I have an ASUS laptop with Windows 10 on it, boot mode is UEFI.
I have disabled Fast Startup, Fast Boot, Secure Boot before installing Ubuntu 20.04 (followed the guide here: https://itsfoss.com/install-ubuntu-1404-dual-boot-mode-windows-8-81-uefi/).
On first startup, the system showed Grub Recovery Mode, I had to type some Grub commands (set prefix, set root, insmod...) to get it to boot.
Second startup, the system booted directly into Windows and I haven't found a way to boot into Ubuntu again (it booted into Windows even when I choose ubuntu from the UEFI boot menu).
I tried booting from the boot USB, installing Boot-Repair but there was no "Recommended repair" option. The report says "The default repair of the Boot-Repair utility would not act on the boot". You can see the report here: https://pastebin.com/3YjYwXXy
Ubuntu is installed on /dev/nvme0n1p5. I also tried fixing grub manually but got an error when trying to mount that partition.
(I have dual boot installed on a few other machines, they all used legacy BIOS mode. This UEFI thing is a pain)
Please help. Thanks in advance!
UPDATE: I tried mounting the EFI System Partition, the ubuntu folder existed but looked like there was some error:
ubuntu@ubuntu:/mnt/efi/EFI$ ls
ls: cannot access 'ubuntu': Input/output error
Boot Microsoft ubuntu
Last few lines of dmesg:
[ 1174.092156] FAT-fs (nvme0n1p1): error, corrupted directory (invalid entries)
[ 1174.092164] FAT-fs (nvme0n1p1): Filesystem has been set read-only
[ 1176.296661] FAT-fs (nvme0n1p1): error, corrupted directory (invalid entries)
[ 1177.390047] FAT-fs (nvme0n1p1): error, corrupted directory (invalid entries)
[ 1181.030055] FAT-fs (nvme0n1p1): error, corrupted directory (invalid entries)
The comp has Intel RST with Optane installed and after some research I found out that maybe Ubuntu won't work well with it. Could that be the cause of the problem and should I disable it?
Thanks.
Update 2: I tried disabling RST following this guide: https://discourse.ubuntu.com/t/ubuntu-installation-on-computers-with-intel-r-rst-enabled/15347, but was unsuccessful (had to go through the recovery steps but the bcdboot command failed). Guess I should stay with the VM option for a little longer.
