1 |
dpavlin |
22 |
.\" $Id: gxemul.1,v 1.49 2006/02/18 14:02:20 debug Exp $ |
2 |
dpavlin |
2 |
.\" |
3 |
dpavlin |
22 |
.\" Copyright (C) 2004-2006 Anders Gavare. All rights reserved. |
4 |
dpavlin |
2 |
.\" |
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 |
22 |
.Dd FEBRUARY 2006 |
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 |
dpavlin |
14 |
.Ar @configfile |
45 |
dpavlin |
2 |
.Nm |
46 |
|
|
.Op userland, other, and general options |
47 |
|
|
.Ar file Op Ar args ... |
48 |
|
|
.Sh DESCRIPTION |
49 |
|
|
.Nm |
50 |
dpavlin |
14 |
is an experimental instruction-level machine emulator. Several |
51 |
|
|
emulation modes are available. In some modes, processors and surrounding |
52 |
|
|
hardware components are emulated well enough to let unmodified operating |
53 |
dpavlin |
20 |
systems (e.g. NetBSD) run inside the emulator as if they were running on a |
54 |
|
|
real machine. |
55 |
dpavlin |
2 |
.Pp |
56 |
dpavlin |
14 |
The processor architecture best emulated by GXemul is MIPS, but other |
57 |
dpavlin |
20 |
architectures (ARM and PowerPC) are also partially emulated. |
58 |
dpavlin |
12 |
.Pp |
59 |
dpavlin |
22 |
MIPS processors are emulated using either a simple binary translation |
60 |
|
|
layer (recompilation into native code), which is used on Alpha and i386 |
61 |
|
|
hosts, or by traditional interpretation (very very slow, but works on any |
62 |
|
|
host platform). |
63 |
dpavlin |
18 |
.Pp |
64 |
dpavlin |
22 |
Non-MIPS processors are emulated using a newer dynamic translation |
65 |
|
|
system (called dyntrans in the rest of this man page). Performance is |
66 |
|
|
somewhere between traditional interpretation and recompilation into native |
67 |
|
|
code. However, the dynamic translation system used in GXemul does NOT |
68 |
|
|
generate native code, and thus doesn't require platform-specific |
69 |
|
|
back-ends. In plain English, this means that the dyntrans system works on |
70 |
|
|
any host platform. |
71 |
dpavlin |
18 |
.Pp |
72 |
dpavlin |
14 |
There are three ways to invoke the emulator: |
73 |
dpavlin |
2 |
.Pp |
74 |
dpavlin |
14 |
1. When emulating a complete machine, configuration options can be entered |
75 |
|
|
directly on the command line. |
76 |
|
|
.Pp |
77 |
|
|
2. Options can be read from a configuration file. |
78 |
|
|
.Pp |
79 |
|
|
3. When emulating a userland environment (syscall-only emulation, not |
80 |
|
|
emulating complete machines), then the program name and its argument |
81 |
|
|
should be given on the command line. (This mode doesn't really work yet.) |
82 |
|
|
.Pp |
83 |
dpavlin |
2 |
The easiest way to use the emulator is to supply settings directly on the |
84 |
|
|
command line. The most important thing you need to supply is the |
85 |
dpavlin |
14 |
file argument. This is the name of a binary file (an ELF, a.out, COFF/ECOFF, |
86 |
dpavlin |
2 |
SREC, or a raw binary image) which you wish to run in the emulator. This file |
87 |
|
|
might be an operating system kernel, or perhaps a ROM image file. |
88 |
|
|
.Pp |
89 |
|
|
If more than one filename is supplied, all files are loaded into memory, |
90 |
|
|
and the entry point (if available) is taken from the last file. |
91 |
|
|
.Pp |
