On 27 September 2018 at 13:46, Daniel Thompson <daniel.thomp...@linaro.org> wrote: > On Thu, Sep 27, 2018 at 10:53:51AM +0000, Udit Kumar wrote: >> > -----Original Message----- >> > From: Grant Likely <grant.lik...@arm.com> >> > Sent: Wednesday, September 26, 2018 6:01 PM >> > To: Udit Kumar <udit.ku...@nxp.com>; boot-architecture@lists.linaro.org; >> > arm.ebbr-disc...@arm.com >> > Cc: n...@arm.com >> > Subject: Re: [Arm.ebbr-discuss] [PATCH 5/7] Refactor ResetSystem() >> > requirements >> >> > From patch 6: >> > > +Functions contained in EFI_RUNTIME_SERVICES are expected to be >> > > +available during both boot services and runtime services. >> > > +However, it isn't always practical for all EFI_RUNTIME_SERVICES >> > > +functions to be callable during runtime services due to hardware >> > limitations. >> > > +If any EFI_RUNTIME_SERVICES functions are only available during boot >> > > +services then firmware shall provide the global >> > > +`RuntimeServicesAvailable` variable to indicate which functions are >> > available during runtime services. >> > > +Functions that are not available during runtime services shall return >> > > +EFI_UNSUPPORTED. >> > >> > Is that clear enough? >> >> Thanks, this is clear where UEFI is saying to return an error say for >> RTC/Variable service. >> >> For reset, there is no error code, in this case, how EFI interface can tell >> to OS that reset >> is not available through runtime. We should document this. > > Interesting. > > Clearly the OS can trivially detect the ResetSystem() is not > implemented/working because it would not otherwise return but this might > need an update to the ECR (which otherwise has language that adds > EFI_UNSUPPORTED as a return type to a function with no return type). >
Instead, we could update the UEFI spec so that ResetSystem() does have a return type, which may be useful in other way as well. (And being able to add the language that says 'EFI_SUCCESS - An error has occurred' is just too appealing) _______________________________________________ boot-architecture mailing list boot-architecture@lists.linaro.org https://lists.linaro.org/mailman/listinfo/boot-architecture
