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# Line 4  Line 4 
4  <table border=0 width=100% bgcolor="#d0d0d0"><tr>  <table border=0 width=100% bgcolor="#d0d0d0"><tr>
5  <td width=100% align=center valign=center><table border=0 width=100%><tr>  <td width=100% align=center valign=center><table border=0 width=100%><tr>
6  <td align="left" valign=center bgcolor="#d0efff"><font color="#6060e0" size="6">  <td align="left" valign=center bgcolor="#d0efff"><font color="#6060e0" size="6">
7  <b>Gavare's eXperimental Emulator:&nbsp;&nbsp;&nbsp;</b></font>  <b>Gavare's eXperimental Emulator:</b></font><br>
8  <font color="#000000" size="6"><b>Introduction</b>  <font color="#000000" size="6"><b>Introduction</b>
9  </font></td></tr></table></td></tr></table><p>  </font></td></tr></table></td></tr></table><p>
10    
11  <!--  <!--
12    
13  $Id: intro.html,v 1.66 2005/11/23 22:03:24 debug Exp $  $Id: intro.html,v 1.110 2007/04/28 00:12:03 debug Exp $
14    
15  Copyright (C) 2003-2005  Anders Gavare.  All rights reserved.  Copyright (C) 2003-2007  Anders Gavare.  All rights reserved.
16    
17  Redistribution and use in source and binary forms, with or without  Redistribution and use in source and binary forms, with or without
18  modification, are permitted provided that the following conditions are met:  modification, are permitted provided that the following conditions are met:
# Line 45  SUCH DAMAGE. Line 45  SUCH DAMAGE.
45  <h2>Introduction</h2>  <h2>Introduction</h2>
46    
47  <p>  <p>
48    <table border="0" width="99%"><tr><td valign="top" align="left">
49  <ul>  <ul>
50    <li><a href="#overview">Overview</a>    <li><a href="#overview">Overview</a>
51    <li><a href="#free">Is GXemul Free software?</a>    <li><a href="#free">Is GXemul Free software?</a>
52    <li><a href="#build">How to compile/build the emulator</a>    <li><a href="#build">How to compile/build the emulator</a>
53    <li><a href="#run">How to run the emulator</a>    <li><a href="#run">How to run the emulator</a>
54    <li><a href="#cpus">Which CPU types does GXemul emulate?</a>    <li><a href="#cpus">Which processor architectures does GXemul emulate?</a>
55      <li><a href="#hosts">Which host architectures are supported?</a>
56    <li><a href="#accuracy">Emulation accuracy</a>    <li><a href="#accuracy">Emulation accuracy</a>
57    <li><a href="#emulmodes">Which machines does GXemul emulate?</a>    <li><a href="#emulmodes">Which machines does GXemul emulate?</a>
   <li><a href="#guestos">Which guest OSes are possible to run in GXemul?</a>  
58  </ul>  </ul>
59    </td><td valign="center" align="center">
60    <a href="20050317-example.png"><img src="20050317-example_small.png"></a>
61    <p>NetBSD/pmax 1.6.2 with X11<br>running in GXemul</td></tr></table>
62    
63    
64    
# Line 69  emulation modes are available. In some m Line 72  emulation modes are available. In some m
72  hardware components are emulated well enough to let unmodified operating  hardware components are emulated well enough to let unmodified operating
73  systems (e.g. NetBSD) run as if they were running on a real machine.  systems (e.g. NetBSD) run as if they were running on a real machine.
74    
75  <p>The processor architecture best emulated by GXemul is MIPS, but other  <p>Devices and processors are not simulated with 100% accuracy. They are
76  architectures such as ARM and PowerPC are also partially emulated.  only ``faked'' well enough to allow guest operating systems to run without
77    complaining too much. Still, the emulator could be of interest for
78  <p>Devices and CPUs are not simulated with 100% accuracy. They are only  academic research and experiments, such as when learning how to write
 ``faked'' well enough to allow guest operating systems run without  
 complaining too much. Still, the emulator could be of interest for  
 academic research and experiments, such as when learning how to write  
79  operating system code.  operating system code.
80    
81  <p>The emulator is written in C, does not depend on third-party libraries  <p>The emulator is written in C, does not depend on third-party libraries,
82  (except X11, but that is optional), and should compile and run on most  and should compile and run on most 64-bit and 32-bit Unix-like systems.
 Unix-like systems.  
83    
84  <p>The emulator contains code which tries to emulate the workings of CPUs  <p>The emulator contains code which tries to emulate the workings of CPUs
85  and surrounding hardware found in real machines, but it does not contain  and surrounding hardware found in real machines, but it does not contain
# Line 95  even actual ROM images. A couple of diff Line 94  even actual ROM images. A couple of diff
94    
95  <p>If you do not have a kernel as a separate file, but you have a bootable  <p>If you do not have a kernel as a separate file, but you have a bootable
96  disk image, then it is sometimes possible to boot directly from that  disk image, then it is sometimes possible to boot directly from that
97  image. (This works for example with DECstation emulation, or when booting  image. (This works for example with DECstation emulation, Dreamcast
98  from ISO9660 CDROM images.)  emulation, or when booting from generic ISO9660 CDROM images if the
99    kernel is included in the image as a plain file.)
100    
101    <p>Thanks to (in no specific order) Joachim Buss, Olivier Houchard, Juli
102    Mallett, Juan Romero Pardines, Carl van Schaik, Alec Voropay, Göran
103    Weinholt, Alexander Yurchenko, and everyone else who has provided me with
104    feedback.
105    
106    
107    
# Line 133  without source code. You need to check a Line 137  without source code. You need to check a
137  The "easiest way out" if you plan to redistribute code from GXemul is, of  The "easiest way out" if you plan to redistribute code from GXemul is, of
138  course, to let it remain open source and simply supply the source code.  course, to let it remain open source and simply supply the source code.
139    
140  <p>(If a stable, unmodified release of GXemul is packaged into binary form,  <p>In case you want to reuse parts of GXemul, but you need to do that
141  and it is clear which version of GXemul was used to build the package,  under a different license (e.g. the GPL), then contact me and I might
142  then it can be argued that the source code is available, just not in that  re-license/dual-license files on a case-by-case basis.
 specific package. Common sense should be used in this case, and not  
 pedanticism.)  
   
