The PCD gArmTokenSpaceGuid.PcdArmArchTimerFreqInHz is used in the
SEC phase (if applicable) to write the platform's counter frequency
to the CNTFRQ system register, as this needs to be done by the highest
exception level implemented.
Under virtualization, we should be able to rely on the host to have
initialized this register to a sane value, as we run at EL1 and only
use the virtual timer, so the PcdArmArchTimerFreqInHz PCD has little
meaning here.
So in either case, by the time we enter the DXE phase, we can use the
CNTFRQ system register to read the frequency instead of looking at the
PCD.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Olivier Martin <olivier.martin@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16090 6f19259b-4bc3-4df7-8a09-765794883524
Move TimerDxe and ArmArchTimerLib to ArmGenericTimerCounterLib, and update all
platforms to select the physical counter instance they have been using
implicitly all along.
Contributed-under: TianoCore Contribution Agreement 1.0
Acked-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-By: Olivier Martin <olivier.martin@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16078 6f19259b-4bc3-4df7-8a09-765794883524
Ard Biesheuvel
Ronald Cron
oliviermartin