92 |
|
|
Apart from the name of a binary file, it is also necessary to select |
93 |
|
|
which specific emulation mode to use. For example, a MIPS-based machine |
94 |
|
|
from DEC (a DECstation) is very different from a MIPS-based machine |
95 |
|
|
from SGI. Use |
96 |
|
|
.Nm |
97 |
|
|
.Fl H |
98 |
|
|
to get a list of available emulation modes. |
99 |
|
|
.Pp |
100 |
dpavlin |
6 |
There are two exceptions to the normal invocation usage mentioned above. |
101 |
|
|
The first is for DECstation emulation: if you have a bootable |
102 |
dpavlin |
2 |
DECstation harddisk or CDROM image, then just supplying the diskimage via |
103 |
|
|
the |
104 |
|
|
.Fl d |
105 |
dpavlin |
6 |
option is sufficient. (The filename of the kernel can then be |
106 |
dpavlin |
2 |
skipped, as the emulator runs the bootblocks from the diskimage directly and |
107 |
|
|
doesn't need the kernel as a separate file.) |
108 |
dpavlin |
6 |
The second is if you supply an ISO9660 CDROM disk image. You may then use |
109 |
|
|
the |
110 |
|
|
.Fl j |
111 |
|
|
option to indicate which file on the CDROM filesystem that should be |
112 |
|
|
loaded into emulated memory. |
113 |
dpavlin |
2 |
.Pp |
114 |
|
|
Machine selection options: |
115 |
|
|
.Bl -tag -width Ds |
116 |
|
|
.It Fl E Ar t |
117 |
|
|
Try to emulate machine type |
118 |
|
|
.Ar "t". |
119 |
dpavlin |
12 |
This option is not always needed, if the |
120 |
|
|
.Fl e |
121 |
|
|
option uniquely selects a machine. |
122 |
dpavlin |
2 |
(Use |
123 |
|
|
.Fl H |
124 |
|
|
to get a list of types.) |
125 |
|
|
.It Fl e Ar st |
126 |
|
|
Try to emulate machine subtype |
127 |
|
|
.Ar "st". |
128 |
|
|
Use this together with |
129 |
|
|
.Fl E . |
130 |
|
|
(This option is not always needed, if a machine type has no subtypes.) |
131 |
|
|
.El |
132 |
|
|
.Pp |
133 |
|
|
Other options: |
134 |
|
|
.Bl -tag -width Ds |
135 |
dpavlin |
12 |
.It Fl A |
136 |
|
|
Disable load/store alignment checks in some cases. This might give a small |
137 |
|
|
increase in performance, but the emulator will not run correctly if the |
138 |
dpavlin |
16 |
emulated code actually tries to do unaligned loads or stores. (This option |
139 |
|
|
is only meaningful when emulating MIPS CPUs, when the host architecture is |
140 |
|
|
Alpha or i386, and binary translation is enabled.) |
141 |
dpavlin |
2 |
.It Fl B |
142 |
dpavlin |
22 |
Disable native translation backends. By default, translation backends are |
143 |
|
|
used if the host+target architecture combination is supported. Currently, |
144 |
|
|
the only supported host architecture for the old bintrans system (used |
145 |
|
|
when emulating MIPS processors) are Alpha and i386. The old bintrans |
146 |
|
|
system will hopefully be removed some day. |
147 |
dpavlin |
2 |
.It Fl C Ar x |
148 |
|
|
Try to emulate a specific CPU type, |
149 |
|
|
.Ar "x". |
150 |
|
|
This overrides the default CPU type for the machine being emulated. |
151 |
|
|
(Use |
152 |
|
|
.Fl H |
153 |
|
|
to get a list of available CPU types.) |
154 |
|
|
.It Fl d Ar name |
155 |
|
|
Add |
156 |
|
|
.Ar name |
157 |
|
|
as a disk image. By adding one or more modifier characters and then a |
158 |
|
|
colon (":") as a prefix to |
159 |
