trunk/man/gxemul.1

.\" $Id: gxemul.1,v 1.21 2005/06/03 23:14:52 debug Exp $
.\"
.\" Copyright (C) 2004-2005  Anders Gavare.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions are met:
.\"
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. The name of the author may not be used to endorse or promote products
.\"    derived from this software without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\" 
.\" 
.\" This is a minimal man page for GXemul. Process this file with
.\"     groff -man -Tascii gxemul.1    or    nroff -man gxemul.1
.\"
.Dd JUNE 2005
.Dt GXEMUL 1
.Os
.Sh NAME
.Nm gxemul
.Nd an experimental machine emulator
.Sh SYNOPSIS
.Nm
.Op machine, other, and general options
.Op file Ar ...
.Nm
.Op general options
.Op Ar @configfile ...
.Nm
.Op userland, other, and general options
.Ar file Op Ar args ...
.Sh DESCRIPTION
.Nm
is an experimental instruction-level machine emulator. It can be used 
to run binary code for (among others) MIPS-based machines.
Several emulation modes are available. For some emulation modes, processors
and surrounding hardware components are emulated well enough to let
unmodified operating systems (eg. NetBSD) run as if they were running on a
real machine.
.Pp
There are three ways to invoke the emulator. When emulating a 
complete machine, settings can be entered directly on the command line, or
they can be read from a configuration file. When emulating a userland 
environment (syscall-only emulation, not emulating complete machines), 
then the program name and its argument should be given on the command 
line.
.Pp
The easiest way to use the emulator is to supply settings directly on the 
command line. The most important thing you need to supply is the
file argument. This is the name of a binary file (an ELF, a.out, ECOFF,
SREC, or a raw binary image) which you wish to run in the emulator. This file
might be an operating system kernel, or perhaps a ROM image file.
.Pp
If more than one filename is supplied, all files are loaded into memory, 
and the entry point (if available) is taken from the last file.
.Pp
Apart from the name of a binary file, it is also necessary to select
which specific emulation mode to use. For example, a MIPS-based machine
from DEC (a DECstation) is very different from a MIPS-based machine
from SGI. Use
.Nm
.Fl H
to get a list of available emulation modes.
.Pp
There are two exceptions to the normal invocation usage mentioned above.
The first is for DECstation emulation: if you have a bootable
DECstation harddisk or CDROM image, then just supplying the diskimage via 
the
.Fl d
option is sufficient. (The filename of the kernel can then be 
skipped, as the emulator runs the bootblocks from the diskimage directly and 
doesn't need the kernel as a separate file.)
The second is if you supply an ISO9660 CDROM disk image. You may then use 
the
.Fl j
option to indicate which file on the CDROM filesystem that should be 
loaded into emulated memory.
.Pp
Machine selection options:
.Bl -tag -width Ds
.It Fl E Ar t
Try to emulate machine type
.Ar "t".
(Use
.Fl H
to get a list of types.)
.It Fl e Ar st
Try to emulate machine subtype
.Ar "st".
Use this together with
.Fl E .
(This option is not always needed, if a machine type has no subtypes.)
.El
.Pp
Other options:
.Bl -tag -width Ds
.It Fl B
Disable dynamic binary translation completely. By default, bintrans
will be turned on if the host architecture supports it.
However, in this release (0.3.X), there is no new bintrans system.
If you want to enable binary translation, use
.Fl "b".
.It Fl b
Use the OLD binary translation subsystem. (Alpha and i386 hosts only.)
.It Fl C Ar x
Try to emulate a specific CPU type,
.Ar "x".
This overrides the default CPU type for the machine being emulated.
(Use
.Fl H
to get a list of available CPU types.)
.It Fl d Ar name
Add
.Ar name
as a disk image. By adding one or more modifier characters and then a
colon (":") as a prefix to
.Ar "name",
you can modify the way the disk image is treated. Available modifiers are:
.Bl -tag -width Ds
.It b
Specifies that this is a boot device.
.It c
CD-ROM.
.It d
DISK (this is the default).
.It f
FLOPPY.
