xref: /freebsd/sys/dev/ofw/ofw_standard.c (revision 9517e866259191fcd39434a97ad849a9b59b9b9f)
1 /*	$NetBSD: Locore.c,v 1.7 2000/08/20 07:04:59 tsubai Exp $	*/
2 
3 /*-
4  * Copyright (C) 1995, 1996 Wolfgang Solfrank.
5  * Copyright (C) 1995, 1996 TooLs GmbH.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by TooLs GmbH.
19  * 4. The name of TooLs GmbH may not be used to endorse or promote products
20  *    derived from this software without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
27  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
28  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
30  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
31  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 /*-
34  * Copyright (C) 2000 Benno Rice.
35  * All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  *
46  * THIS SOFTWARE IS PROVIDED BY Benno Rice ``AS IS'' AND ANY EXPRESS OR
47  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
48  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
49  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
50  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
51  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
52  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
53  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
54  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
55  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
56  */
57 
58 #include <sys/cdefs.h>
59 __FBSDID("$FreeBSD$");
60 
61 #include <sys/param.h>
62 #include <sys/kernel.h>
63 #include <sys/malloc.h>
64 #include <sys/systm.h>
65 
66 #include <machine/stdarg.h>
67 
68 #include <dev/ofw/ofwvar.h>
69 #include <dev/ofw/openfirm.h>
70 
71 #include "ofw_if.h"
72 
73 static void ofw_std_init(ofw_t ofw, void *openfirm);
74 static int ofw_std_test(ofw_t ofw, const char *name);
75 static int ofw_std_interpret(ofw_t ofw, const char *cmd, int nreturns,
76     unsigned long *returns);
77 static phandle_t ofw_std_peer(ofw_t ofw, phandle_t node);
78 static phandle_t ofw_std_child(ofw_t ofw, phandle_t node);
79 static phandle_t ofw_std_parent(ofw_t ofw, phandle_t node);
80 static phandle_t ofw_std_instance_to_package(ofw_t ofw, ihandle_t instance);
81 static ssize_t ofw_std_getproplen(ofw_t ofw, phandle_t package,
82     const char *propname);
83 static ssize_t ofw_std_getprop(ofw_t ofw, phandle_t package,
84     const char *propname, void *buf, size_t buflen);
85 static int ofw_std_nextprop(ofw_t ofw, phandle_t package, const char *previous,
86     char *buf, size_t);
87 static int ofw_std_setprop(ofw_t ofw, phandle_t package, const char *propname,
88     const void *buf, size_t len);
89 static ssize_t ofw_std_canon(ofw_t ofw, const char *device, char *buf,
90     size_t len);
91 static phandle_t ofw_std_finddevice(ofw_t ofw, const char *device);
92 static ssize_t ofw_std_instance_to_path(ofw_t ofw, ihandle_t instance,
93     char *buf, size_t len);
94 static ssize_t ofw_std_package_to_path(ofw_t ofw, phandle_t package, char *buf,
95     size_t len);
96 static int ofw_std_call_method(ofw_t ofw, ihandle_t instance,
97     const char *method, int nargs, int nreturns,
98     unsigned long *args_and_returns);
99 static ihandle_t ofw_std_open(ofw_t ofw, const char *device);
100 static void ofw_std_close(ofw_t ofw, ihandle_t instance);
101 static ssize_t ofw_std_read(ofw_t ofw, ihandle_t instance, void *addr,
102     size_t len);
103 static ssize_t ofw_std_write(ofw_t ofw, ihandle_t instance, const void *addr,
104     size_t len);
105 static int ofw_std_seek(ofw_t ofw, ihandle_t instance, uint64_t pos);
106 static caddr_t ofw_std_claim(ofw_t ofw, void *virt, size_t size, u_int align);
107 static void ofw_std_release(ofw_t ofw, void *virt, size_t size);
108 static void ofw_std_enter(ofw_t ofw);
109 static void ofw_std_exit(ofw_t ofw);
110 
111 static ofw_method_t ofw_std_methods[] = {
112 	OFWMETHOD(ofw_init,			ofw_std_init),
113 	OFWMETHOD(ofw_peer,			ofw_std_peer),
114 	OFWMETHOD(ofw_child,			ofw_std_child),
115 	OFWMETHOD(ofw_parent,			ofw_std_parent),
116 	OFWMETHOD(ofw_instance_to_package,	ofw_std_instance_to_package),