|
|
.Ar "name", |
160 |
dpavlin |
6 |
you can modify the way the disk image is treated. Available modifiers are: |
161 |
dpavlin |
2 |
.Bl -tag -width Ds |
162 |
|
|
.It b |
163 |
|
|
Specifies that this is a boot device. |
164 |
|
|
.It c |
165 |
dpavlin |
4 |
CD-ROM. |
166 |
dpavlin |
2 |
.It d |
167 |
dpavlin |
4 |
DISK (this is the default). |
168 |
|
|
.It f |
169 |
|
|
FLOPPY. |
170 |
dpavlin |
6 |
.It gH;S; |
171 |
|
|
Override the default geometry; use H heads and S sectors-per-track. |
172 |
|
|
(The number of cylinders is calculated automatically.) |
173 |
dpavlin |
2 |
.It i |
174 |
dpavlin |
22 |
IDE. (This is the default for most machine types.) |
175 |
dpavlin |
2 |
.It r |
176 |
|
|
Read-only (don't allow changes to be written to the file). |
177 |
dpavlin |
4 |
.It s |
178 |
dpavlin |
22 |
SCSI. |
179 |
dpavlin |
2 |
.It t |
180 |
dpavlin |
4 |
Tape. |
181 |
dpavlin |
2 |
.It 0-7 |
182 |
dpavlin |
6 |
Force a specific ID number. |
183 |
dpavlin |
2 |
.El |
184 |
|
|
.Pp |
185 |
dpavlin |
14 |
Unless otherwise specified, filenames ending with ".iso" or ".cdr" are |
186 |
|
|
assumed to be CDROM images. Most others are assumed to be disks. Depending |
187 |
|
|
on which machine is being emulated, the default for disks can be either |
188 |
|
|
SCSI or IDE. Some disk images that are very small are assumed to be floppy |
189 |
|
|
disks. (If you are not happy with the way a disk image is detected, then |
190 |
|
|
you need to use explicit prefixes to force a specific type.) |
191 |
dpavlin |
6 |
.Pp |
192 |
|
|
For floppies, the gH;S; prefix is ignored. Instead, the number of |
193 |
|
|
heads and cylinders are assumed to be 2 and 80, respectively, and the |
194 |
|
|
number of sectors per track is calculated automatically. (This works for |
195 |
|
|
720KB, 1.2MB, 1.44MB, and 2.88MB floppies.) |
196 |
dpavlin |
2 |
.It Fl I Ar x |
197 |
|
|
Emulate clock interrupts at |
198 |
|
|
.Ar x |
199 |
|
|
Hz. (This affects emulated clock devices only, not actual runtime speed. |
200 |
|
|
This disables automatic clock adjustments, which is otherwise turned on.) |
201 |
|
|
(This option is probably only valid for DECstation emulation.) |
202 |
|
|
.It Fl i |
203 |
|
|
Display each instruction as it is being executed. |
204 |
|
|
.It Fl J |
205 |
dpavlin |
18 |
Disable some speed tricks. For MIPS emulation, these are mostly |
206 |
dpavlin |
22 |
timing-related. For non-MIPS emulation (i.e. modes using dyntrans), |
207 |
dpavlin |
18 |
this flag disables the use of "instruction combinations". |
208 |
dpavlin |
2 |
.It Fl j Ar n |
209 |
|
|
Set the name of the kernel to |
210 |
|
|
.Ar "n". |
211 |
dpavlin |
10 |
When booting from an ISO9660 filesystem, the emulator will try to boot |
212 |
|
|
using this file. (In some emulation modes, eg. DECstation, this name is passed |
213 |
dpavlin |
6 |
along to the boot program. Useful names are "bsd" for OpenBSD/pmax, |
214 |
|
|
or "vmunix" for Ultrix.) |
215 |
dpavlin |
2 |
.It Fl M Ar m |
216 |
|
|
Emulate |
217 |
|
|
.Ar m |
218 |
|
|
MBs of physical RAM. This overrides the default amount of RAM for the |
219 |
|
|
selected machine type. |
220 |
|
|
.It Fl m Ar nr |
221 |
|
|
Run at most |
222 |
|
|
.Ar nr |
223 |
|
