Okoken's notes

The Logicool K480 as a bluetooth keyboard surely can be direclty used for Steamdeck.
But as a well known issue, there is no official driver provided for Linux platform, therefore F1~F12 work as Multimedia Keys in default instead of Function Keys.

Not acceptable at all.

Noticed that an AUR package k480-function-keys-conf-git is provided as a solution, but cannot be used directly due to 2 issues:
💣 one of the checksum inside is wrong
💣 compile will fail because the linux-neptune-headers used by SteamOS has a special structure

Below is the solution to solve the issues and use it.

1. To download the snapshot directly and extract it to your local, e.g., ./k480-function-keys-conf-git.

   https://aur.archlinux.org/cgit/aur.git/snapshot/k480-function-keys-conf-git.tar.gz

2. To replace the checksum in both .SRCINFO and PKGBUILD

   Before: 2caee64458f1c921845f22aeae1b034eebfe3b39f9fe9b317fe0bbae500a535c
   After: 356e31ae1a2d835e020f8c54ab28eae0d4265869cb5f94c6503d02dd1f6eae32

3. To modify below part in the PKGBUILD.

   Before:

   build() {
   cd "$srcdir/$_pkgname"
   ./build.sh
   }

   After:

   build() {
   cd "$srcdir/$_pkgname"
   sed -i '/gcc -o $file file.c/c\gcc -I /usr/lib/modules/(uname -r)/build/include/uapi -I /usr/lib/modules/$(uname -r)/build/arch/x86/include/generated/uapi -I /usr/lib/modules/$(uname -r)/build/arch/x86/include/uapi -I /usr/lib/modules/$(uname -r)/build/include -o $file $file.c' ./build.sh
   ./build.sh
   }

4. Use pacman to install packages [linux-neptune-headers glibc base-devel], then run below command in ./k480-function-keys-conf-git (the same folder PKGBUILD inside).

   makepkg -sci --noconfirm

5. Reboot your system and F1~F12 should work as Function Keys in default now.