ResetSystem() was over-specified in the document. UEFI already documents the behaviour of ResetSystem() sufficiently. Add notes on expected behaviour when platform specific or standard interface methods are available.
Resolves: #29 Signed-off-by: Grant Likely <grant.lik...@arm.com> --- source/chapter2-uefi.rst | 29 ++++++++++++----------------- 1 file changed, 12 insertions(+), 17 deletions(-) diff --git a/source/chapter2-uefi.rst b/source/chapter2-uefi.rst index 239fd8c..a6b3ff7 100644 --- a/source/chapter2-uefi.rst +++ b/source/chapter2-uefi.rst @@ -158,23 +158,18 @@ and the OS must use a device driver to control the RTC. UEFI Reset and Shutdown ----------------------- -The UEFI Runtime service ResetSystem() must implement the following commands, -for purposes of power management and system control. - -- EfiResetCold() -- EfiResetShutdown() - * EfiResetShutdown must not reboot the system. - -If firmware updates are supported through the Runtime Service of -UpdateCapsule(), then ResetSystem() might need to support the following -command: - -- EfiWarmReset() - -.. note:: On platforms implementing the Power State Coordination Interface - specification [PSCI]_, it is still required that EBBR compliant - Operating Systems calls to reset the system will go via Runtime Services - and not directly to PSCI. +ResetSystem() is required to be implemented in boot services, but it is +optional for runtime services. +The Operating System is not required to use ResetSystem() to reboot or reset the +platform if it has a standard method or device driver for performing a reset. + +On AArch64 platforms implementing the Power State Coordination Interface +[PSCI]_, the Operating System should call PSCI directly to perform a reset, +unless a specific reset is required after a call to UpdateCapsule(). + +.. note:: Even if the platform implements PSCI, it is recommended for firmware + to implement ResetSystem(), even if it simply performs the same PSCI call + that an Operating System would do. Runtime Variable Access ----------------------- -- 2.13.0 _______________________________________________ boot-architecture mailing list boot-architecture@lists.linaro.org https://lists.linaro.org/mailman/listinfo/boot-architecture
