Welcome to Plan 9 VX.

Plan 9 VX has been built and run successfully on Linux 2.6
(Ubuntu Gutsy and Hoary), FreeBSD 7, and OS X 10.4.11.
It is likely that it will work on newer machines too.  

In addition to the code in this directory, you need a copy
of a Plan 9 distribution tree.  If you need one, you can find
a stripped-down tree at http://swtch.com/9vx/9vx.tgz.
(That file also contains a pre-built 9vx binary.)

The easiest way to invoke 9vx is to copy it to the root of 
a Plan 9 distribution tree, cd into that directory, and run "9vx".
Alternately, you can tell 9vx where the root is with the -r flag:

	9vx -r /var/tmp/plan9

9vx also takes a -u flag to set the user name.  If you are using
a stock distribution tree, you will get a better environment 
if you run

	9vx -u glenda

to log in as the default user, glenda.

If all goes well, 9vx should fork itself into the background and
an X11 window should appear running rio, the Plan 9 window
manager (or, if not acting as glenda, a shell prompt).
Even on Darwin, the graphics are via X11.  I have the relevant
Carbon code in another project, but I need to merge it in.

There is also a "-t" option, which causes 9vx to use
the terminal on standard input/output for I/O instead of 
creating an X console.  This option also keeps 9vx from forking
itself into the background.  It's useful mainly for debugging.

At this point you have a Plan 9 system, and it should behave
not much differently from any other Plan 9 system.  If it 
behaves differently in a bad way, please send email to 
rsc@swtch.com to report a bug.

The 9vx kernel provides the following devices that provide
access to host resources.

	#A	audio (via /dev/dsp; #A1 is /dev/dsp1, etc.)
	#i	draw (via X11)
	#I	ip stack (including cs)
	#m	mouse, snarf (via X11)
	#Z	local file system (#U is /; #Uplan9 is -r root)

Notice that done of these enforce permissions--they all
execute as the user who started 9vx--so it wouldn't be a
great idea to use 9vx as a replacement for a multiuser system.
Even the user "none" has full access to the local file system via #Z.

Enjoy!

Russ Cox
rsc@swtch.com
June 2008


P. S.  Some people have reported getting the following error:

9vx: ../../src/xcb_lock.c:33: _XCBUnlockDisplay: \
	Assertion `xcb_get_request_setn(dpy->xcb->connection) \
	== dpy->request' failed.

This is a problem with the X11 libraries that has been known
since January and was supposedly fixed in the latest X11 library
sources in March, but the big Linux distributions haven't picked
up the fixes yet.  See these URLs:

https://bugs.launchpad.net/ubuntu-mobile/+bug/185311
http://lists.freedesktop.org/archives/xcb/2008-March/003347.html
https://bugs.freedesktop.org/show_bug.cgi?id=14211
http://forum.tuxx-home.at/viewtopic.php?f=10&t=565

Supposedly, the XCB error can only happen in improperly locked
X programs, but they seem to assume that you're using LockDisplay
and UnlockDisplay to mediate access to the X server instead of
using your own locks, something that is explicitly permitted in the
manual page.  I think they're code is just broken.  If you find locking
errors in the 9vx x11 code, I'd like to know about them.

P. P. S.  Plan 9 VX is much more demanding of the OS than 
libvx32 itself is.  Some systems, usually older ones, are *not*
compatible with Plan 9 VX.

Plan 9 VX is known *not* to work on old Linux systems running
Linux 2.4 kernels or the old LinuxThreads pthreads implementation
that was the default on 2.4-based systems but crept into some 
2.6 distributions.

Plan 9 VX is known *not* to work on FreeBSD 6, due to an 
incompatibility between libkse (the implementation of pthreads)
and libvx32.  FreeBSD 7 replaced libkse with a new thread library
that is just great.

COMPILATION ERRORS?
The libpcap development libraries are needed to compile this
version of 9vx. Alternatively, set PLAN9PCAP to nopcap in the
Makefrag file.