.It gH;S;
Override the default geometry; use H heads and S sectors-per-track.
(The number of cylinders is calculated automatically.)
.It i
IDE.
.It r
Read-only (don't allow changes to be written to the file).
.It s
SCSI (this is the default for most machine types).
.It t
Tape.
.It 0-7
Force a specific ID number.
.El
.Pp
Unless otherwise specified, filenames ending with ".iso" are assumed to be
CDROM images. Most others are assumed to be disks. Depending on which
machine is being emulated, the default for disks can be either SCSI or
IDE. Some disk images that are very small are assumed to be floppy disks.
(If you are not happy with the way a disk image is detected, then you need 
to use explicit prefixes to force a specific type.)
.Pp
For floppies, the gH;S; prefix is ignored. Instead, the number of 
heads and cylinders are assumed to be 2 and 80, respectively, and the 
number of sectors per track is calculated automatically. (This works for 
720KB, 1.2MB, 1.44MB, and 2.88MB floppies.)
.It Fl I Ar x
Emulate clock interrupts at
.Ar x
Hz. (This affects emulated clock devices only, not actual runtime speed.
This disables automatic clock adjustments, which is otherwise turned on.)
(This option is probably only valid for DECstation emulation.)
.It Fl i
Display each instruction as it is being executed.
.It Fl J
Disable some speed tricks.
.It Fl j Ar n
Set the name of the kernel to
.Ar "n".
When booting from an ISO9660 filesystem, the kernel will try to boot from 
this file. (In some emulation modes, eg. DECstation, this name is passed 
along to the boot program. Useful names are "bsd" for OpenBSD/pmax, 
or "vmunix" for Ultrix.)
.It Fl M Ar m
Emulate
.Ar m
MBs of physical RAM. This overrides the default amount of RAM for the 
selected machine type.
.It Fl m Ar nr
Run at most
.Ar nr
instructions (on any cpu).
.It Fl N
Display nr of instructions/second average, at regular intervals.
.It Fl n Ar nr
Set nr of CPUs (for SMP experiments).
.It Fl O
Force a "netboot" (tftp instead of disk), even when a disk image is
present (for DECstation, SGI, and ARC emulation).
.It Fl o Ar arg
Set the boot argument (for DEC, ARC, or SGI emulation).
Default
.Ar arg
for DEC is "-a", for ARC "-aN".
.It Fl p Ar pc
Add a breakpoint. (Remember to use the "0x" prefix for hex.)
.It Fl Q
Disable the built-in PROM emulation. This is useful for running raw ROM
images from real machines.
.It Fl R
Use a random bootstrap cpu, instead of CPU nr 0. (For SMP experiments.)
.It Fl r
Dump register contents for every executed instruction.
.It Fl S
Initialize the emulated RAM to random data, instead of zeroes.
.It Fl T
Enter the single-step debugger on unimplemented memory accesses.
.It Fl t
Show a trace tree of all function calls being made.
.It Fl U
Enable slow_serial_interrupts_hack_for_linux.
.It Fl X
Use X11.
.It Fl x
Open up new xterms for emulated serial ports. (Default is to open up 
xterms when using configuration files, but not when starting an 
emulation with settings directly on the command line.)
.It Fl Y Ar n
Scale down framebuffer windows by
.Ar n
x
.Ar n
times.
.It Fl y Ar x
Set max_random_cycles_per_chunk to
.Ar x
(experimental).
.It Fl Z Ar n
Set the number of graphics cards, for emulating a dual-head or tripple-head
environment. (Only for DECstation emulation so far.)
.It Fl z Ar disp
Add
.Ar disp
as an X11 display to use for framebuffers.
.El
.Pp
Userland options:
.Bl -tag -width Ds
.It Fl u Ar emul-mode
Userland-only (syscall) emulation. (Use
.Fl H
to get a list of available emulation modes.) Some (but not all) of the
options listed under Other options above can also be used with userland
emulation.
.El
.Pp
General options:
.Bl -tag -width Ds
.It Fl D
Guarantee fully deterministic behavior. Normally, the emulator calls
srandom() with a seed based on the current time at startup. When the
.Fl D
option is used, the srandom() call is skipped, which should cause two 
subsequent invocations of the emulator to be identical, if all other 
settings are identical and no user input is taking place. (If this option 
is used, then
.Fl I
must also be used.)
