On 11 February 2014 01:01, Steve McIntyre <[email protected]> wrote: > Gah... > > Just ended up playing with Colin's thinkpad; he'd reported problems > with installation that sounded odd. Worked through it, and found a > hole in what we recognise and support during installation (and maybe > later). > > We have a machine with both UEFI and BIOS-mode boot available, with an > existing BIOS-mode Windows installation (e.g. Windows 7 in this case) > *but* the machine is set up to try and boot UEFI first and *then* fall > back to BIOS (for some reason). > > The existing Windows installation boots via the fallback, and the user > has no reason to ever investigate this. However, d-i will happily boot > in UEFI mode. When we get to partitioning, there is no EFI System > Partition (ESP), as Windows isn't using one. We then get to either of > two potentially bad cases: > > (a) the user shuffles partitions around and makes an ESP, installs > the system OK including grub-efi. They then have a machine that > will boot via UEFI to grub, but maybe will not be able to boot > Windows. I've not tested this directly yet, but I can see this > happening. To get to their existing Windows installation, the > user will have to switch boot mode in the firmware setup - bad. > > (b) the user does not make an ESP, installs a system but grub-efi > fails to install properly for that reason. I'm seeing bug reports > that suggest this path does *not* necessarily give a clear error > to the user, maybe in some cases no error at all. They reboot > their newly-installed system and find it immediately goes into > Windows with no sign of their new Debian installation at all. > > How do we fix this? I think we need to find some way of detecting how > an existing Windows installation boots, *iff* the user is clearly > trying to set up a dual-boot system. If the existing Windows > installation is in BIOS-mode, we should *not* follow the UEFI path > through partitioning and bootloader installation; instead, we should > fall back to the existing generic/BIOS cases in various places. I > don't see this being *easy* to do, but there aren't many code paths to > worry about AFAIK. > > What do people think?
As a data point, a few bug reports in Ubuntu were also filed about similar behavior. A metabug is probably https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/1050940 (note that the bug there is quite vocal) I don't now the right answer here. But e.g. my motherboard has configuration options to choose priority of UEFI vs BIOS boot for all device types, such that it can do BIOS-only on removable media / usb sticks, but UEFI on the hard-drives =) but i guess it's users fault for changing non-default firmware settings. It seems however, that "existing BIOS installation" is a common enough case to warrant support for ( it doesn't have to be Windows7, it could also be other operating systems expecting bios boot). -- Regards, Dimitri. -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected] Archive: http://lists.debian.org/CANBHLUjv834XHhZ=yFOsRr1Mvj=ehzbgpgbpeqibd3wpqht...@mail.gmail.com