143    
144    
145    
# Line 154  Uncompress the .tar.gz distribution file Line 155  Uncompress the .tar.gz distribution file
155          $ <b>make</b>          $ <b>make</b>
156  </pre>  </pre>
157    
158  <p>This should work on most Unix-like systems. If it doesn't, then  <p>This should work on most Unix-like systems. GXemul does not require any
159  mail me a bug report.  specific libraries to build, however, if you build on a system which does
160    not have X11 libraries installed, some functionality will be lost.
161    
162  <p>The emulator's performance is highly dependent on both runtime settings  <p>The emulator's performance is highly dependent on both runtime settings
163  and on compiler settings, so you might want to experiment with different  and on compiler settings, so you might want to experiment with different
164  CC and CFLAGS environment variable values. For example, on an AMD Athlon  CC and CFLAGS environment variable values. For example, on an AMD Athlon
165  host, you might want to try setting <tt>CFLAGS</tt> to <tt>-march=athlon  host, you might want to try setting <tt>CFLAGS</tt> to <tt>-march=athlon</tt>
166  -O3</tt> before running <tt>configure</tt>.  before running <tt>configure</tt>.
167    
168    
169    
# Line 212  their original meaning in those xterm wi Line 214  their original meaning in those xterm wi
214    
215  <p><br>  <p><br>
216  <a name="cpus"></a>  <a name="cpus"></a>
217  <h3>Which CPU types does GXemul emulate?</h3>  <h3>Which processor architectures does GXemul emulate?</h3>
218    
219  <h4>MIPS:</h4>  The architectures that are emulated well enough to let at least one
220    guest operating system run (per architecture) are ARM, MIPS, PowerPC,
221    and SuperH.
222    
223    <p>Please read the page about <a href="guestoses.html">guest operating
224    systems</a> for more information about the machines and operating systems
225    that can be considered "working" in the emulator.
226    
 Emulation of R4000, which is a 64-bit CPU, was my initial goal.  
 R2000/R3000-like CPUs (32-bit), R1x000, and generic MIPS32/MIPS64-style  
 CPUs are also emulated, and are hopefully almost as stable as the R4000  
 emulation. Several guest operating systems for MIPS can run inside  
 the emulator.  
227    
 <p>(For MIPS emulation, I have written an experimental dynamic binary  
 translation subsystem, for Alpha and i386 hosts. This gives higher total  
 performance than interpreting one instruction at a time and executing it.  
 If you wish to disable bintrans, add <b>-B</b> to the command line.)  
228    
 <h4>ARM:</h4>  
229    
 ARM emulation is good enough to run NetBSD/cats 2.1 and OpenBSD/cats 3.8,  
 but it is not as tested or fine-tuned as the MIPS emulation mode.  
230    
 <h4>PowerPC:</h4>  
231    
232  PowerPC emulation is still in its beginning stages, but good enough  <p><br>
233  to run NetBSD/prep 2.1.  <a name="hosts"></a>
234    <h3>Which host architectures are supported?</h3>
235    
236    GXemul should compile and run on any modern host architecture (64-bit or
237    32-bit word-length).
238    
239  <p>Non-MIPS emulation modes use dynamic translation, but not recompilation  <p>Note: The <a href="translation.html">dynamic translation</a> engine
240  into native code. This makes it possible to run on any host platform.  does <i>not</i> require backends for native code generation to be written
241    for each individual host architecture; the intermediate representation
242    that the dyntrans system uses can be executed on any host architecture.
243    
244    
245    
# Line 249  into native code. This makes it possible Line 250  into native code. This makes it possible
250  <h3>Emulation accuracy:</h3>  <h3>Emulation accuracy:</h3>
