The ARM ArmMmuLib code currently does not take into account that setting permissions on a region should take into account that a region may not be mapped yet to begin with. So when updating a section descriptor whose old value is zero, pass in the address explicitly. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>