Kernel 5.4 doesn't start after update but 5.10 it starts

[moson]

See this:

[Stable Update] 2021-06-14 - Kernels, Browsers, Mesa, Deepin, Systemd, Gnome Apps 40.2, Pipewire, Haskell

Every body who’s going to update keep in mind that you need to use linux510 or above in order to boot after this update. If you have only linux54 or below hold on your horses and wait for a fix from philm or simply edit /etc/mkinitcpio.conf with uncommenting of the line #COMPRESSION="gzip" after the update, then do sudo mkinitcpio -P and only then reboot. UPD: Ok disregard the above, philm nailed it.