| 1 |
<html><head><title>Gavare's eXperimental Emulator: Experimenting with GXemul</title> |
| 2 |
<meta name="robots" content="noarchive,nofollow,noindex"></head> |
| 3 |
<body bgcolor="#f8f8f8" text="#000000" link="#4040f0" vlink="#404040" alink="#ff0000"> |
| 4 |
<table border=0 width=100% bgcolor="#d0d0d0"><tr> |
| 5 |
<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"> |
| 7 |
<b>Gavare's eXperimental Emulator:</b></font><br> |
| 8 |
<font color="#000000" size="6"><b>Experimenting with GXemul</b> |
| 9 |
</font></td></tr></table></td></tr></table><p> |
| 10 |
|
| 11 |
<!-- |
| 12 |
|
| 13 |
$Id: experiments.html,v 1.110 2007/06/15 18:07:08 debug Exp $ |
| 14 |
|
| 15 |
Copyright (C) 2003-2007 Anders Gavare. All rights reserved. |
| 16 |
|
| 17 |
Redistribution and use in source and binary forms, with or without |
| 18 |
modification, are permitted provided that the following conditions are met: |
| 19 |
|
| 20 |
1. Redistributions of source code must retain the above copyright |
| 21 |
notice, this list of conditions and the following disclaimer. |
| 22 |
2. Redistributions in binary form must reproduce the above copyright |
| 23 |
notice, this list of conditions and the following disclaimer in the |
| 24 |
documentation and/or other materials provided with the distribution. |
| 25 |
3. The name of the author may not be used to endorse or promote products |
| 26 |
derived from this software without specific prior written permission. |
| 27 |
|
| 28 |
THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| 29 |
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 30 |
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 31 |
ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| 32 |
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 33 |
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 34 |
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 35 |
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 36 |
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 37 |
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 38 |
SUCH DAMAGE. |
| 39 |
|
| 40 |
--> |
| 41 |
|
| 42 |
<a href="./">Back to the index</a> |
| 43 |
|
| 44 |
<p><br> |
| 45 |
<h2>Experimenting with GXemul</h2> |
| 46 |
|
| 47 |
<p> |
| 48 |
<ul> |
| 49 |
<li><a href="#hello">Hello world</a> |
| 50 |
<li><a href="#expdevices">Experimental devices</a> |
| 51 |
</ul> |
| 52 |
|
| 53 |
|
| 54 |
|
| 55 |
|
| 56 |
|
| 57 |
|
| 58 |
<p><br> |
| 59 |
<a name="hello"></a> |
| 60 |
<h3>Hello world:</h3> |
| 61 |
|
| 62 |
You might want to use the emulator to develop programs on your own, |
| 63 |
not just run precompiled kernels such as NetBSD. To get started, I recommend |
| 64 |
that you do two things: |
| 65 |
|
| 66 |
<p> |
| 67 |
<ul> |
| 68 |
<li>Build and install a cross-compiler for your chosen target, |
| 69 |
e.g. <tt>mips64-unknown-elf</tt>. |
| 70 |
GCC is usually a good compiler choice, because it is portable |
| 71 |
and in wide-spread use. (Other compilers should work too.) |
| 72 |
|
| 73 |
<p> |
| 74 |
<li>Compile the Hello World demo program for your chosen target, and run |
| 75 |
it in the emulator. |
| 76 |
</ul> |
| 77 |
|
| 78 |
<p>The Hello World demo program is included in the GXemul source |
| 79 |
code distribution, in the <a href="../demos/hello/"><tt>demos/hello/</tt></a> |
| 80 |
