On Thu, Nov 28, 2024 at 04:21:09PM +0100, Ard Biesheuvel wrote: > On Thu, 28 Nov 2024 at 15:46, Johan Hovold <johan@xxxxxxxxxx> wrote: > > > > On Thu, Nov 28, 2024 at 12:05:09PM +0100, Ard Biesheuvel wrote: > > > > > If you're happy to experiment more, you could try and register a > > > notification for EFI_EVENT_GROUP_BEFORE_EXIT_BOOT_SERVICES using > > > CreateEventEx(), and see if it gets called when ExitBootServices() is > > > called. That would at least help narrow it down. > > > > Thanks for the suggestion. > > > > I see the notify function being called when I signal it as well as on > > each ExitBootServices(). > > Interesting. That means the EDK2 fork is fairly recent. > > FYI https://github.com/tianocore/edk2/pull/6481 Nice find. > > With an efi_printk() in the callback ExitBootServices() fails as > > expected, but with an empty function the kernel seems to start every > > time. > > > > Interestingly, ExitBootServices() now succeeds also if I add back the > > CloseEvent() call. In fact, it works also if I never signal the event > > (i.e. if I just create and close the event). > > Is it still invoked by the firmware if you closed the event before EBS()? No, I just reconfirmed that then it is only called when I signal it before closing (or never if don't signal the event). Johan
