(cc Hans) On Thu, 21 Mar 2024 at 23:05, Clayton Craft <clayton@xxxxxxxxxxxxx> wrote: > > I've been chasing a problem with 32-bit EFI mixed mode booting on two different > (x86_64) Intel Bay Trail platforms, where the system reboots or hangs seemingly > very early somewhere before or after loading the kernel. I've not been able to > get any output from the kernel or stub over efifb when the issue happens[0], and > do not have serial console access on these systems. > > v6.8 fails for me, and presumably so does everything back to v6.2. v6.1 is able > to boot OK on these platforms with mixed mode, and it looks like there are a lot > of changes from 6.1..6.2 for EFI/mixed mode booting. v6.1 just received some EFI related backports, so please check the latest v6.1.y as well. > I did managed to bisect the > issue to: > > commit e2ab9eab324cdf240de89741e4a1aa79919f0196 > Author: Ard Biesheuvel <ardb@xxxxxxxxxx> > Date: Tue Nov 22 17:10:02 2022 +0100 > > x86/boot/compressed: Move 32-bit entrypoint code into .text section > > However I'm not sure how to proceed from here, or if my bisect is all that > useful since the commit seems to be in the middle of a bunch of changes I do not > understand. I've been using systemd-boot to test this (both the full bootloader > and UKI w/ the sd-boot stub). Is 32-bit mixed mode on x86_64 working for others? > I usually test on 32-bit OVMF built with LOAD_X64_ON_IA32_ENABLE, which allows the use of the compat entry point. This is different from the EFI handover protocol, and I am not sure which one you are using. I have never had any reports, or noticed any issues myself. Last time I tried (some weeks ago) it was working for me. CC'ing Hans who may have more data points.
