Comment # 11 on bug 1122614 from Michael Chang

(In reply to Guillaume GARDET from comment #10)
> (In reply to Michael Chang from comment #8)
> > Hm. Now that it seems to me the serial console problem could be related. Try
> > if this work ? 
> > 
> >   grub2-install --modules=serial
> 
> 
> It returns:
>   Installing for arm-uboot platform.
>   grub2-install: warning: no hints available for your platform. Expect
> reduced performance.
>   grub2-install: error: cannot open `/usr/share/grub2/arm-uboot/serial.mod':
> No such file or directory.
> 
> 
> And there is no grub.efi in /usr/share/grub2/arm-uboot/ is it expected?

Sorry I think the correct command is :

  grub2-install --with-platform=arm-efi -no-nvram --removable --modules=serial

The default architecture of grub utility we packaged for armv7 is arm-uboot. 
While running it will detect efi firmware through the presence of
/sys/firmware/efi and change the installation to arm-efi architecture
accordingly. For the EFI on U-Boot, no efi boot variable on the system so no 
/sys/firmware/efi, therefore we need to manually specify the platform
parameters for grub-install (This is also how update-bootloader handles it)