Chris Ramsden wrote: > On 2018-05-14 01:21, songbird wrote: >> Pascal Hambourg wrote: >> ... >>> I agree with the author. If you want to keep the existing EFI Windows >>> installation and have a convenient dual boot with GRUB, you'll have to >>> set up your favourite distribution to boot in EFI mode. If you want to >>> go back to legacy boot, including for Windows, you'll have to >>> repartition the disk to MSDOS format and reinstall Windows. >> all i know is that if your bios doesn't boot in >> UEFI mode and you don't know anything about what this >> means you can end up installing Debian without UEFI >> support and then it can be rather fun to get it back. >> >> i managed to have grub do an install to a stable >> partition without UEFI and i messed up the testing >> setup i had. it took me some while to figure out >> what went wrong and how to fix it. if you don't >> really understand grub rescue commands and there >> isn't a working system you can use to connect and >> find help for the commands you need to enter it's >> very frustrating. >> >> the Debian UEFI pages helped a great deal but >> there were other things i had to figure out coming in >> cold to UEFI. >> >> how to create a /boot/efi partition, what goes in >> it, mounting it, clearing and putting in new efibootmgr >> entries, etc. >> >> refind was useful and at least it does what i expect >> it to do. grub, i dislike how it assumed things i >> didn't want to do. alas, i didn't know how different >> UEFI was from bios mode. >> >> i still haven't redone my efibootmgr entries but >> refind doesn't care, i can create custom entries in >> that config file and they work that is all i really >> need at this point. >> >> >> songbird >> > Hmm, do you have any useful references?
https://wiki.debian.org/UEFI https://wiki.debian.org/GrubEFIReinstall and http://www.rodsbooks.com/refind/ > I got a new Dell computer, shrunk the existing partitions down and > successfully installed grub2 and got a windows10/Linux multi boot using > grub. Then later I tried to upgrade my Linux and soon found that I was > getting error messages about grub not being able to find necessary > features on the boot device. yep. do not install stable after testing is all i can recommend at this point (based upon my experience) and of course keep a working/verified netinst image handy. > I tried to rebuild it with a clean install of Windows 10, reasoning that > if I could get it back to the original configuration, I could repeat the > original exercise. But alas, no, it remains stubbornly unable to install > grub2 alongside the windows bootloader. I got it to a state where I > could use the BIOS POST boot screen to choose a boot option, but this > wasn't the original successful arrangement where grub offered me the > Linux/windows loader choice. > > I gave up, wiped windows and went through with a clean Linux install. I > don't really want windows that much, but it irks me that I haven't been > able to fathom out how to return to the original state in which it was > shipped. Your words hint at many things I became vaguely aware of but > totally failed to grasp. The other posters to this thread have at least > reassured me that it isn't easy or trivial to get right. i was rather surprised by it all but i'd been living in the dark ages for years anyways. songbird
