[ Adding Matthew for reals this time ] On Wed, 07 Aug, at 09:19:08PM, Matt Fleming wrote: > [ Readding Matthew Garrett to the Cc list, seeing as we both got removed > for some unknown reason ] > > On Wed, 07 Aug, at 10:23:56AM, Andrew Fish wrote: > > > OK so I think I need some Cliff Notes here to help me understand what > > is going on... > > > > type 4 is EfiBootServicesData and attr 0x0f is cache attributes with > > no request for a runtime mapping. This is not runtime memory so to the > > OS loader it is just memory EFI has used that will get freed back to > > the OS after ExitBootServices(), along with EfiBootServicesCode, > > EfiLoaderCode, and EfiLoaderData. The EfiLoaderCode and EfiLoaderData > > also get freed back to the OS and they just exist for the convenience > > of the OS loader. > > > > So I can't figure out why this maters? Given: > > We've seen a bunch of systems that make calls into EfiBootServicesCode > after ExitBootServices(). There were some Apple machines in that list, > though I don't have the details but Matthew should. > > So we map these regions unconditionally and in their original state, > otherwise the firmware will generate fatal page faults when trying to > access those memory regions. -- Matt Fleming, Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