subdirectory. The README files in the demo directories have several |
| 81 |
examples of how the demo programs can be built. |
| 82 |
|
| 83 |
<p>Hopefully this is enough to get you inspired. :-) |
| 84 |
|
| 85 |
|
| 86 |
|
| 87 |
|
| 88 |
|
| 89 |
|
| 90 |
<p><br> |
| 91 |
<a name="expdevices"></a> |
| 92 |
<h3>Experimental devices:</h3> |
| 93 |
|
| 94 |
The emulator has several modes where it doesn't emulate any real machine. |
| 95 |
It can either run in "bare" mode, where no devices are included by default |
| 96 |
(just the CPU), or in a "test" mode where some simple devices are |
| 97 |
emulated. |
| 98 |
|
| 99 |
<p>The test machines (<tt>testmips</tt>, <tt>testppc</tt>, etc) have the |
| 100 |
following experimental devices: |
| 101 |
|
| 102 |
<p> |
| 103 |
<center><table border="0" width="80%"> |
| 104 |
|
| 105 |
<tr> |
| 106 |
<td align="left" valign="top" width="200"> |
| 107 |
<a name="expdevices_cons"><b><tt>cons</tt>:</b></a> |
| 108 |
<p>A simple console device, for writing |
| 109 |
characters to the controlling terminal |
| 110 |
and receiving keypresses. |
| 111 |
<p>Source code: <font color="#0000f0"><tt>src/devices/dev_cons.c</tt></font> |
| 112 |
<p>Include file: <font color="#0000f0"><tt>dev_cons.h</tt></font> |
| 113 |
<br>Default physical address:  <font color="#0000f0">0x10000000</font> |
| 114 |
</td> |
| 115 |
<td align="left" valign="top" width="25"> </td> |
| 116 |
<td align="left" valign="top"> |
| 117 |
<table border="0"> |
| 118 |
<tr> |
| 119 |
<td align="left" valign="top"><i><u>Offset:</u></i> </td> |
| 120 |
<td align="left" valign="top"><i><u>Effect:</u></i></td> |
| 121 |
</tr> |
| 122 |
<tr> |
| 123 |
<td align="left" valign="top"><tt>0x00</tt></td> |
| 124 |
<td align="left" valign="top"> |
| 125 |
Read: <b><tt>getchar()</tt></b> (non-blocking; returns |
| 126 |
<tt>0</tt> if no char was available)<br> |
| 127 |
Write: <b><tt>putchar(ch)</tt></b></td> |
| 128 |
</tr> |
| 129 |
<tr> |
| 130 |
<td align="left" valign="top"><tt>0x10</tt></td> |
| 131 |
<td align="left" valign="top">Read or write: <b><tt>halt()</tt></b><br> |
| 132 |
(Useful for exiting the emulator.)</td> |
| 133 |
</tr> |
| 134 |
</table> |
| 135 |
</td> |
| 136 |
</tr> |
| 137 |
|
| 138 |
<tr height="15"> |
| 139 |
<td height="15"> </td> |
| 140 |
</tr> |
| 141 |
|
| 142 |
<tr> |
| 143 |
<td align="left" valign="top"> |
| 144 |
<a name="expdevices_mp"><b><tt>mp</tt>:</b></a> |
| 145 |
<p>This device controls the behaviour of CPUs in an emulated |
| 146 |
multi-processor system. |
| 147 |
<p>Source code: <font color="#0000f0"><tt>src/devices/dev_mp.c</tt></font> |
| 148 |
<p>Include file: <font color="#0000f0"><tt>dev_mp.h</tt></font> |
| 149 |
<br>Default physical address:  <font color="#0000f0">0x11000000</font> |
| 150 |
</td> |
| 151 |
<td></td> |
| 152 |
<td align="left" valign="top"> |
| 153 |
<table border="0"> |
| 154 |
<tr> |
| 155 |
<td align="left" valign="top"><i><u>Offset:</u></i> </td> |
| 156 |
<td align="left" valign="top"><i><u>Effect:</u></i></td> |
| 157 |
</tr> |
| 158 |
<tr> |
| 159 |
<td align="left" valign="top"><tt>0x0000</tt></td> |
| 160 |
<td align="left" valign="top">Read: <b><tt>whoami()</tt></b>. |
| 161 |
Returns the id of the CPU doing the read.</td> |
| 162 |
</tr> |
| 163 |
<tr> |
| 164 |
<td align="left" valign="top"><tt>0x0010</tt></td> |
| 165 |
