Linux from scratch

[Alexandru Juncu]

Hello!

I am not a professional kernel developer but I do like learning how
things work..especially operating systems like linux. I know the basis
stuff  about the linux kernel (enough to write a very simple kernel
module).  But I wanted to learn how things like a simple scheduler or
a memory manager would work.

Only reading the current kernel code is sometimes difficult because
all the layers of abstraction implemented in order to make Linux code
scale.  So I was thinking taking a much much older version of the
kernel and starting to analyze it. Something like...v0.01. Seems like
I'm on a good track since sched.c in v0.01 has 250 lines while shed.h
in the current kernel has 1200 :P.

But I couldn't get v0.01 to compile and I've search the Internet and
found that it needs a _lot_ of hacking to get it to work. So I moved
to try 1.0 which seems to have all of the basic features implemented
yet simple enough  to understand. But I am still  having trouble
compiling (having trouble with header files...). Although I could just
read the code and try to figure out what it does, I would like to be
able to modify it and compile and run it.

In order to avoid useless trial and error, I wanted to ask other
people that maybe did this: What is the oldest kernel version that can
be compiled on a current system and then pun on a virtual machine like
qemu-kvm or vmware?

On a side note, I did look into the "Linux from scratch" documentation
project, but that seems to tell you how to build a distribution, not a
kernel.

Thank you.