251    
252  GXemul is an instruction-level emulator; things that would happen in  GXemul is an instruction-level emulator; things that would happen in
253  several steps within a real CPU are not taken into account (eg. pipe-line  several steps within a real CPU are not taken into account (e.g. pipe-line
254  stalls or out-of-order execution). Still, instruction-level accuracy seems  stalls or out-of-order execution). Still, instruction-level accuracy seems
255  to be enough to be able to run complete guest operating systems inside the  to be enough to be able to run complete guest operating systems inside the
256  emulator.  emulator.
257    
258  <p>Caches are by default not emulated. In some cases, the existance of  <p>The existance of instruction and data caches is "faked" to let
259  caches is "faked" to let operating systems think that they are there.  operating systems think that they are there, but for all practical
260  (There is some old code for R2000/R3000 caches, but it has probably  purposes, these caches are non-working.
261  suffered from bitrot by now.)  
262    <p>The emulator is in general <i>not</i> timing-accurate, neither at the
263  <p>The emulator is <i>not</i> timing-accurate. It can be run in a  instruction level nor on any higher level. An attempt is made to let
264  "deterministic" mode, <tt><b>-D</b></tt>. The meaning of deterministic is  emulated clocks run at the same speed as the host (i.e. an emulated timer
265  simply that running two emulations with the same settings will result in  running at 100 Hz will interrupt around 100 times per real second), but
266  identical runs. Obviously, this requires that no user interaction is  since the host speed may vary, e.g. because of other running processes,
267  taking place, and that clock speeds are fixed with the <tt><b>-I</b></tt>  there is no guarantee as to how many instructions will be executed in
268  option. (Deterministic in this case does <i>not</i> mean that the  each of these 100 Hz cycles.
269  emulation will be identical to some actual real-world machine.)  
270    <p>If the host is very slow, the emulated clocks might even lag behind
271  <p><font color="#ff0000">(Oops/TODO: User interaction means <i>both</i>  the real-world clock.
 input to the emulated program/OS, and interacting with the emulator  
 itself. Breaking into the debugger and then continuing execution may  
 affect when/how interrupts occur.)</font>  
272    
273    
274    
# Line 286  are emulated well enough to run at least Line 284  are emulated well enough to run at least
284    
285  <p>  <p>
286  <ul>  <ul>
287    <li><b><u>MIPS</u></b>    <li><b><u>ARM</u></b>
288    <ul>    <ul>
289      <li><b>DECstation 5000/200</b>&nbsp;&nbsp;("3max")      <li><b>CATS</b> (<a href="guestoses.html#netbsdcatsinstall">NetBSD/cats</a>,
290      <p>          <a href="guestoses.html#openbsdcatsinstall">OpenBSD/cats</a>)
291      <li><b>Acer Pica-61</b>&nbsp;&nbsp;(an ARC machine)      <li><b>IQ80321</b> (<a href="guestoses.html#netbsdevbarminstall">NetBSD/evbarm</a>)
292      <p>      <li><b>NetWinder</b> (<a href="guestoses.html#netbsdnetwinderinstall">NetBSD/netwinder</a>)
     <li><b>NEC MobilePro 770, 780, 800, and 880</b>&nbsp;&nbsp;(HPCmips machines)  
     <p>  
     <li><b>Cobalt</b>  
     <p>  
     <li><b>Malta</b> (evbmips)  
     <p>  
     <li><b>SGI O2 ("IP32")</b>  
         <br><small>(Enough for root-on-nfs, but not for disk boot.)</small>  
293    </ul>    </ul>
294    <p>    <p>
295    <li><b><u>ARM</u></b>    <li><b><u>MIPS</u></b>
296    <ul>    <ul>
297      <li><b>CATS</b>      <li><b>DECstation 5000/200</b> (<a href="guestoses.html#netbsdpmaxinstall">NetBSD/pmax</a>,
