Here's my somewhat strange multi-boot config:
- Windows 10 on a Surface Pro 4 (no secure boot)
- Ubuntu 20.04 LTS on /dev/nvme0n1p5 partition
- Lubuntu 21.10 on /dev/sda2 (SD card in built-in slot seen as /dev/sda)
For whatever reason, maybe because this is old tired hardware, I can't get into Lubuntu except by booting the Ubuntu partition from the UEFI firmware menu (hold down the Vol+ button when booting), then select the same (default) menuentry that fails when I bypass this mechanism and boot without mashing the Volume Up button.
The message when I select the Lubuntu or Advanced Lubuntu item is: "Can't find device: xxx(GUID)xxx; No such HD1; You need to load the kernel first".
Interestingly, Windows 10 boots OK either way? It's almost like I'm missing a modprobe to reveal /dev/sda. Also, USB mouse attached to Hub through the one USB 3.0 port sometimes won't work to scroll through the entries.
Maybe I should make the UEFI menuentry be the default? That way if the usb mouse/keyboard aren't functional, at least it will return to the menu where my (tri-) boot successfully launches.
Thanks for any advice or input!