.It Fl H
Display a list of available CPU types, machine types, and userland
emulation modes. (Most of these don't work. Please read the documentation
included in the
.Nm
distribution for details on which modes that actually work.)
.It Fl h
Display a list of all available command line options.
.It Fl K
Force the single-step debugger to be entered at the end of a simulation.
.It Fl q
Quiet mode; this suppresses startup messages.
.It Fl s
Show opcode usage statistics after the simulation.
.It Fl V
Start up in the single-step debugger, paused.
.It Fl v
Verbose debug messages.
.El
.Pp
Configuration file startup:
.Bl -tag -width Ds
.It @ Ar configfile
Start an emulation based on the contents of
.Ar "configfile".
.El
.Pp
For more information, please read the documentation in the doc/
subdirectory of the
.Nm
distribution.
.Sh EXAMPLES
The following command will start NetBSD/pmax on an emulated DECstation 
5000/200 (3MAX), with the old bintrans system enabled:
.Pp
.Dl "gxemul -E dec -e 3max -b -d netbsddisk.img"
.Pp
netbsddisk.img should be a raw disk image containing a bootable 
NetBSD/pmax filesystem.
.Pp
The following command will start an emulation session based on settings in 
the configuration file "mysession". The -v option tells gxemul to be
verbose.
.Pp
.Dl "gxemul -v @mysession"
.Pp
If you have compiled the small Hello World program mentioned in the
.Nm
documentation, the following command will start up an
emulated test machine in "paused" mode:
.Pp
.Dl "gxemul -E testmips -V hello_mips"
.Pp
(Paused mode means that you enter the interactive single-step debugger
directly at startup, instead of launching the Hello World program.)
.Pp
Please read the documentation for more details.
.Sh BUGS
There are many bugs. Some of the known bugs are listed in the BUGS
file in the
.Nm
source distribution, some are indirectly mentioned in the TODO file.
.Pp
There is no new bintrans system in this release, so you will need to add
.Fl b
to select the old bintrans system, if you want speed.
.Pp
.Nm
does not simulate individual pipe-line stages or penalties caused by
branch-prediction misses, so it cannot be used for accurate performance 
measurement.
.Pp
.Nm
is not timing-accurate.
.Sh AUTHOR
Anders Gavare <anders@gavare.se>
.Pp
See http://gavare.se/gxemul/ for more information.
1	dpavlin	6	.\" $Id: gxemul.1,v 1.21 2005/06/03 23:14:52 debug Exp $
2	dpavlin	2	.\"
3			.\" Copyright (C) 2004-2005 Anders Gavare. All rights reserved.
4			.\"
5			.\" Redistribution and use in source and binary forms, with or without
6			.\" modification, are permitted provided that the following conditions are met:
7			.\"
8			.\" 1. Redistributions of source code must retain the above copyright
9			.\" notice, this list of conditions and the following disclaimer.
10			.\" 2. Redistributions in binary form must reproduce the above copyright
11			.\" notice, this list of conditions and the following disclaimer in the
12			.\" documentation and/or other materials provided with the distribution.
13			.\" 3. The name of the author may not be used to endorse or promote products
14			.\" derived from this software without specific prior written permission.
15			.\"
16			.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17			.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18			.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19			.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20			.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21			.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22			.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23			.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24			.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25			.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26			.\" SUCH DAMAGE.
27			.\"
28			.\"
29			.\" This is a minimal man page for GXemul. Process this file with
30			.\" groff -man -Tascii gxemul.1 or nroff -man gxemul.1
31			.\"
32	dpavlin	6	.Dd JUNE 2005
33	dpavlin	2	.Dt GXEMUL 1
34			.Os
35			.Sh NAME
36			.Nm gxemul
37			.Nd an experimental machine emulator
38			.Sh SYNOPSIS
39			.Nm
40			.Op machine, other, and general options
41			.Op file Ar ...
