I made tests using grml 2013.09-rc1 32bits and 64bits versions using boot options for work with brazilian portuguese keyboard layouts abnt and abnt2.

at grml boot press (key tab) and add following options:

xkeyboard=br lang=br tz=America/Sao_Paulo

After this quick boot if you choose q (you go to terminal session with correct keyboard layout for computers sold here in Brazil that use abnt/abnt2 layout.

If you choose x (for graphics options) xkeyboard brings rigth keyboard map for work with iceweasel (firefox) browser, (like chars /, :, ", ').

And about not less import time zone tz=America/Sao_Paulo or tz=America/Brasilia (all very important for disk, file timestamps not in utc time but in brazil localtime utc -3).

thanks.