|
instructions (on any cpu). |
224 |
|
|
.It Fl N |
225 |
|
|
Display nr of instructions/second average, at regular intervals. |
226 |
|
|
.It Fl n Ar nr |
227 |
dpavlin |
22 |
Set nr of CPUs (for SMP experiments). Note: The emulator allocates quite a |
228 |
|
|
lot of virtual memory for per-CPU translation tables. On 64-bit hosts, |
229 |
|
|
this is normally not a problem. On 32-bit hosts, this can use up all |
230 |
|
|
available virtual userspace memory. The solution is to either run the |
231 |
|
|
emulator on a 64-bit host, or limit the number of emulated CPUs to a |
232 |
|
|
reasonable number (say, less than 32). |
233 |
dpavlin |
2 |
.It Fl O |
234 |
|
|
Force a "netboot" (tftp instead of disk), even when a disk image is |
235 |
|
|
present (for DECstation, SGI, and ARC emulation). |
236 |
|
|
.It Fl o Ar arg |
237 |
dpavlin |
16 |
Set the boot argument (mostly useful for DEC, ARC, or SGI emulation). |
238 |
dpavlin |
2 |
Default |
239 |
|
|
.Ar arg |
240 |
dpavlin |
16 |
for DEC is "-a", for ARC/SGI it is "-aN", and for CATS it is "-A". |
241 |
dpavlin |
2 |
.It Fl p Ar pc |
242 |
dpavlin |
6 |
Add a breakpoint. (Remember to use the "0x" prefix for hex.) |
243 |
dpavlin |
2 |
.It Fl Q |
244 |
|
|
Disable the built-in PROM emulation. This is useful for running raw ROM |
245 |
|
|
images from real machines. |
246 |
|
|
.It Fl R |
247 |
|
|
Use a random bootstrap cpu, instead of CPU nr 0. (For SMP experiments.) |
248 |
|
|
.It Fl r |
249 |
|
|
Dump register contents for every executed instruction. |
250 |
|
|
.It Fl S |
251 |
|
|
Initialize the emulated RAM to random data, instead of zeroes. |
252 |
|
|
.It Fl T |
253 |
|
|
Enter the single-step debugger on unimplemented memory accesses. |
254 |
|
|
.It Fl t |
255 |
|
|
Show a trace tree of all function calls being made. |
256 |
|
|
.It Fl U |
257 |
|
|
Enable slow_serial_interrupts_hack_for_linux. |
258 |
|
|
.It Fl X |
259 |
dpavlin |
22 |
Use X11. This option enables graphical framebuffers. |
260 |
dpavlin |
2 |
.It Fl x |
261 |
dpavlin |
22 |
Open up new xterms for emulated serial ports. The default behaviour is to |
262 |
|
|
open up xterms when using configuration files, or if X11 is enabled. When |
263 |
|
|
starting up a simple emulation session with settings directly on the |
264 |
|
|
command line, and neither |
265 |
|
|
.Fl X |
266 |
|
|
nor |
267 |
|
|
.Fl x |
268 |
|
|
is used, then all output is confined to the terminal that |
269 |
|
|
.Nm |
270 |
|
|
started in. |
271 |
dpavlin |
2 |
.It Fl Y Ar n |
272 |
|
|
Scale down framebuffer windows by |
273 |
|
|
.Ar n |
274 |
|
|
x |
275 |
|
|
.Ar n |
276 |
dpavlin |
20 |
times. This option is useful when emulating a very large framebuffer, and |
277 |
|
|
the actual display is of lower resolution. If |
278 |
|
|
.Ar n |
279 |
|
|
is negative, then there will be no scaledown, but emulation of certain |
280 |
|
|
graphic controllers will be scaled up |
281 |
|
|
by |
282 |
|
|
.Ar -n |
283 |
|
|
times instead. E.g. Using |
284 |
|
|
.Ar -2 |
285 |
|
|
with VGA text mode emulation will result in 80x25 character cells rendered |
286 |
|
|
in a 1280x800 window, instead of the normal resolution of 640x400. |
287 |
dpavlin |
2 |
.It Fl y Ar x |
288 |
