How to reinstall grub2 efi bootloader on ubuntu

grub-reinstall

#hd-efi=/dev/sda1
#hd-root=/dev/sda2
#hd-hdd=/dev/sda

[ -d /sys/firmware/efi ] && echo "EFI boot on HDD" || echo "Legacy boot on HDD"

sudo mount $hd-root /mnt
#if UEFi
sudo mount $hd-efi /mnt/boot/efi
for i in /dev /dev/pts /proc /sys /run; do sudo mount -B $i /mnt$i; done
sudo chroot /mnt 
grub-install /dev/sda
update-grub

#grub-install error
#Installing for i386-pc platform.
#grub-install: warning: this GPT partition label contains no BIOS Boot Partition; embedding won't be possible.
#grub-install: error: embedding is not possible, but this is required for cross-disk install.

#try on live boot
parted $hd-hdd set 1 bios_grub on
parted $hd-hdd print

#retry in chroot
grub-install /dev/sda
update-grub