<td align="left" valign="top">Read: <b><tt>ncpus()</tt></b>. |
| 166 |
Returns the number of CPUs in the system.</td> |
| 167 |
</tr> |
| 168 |
<tr> |
| 169 |
<td align="left" valign="top"><tt>0x0020</tt></td> |
| 170 |
<td align="left" valign="top">Write: <b><tt>startupcpu(i)</tt></b>. |
| 171 |
Starts CPU i. It begins execution at the address |
| 172 |
set by a write to startupaddr (see below).</td> |
| 173 |
</tr> |
| 174 |
<tr> |
| 175 |
<td align="left" valign="top"><tt>0x0030</tt></td> |
| 176 |
<td align="left" valign="top">Write: <b><tt>startupaddr(addr)</tt></b>. |
| 177 |
Sets the starting address for CPUs.</td> |
| 178 |
</tr> |
| 179 |
<tr> |
| 180 |
<td align="left" valign="top"><tt>0x0040</tt></td> |
| 181 |
<td align="left" valign="top">Write: <b><tt>pause_addr(addr)</tt></b>. |
| 182 |
Sets the pause address. (NOTE: This is not |
| 183 |
used anymore.)</td> |
| 184 |
</tr> |
| 185 |
<tr> |
| 186 |
<td align="left" valign="top"><tt>0x0050</tt></td> |
| 187 |
<td align="left" valign="top">Write: <b><tt>pause_cpu(i)</tt></b>. |
| 188 |
Pauses all CPUs <i>except</i> CPU i.</td> |
| 189 |
</tr> |
| 190 |
<tr> |
| 191 |
<td align="left" valign="top"><tt>0x0060</tt></td> |
| 192 |
<td align="left" valign="top">Write: <b><tt>unpause_cpu(i)</tt></b>. |
| 193 |
Unpauses CPU i.</td> |
| 194 |
</tr> |
| 195 |
<tr> |
| 196 |
<td align="left" valign="top"><tt>0x0070</tt></td> |
| 197 |
<td align="left" valign="top">Write: <b><tt>startupstack(addr)</tt></b>. |
| 198 |
Sets the startup stack address. (CPUs started with |
| 199 |
startupcpu() above will have their stack pointer |
| 200 |
set to this value.)</td> |
| 201 |
</tr> |
| 202 |
<tr> |
| 203 |
<td align="left" valign="top"><tt>0x0080</tt></td> |
| 204 |
<td align="left" valign="top">Read: <b><tt>hardware_random()</tt></b>. |
| 205 |
This produces a "random" number.</td> |
| 206 |
</tr> |
| 207 |
<tr> |
| 208 |
<td align="left" valign="top"><tt>0x0090</tt></td> |
| 209 |
<td align="left" valign="top">Read: <b><tt>memory()</tt></b>. |
| 210 |
Returns the number of bytes of RAM in the system.</td> |
| 211 |
</tr> |
| 212 |
<tr> |
| 213 |
<td align="left" valign="top"><tt>0x00a0</tt></td> |
| 214 |
<td align="left" valign="top">Write: <b><tt>ipi_one((nr << 16) + cpuid)</tt></b>. |
| 215 |
Sends IPI <tt>nr</tt> to a specific CPU.</td> |
| 216 |
</tr> |
| 217 |
<tr> |
| 218 |
<td align="left" valign="top"><tt>0x00b0</tt></td> |
| 219 |
<td align="left" valign="top">Write: <b><tt>ipi_many((nr << 16) + cpuid)</tt></b>. |
| 220 |
Sends IPI <tt>nr</tt> to all CPUs <i>except</i> |
| 221 |
the specified one.</td> |
| 222 |
</tr> |
| 223 |
<tr> |
| 224 |
<td align="left" valign="top"><tt>0x00c0</tt></td> |
| 225 |
<td align="left" valign="top">Read: <b><tt>ipi_read()</tt></b>. |
| 226 |
Returns the next pending IPI. 0 is returned if there is no |
| 227 |
pending IPI (so 0 shouldn't be used for valid IPIs). |
| 228 |
Hardware int 6 is deasserted when the IPI queue is empty. |
| 229 |
<br>Write: <b><tt>ipi_flush()</tt></b>. |
| 230 |
Clears the IPI queue, discarding any pending IPIs.</td> |
| 231 |
</tr> |
| 232 |
<tr> |
| 233 |
<td align="left" valign="top"><tt>0x00d0</tt></td> |
| 234 |
<td align="left" valign="top">Read: <b><tt>ncycles()</tt></b>. |
| 235 |
Returns approximately the number of cycles executed on |
| 236 |
this CPU. Note: this value is not updated for every instruction, |