|
|
Set max_random_cycles_per_chunk to |
289 |
|
|
.Ar x |
290 |
|
|
(experimental). |
291 |
|
|
.It Fl Z Ar n |
292 |
|
|
Set the number of graphics cards, for emulating a dual-head or tripple-head |
293 |
|
|
environment. (Only for DECstation emulation so far.) |
294 |
|
|
.It Fl z Ar disp |
295 |
|
|
Add |
296 |
|
|
.Ar disp |
297 |
|
|
as an X11 display to use for framebuffers. |
298 |
|
|
.El |
299 |
|
|
.Pp |
300 |
|
|
Userland options: |
301 |
|
|
.Bl -tag -width Ds |
302 |
|
|
.It Fl u Ar emul-mode |
303 |
|
|
Userland-only (syscall) emulation. (Use |
304 |
|
|
.Fl H |
305 |
|
|
to get a list of available emulation modes.) Some (but not all) of the |
306 |
|
|
options listed under Other options above can also be used with userland |
307 |
|
|
emulation. |
308 |
|
|
.El |
309 |
|
|
.Pp |
310 |
|
|
General options: |
311 |
|
|
.Bl -tag -width Ds |
312 |
dpavlin |
22 |
.It Fl c Ar cmd |
313 |
|
|
Add |
314 |
|
|
.Ar cmd |
315 |
|
|
as a command to run before starting the simulation. A similar effect can |
316 |
|
|
be achieved by using the |
317 |
|
|
.Fl V |
318 |
|
|
option, and entering the commands manually. |
319 |
dpavlin |
2 |
.It Fl D |
320 |
dpavlin |
6 |
Guarantee fully deterministic behavior. Normally, the emulator calls |
321 |
dpavlin |
2 |
srandom() with a seed based on the current time at startup. When the |
322 |
|
|
.Fl D |
323 |
|
|
option is used, the srandom() call is skipped, which should cause two |
324 |
dpavlin |
6 |
subsequent invocations of the emulator to be identical, if all other |
325 |
|
|
settings are identical and no user input is taking place. (If this option |
326 |
|
|
is used, then |
327 |
dpavlin |
2 |
.Fl I |
328 |
|
|
must also be used.) |
329 |
|
|
.It Fl H |
330 |
|
|
Display a list of available CPU types, machine types, and userland |
331 |
|
|
emulation modes. (Most of these don't work. Please read the documentation |
332 |
|
|
included in the |
333 |
|
|
.Nm |
334 |
|
|
distribution for details on which modes that actually work.) |
335 |
|
|
.It Fl h |
336 |
|
|
Display a list of all available command line options. |
337 |
|
|
.It Fl K |
338 |
|
|
Force the single-step debugger to be entered at the end of a simulation. |
339 |
|
|
.It Fl q |
340 |
|
|
Quiet mode; this suppresses startup messages. |
341 |
|
|
.It Fl s |
342 |
dpavlin |
18 |
For MIPS emulation: Show opcode usage statistics after the simulation. |
343 |
|
|
For non-MIPS emulation (i.e. using dyntrans): Save statistics to a file at |
344 |
|
|
regular intervals of which physical addresses that were executed. |
345 |
dpavlin |
2 |
.It Fl V |
346 |
|
|
Start up in the single-step debugger, paused. |
347 |
|
|
.It Fl v |
348 |
dpavlin |
22 |
Increase verbosity (show more debug messages). This option can be used |
349 |
|
|
multiple times. |
350 |
dpavlin |
2 |
.El |
351 |
|
|
.Pp |
352 |
|
|
Configuration file startup: |
353 |
|
|
.Bl -tag -width Ds |
354 |
|
|
.It @ Ar configfile |
355 |
|
|
Start an emulation based on the contents of |
356 |
|
|
.Ar "configfile". |
357 |
|
|
.El |
358 |
|
|
.Pp |
359 |
|
|
For more information, please read the documentation in the doc/ |
360 |
|
|
subdirectory of the |
361 |
|
|
.Nm |
362 |
|
|
distribution. |
363 |
|
|
