Think about it, for a moment, dear padewan ...
How is it possible to "boot the system from a ramdisk," when a "ramdisk" is but a figment of an operating-system's imagination?
The answer, of course, is that it isn't.
The "initial ramdisk" concept is ... how shall I say it?
... a "necessary hack." In order to satisfy the requirements of "distro" writers, who needed to write distros that could successfully boot on "any ol' hardware in the world" (without any advance knowledge of just what that hardware might be), Linux designers came up with the idea of a quasi-intermediate stage in the boot process, in which the designers could run hardware-discovery scripts and, based on the results thereof, automagically load the appropriate device drivers.
If it sounds very complicated and magical ... well ... it is,
actually . . .