On Thu, Mar 17, 2016 at 04:40:38PM +0100, Ard Biesheuvel wrote: > On 17 March 2016 at 16:31, Leif Lindholm <[email protected]> wrote: > > On Thu, Mar 17, 2016 at 02:55:00PM +0100, Ard Biesheuvel wrote: > >> The function ArmClearMemoryRegionReadOnly() was supposed to undo the > >> effect of ArmSetMemoryRegionReadOnly(), but instead, it sets the > >> permissions > >> to EL0-no access, EL1-read-only. Since the EL0 bit should be 1 to align > >> with EL2/3 (where the bit is SBO), use TT_AP_RW_RW instead, which makes the > >> entry read-write for EL0 when executing at EL1, and read-write for all > >> other > >> levels. > >> > >> Contributed-under: TianoCore Contribution Agreement 1.0 > >> Signed-off-by: Ard Biesheuvel <[email protected]> > > > > Happy with the RO->RW, confused by the NO->RW. > > I presume this is about consistency? > > Why do we need access for EL0? > > > > We don't. But when running on EL2 or EL3, the same bit needs to be > set, so either we have two separate definitions, for EL1 and EL2/3, or > we just set the bit for EL0 as well, which shouldn't matter anyway > since we never return to EL0
OK, that makes sense: Reviewed-by: Leif Lindholm <[email protected]> _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
