Installing Desktop ARM64 on ARM64 laptop crashes when installing GRUB

[Dan]

I've attempted to install Ubuntu Desktop 25.10 ARM64 on a Lenovo Yoga C630.
The live USB disk works fine. I've tried installing it to a second USB disk so I don't overwrite Windows, so there is a chance that it won't happen when installing to the internal SSD, though I'm pretty sure it will due to the nature of the installation.

The installer proceeds as normal until it reaches the stage of installing GRUB, then it fails because "EFI Variables are not supported on this system". I'm not sure whether the hardware doesn't support EFI variables or it's just because the efivars module is missing from the installation media. If I install grub manually using the grub-install command, after reboot grub can't find /boot and falls into a rescue grub shell. Furthermore, it does not copy the DTB files nor the detection script.

The only way I eventually got it to boot was by manually copying the DTB files and the detection script from the live USB's EFI and boot directories into the target disk. Since this involves manually editing grub.cfg, any updates that involve update-grub are likely to overwrite it, resulting in having to edit it again.

[Tobias Heider (tobhe)]

This sounds like a kernel issue. The Yoga being a Snapdragon might actually mean it does not support EFI variables.

There is a workaround in the kernel which many other Qualcomm machines use. I think the device would have to be on this list: https://github.com/torvalds/linux/blob/master/drivers/firmware/qcom/qcom_scm.c#L1993-L2019