10 |
|
|
11 |
<!-- |
<!-- |
12 |
|
|
13 |
$Id: technical.html,v 1.75 2006/12/30 13:30:51 debug Exp $ |
$Id: technical.html,v 1.76 2007/06/15 18:07:08 debug Exp $ |
14 |
|
|
15 |
Copyright (C) 2004-2007 Anders Gavare. All rights reserved. |
Copyright (C) 2004-2007 Anders Gavare. All rights reserved. |
16 |
|
|
107 |
<a name="net"></a> |
<a name="net"></a> |
108 |
<h3>Networking</h3> |
<h3>Networking</h3> |
109 |
|
|
110 |
<font color="#ff0000">NOTE/TODO: This section is very old and a bit |
<font color="#ff0000">NOTE/TODO: This section is very old.</font> |
|
out of date.</font> |
|
111 |
|
|
112 |
<p>Running an entire operating system under emulation is very interesting |
<p>Running an entire operating system under emulation is very interesting |
113 |
in itself, but for several reasons, running a modern OS without access to |
in itself, but for several reasons, running a modern OS without access to |
309 |
<a name="devices"></a> |
<a name="devices"></a> |
310 |
<h3>Emulation of hardware devices</h3> |
<h3>Emulation of hardware devices</h3> |
311 |
|
|
312 |
Each file called <tt>dev_*.c</tt> in the <tt>src/device/</tt> directory is |
Each file called <tt>dev_*.c</tt> in the |
313 |
|
<a href="../src/devices/"><tt>src/devices/</tt></a> directory is |
314 |
responsible for one hardware device. These are used from |
responsible for one hardware device. These are used from |
315 |
<tt>src/machines/machine_*.c</tt>, when initializing which hardware a particular |
<a href="../src/machines/"><tt>src/machines</tt></a><tt>/machine_*.c</tt>, |
316 |
machine model will be using, or when adding devices to a machine using the |
when initializing which hardware a particular machine model will be using, |
317 |
<tt>device()</tt> command in configuration files. |
or when adding devices to a machine using the <tt>device()</tt> command in |
318 |
|
<a href="configfiles.html">configuration files</a>. |
319 |
|
|
320 |
<p>(I'll be using the name "<tt>foo</tt>" as the name of the device in all |
<p>(I'll be using the name "<tt>foo</tt>" as the name of the device in all |
321 |
these examples. This is pseudo code, it might need some modification to |
these examples. This is pseudo code, it might need some modification to |
330 |
<pre> |
<pre> |
331 |
DEVINIT(foo) |
DEVINIT(foo) |
332 |
{ |
{ |
333 |
struct foo_data *d = malloc(sizeof(struct foo_data)); |
struct foo_data *d; |
334 |
|
|
335 |
if (d == NULL) { |
CHECK_ALLOCATION(d = malloc(sizeof(struct foo_data))); |
|
fprintf(stderr, "out of memory\n"); |
|
|
exit(1); |
|
|
} |
|
336 |
memset(d, 0, sizeof(struct foo_data)); |
memset(d, 0, sizeof(struct foo_data)); |
337 |
|
|
338 |
/* |
/* |
339 |
* Set up stuff here, for example fill d with useful |
* Set up stuff here, for example fill d with useful |
340 |
* data. devinit contains settings like address, irq_nr, |
* data. devinit contains settings like address, irq path, |
341 |
* and other things. |
* and other things. |
342 |
* |
* |
343 |
* ... |
* ... |
344 |
*/ |
*/ |
345 |
|
|
346 |
|
INTERRUPT_CONNECT(devinit->interrupt_path, d->irq); |
347 |
|
|
348 |
memory_device_register(devinit->machine->memory, devinit->name, |
memory_device_register(devinit->machine->memory, devinit->name, |
349 |
devinit->addr, DEV_FOO_LENGTH, |
devinit->addr, DEV_FOO_LENGTH, |
368 |
should be defined. |
should be defined. |
369 |
<pre> |
<pre> |
370 |
struct foo_data { |
struct foo_data { |
371 |
int irq_nr; |
struct interrupt irq; |
372 |
/* ... */ |
/* ... */ |
373 |
} |
} |
374 |
</pre><br> |
</pre><br> |
375 |
(There is an exception to this rule; ugly hacks which allow |
(There is an exception to this rule; some legacy code and other |
376 |
code in <tt>src/machine.c</tt> to use some structures makes it |
ugly hacks have their device structs defined in |
377 |
necessary to place the <tt>struct foo_data</tt> in |
<tt>src/include/devices.h</tt> instead of <tt>dev_foo.c</tt>. |
378 |
<tt>src/include/devices.h</tt> instead of in <tt>dev_foo.c</tt> |
New code should not add stuff to <tt>devices.h</tt>.) |
|
itself. This is useful for example for interrupt controllers.) |
|
379 |
<p> |
<p> |
380 |
<li>If <tt>foo</tt> has a tick function (that is, something that needs to be |
<li>If <tt>foo</tt> has a tick function (that is, something that needs to be |
381 |
run at regular intervals) then <tt>FOO_TICKSHIFT</tt> and a tick |
run at regular intervals) then <tt>FOO_TICKSHIFT</tt> and a tick |
383 |
<pre> |
<pre> |
384 |
#define FOO_TICKSHIFT 14 |
#define FOO_TICKSHIFT 14 |
385 |
|
|
386 |
void dev_foo_tick(struct cpu *cpu, void *extra) |
DEVICE_TICK(foo) |
387 |
{ |
{ |
388 |
struct foo_data *d = (struct foo_data *) extra; |
struct foo_data *d = extra; |
389 |
|
|
390 |
if (.....) |
if (.....) |
391 |
cpu_interrupt(cpu, d->irq_nr); |
INTERRUPT_ASSERT(d->irq); |
392 |
else |
else |
393 |
cpu_interrupt_ack(cpu, d->irq_nr); |
INTERRUPT_DEASSERT(d->irq); |
394 |
} |
} |
395 |
</pre><br> |
</pre><br> |
396 |
|
|
419 |
struct foo_data *d = extra; |
struct foo_data *d = extra; |
420 |
uint64_t idata = 0, odata = 0; |
uint64_t idata = 0, odata = 0; |
421 |
|
|
422 |
idata = memory_readmax64(cpu, data, len); |
if (writeflag == MEM_WRITE) |
423 |
|
idata = memory_readmax64(cpu, data, len); |
424 |
|
|
425 |
switch (relative_addr) { |
switch (relative_addr) { |
426 |
/* .... */ |
|
427 |
|
/* Handle accesses to individual addresses within |
428 |
|
the device here. */ |
429 |
|
|
430 |
|
/* ... */ |
431 |
|
|
432 |
} |
} |
433 |
|
|
434 |
if (writeflag == MEM_READ) |
if (writeflag == MEM_READ) |