| 237 |
so it cannot be used for small measurements.</td> |
| 238 |
</tr> |
| 239 |
</table> |
| 240 |
</td> |
| 241 |
</tr> |
| 242 |
|
| 243 |
<tr height="15"> |
| 244 |
<td height="15"> </td> |
| 245 |
</tr> |
| 246 |
|
| 247 |
<tr> |
| 248 |
<td align="left" valign="top"> |
| 249 |
<a name="expdevices_fb"><b><tt>fb</tt>:</b></a> |
| 250 |
<p>A simple linear framebuffer, for graphics output. |
| 251 |
640 x 480 pixels, 3 bytes per pixel (red, green, blue, 8 bits each). |
| 252 |
<p>Source code: <font color="#0000f0"><tt>src/devices/dev_fb.c</tt></font> |
| 253 |
<p>Include file: <font color="#0000f0"><tt>dev_fb.h</tt></font> |
| 254 |
<br>Default physical address:  <font color="#0000f0">0x12000000</font> |
| 255 |
</td> |
| 256 |
<td></td> |
| 257 |
<td align="left" valign="top"> |
| 258 |
<table border="0"> |
| 259 |
<tr> |
| 260 |
<td align="left" valign="top"><i><u>Offset:</u></i> </td> |
| 261 |
<td align="left" valign="top"><i><u>Effect:</u></i></td> |
| 262 |
</tr> |
| 263 |
<tr> |
| 264 |
<td align="left" valign="top"><tt>0x00000-</tt><br><tt>0xe0fff</tt></td> |
| 265 |
<td align="left" valign="top">Read: read pixel values. |
| 266 |
<br>Write: write pixel values.</td> |
| 267 |
</tr> |
| 268 |
</table> |
| 269 |
</td> |
| 270 |
</tr> |
| 271 |
|
| 272 |
<tr height="15"> |
| 273 |
<td height="15"> </td> |
| 274 |
</tr> |
| 275 |
|
| 276 |
<tr> |
| 277 |
<td align="left" valign="top"> |
| 278 |
<a name="expdevices_disk"><b><tt>disk</tt>:</b></a> |
| 279 |
<p>Disk controller, which can read from and write |
| 280 |
to emulated IDE disks. It does not use interrupts; read and |
| 281 |
write operations finish instantaneously. |
| 282 |
<p>Source code: <font color="#0000f0"><tt>src/devices/dev_disk.c</tt></font> |
| 283 |
<p>Include file: <font color="#0000f0"><tt>dev_disk.h</tt></font> |
| 284 |
<br>Default physical address:  <font color="#0000f0">0x13000000</font> |
| 285 |
</td> |
| 286 |
<td></td> |
| 287 |
<td align="left" valign="top"> |
| 288 |
<table border="0"> |
| 289 |
<tr> |
| 290 |
<td align="left" valign="top"><i><u>Offset:</u></i> </td> |
| 291 |
<td align="left" valign="top"><i><u>Effect:</u></i></td> |
| 292 |
</tr> |
| 293 |
<tr> |
| 294 |
<td align="left" valign="top"><tt>0x0000</tt></td> |
| 295 |
<td align="left" valign="top">Write: Set the offset (in bytes) from the beginning |
| 296 |
of the disk image. This offset will be used for the next read/write operation.</td> |
| 297 |
</tr> |
| 298 |
<tr> |
| 299 |
<td align="left" valign="top"><tt>0x0010</tt></td> |
| 300 |
<td align="left" valign="top">Write: Select the IDE ID to be used in the next |
| 301 |
read/write operation.</td> |
| 302 |
</tr> |
| 303 |
<tr> |
| 304 |
<td align="left" valign="top"><tt>0x0020</tt></td> |
| 305 |
<td align="left" valign="top">Write: Start a read or write operation. |
| 306 |
(Writing <tt>0</tt> means a Read operation, a <tt>1</tt> means a |
| 307 |
Write operation.)</td> |
| 308 |
</tr> |
| 309 |
<tr> |
| 310 |
<td align="left" valign="top"><tt>0x0030</tt></td> |
| 311 |
<td align="left" valign="top">Read: Get status of the last operation. |
| 312 |
(Status 0 means failure, non-zero means success.)</td> |
| 313 |
</tr> |
| 314 |
<tr> |
| 315 |
<td align="left" valign="top"><tt>0x4000-</tt><br><tt>0x41ff</tt> </td> |
| 316 |
