Cannot install GRUB2-EFI in my Micro-SD Card

[Dorian VEGARA]

Hello to everyone,

I need to install GRUB2 for EFI computer in my micro-SD card. But when
I type the command grub2-install, an error appears :
" grub2-install : error : /usr/lib/grub/x86_64-efi/modinfo.sh doesn't
exist. Use --target or --directory. "

Let me introduce what I have done.
1. First, I configured my micro-SD card : there is a fat32 partition
with the boot flag, and another partition (ext3).
2. I created a repertory A that mounts the fat32 partition.
3. In this repertory A, I created a repertory " boot " in which I
created another repertory, named "EFI".
4. My distro is Fedora 21 ; I typed this command to install GRUB2 :
grub2-install --boot-directory=/dev/A/boot
--target=/boot/efi/EFI/BOOT/grubx64.efi
--efi-directory=/dev/A/boot/EFI /dev/sdc

(/dev/sdc seems to be my microSD-card)

So, when I launch this command, the error appears. Indeed, the
repertory "x86_64-efi" doesn't exist in "/usr/lib/grub".

Why ? Did I forget a step ? Have I to install a package ?
Thanks a lot.

Best regards,
Dorian