298            <a href="guestoses.html#openbsdpmaxinstall">OpenBSD/pmax</a>,
299            <a href="guestoses.html#ultrixinstall">Ultrix</a>,
300            <a href="guestoses.html#declinux">Linux/DECstation</a>,
301            <a href="guestoses.html#sprite">Sprite</a>)
302        <li><b>Acer Pica-61</b> (<a href="guestoses.html#netbsdarcinstall">NetBSD/arc</a>)
303        <li><b>NEC MobilePro 770, 780, 800, 880</b> (<a href="guestoses.html#netbsdhpcmipsinstall">NetBSD/hpcmips</a>)
304        <li><b>Cobalt</b> (<a href="guestoses.html#netbsdcobaltinstall">NetBSD/cobalt</a>)
305        <li><b>Malta</b> (<a href="guestoses.html#netbsdevbmipsinstall">NetBSD/evbmips</a>, Linux/Malta <font color="#0000e0">(<super>*1</super>)</font>)
306        <li><b>Algorithmics P5064</b> (<a href="guestoses.html#netbsdalgorinstall">NetBSD/algor</a>)
307        <li><b>SGI O2 (aka IP32)</b> <font color="#0000e0">(<super>*2</super>)</font>
308            (<a href="guestoses.html#netbsdsgimips">NetBSD/sgi</a>)
309    </ul>    </ul>
310    <p>    <p>
311    <li><b><u>PowerPC</u></b>    <li><b><u>PowerPC</u></b>
312    <ul>    <ul>
313      <li><b>PReP (PowerPC Reference Platform)</b>      <li><b>IBM 6050/6070 (PReP, PowerPC Reference Platform)</b> (<a href="guestoses.html#netbsdprepinstall">NetBSD/prep</a>)
314        <li><b>MacPPC (generic "G4" Macintosh)</b> (<a href="guestoses.html#netbsdmacppcinstall">NetBSD/macppc</a>)
315      </ul>
316      <p>
317      <li><b><u>SuperH</u></b>
318      <ul>
319        <li><b>Sega Dreamcast</b> (<a href="dreamcast.html#netbsd_generic_md">NetBSD/dreamcast</a>, <a href="dreamcast.html#linux_live_cd">Linux/dreamcast</a>)
320        <li><b>Landisk</b> (<a href="guestoses.html#openbsdlandiskinstall">OpenBSD/landisk</a>)
321    </ul>    </ul>
322  </ul>  </ul>
323    
324    <p>
325    <small><font color="#0000e0">(<super>*1</super>)</font> =
326    Linux/Malta may be run as a guest OS, however I have not yet found any stable
327    URL to pre-compiled Linux/Malta kernels. Thus, Linux/Malta emulation is not
328    tested for every release of the emulator; sometimes it works, sometimes
329    it doesn't.</small>
330    
331    <br><small><font color="#0000e0">(<super>*2</super>)</font> =
332    SGI O2 emulation is enough for root-on-nfs, but not for disk boot.</small>
333    
334    
335  <p>There is code in GXemul for emulation of many other machine types; the  <p>There is code in GXemul for emulation of many other machine types; the
336  degree to which these work range from almost being able to run a complete  degree to which these work range from almost being able to run a complete
337  OS, to almost completely unsupported (perhaps just enough support to  OS, to almost completely unsupported (perhaps just enough support to
# Line 327  such as: Line 346  such as:
346    <li>a console I/O device (putchar() and getchar()...)    <li>a console I/O device (putchar() and getchar()...)
347    <li>an inter-processor communication device, for SMP experiments    <li>an inter-processor communication device, for SMP experiments
348    <li>a very simple linear framebuffer device (for graphics output)    <li>a very simple linear framebuffer device (for graphics output)
349    <li>a simple SCSI disk controller    <li>a simple disk controller
350    <li>a simple ethernet controller    <li>a simple ethernet controller
351      <li>a real-time clock device
352  </ul>  </ul>
353    
354  <p>This mode is useful if you wish to run experimental code, but do not  <p>This mode is useful if you wish to run experimental code, but do not
# Line 343  href="experiments.html#expdevices">here< Line 363  href="experiments.html#expdevices">here<
363    
364    
365    
   