<td align="left" valign="top">Read/Write: 512 bytes data buffer.</td> |
| 317 |
</tr> |
| 318 |
</table> |
| 319 |
</td> |
| 320 |
</tr> |
| 321 |
|
| 322 |
<tr height="15"> |
| 323 |
<td height="15"> </td> |
| 324 |
</tr> |
| 325 |
|
| 326 |
<tr> |
| 327 |
<td align="left" valign="top"> |
| 328 |
<a name="expdevices_ether"><b><tt>ether</tt>:</b></a> |
| 329 |
<p>A simple ethernet controller, enough to send |
| 330 |
and receive packets on a simulated network. |
| 331 |
<p>Source code: <font color="#0000f0"><tt>src/devices/dev_ether.c</tt></font> |
| 332 |
<p>Include file: <font color="#0000f0"><tt>dev_ether.h</tt></font> |
| 333 |
<br>Default physical address:  <font color="#0000f0">0x14000000</font> |
| 334 |
</td> |
| 335 |
<td></td> |
| 336 |
<td align="left" valign="top"> |
| 337 |
<table border="0"> |
| 338 |
<tr> |
| 339 |
<td align="left" valign="top"><i><u>Offset:</u></i> </td> |
| 340 |
<td align="left" valign="top"><i><u>Effect:</u></i></td> |
| 341 |
</tr> |
| 342 |
<tr> |
| 343 |
<td align="left" valign="top"><tt>0x0000-</tt><br><tt>0x3fff</tt></td> |
| 344 |
<td align="left" valign="top">Read/write buffer for the packet to be sent/received.</td> |
| 345 |
</tr> |
| 346 |
<tr> |
| 347 |
<td align="left" valign="top"><tt>0x4000</tt></td> |
| 348 |
<td align="left" valign="top">Read: status word, one or more of these: |
| 349 |
<br><tt>0x01</tt> = something was received (because of |
| 350 |
the last command) |
| 351 |
<br><tt>0x02</tt> = more packets are available |
| 352 |
<br><i>NOTE:</i> Whenever the status word is non-zero, |
| 353 |
an interrupt is asserted. Reading the status word |
| 354 |
clears it, and deasserts the interrupt.</td> |
| 355 |
</tr> |
| 356 |
<tr> |
| 357 |
<td align="left" valign="top"><tt>0x4010</tt></td> |
| 358 |
<td align="left" valign="top">Read: get the Length of the received packet |
| 359 |
<br>Write: set the Length of the next packet to transmit</td> |
| 360 |
</tr> |
| 361 |
<tr> |
| 362 |
<td align="left" valign="top"><tt>0x4020</tt></td> |
| 363 |
<td align="left" valign="top">Write: command: |
| 364 |
<br><tt>0x00:</tt> receive a packet |
| 365 |
<br><tt>0x01:</tt> send a packet</td> |
| 366 |
</tr> |
| 367 |
</table> |
| 368 |
</td> |
| 369 |
</tr> |
| 370 |
|
| 371 |
<tr height="15"> |
| 372 |
<td height="15"> </td> |
| 373 |
</tr> |
| 374 |
|
| 375 |
<tr> |
| 376 |
<td align="left" valign="top"> |
| 377 |
<a name="expdevices_rtc"><b><tt>rtc</tt>:</b></a> |
| 378 |
<p>A Real-Time Clock, used to retrieve the current time |
| 379 |
and to cause periodic interrupts. |
| 380 |
<p>Source code: <font color="#0000f0"><tt>src/devices/dev_rtc.c</tt></font> |
| 381 |
<p>Include file: <font color="#0000f0"><tt>dev_rtc.h</tt></font> |
| 382 |
<br>Default physical address:  <font color="#0000f0">0x15000000</font> |
| 383 |
</td> |
| 384 |
<td></td> |
| 385 |
<td align="left" valign="top"> |
| 386 |
<table border="0"> |
| 387 |
<tr> |
| 388 |
<td align="left" valign="top"><i><u>Offset:</u></i> </td> |
| 389 |
<td align="left" valign="top"><i><u>Effect:</u></i></td> |
| 390 |
</tr> |
| 391 |
<tr> |
| 392 |
<td align="left" valign="top"><tt>0x0000</tt></td> |
| 393 |
<td align="left" valign="top">Read or Write: Trigger a clock update (a gettimeofday() on the host).</td> |
| 394 |
</tr> |
| 395 |
<tr> |
| 396 |
<td align="left" valign="top"><tt>0x0010</tt></td> |
| 397 |
