Is it possible to boot linux without a initrd.img ? I am planning to add default drivers as a part-of-kernel itself and avoid initrd completely.
What are the modules that should be made part-of-the-kernel instead of loadable modules ?
It is, unless your root volume is on an LVM, on a dmcrypt partition, or otherwise requires commands to be run before it can be accessed.
I haven't used an initrd on my server in years. You need at a minimum these modules built in: