2 3
Place EFI GPT (0xEE) partition first in MBR (good for GRUB)? (Y/N): N

Creating entry for GPT partition #1 (MBR partition #2)
Enter an MBR hex code (default EF): 
Set the bootable flag? (Y/N): N

Creating entry for GPT partition #2 (MBR partition #3)
Enter an MBR hex code (default EF): 
Set the bootable flag? (Y/N): N

Creating entry for GPT partition #3 (MBR partition #4)
Enter an MBR hex code (default 83): 
Set the bootable flag? (Y/N): Y

Recovery/transformation command (? for help): x
Expert command (? for help): h
Expert command (? for help): w

Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
PARTITIONS!!

Do you want to proceed? (Y/N): Y

EFI_MOUNTPOINT=/run/media/avouch/EFS
DATA_MOUNTPOINT=/run/media/avouch/Backup

DISK=/dev/sdc
EFI_DRIVE=/dev/sdc2
DATA_DRIVE=/dev/sdc3


sudo mount -t vfat $EFI_DRIVE $EFI_MOUNTPOINT
sudo mount -t vfat $DATA_DRIVE $DATA_MOUNTPOINT


sudo mkdir -p $DATA_MOUNTPOINT/boot/grub

sudo grub-install --target=x86_64-efi --efi-directory=$EFI_MOUNTPOINT --boot-directory=$DATA_MOUNTPOINT/boot --removable --recheck

sudo grub-install --target=i386-pc --boot-directory=$DATA_MOUNTPOINT/boot --recheck $DISK




