I have strange flickering at boot. Here is some parts of dmesg output:
[ 0.000000] Console: colour dummy device 80x25
[ 0.000000] console [tty0] enabled
[ 0.478890] efifb: probing for efifb
[ 0.479759] efifb: framebuffer at 0xe0000000, mapped to 0xffffc90004800000, using 5628k, total 5625k
[ 0.479761] efifb: mode is 1600x900x32, linelength=6400, pages=1
[ 0.479761] efifb: scrolling: redraw
[ 0.479763] efifb: Truecolor: size=8:8:8:8, shift=24:16:8:0
[ 0.483305] Console: switching to colour frame buffer device 200x56
[ 0.486754] fb0: EFI VGA frame buffer device
[ 0.486760] intel_idle: MWAIT substates: 0x21120
[ 0.486761] intel_idle: v0.4 model 0x3A
[ 0.486762] intel_idle: lapic_timer_reliable_states 0xffffffff
[ 0.539341] fb: conflicting fb hw usage inteldrmfb vs EFI VGA - removing generic driver
[ 0.539353] Console: switching to colour dummy device 80x25
[ 1.704310] Console: switching to colour frame buffer device 200x56
[ 1.707825] i915 0000:00:02.0: fb0: inteldrmfb frame buffer device
[ 1.707826] i915 0000:00:02.0: registered panic notifier
Looks like console switching from one resolution to another. Why it happens?
I use rEFInd bootloader. This is kernel options that i have in refind_linux.conf:
root=/dev/sda5 rw rootfstype=ext4 add_efi_memmap systemd.unit=graphical.target libahci.ignore_sss=1
Another question, why by default arch load arch-fallback kernel?
Kernel command line: root=/dev/sda5 rw rootfstype=ext4 add_efi_memmap systemd.unit=graphical.target libahci.ignore_sss=1 initrd=EFI\arch\initramfs-arch-fallback.img
By default, it loads the kernel and initramfs you have set it to load... I guess I am trying to say there is no default. You have set this up. (If you haven't, then you are not using Arch).
Since you use rEFInd, you just need to edit the refind_linux.conf to be what you want.
When it flickers, the i915 module is being loaded and the system is switching to KMS. This is totally normal, as it is just moving from the most basic graphics mode (the generic efi) to the hardware specific driver.
I would like to commend you on a very good first post though. You provided the necessary information to get an answer. Though with a bit of digging, you would have been able to find the answer. But it is refreshing to see a post count of one without a question like "My thingy is broken, why?" and a title of "SWEET JESUS HELP ME!"
So thank you.