How can I configure the keyboard layout for the FileVault 2 unlock screen? I installed Mac OS X Lion and enabled FileVault to have a full disk encryption of my system disk. I bought my Mac with a French keyboard (since I'm French and used to this layout) but my Mac is configured to be in English, except for the keyboard layout.

However, after enabling FileVault, my Mac rebooted and I was greeted with the FileVault unlock screen and asked for my password. I entered it, and was told it was incorrect. After many try, I suspected that the keyboard layout was not French but US. I managed to enter my keyboard with this mapping and it was accepted (I'm lucky that I know enough of the Us keyboard layout to do that).

I went to the System Preferences, but I didn't see an option to change the keyboard layout on the FileVault unlock screen. Nor did I see an option to changed it when I was blocked at the prompt.

So, I'm wondering how can I change the keyboard layout of the FileVault unlock screen?
The following works.

System Preferences -> Login -> Login Options -> Check Enable Show Input menu in login window