<td align="left" valign="top">Read: Seconds since 1st January 1970</td> |
| 398 |
</tr> |
| 399 |
<tr> |
| 400 |
<td align="left" valign="top"><tt>0x0020</tt></td> |
| 401 |
<td align="left" valign="top">Read: Microseconds</td> |
| 402 |
</tr> |
| 403 |
<tr> |
| 404 |
<td align="left" valign="top"><tt>0x0100</tt></td> |
| 405 |
<td align="left" valign="top">Read: Get the current |
| 406 |
timer interrupt frequency.<br>Write: Set the timer |
| 407 |
interrupt frequency. (Writing 0 disables the timer.)</td> |
| 408 |
</tr> |
| 409 |
<tr> |
| 410 |
<td align="left" valign="top"><tt>0x0110</tt></td> |
| 411 |
<td align="left" valign="top">Read or Write: Acknowledge |
| 412 |
one timer interrupt. (Note that if multiple interrupts |
| 413 |
are pending, only one is acknowledged.)</td> |
| 414 |
</tr> |
| 415 |
</table> |
| 416 |
</td> |
| 417 |
</tr> |
| 418 |
|
| 419 |
<tr height="15"> |
| 420 |
<td height="15"> </td> |
| 421 |
</tr> |
| 422 |
|
| 423 |
<tr> |
| 424 |
<td align="left" valign="top"> |
| 425 |
<a name="expdevices_irqc"><b><tt>irqc</tt>:</b></a> |
| 426 |
<p>An Interrupt Controller. (Note: Not used for the MIPS test machine.) |
| 427 |
<p>Source code: <font color="#0000f0"><tt>src/devices/dev_irqc.c</tt></font> |
| 428 |
<p>Include file: <font color="#0000f0"><tt>dev_irqc.h</tt></font> |
| 429 |
<br>Default physical address:  <font color="#0000f0">0x16000000</font> |
| 430 |
</td> |
| 431 |
<td></td> |
| 432 |
<td align="left" valign="top"> |
| 433 |
<table border="0"> |
| 434 |
<tr> |
| 435 |
<td align="left" valign="top"><i><u>Offset:</u></i> </td> |
| 436 |
<td align="left" valign="top"><i><u>Effect:</u></i></td> |
| 437 |
</tr> |
| 438 |
<tr> |
| 439 |
<td align="left" valign="top"><tt>0x0</tt></td> |
| 440 |
<td align="left" valign="top">Read: IRQ status as a 32-bit word, one bit per interrupt source.</td> |
| 441 |
</tr> |
| 442 |
<tr> |
| 443 |
<td align="left" valign="top"><tt>0x4</tt></td> |
| 444 |
<td align="left" valign="top">Write: Mask one interrupt source. Value should be an integer 0..31.</td> |
| 445 |
</tr> |
| 446 |
<tr> |
| 447 |
<td align="left" valign="top"><tt>0x8</tt></td> |
| 448 |
<td align="left" valign="top">Write: Unmask one interrupt source. Value should be an integer 0..31.</td> |
| 449 |
</tr> |
| 450 |
</table> |
| 451 |
</td> |
| 452 |
</tr> |
| 453 |
|
| 454 |
</table></center> |
| 455 |
|
| 456 |
<p>The include files for the test machine devices are found in |
| 457 |
<a href="../src/include/testmachine/"><tt>src/include/testmachine/</tt></a>. |
| 458 |
|
| 459 |
<p>While these devices may resemble real-world hardware, they are |
| 460 |
intentionally made simpler to use. (An exception is the framebuffer; |
| 461 |
some machines actually have simple linear framebuffers like this.) |
| 462 |
|
| 463 |
<p>If the physical address is <tt>0x10000000</tt>, then for MIPS that |
| 464 |
means that it can be accessed at virtual address |
| 465 |
<tt>0xffffffffb0000000</tt>. (Actually it can be accessed at |
| 466 |
<tt>0xffffffff90000000</tt> too, but devices should usually be accessed in |
| 467 |
a non-cached manner.) |
| 468 |
|
| 469 |
<p>When using the ARM or PPC test machines, the addresses are |
| 470 |
<tt>0x10000000</tt>, <tt>0x11000000</tt> etc., so no need to add any |
| 471 |
virtual displacement. |
| 472 |
|
| 473 |
<p>The <tt>mp</tt>, <tt>disk</tt>, and <tt>ether</tt> devices are agnostic |
