Booting LibreElec from GPT SSD via grub4dos

1st Official Post

    I can boot into grub4dos on my laptop with a GPT partitioned SSD by selecting Legacy mode from the Boot Menu (after some fiddling) but I'm not sure what I need to use to boot LibreElec.

    I tried:

    root (hd0,5)

    kernel /KERNEL boot=UUID=LE-BOOT disk=UUID=LE-STORAGE quiet

    where LE-BOOT is the label for the FAT32 partition (hd0,5) containing SYSTEM, KERNEL, etc. and LE-STORAGE is the label for the ext3 partition (h0,6).

    It starts to boot but then says "error in mount_flash: mount_common: Could not mount UUID=LE-BOOT", so I wonder if the kernel can't recognise the volume labels assigned in Windows (confirmed in BootICE and MiniTool Partition Wizard) or if it's the GPT partitioning that it can't cope with?

    I also tried:

    root (hd0,5)

    kernel /KERNEL boot=sda6 disk=sda7 quiet

    but that just gave me "error in mount_flash: mount_part: Unknown filesystem sda6"

    • Official Post

    This is not really a question for the General support section, mainly because dual boot stuff is outside the scope of LibreELEC.

    Seeing the LibreELEC system partition is the sixth partition on your SSD, what else is installed on there? Did you create the LibreELEC storage EXT3 partition manually? Not EXT4? I can think of reasons to use EXT3, but I think the differences for LibreELEC are trivial.

    First you state that 0,5=boot and 0,6=storage, later it's boot=sda6 disk=sda7...?

    Personally I use Ubuntu Linux and use GRUB to do the LibreELEC booting from a separate SSD. LibreELEC should support GPT afaik, but sometimes some machines are simply allergic to LE. Or vice versa.

    Windows 10 is the other OS. A shown in the attached screenshot of BootICE, that uses partitions for Recovery, ESP/BOOT, MSR, Windows 10 itself and then I've got a Data partition.

    In grub4dos terms that's (hd0,0) to (hd0,4) but I believe Linux uses sda1-5.

    I think I probably did create the ext3 partition manually, using MiniTool Partition Wizard. I don't know if it didn't have the option to create ext4 or if there was some other reason but I guess it's not relevant to this boot issue.

    What command do you use to boot LibreELEC from GRUB?

    • Official Post
    Quote from Dangermouse

    What command do you use to boot LibreELEC from GRUB?

    I still use the simple grub version, placed in Ubuntu's /etc/grub.d/40_custom file.

    I also have multiple disks in that machine, and LibreELEC is installed twice on the 4th disk (both official and Milhouse builds).

    Code
    menuentry "LibreELEC 9.x Official" {
set root=(hd3,1)
linux /KERNEL boot=/dev/sdd1 disk=/dev/sdd2 quiet
}
menuentry "LibreELEC 9.x Milhouse" {
set root=(hd3,3)
linux /KERNEL boot=/dev/sdd3 disk=/dev/sdd4 quiet
}

    Sorry, I spoke to soon. It boots fine now but it's not saving the settings, so I'm prompted with the Setup screens each time I boot. Do I need to add something to the grub entry to make it persistent?

    I looked at the mounts in LibreELEC and sda6 is mounted as /flash and sda7 as /var/media/(something)

    I reformatted as ext4 (MiniTool can do that so I don't know why I used ext3 before) but it turned out that the problem was a typo I'd made, putting an extra / in the command. It's working fine now thanks.