.Sh EXAMPLES |
364 |
|
|
The following command will start NetBSD/pmax on an emulated DECstation |
365 |
dpavlin |
10 |
5000/200 (3MAX): |
366 |
dpavlin |
2 |
.Pp |
367 |
dpavlin |
12 |
.Dl "gxemul -e 3max -d nbsd_pmax.img" |
368 |
dpavlin |
2 |
.Pp |
369 |
dpavlin |
10 |
nbsd_pmax.img should be a raw disk image containing a bootable |
370 |
dpavlin |
2 |
NetBSD/pmax filesystem. |
371 |
|
|
.Pp |
372 |
|
|
The following command will start an emulation session based on settings in |
373 |
|
|
the configuration file "mysession". The -v option tells gxemul to be |
374 |
|
|
verbose. |
375 |
|
|
.Pp |
376 |
|
|
.Dl "gxemul -v @mysession" |
377 |
|
|
.Pp |
378 |
|
|
If you have compiled the small Hello World program mentioned in the |
379 |
|
|
.Nm |
380 |
|
|
documentation, the following command will start up an |
381 |
|
|
emulated test machine in "paused" mode: |
382 |
|
|
.Pp |
383 |
|
|
.Dl "gxemul -E testmips -V hello_mips" |
384 |
|
|
.Pp |
385 |
|
|
(Paused mode means that you enter the interactive single-step debugger |
386 |
|
|
directly at startup, instead of launching the Hello World program.) |
387 |
|
|
.Pp |
388 |
|
|
Please read the documentation for more details. |
389 |
|
|
.Sh BUGS |
390 |
|
|
There are many bugs. Some of the known bugs are listed in the BUGS |
391 |
|
|
file in the |
392 |
|
|
.Nm |
393 |
dpavlin |
12 |
source distribution, some are indirectly mentioned in the TODO file, |
394 |
|
|
and some are mentioned in the source code itself. |
395 |
dpavlin |
2 |
.Pp |
396 |
dpavlin |
22 |
The binary translation subsystem used for emulating MIPS processors is |
397 |
|
|
really terrible, but it is less terrible than running without it. It will |
398 |
|
|
be removed once the newer MIPS dyntrans emulation mode works well enough. |
399 |
dpavlin |
2 |
.Pp |
400 |
dpavlin |
12 |
Userland (syscall-only) emulation doesn't really work yet. |
401 |
|
|
.Pp |
402 |
dpavlin |
16 |
Emulation of MIPS CPUs is done differently from other emulation modes; the |
403 |
dpavlin |
20 |
documentation sometimes only reflects the way things work with MIPS |
404 |
dpavlin |
16 |
emulation, and it is incorrect when applied to e.g. ARM emulation. |
405 |
|
|
.Pp |
406 |
dpavlin |
2 |
.Nm |
407 |
dpavlin |
22 |
is in general not cycle-accurate; it does not simulate individual |
408 |
|
|
pipe-line stages or penalties caused by branch-prediction misses or |
409 |
|
|
cache misses, so it cannot be used for accurate simulation of any actual |
410 |
|
|
real-world processor. |
411 |
dpavlin |
6 |
.Pp |
412 |
|
|
.Nm |
413 |
dpavlin |
22 |
is not timing-accurate, i.e. clocks inside the emulator are in general |
414 |
|
|
not at all synched with clocks in the real world. There are a few |
415 |
|
|
exceptions to this rule (the mc146818 device tries to automagically |
416 |
|
|
adjust emulated timer ticks to actual emulation speed). |
417 |
dpavlin |
2 |
.Sh AUTHOR |
418 |
dpavlin |
22 |
GXemul is Copyright (C) 2003-2006 Anders Gavare <anders@gavare.se> |
419 |
dpavlin |
2 |
.Pp |
420 |
dpavlin |
22 |
See http://gavare.se/gxemul/ for more information. For other Copyright |
421 |
|
|
messages, see the corresponding parts of the source code and/or |
422 |
|
|
documentation. |