 <p><br>  
 <a name="guestos"></a>  
 <h3>Which guest OSes are possible to run in GXemul?</h3>  
   
 This table lists the guest OSes that run well enough to be considered  
 working in the emulator. They can boot from a harddisk image and be  
 interacted with similar to a real machine.  
   
 <p>  
 <center><table border="0">  
         <tr>  
           <td width="10"></td>  
           <td align="center"><a href="20050317-example.png"><img src="20050317-example_small.png"></a></td>  
           <td width="15"></td>  
           <td><a href="http://www.netbsd.org/Ports/pmax/">NetBSD/pmax</a>  
                 <br>DECstation 5000/200</td>  
           <td width="30"></td>  
           <td align="center"><a href="20041024-netbsd-arc-installed.gif"><img src="20041024-netbsd-arc-installed_small.gif"></a></td>  
           <td width="15"></td>  
           <td><a href="http://www.netbsd.org/Ports/arc/">NetBSD/arc</a>  
                 <br>Acer Pica-61</td>  
   
         </tr>  
   
         <tr><td height="10"></td></tr>  
   
         <tr>  
           <td></td>  
           <td align="center"><a href="openbsd-pmax-20040710.png"><img src="openbsd-pmax-20040710_small.png"></a></td>  
           <td></td>  
           <td><a href="http://www.openbsd.org/pmax.html">OpenBSD/pmax</a>  
                 <br>DECstation 5000/200</td>  
           <td></td>  
           <td align="center"><a href="20041024-openbsd-arc-installed.gif"><img src="20041024-openbsd-arc-installed_small.gif"></a></td>  
           <td></td>  
           <td><a href="http://www.openbsd.org/arc.html">OpenBSD/arc</a>  
                 <br>Acer Pica-61</td>  
         </tr>  
   
         <tr><td height="10"></td></tr>  
   
         <tr>  
           <td></td>  
           <td align="center"><a href="ultrix4.5-20040706.png"><img src="ultrix4.5-20040706_small.gif"></a></td>  
           <td></td>  
           <td>Ultrix/RISC<br>DECstation 5000/200</td>  
           <td></td>  
           <td align="center"><a href="20041213-debian_4.png"><img src="20041213-debian_4_small.gif"></a></td>  
           <td></td>  
           <td><a href="http://www.debian.org/">Debian&nbsp;GNU/Linux</a>&nbsp;<super>*</super>  
                 <br>DECstation 5000/200</td>  
         </tr>  
   
