--- trunk/README	2007/10/08 16:18:51	14
+++ trunk/README	2007/10/08 16:22:56	44
@@ -1,29 +1,88 @@
-Gavare's eXperimental Emulator   --   GXemul 0.3.6
-==================================================
 
-Copyright (C) 2003-2005  Anders Gavare.
 
+          --------------------------------------------------------
+            Gavare's eXperimental Emulator   --   GXemul 0.4.6.1
+          --------------------------------------------------------
 
-Overview
---------
 
-GXemul is an experimental instruction-level machine emulator. Several
-emulation modes are available. In some modes, processors and surrounding
-hardware components are emulated well enough to let unmodified operating
-systems (e.g. NetBSD) run as if they were running on a real machine.
+Copyright (C) 2003-2007  Anders Gavare
+
+
+
+Overview  --  What is GXemul?
+-----------------------------
+
+GXemul is a framework for full-system computer architecture emulation. 
+Several processor architectures and machine types have been implemented. 
+It is working well enough to allow unmodified "guest" operating systems to 
+run inside the emulator, as if they were running on real hardware.
+
+The emulator emulates (networks of) real machines. The machines may 
+consist of ARM, MIPS, PowerPC, and SuperH processors, and various 
+surrounding hardware components such as framebuffers, busses, interrupt 
+controllers, ethernet controllers, disk controllers, and serial port 
+controllers.
+
+GXemul, including the dynamic translation system, is implemented in 
+portable C, which means that the emulator will run on practically any host 
+architecture.
+
+The documentation lists the machines and guest operating systems that can 
+be regarded as "working" in GXemul. The best working guest operating 
+systems are probably NetBSD/pmax and NetBSD/cats.
+
+Possible uses of GXemul include:
+
+ o)  running guest operating systems in a "sandboxed" environment
+
+ o)  compiling your source code inside a guest operating system which you
+     otherwise would not have access to (e.g. various exotic ports of
+     NetBSD), to make sure that your source code is portable to those
+     platforms
+
+ o)  educational purposes, e.g. to learn how to write code for MIPS
+
+ o)  hobby operating system development; the emulator can be used as a
+     complement to testing your code on real hardware
+
+ o)  simulating (ethernet) networks of computers running various
+     operating systems, to study their interaction with each other
+
+ o)  debugging code in general
+
+Use your imagination :-)
+
+
+
+GXemul's limitations
+--------------------
+
+ o)  GXemul is not a cycle-accurate simulator, because it does not simulate
+     things smaller than an instruction. Pipe-line stalls, instruction latency
+     effects etc. are more or less completely ignored.
+
+ o)  Hardware devices have been implemented in an ad-hoc and as-needed manner,
+     usually only enough to fool certain guest operating systems, e.g. NetBSD,
+     that the hardware devices exist and function well enough for those guest
+     operating systems to use them.
+
+     (A consequence of this is that a machine mode may be implemented well
+     enough to run NetBSD for that machine mode, but other guest operating
+     systems may not run at all, or behave strangely.)
 
-The processor architecture best emulated by GXemul is MIPS, but other
-architectures are also partially emulated.
 
 
 Quick start
 -----------
 
 To compile, type './configure' and then 'make'. This should work on most
-Unix-like systems. If not, then please mail me a bug report.
+Unix-like systems. If it does not, then please mail me a bug report.
+
+You might want to experiment with various CC and CFLAGS environment
+variable settings, to get optimum performance.
 
 If you are impatient, and want to try out running a guest operating system 
-inside GXemul, please read this:  doc/guestoses.html#netbsdinstall
+inside GXemul, read this:  doc/guestoses.html#netbsdpmaxinstall
 
 If you want to use GXemul for experimenting with code of your own, 
 then I suggest you compile a Hello World program according to the tips 
@@ -33,6 +92,7 @@
 more detailed information on how to use the emulator.
 
 
+
 Feedback
 --------