Looks like someone has the Linux kernel running on top of itself as a user
mode virtual machine.
There's an entry on freshmeat for it:
The user-mode Linux kernel is a port of the Linux kernel to its own system
call interface. It runs in a set of processes, resulting in a user-mode
virtual machine. It is a nearly fully-functional 2.3.31 kernel, lacking
only preemption and kernel modules. Its hardware support includes block
devices, a console, virtual consoles, a serial line, and a network device.
People who should try it out include developers who want to do kernel
development and debugging in user space with gdb, gprof, gcov, etc, anyone
who wants to safely try out the latest kernel, anyone who wants to try out
new distributions, and the terminally curious who want to poke around
inside a running system.
It's GPL'd of course.
The website is here:
http://www.mv.com/ipusers/karaya/uml/index.html
The ftp is here:
ftp://user-mode-linux.sourceforge.net/pub/user-mode-linux/
Sincerely,
Nelson Rush
"If a packet hits a pocket on a socket on a port, and the bus is
interrupted as a very last resort, and the address of the memory makes your
floppy disk abort, then the socket packet pocket has an error to report!"