42			.Nm
43			.Op general options
44			.Op Ar @configfile ...
45			.Nm
46			.Op userland, other, and general options
47			.Ar file Op Ar args ...
48			.Sh DESCRIPTION
49			.Nm
50			is an experimental instruction-level machine emulator. It can be used
51			to run binary code for (among others) MIPS-based machines.
52			Several emulation modes are available. For some emulation modes, processors
53			and surrounding hardware components are emulated well enough to let
54	dpavlin	6	unmodified operating systems (eg. NetBSD) run as if they were running on a
55	dpavlin	2	real machine.
56			.Pp
57			There are three ways to invoke the emulator. When emulating a
58			complete machine, settings can be entered directly on the command line, or
59			they can be read from a configuration file. When emulating a userland
60			environment (syscall-only emulation, not emulating complete machines),
61			then the program name and its argument should be given on the command
62			line.
63			.Pp
64			The easiest way to use the emulator is to supply settings directly on the
65			command line. The most important thing you need to supply is the
66			file argument. This is the name of a binary file (an ELF, a.out, ECOFF,
67			SREC, or a raw binary image) which you wish to run in the emulator. This file
68			might be an operating system kernel, or perhaps a ROM image file.
69			.Pp
70			If more than one filename is supplied, all files are loaded into memory,
71			and the entry point (if available) is taken from the last file.
72			.Pp
73			Apart from the name of a binary file, it is also necessary to select
74			which specific emulation mode to use. For example, a MIPS-based machine
75			from DEC (a DECstation) is very different from a MIPS-based machine
76			from SGI. Use
77			.Nm
78			.Fl H
79			to get a list of available emulation modes.
80			.Pp
81	dpavlin	6	There are two exceptions to the normal invocation usage mentioned above.
82			The first is for DECstation emulation: if you have a bootable
83	dpavlin	2	DECstation harddisk or CDROM image, then just supplying the diskimage via
84			the
85			.Fl d
86	dpavlin	6	option is sufficient. (The filename of the kernel can then be
87	dpavlin	2	skipped, as the emulator runs the bootblocks from the diskimage directly and
88			doesn't need the kernel as a separate file.)
89	dpavlin	6	The second is if you supply an ISO9660 CDROM disk image. You may then use
90			the
91			.Fl j
92			option to indicate which file on the CDROM filesystem that should be
93			loaded into emulated memory.
94	dpavlin	2	.Pp
95			Machine selection options:
96			.Bl -tag -width Ds
97			.It Fl E Ar t
98			Try to emulate machine type
99			.Ar "t".
100			(Use
101			.Fl H
102			to get a list of types.)
103			.It Fl e Ar st
104			Try to emulate machine subtype
105			.Ar "st".
106			Use this together with
107			.Fl E .
108			(This option is not always needed, if a machine type has no subtypes.)
109			.El
110			.Pp
111			Other options:
112			.Bl -tag -width Ds
113			.It Fl B
114			Disable dynamic binary translation completely. By default, bintrans
115			will be turned on if the host architecture supports it.
116	dpavlin	6	However, in this release (0.3.X), there is no new bintrans system.
117	dpavlin	2	If you want to enable binary translation, use
118			.Fl "b".
119			.It Fl b
120			Use the OLD binary translation subsystem. (Alpha and i386 hosts only.)
121			.It Fl C Ar x
122			Try to emulate a specific CPU type,
123			.Ar "x".
124			This overrides the default CPU type for the machine being emulated.
125			(Use
126			.Fl H
127			to get a list of available CPU types.)
128			.It Fl d Ar name
129			Add
130			.Ar name
131			as a disk image. By adding one or more modifier characters and then a
132			colon (":") as a prefix to
133			.Ar "name",
134	dpavlin	6	you can modify the way the disk image is treated. Available modifiers are:
135	dpavlin	2	.Bl -tag -width Ds
136			.It b
137			Specifies that this is a boot device.
138			.It c
139	dpavlin	4	CD-ROM.
140	dpavlin	2	.It d
141	dpavlin	4	DISK (this is the default).
