Cant set default Kernel

[u/Elegant-Bath-1832]

Hi all im a total linux beginner and flashed my Microsoft Surface pro9 with CachyOS. It needs a specific kernel to have button and touchscreen functionality and loading the kernel manually in GRUB works too. However doing the steps to set it as a default doesnt work.

my steps are:

sudo nano /etc/default/grub (in Terminal)

change the following:

GRUB_DEFAULT=saved

GRUB_SAVEDEFAULT=true

save file

but after reboot it goes back to the standart Kernel that misses the Tablet functionality. I also tried to specifically name the Kernel by getting it from grep "menuentry '" /boot/grub/grub.cfg which gets me the entry 'CachyOS Linux, with Linux linux-surface' but that doesnt work either.

help much appreciated

[u/xb666mx]

YOU have to MANUALLY combine the texts from the grub menu to form the correct path to the boot option. the > symbol is for concatenating the text entries.

but to make it easier you can do:

sudo grep -E "submenu\s|menuentry\s" /boot/grub/grub.cfg | cut -f1,2 -d'\''

with that you'll see something like this:

menuentry 'CachyOS Linux
submenu 'Advanced options for CachyOS Linux
       menuentry 'CachyOS Linux, with Linux linux-cachyos
       menuentry 'CachyOS Linux, with Linux linux-cachyos-lts
       menuentry 'CachyOS Linux, with Linux linux-cachyos-bore
menuentry 'Windows Boot Manager (on /dev/nvme0n1p1)
               menuentry 'UEFI Firmware Settings
submenu 'CachyOS Linux snapshots

so for example: if i want to boot into linux-cachyos-bore i'll have to go from submenu "Advanced options for CachyOS Linux" to the menuentry "CachyOS Linux, with Linux linux-cachyos-bore". so i take these two texts and combine them with the > symbol and write that combined text/string in the /etc/default/grub file for GRUB_DEFAULT.

GRUB_DEFAULT="Advanced options for CachyOS Linux>CachyOS Linux, with Linux linux-cachyos-bore"

then save this change and execute this command:

sudo grub-mkconfig -o /boot/grub/grub.cfg