On Tue, Jul 12, 2016 at 12:52 PM, Leandro Gustavo Biss Becker <lbec...@fedoraproject.org> wrote: > Hello. > > I'm trying to use a newer version of GRUB2 (grub2-efi-2.02-0.34.fc24.x86_64) > for UEFI PXE booting Linux (Clonezilla) and also a custom UEFI application > (custom shell) that needs access to the TCP4 UEFI stack in firmware (depends > of the scenario). Using older versions of GRUB2 it is working, but with newer > versions, when it chainloads the custom UEFI application all the UEFI Network > Protocols are gone (error 14 when calling > gBS->LocateProtocol(&gEfiPxeBaseCodeProtocolGuid, ...). > > I need the newer version because the new netboot capabilities that looks for > a cfg file using the MAC Address as grub.cfg-01-AA-BB-CC-DD-EE-FF. > Is newer versions of grub2 unloading UEFI protocols (maybe calling UEFI's > Boot Services ExitBootServices) before chainloading UEFI applications? > > PS: Is this the correct forum for this matter?
Sure. But maybe not too many people have done UEFI PXE booting. I've done PXE and know enough about UEFI to stop now and forever hold my peace, but I've never done UEFI PXE. My understanding is that PXE is booting is going to talk to a DHCP server which should be configured to recognize UEFI specifically, so it can hand over the proper kind of bootloader, in this case an EFI version of GRUB2. What I don't know is how that works exactly. Does the PXE client-server connection permit the transfer of multiple files? For example.... Fedora builds a grubx64.efi (the boot.img and core.img) within their build system and then signs it in order to support UEFI Secure Boot. But this signed binary doesn't contain all of GRUB's modules. Those are in a separate package that isn't installed by default, in grub2-efi-modules. So maybe the server doesn't have those modules installed with the new version of GRUB? Or maybe they're not baked into the Fedora built grubx64.efi? So I'd figure out what's different between the old GRUB and new GRUB verions, and see if what's missing is a regression, or if it's that those modules were pulled out into grub2-efi-modules on purpose. And then if there's some way between PXE client-server and GRUB for GRUB to get any of those modules, or if they must be baked into the grubx64.efi (the actual EFI OSLoader, or bootloader). If it does, then it might be that you have to build your own grubx64.efi using grub2-install or one of the other script commands for this purpose, and explicitly add in the modules that you need baked into that grubx64.efi. The next thing is whether or not you need Secure Boot support. If you do, then there's a kind of chainloading that has to happen, where the first thing loaded is shim.efi, then mokutil.efi so that your own key can be registered with the firmware, and then your own signed grubx64.efi. Maybe that's enough for now to start looking. -- Chris Murphy -- users mailing list users@lists.fedoraproject.org To unsubscribe or change subscription options: https://lists.fedoraproject.org/admin/lists/users@lists.fedoraproject.org Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
