[arch-general] Grub-efi install issue

Hi all, I am trying to install arch to a efi system and got as far as the configure the packages but grub install is whare I am stuck. First off, in the wiki it says to mount the efi partition, but it doesn't say whare to mount it to.  Secondly, I run the following to install grub-install --target=x86_64-efi --efi-directory=/dev/sda1 --bootloader-id=GRUB and get the following error. something about unable to get the udev.  What am I missing?  Would something rong?  The wiki artical s a bit confusing. Thanks.