142			.It f
143			FLOPPY.
144	dpavlin	6	.It gH;S;
145			Override the default geometry; use H heads and S sectors-per-track.
146			(The number of cylinders is calculated automatically.)
147	dpavlin	2	.It i
148	dpavlin	4	IDE.
149	dpavlin	2	.It r
150			Read-only (don't allow changes to be written to the file).
151	dpavlin	4	.It s
152			SCSI (this is the default for most machine types).
153	dpavlin	2	.It t
154	dpavlin	4	Tape.
155	dpavlin	2	.It 0-7
156	dpavlin	6	Force a specific ID number.
157	dpavlin	2	.El
158			.Pp
159	dpavlin	6	Unless otherwise specified, filenames ending with ".iso" are assumed to be
160			CDROM images. Most others are assumed to be disks. Depending on which
161			machine is being emulated, the default for disks can be either SCSI or
162			IDE. Some disk images that are very small are assumed to be floppy disks.
163			(If you are not happy with the way a disk image is detected, then you need
164			to use explicit prefixes to force a specific type.)
165			.Pp
166			For floppies, the gH;S; prefix is ignored. Instead, the number of
167			heads and cylinders are assumed to be 2 and 80, respectively, and the
168			number of sectors per track is calculated automatically. (This works for
169			720KB, 1.2MB, 1.44MB, and 2.88MB floppies.)
170	dpavlin	2	.It Fl I Ar x
171			Emulate clock interrupts at
172			.Ar x
173			Hz. (This affects emulated clock devices only, not actual runtime speed.
174			This disables automatic clock adjustments, which is otherwise turned on.)
175			(This option is probably only valid for DECstation emulation.)
176			.It Fl i
177			Display each instruction as it is being executed.
178			.It Fl J
179			Disable some speed tricks.
180			.It Fl j Ar n
181			Set the name of the kernel to
182			.Ar "n".
183	dpavlin	6	When booting from an ISO9660 filesystem, the kernel will try to boot from
184			this file. (In some emulation modes, eg. DECstation, this name is passed
185			along to the boot program. Useful names are "bsd" for OpenBSD/pmax,
186			or "vmunix" for Ultrix.)
187	dpavlin	2	.It Fl M Ar m
188			Emulate
189			.Ar m
190			MBs of physical RAM. This overrides the default amount of RAM for the
191			selected machine type.
192			.It Fl m Ar nr
193			Run at most
194			.Ar nr
195			instructions (on any cpu).
196			.It Fl N
197			Display nr of instructions/second average, at regular intervals.
198			.It Fl n Ar nr
199			Set nr of CPUs (for SMP experiments).
200			.It Fl O
201			Force a "netboot" (tftp instead of disk), even when a disk image is
202			present (for DECstation, SGI, and ARC emulation).
203			.It Fl o Ar arg
204			Set the boot argument (for DEC, ARC, or SGI emulation).
205			Default
206			.Ar arg
207	dpavlin	6	for DEC is "-a", for ARC "-aN".
208	dpavlin	2	.It Fl p Ar pc
209	dpavlin	6	Add a breakpoint. (Remember to use the "0x" prefix for hex.)
210	dpavlin	2	.It Fl Q
211			Disable the built-in PROM emulation. This is useful for running raw ROM
212			images from real machines.
213			.It Fl R
214			Use a random bootstrap cpu, instead of CPU nr 0. (For SMP experiments.)
215			.It Fl r
216			Dump register contents for every executed instruction.
217			.It Fl S
218			Initialize the emulated RAM to random data, instead of zeroes.
219			.It Fl T
220			Enter the single-step debugger on unimplemented memory accesses.
221			.It Fl t
222			Show a trace tree of all function calls being made.
223			.It Fl U
224			Enable slow_serial_interrupts_hack_for_linux.
225			.It Fl X
226			Use X11.
227			.It Fl x
228			Open up new xterms for emulated serial ports. (Default is to open up
229			xterms when using configuration files, but not when starting an
230			emulation with settings directly on the command line.)
231			.It Fl Y Ar n
232			Scale down framebuffer windows by
233			.Ar n
234			x
235			.Ar n
236			times.
