boot1.efi and ConsoleControl on HP 840G1/G2
manu at bidouilliste.com
Thu Nov 19 11:16:30 UTC 2015
After hours I've found why I couldn't use properly FreeBSD on my HP 840G1/G2 laptop.
What is happening right now with -current is that the kernel framebuffer is garbage (https://www.bidouilliste.com/images/efi/IMG_2650.JPG).
The problem is that boot1.efi calls ConsoleControl which, from my findings, is not in the UEFI specs but was only in the EDK implementation.
This should not be a problem as LocateProtocol should return != EFI_SUCCESS but on my laptops (and probably others) this is not the case.
After removing the ConsoleControl related lines and recompiling boot1.efi I can now boot FreeBSD.
I'm pretty sure that this would not be a problem on other machine (with the patch I can still boot correctly FreeBSD on my Samsung 870Z laptop) but I would prefer that other people test it.
I've opened a bug on bugzilla (https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=204674) if some people want to try the patch.
Emmanuel Vadot <manu at bidouilliste.com>
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