Thanks for the ideas! Here are some outputs:
Tried running mkinitcpio -p linux manually:
/boot # mkinitcpio -p linux
==> Building image from preset: /etc/mkinitcpio.d/linux.preset: 'default'
-> -k /boot/vmlinuz-linux -c /etc/mkinitcpio.conf -g /boot/initramfs-linux.img
==> ERROR: invalid kernel specified: `/boot/vmlinuz-linux'
==> Building image from preset: /etc/mkinitcpio.d/linux.preset: 'fallback'
-> -k /boot/vmlinuz-linux -c /etc/mkinitcpio.conf -g /boot/initramfs-linux-fallback.img -S autodetect
==> ERROR: invalid kernel specified: `/boot/vmlinuz-linux'
/boot # ls -l
total 14052
drwxr-xr-x 5 root root 4096 Feb 18 11:38 EFI/
drwxr-xr-x 6 root root 4096 Aug 14 05:23 grub/
-rwxr-xr-x 1 root root 4769792 Jun 9 08:35 intel-ucode.img
-rwxr-xr-x 1 root root 9606464 Aug 13 22:29 vmlinuz-linux
I have no /boot/initramfs-linux.img
/etc # show_uncommented_lines.sh mkinitcpio.conf
MODULES=()
BINARIES=()
FILES=()
HOOKS=(base udev autodetect modconf block filesystems keyboard fsck)
/etc/mkinitcpio.d # cat linux.preset
# mkinitcpio preset file for the 'linux' package
ALL_config="/etc/mkinitcpio.conf"
ALL_kver="/boot/vmlinuz-linux"
PRESETS=('default' 'fallback')
#default_config="/etc/mkinitcpio.conf"
default_image="/boot/initramfs-linux.img"
#default_options=""
#fallback_config="/etc/mkinitcpio.conf"
fallback_image="/boot/initramfs-linux-fallback.img"
fallback_options="-S autodetect"
This machine has been running Artix fine for almost two years. I haven't modified /etc/mkinitcpio.conf, /etc/mkinitcpio.d/linux.preset, or /etc/default/grub recently.
I do recall that because I have an MSI motherboard, I had to add --removable to the grub-mkconfig line:
grub-install --target=x86_64-efi --efi-directory=/boot/ --bootloader-id=grub --removable
I can't find any notes on this, but I believe it causes a change in where BOOTX64.EFI is stored. Mine is located at
/boot/EFI/BOOT/BOOTX64.EFI
Could you please check where yours is? Thanks again.