237			.It Fl y Ar x
238			Set max_random_cycles_per_chunk to
239			.Ar x
240			(experimental).
241			.It Fl Z Ar n
242			Set the number of graphics cards, for emulating a dual-head or tripple-head
243			environment. (Only for DECstation emulation so far.)
244			.It Fl z Ar disp
245			Add
246			.Ar disp
247			as an X11 display to use for framebuffers.
248			.El
249			.Pp
250			Userland options:
251			.Bl -tag -width Ds
252			.It Fl u Ar emul-mode
253			Userland-only (syscall) emulation. (Use
254			.Fl H
255			to get a list of available emulation modes.) Some (but not all) of the
256			options listed under Other options above can also be used with userland
257			emulation.
258			.El
259			.Pp
260			General options:
261			.Bl -tag -width Ds
262			.It Fl D
263	dpavlin	6	Guarantee fully deterministic behavior. Normally, the emulator calls
264	dpavlin	2	srandom() with a seed based on the current time at startup. When the
265			.Fl D
266			option is used, the srandom() call is skipped, which should cause two
267	dpavlin	6	subsequent invocations of the emulator to be identical, if all other
268			settings are identical and no user input is taking place. (If this option
269			is used, then
270	dpavlin	2	.Fl I
271			must also be used.)
272			.It Fl H
273			Display a list of available CPU types, machine types, and userland
274			emulation modes. (Most of these don't work. Please read the documentation
275			included in the
276			.Nm
277			distribution for details on which modes that actually work.)
278			.It Fl h
279			Display a list of all available command line options.
280			.It Fl K
281			Force the single-step debugger to be entered at the end of a simulation.
282			.It Fl q
283			Quiet mode; this suppresses startup messages.
284			.It Fl s
285			Show opcode usage statistics after the simulation.
286			.It Fl V
287			Start up in the single-step debugger, paused.
288			.It Fl v
289			Verbose debug messages.
290			.El
291			.Pp
292			Configuration file startup:
293			.Bl -tag -width Ds
294			.It @ Ar configfile
295			Start an emulation based on the contents of
296			.Ar "configfile".
297			.El
298			.Pp
299			For more information, please read the documentation in the doc/
300			subdirectory of the
301			.Nm
302			distribution.
303			.Sh EXAMPLES
304			The following command will start NetBSD/pmax on an emulated DECstation
305			5000/200 (3MAX), with the old bintrans system enabled:
306			.Pp
307			.Dl "gxemul -E dec -e 3max -b -d netbsddisk.img"
308			.Pp
309			netbsddisk.img should be a raw disk image containing a bootable
310			NetBSD/pmax filesystem.
311			.Pp
312			The following command will start an emulation session based on settings in
313			the configuration file "mysession". The -v option tells gxemul to be
314			verbose.
315			.Pp
316			.Dl "gxemul -v @mysession"
317			.Pp
318			If you have compiled the small Hello World program mentioned in the
319			.Nm
320			documentation, the following command will start up an
321			emulated test machine in "paused" mode:
322			.Pp
323			.Dl "gxemul -E testmips -V hello_mips"
324			.Pp
325			(Paused mode means that you enter the interactive single-step debugger
326			directly at startup, instead of launching the Hello World program.)
327			.Pp
328			Please read the documentation for more details.
329			.Sh BUGS
330			There are many bugs. Some of the known bugs are listed in the BUGS
331			file in the
332			.Nm
333			source distribution, some are indirectly mentioned in the TODO file.
334			.Pp
335	dpavlin	6	There is no new bintrans system in this release, so you will need to add
336	dpavlin	2	.Fl b
337			to select the old bintrans system, if you want speed.
338			.Pp
339			.Nm
340			does not simulate individual pipe-line stages or penalties caused by
341			branch-prediction misses, so it cannot be used for accurate performance
342			measurement.
343	dpavlin	6	.Pp
344			.Nm
345			is not timing-accurate.
346	dpavlin	2	.Sh AUTHOR
347			Anders Gavare <anders@gavare.se>
348			.Pp
349			See http://gavare.se/gxemul/ for more information.