Linux kernel without root filesystem?

Hi friends,

This question generated in my mind for some unknown reason. Hope it isn't a silly question. :lol:

I don't have any board or my own PC at hand right now to make it out. So I am just finding the answer by "pencil and paper". But when I have the answer, I am not so sure about it. Then I think knowing the exact answer will help to fix some (among many) holes in my knowledge of Linux.

In my opinion, the Linux kernel can boot up successfully without mounting any root filesystem. To do this, just disable root filesystem mouting option when configuring the kernel. In this case, ofcourse, that system can't perform any user interaction, no kernel modules to be loaded except for built-in kernel modules, no startup script to configure network interface or start up user-space program, ofcourse no user-space programs exist also. Ofcourse, a system like this is so useless. I just wonder such a system can boot up successfully or not, with, for example, one application which is a built-in kernel modules which repeatly output some texts to console to indicate that the kernel is still running.

How is your idea :?:

Eventually, when I really practice it, I will post my result here. :wink:

sounds interesting

Just wanted to add a note that something very similar is done with clustering software. If you look around for clustermatic, you'll see that they put out a sort of Linux BIOS that boots to the kernel with little else. This isn't quite what you're talking about, but it's similar and also useful. The slave nodes that only boot to the kernel can still be controlled by the master computer. This means that the slave nodes can be built with only the most basic pieces (case, power supply, mobo, cpu, RAM, ethernet of some sort, and enough fans to keep it cool).

Isn't it easier to use ramdisk?