<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW --- - [snb efi gmux] imac 12,1 blank screen upon booting" href="https://bugs.freedesktop.org/show_bug.cgi?id=59431#c37">Comment # 37</a> on <a class="bz_bug_link bz_status_NEW " title="NEW --- - [snb efi gmux] imac 12,1 blank screen upon booting" href="https://bugs.freedesktop.org/show_bug.cgi?id=59431">bug 59431</a> from <a class="email" href="mailto:kc@cobradevil.org" title="William <kc@cobradevil.org>"> William</a> <pre>(In reply to <a href="show_bug.cgi?id=59431#c36">comment #36</a>) > William: Regarding the issue with efifb not working without the patch I > supplied, it seems the information efifb requires normally either comes from > the bootloader, or else the kernel can discover the information itself if > booted using the EFI stub or EFI handover protocol. The failure to work on > your system without the quirk could be due to either a bug in the EFI > firmware or a problem with how the kernel is being booted. > > Do you have working graphics in your bootloader? If so the problem is > probably with how the kernel is booted. Are you using the standard Ubuntu > boot setup (i.e. grub2), and are you modifying it in any way? I have no graphics setup or at least not that i am aware off. I get a ncurses based menu where i can choose the different kernels i have installed. Right now i cannot seem to get a console even with or without the gfxpayload=keep option on the 32bit kernel. When starting the same usb stick on a macbook air it works with both the 32bit kernel and the 64bit kernel. We don't use the default ubuntu grub install because we setup a small efiboot environment using grub-mkimage. grub-mkimage -O x86_64-efi -o bootx64.efi search_fs_uuid fat ext2 normal boot configfile linux We then install this onto a small fat partition 8 MB. I will attach the efiboot with the grub options. I think the main problem is that we are starting a 32bit kernel from a 64bit firmware. I had earlier issues with that even on the standard macbook air see also: <a href="https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1082059">https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1082059</a> But this has been addressed. I think something else is going wrong with setting up efifb with a 32bit kernel booted from 64 bit firmware and that that is the reason i don't get a console. >From the dmesg log i see connector 4 is vga-1 on 64bit kernel and vga-2 on the 32bit kernel, not sure if that could mean anything.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>