         <tr><td height="10"></td></tr>  
   
         <tr>  
           <td></td>  
           <td align="center"><a href="sprite-20040711.png"><img src="sprite-20040711_small.png"></a></td>  
           <td></td>  
           <td><a href="http://www.cs.berkeley.edu/projects/sprite/retrospective.html">Sprite</a>  
                 <br>DECstation 5000/200</td>  
           <td></td>  
           <td align="center"><a href="20041129-redhat_mips.png"><img src="20041129-redhat_mips_small.png"></a></td>  
           <td></td>  
           <td>Redhat&nbsp;Linux&nbsp;<super>*</super>  
                 <br>DECstation 5000/200</td>  
         </tr>  
   
         <tr><td height="10"></td></tr>  
   
         <tr>  
           <td></td>  
           <td align="center"><a href="20050427-netbsd-hpcmips-2.png"><img src="20050427-netbsd-hpcmips-2_small.png"></a></td>  
           <td></td>  
           <td><a href="http://www.netbsd.org/Ports/hpcmips/">NetBSD/hpcmips</a>  
                 <br>NEC MobilePro 770, 780, 800, 880</td>  
           <td></td>  
           <td align="center"><a href="20050413-netbsd-cobalt.png"><img src="20050413-netbsd-cobalt_small.png"></a></td>  
           <td></td>  
           <td><a href="http://www.netbsd.org/Ports/cobalt/">NetBSD/cobalt</a>  
                 <br>Cobalt</td>  
         </tr>  
   
         <tr><td height="10"></td></tr>  
   
         <tr>  
           <td></td>  
           <td align="center"><a href="20050626-netbsd-sgimips-netboot.png"><img src="20050626-netbsd-sgimips-netboot_small.png"></a></td>  
           <td></td>  
           <td><a href="http://www.netbsd.org/Ports/sgimips/">NetBSD/sgimips</a>  
                 <br>SGI O2 ("IP32")</td>  
           <td></td>  
           <td align="center"><a href="20050622-netbsd-evbmips-malta.png"><img src="20050622-netbsd-evbmips-malta_small.png"></a></td>  
           <td></td>  
           <td><a href="http://www.netbsd.org/Ports/evbmips/">NetBSD/evbmips</a>  
                 <br>5Kc (and 4Kc) Malta<br>evaluation boards</td>  
           <td></td>  
         </tr>  
   
         <tr><td height="10"></td></tr>  
   
         <tr>  
           <td></td>  
           <td align="center"><a href="20051007-netbsd-cats-installed.png"><img src="20051007-netbsd-cats-installed_small.png"></a></td>  
           <td></td>  
           <td><a href="http://www.netbsd.org/Ports/cats/">NetBSD/cats</a>  
                 <br>CATS</td>  
           <td></td>  
           <td align="center"><a href="20051007-openbsd-cats-installed.png"><img src="20051007-openbsd-cats-installed_small.png"></a></td>  
           <td></td>  
           <td><a href="http://www.openbsd.org/cats.html">OpenBSD/cats</a>  
                 <br>CATS</td>  
           <td></td>  
         </tr>  
   
         <tr><td height="10"></td></tr>  
   
         <tr>  
           <td></td>  
           <td align="center"><a href="20051123-netbsd-prep.png"><img src="20051123-netbsd-prep_small.png"></a></td>  
           <td></td>  
           <td><a href="http://www.netbsd.org/Ports/prep/">NetBSD/prep</a>  
                 <br>PReP</td>  
           <td></td>  
         </tr>  
   
 </table></center>  
   
   
 <p><br>  
   
 <super>*</super> Although Linux runs under DECstation emulation, the  
 default 2.4.27 kernel in Debian GNU/Linux does not support keyboards on  
 the 5000/200 (the specific DECstation model being emulated), so when the  
 login prompt is reached you cannot interact with the system. Kaj-Michael  
 Lang has compiled and made available a newer kernel from the current  
 mips-linux development tree. You can find it here: <a  
 href="http://home.tal.org/~milang/o2/kernels/">http://home.tal.org/~milang/o2/kernels</a>/<a  
 href="http://home.tal.org/~milang/o2/kernels/vmlinux-2.4.29-rc2-r3k-mipsel-decstation">vmlinux-2.4.29-rc2-r3k-mipsel-decstation</a>  
 This newer kernel supports keyboard input, but it does not have Debian's  
 ethernet patches, so you will not be able to use keyboard/framebuffer  
 <i>and</i> networking at the same time.  
   
   
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