| 474 |
when it comes to word-length. For example, when reading offset |
| 475 |
<tt>0x0000</tt> of the <tt>mp</tt> device, you may use any kind of read |
| 476 |
(an 8-bit read will work just as well as a 64-bit read, although the value |
| 477 |
will be truncated to 8 bits in the first case). You can <i>not</i>, |
| 478 |
however, read one byte from <tt>0x0000</tt> and one from <tt>0x0001</tt>, |
| 479 |
and combine the result. The read from <tt>0x0001</tt> will be invalid. |
| 480 |
|
| 481 |
<p>The <tt>cons</tt> device should be accessed using 8-bit reads |
| 482 |
and writes. Doing a getchar() (ie reading from offset <tt>0x00</tt>) |
| 483 |
returns <tt>0</tt> if no character was available. Whenever a character is |
| 484 |
available, the <tt>cons</tt> device' interrupt is asserted. When there are |
| 485 |
no more available characters, the interrupt is deasserted. (Remember that |
| 486 |
the interrupt has to be unmasked to be able to actually cause an |
| 487 |
interrupt.) |
| 488 |
|
| 489 |
<p>IPIs (inter-processor interrupts) are controlled by the <tt>mp</tt> |
| 490 |
device. Whenever an IPI is "sent" from a source to one or more target |
| 491 |
CPUs, the interrupt is asserted on the target CPUs, and the IPI number is |
| 492 |
added last in the IPI queue for each of the target CPUs. It is then up to |
| 493 |
those CPUs to individually read from offset <tt>0x00c0</tt>, to figure out |
| 494 |
what kind of IPI it was. |
| 495 |
|
| 496 |
|
| 497 |
|
| 498 |
<p>Interrupt mappings are as follows: |
| 499 |
|
| 500 |
<p><center> |
| 501 |
<table border="1"> |
| 502 |
<tr><td align="center"> |
| 503 |
<b><tt>testmips</tt></b> (as native MIPS interrupts) |
| 504 |
</td></tr> |
| 505 |
<tr><td> |
| 506 |
<table border="0"> |
| 507 |
<tr><td align="center">IRQ:</td><td> </td> |
| 508 |
<td>Used for:</td></tr> |
| 509 |
<tr><td align="center">7</td><td></td> |
| 510 |
<td>MIPS count/compare interrupt</td></tr> |
| 511 |
<tr><td align="center">6</td><td></td> |
| 512 |
<td><tt>mp</tt> (inter-processor interrupts)</td></tr> |
| 513 |
<tr><td align="center">4</td><td></td> |
| 514 |
<td><tt>rtc</tt></td></tr> |
| 515 |
<tr><td align="center">3</td><td></td> |
| 516 |
<td><tt>ether</tt></td></tr> |
| 517 |
<tr><td align="center">2</td><td></td> |
| 518 |
<td><tt>cons</tt></td></tr> |
| 519 |
</table> |
| 520 |
</td></tr> |
| 521 |
</table> |
| 522 |
|
| 523 |
<p><table border="1"> |
| 524 |
<tr><td align="center"> |
| 525 |
<b><tt>testarm</tt> and others</b> (via the <tt>irqc</tt> device) |
| 526 |
</td></tr> |
| 527 |
<tr><td> |
| 528 |
<table border="0"> |
| 529 |
<tr><td align="center">IRQ:</td><td> </td> |
| 530 |
<td>Used for:</td></tr> |
| 531 |
<tr><td align="center">6</td><td></td> |
| 532 |
<td><tt>mp</tt> (inter-processor interrupts)</td></tr> |
| 533 |
<tr><td align="center">4</td><td></td> |
| 534 |
<td><tt>rtc</tt></td></tr> |
| 535 |
<tr><td align="center">3</td><td></td> |
| 536 |
<td><tt>ether</tt></td></tr> |
| 537 |
<tr><td align="center">2</td><td></td> |
| 538 |
<td><tt>cons</tt></td></tr> |
| 539 |
</table> |
| 540 |
</td></tr> |
| 541 |
</table> |
| 542 |
</center> |
| 543 |
|
| 544 |
|
| 545 |
|
| 546 |
<p><br> |
| 547 |
|
| 548 |
|
| 549 |
|
| 550 |
</p> |
| 551 |
|
| 552 |
</body> |
| 553 |
</html> |
Parent Directory
| 
Revision Log