On Fri, May 18, 2018 at 02:06:11PM +0100, Grant Likely wrote: > Document the requirements for secure firmware to implement PSCI, > particularly in regard to multiprocessor CPU startup protocol. PSCI is > by far the preferred solution, but make allowance for the other existing > methods. > > Signed-off-by: Grant Likely <[email protected]>
Reviewed-by: Daniel Thompson <[email protected]> > --- > source/ebbr.rst | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > > diff --git a/source/ebbr.rst b/source/ebbr.rst > index 700feba..59af3c9 100644 > --- a/source/ebbr.rst > +++ b/source/ebbr.rst > @@ -309,6 +309,25 @@ the aid of the Operating System. > .. note:: This normally requires dedicated storage for UEFI variables that is > not directly accessible from the Operating System. > > +****************************** > +Priviledged or Secure Firmware > +****************************** > + > +Multiprocessor Startup Protocol > +=============================== > +Firmware resident in Trustzone EL3 must implement and conform to the > +Power State Coordination Interface specification[PSCI_]. > + > +Platforms without EL3 must implement one of: > + > +- PSCI at EL2 (leaving only EL1 available to an operating system) > +- MP Startup for Arm[MPSTART_] (ACPI Parking Protocol) on an ACPI platform > +- Linux AArch64 spin tables[LINUXA64BOOT_] on a Devicetree platform > + > +However, the MP Startup and Spintable protocols are strongly discouraged. > +Future versions of this specification will only allow PSCI, and PSCI should > +be implemented in all new designs. > + > **************************************** > APPENDIX A - Required UEFI Boot Services > **************************************** > @@ -542,6 +561,12 @@ EFI_ISCSI_INITIATOR_NAME_PROTOCOL 16.2 > .. [DTSPEC] `Devicetree specification v0.2 > > <https://github.com/devicetree-org/devicetree-specification/releases/tag/v0.2>`_, > `Devicetree.org <https://devicetree.org>`_ > +.. [LINUXA64BOOT] `Linux Documentation/arm64/booting.txt > + > <https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/tree/Documentation/arm64/booting.txt>`_, > + Linux kernel > +.. [MPSTART] `MP Startup for Arm > + > <https://acpica.org/sites/acpica/files/MP%20Startup%20for%20ARM%20platforms.doc>`_, > + 20 December 2012, `Microsoft <http://microsoft.com>`_ > .. [PSCI] `Power State Coordination Interface Issue D (PSCI v1.1) > > <http://infocenter.arm.com/help//topic/com.arm.doc.den0022d/Power_State_Coordination_Interface_PDD_v1_1_DEN0022D.pdf>`_, > 21 April 2017, `Arm Limited <http://arm.com>`_ > -- > 2.13.0 > > _______________________________________________ > Arm.ebbr-discuss mailing list > [email protected] _______________________________________________ boot-architecture mailing list [email protected] https://lists.linaro.org/mailman/listinfo/boot-architecture
