xorg server crushes because of custom kernel

I did compile custom linux kernel, without using modules, but when I try to start x server, screen freezes, it even does not allow switch to other tty.The major difference in logs of X server is the line:

[...] xf86EnableIO: failed to enable I/O ports 0000-03ff (Function not implemented)

It seems, that I disabled some major feature in kernel config, but I have no idea which one it is.

Question is: which config option causes this behaviour?

Or how can it be determined? maybe, an abstract 'not implemented' can be traced some way?

• Linux version : 6.4.0.
• Graphics driver: intel i915.
• Required firmware included