117 	OFWMETHOD(ofw_getproplen,		ofw_std_getproplen),
118 	OFWMETHOD(ofw_getprop,			ofw_std_getprop),
119 	OFWMETHOD(ofw_nextprop,			ofw_std_nextprop),
120 	OFWMETHOD(ofw_setprop,			ofw_std_setprop),
121 	OFWMETHOD(ofw_canon,			ofw_std_canon),
122 	OFWMETHOD(ofw_finddevice,		ofw_std_finddevice),
123 	OFWMETHOD(ofw_instance_to_path,		ofw_std_instance_to_path),
124 	OFWMETHOD(ofw_package_to_path,		ofw_std_package_to_path),
125 
126 	OFWMETHOD(ofw_test,			ofw_std_test),
127 	OFWMETHOD(ofw_call_method,		ofw_std_call_method),
128 	OFWMETHOD(ofw_interpret,		ofw_std_interpret),
129 	OFWMETHOD(ofw_open,			ofw_std_open),
130 	OFWMETHOD(ofw_close,			ofw_std_close),
131 	OFWMETHOD(ofw_read,			ofw_std_read),
132 	OFWMETHOD(ofw_write,			ofw_std_write),
133 	OFWMETHOD(ofw_seek,			ofw_std_seek),
134 	OFWMETHOD(ofw_claim,			ofw_std_claim),
135 	OFWMETHOD(ofw_release,			ofw_std_release),
136 	OFWMETHOD(ofw_enter,			ofw_std_enter),
137 	OFWMETHOD(ofw_exit,			ofw_std_exit),
138 
139 	{ 0, 0 }
140 };
141 
142 static ofw_def_t ofw_std = {
143 	OFW_STD_DIRECT,
144 	ofw_std_methods,
145 	0
146 };
147 OFW_DEF(ofw_std);
148 
149 static int (*openfirmware)(void *);
150 
151 /* Initializer */
152 
153 static void
154 ofw_std_init(ofw_t ofw, void *openfirm)
155 {
156 
157 	openfirmware = (int (*)(void *))openfirm;
158 }
159 
160 /*
161  * Generic functions
162  */
163 
164 /* Test to see if a service exists. */
165 static int
166 ofw_std_test(ofw_t ofw, const char *name)
167 {
168 	static struct {
169 		cell_t name;
170 		cell_t nargs;
171 		cell_t nreturns;
172 		cell_t service;
173 		cell_t missing;
174 	} args = {
175 		(cell_t)"test",
176 		1,
177 		1,
178 	};
179 
180 	args.service = (cell_t)name;
181 	if (openfirmware(&args) == -1)
182 		return (-1);
183 	return (args.missing);
184 }
185 
186 static int
187 ofw_std_interpret(ofw_t ofw, const char *cmd, int nreturns,
188     unsigned long *returns)
189 {
190 	static struct {
191 		cell_t name;
192 		cell_t nargs;
193 		cell_t nreturns;
194 		cell_t slot[16];
195 	} args = {
196 		(cell_t)"interpret",
197 		1,
198 	};
199 	cell_t status;
200 	int i = 0, j = 0;
201 
202 	args.nreturns = ++nreturns;
203 	args.slot[i++] = (cell_t)cmd;
204 	if (openfirmware(&args) == -1)
205 		return (-1);
206 	status = args.slot[i++];
207 	while (i < 1 + nreturns)
208 		returns[j++] = args.slot[i++];
209 	return (status);
210 }
211 
212 /*
213  * Device tree functions
214  */
215 
216 /* Return the next sibling of this node or 0. */
217 static phandle_t
218 ofw_std_peer(ofw_t ofw, phandle_t node)
219 {
220 	static struct {
221 		cell_t name;
222 		cell_t nargs;
223 		cell_t nreturns;
224 		cell_t node;
225 		cell_t next;
226 	} args = {
227 		(cell_t)"peer",
228 		1,
229 		1,
230 	};
231 
232 	args.node = node;
233 	if (openfirmware(&args) == -1)
234 		return (-1);
235 	return (args.next);
236 }
237 
238 /* Return the first child of this node or 0. */
239 static phandle_t
240 ofw_std_child(ofw_t ofw, phandle_t node)
241 {
242 	static struct {
243 		cell_t name;
244 		cell_t nargs;
245 		cell_t nreturns;
246 		cell_t node;
247 		cell_t child;
248 	} args = {
249 		(cell_t)"child",
250 		1,
251 		1,
252 	};
253 
254 	args.node = node;
255 	if (openfirmware(&args) == -1)
256 		return (-1);
257 	return (args.child);
258 }
259 
260 /* Return the parent of this node or 0. */
261 static phandle_t
262 ofw_std_parent(ofw_t ofw, phandle_t node)
263 {
264 	static struct {
265 		cell_t name;
266 		cell_t nargs;
267 		cell_t nreturns;
268 		cell_t node;
269 		cell_t parent;
270 	} args = {
271 		(cell_t)"parent",
272 		1,
273 		1,
274 	};
275 
276 	args.node = node;
277 	if (openfirmware(&args) == -1)
278 		return (-1);
279 	return (args.parent);
280 }
281 
282 /* Return the package handle that corresponds to an instance handle. */
283 static phandle_t
284 ofw_std_instance_to_package(ofw_t ofw, ihandle_t instance)
285 {
286 	static struct {
287 		cell_t name;
288 		cell_t nargs;
289 		cell_t nreturns;
290 		cell_t instance;
291 		cell_t package;
292 	} args = {
293 		(cell_t)"instance-to-package",
294 		1,
295 		1,
296 	};
297 
298 	args.instance = instance;
299 	if (openfirmware(&args) == -1)
300 		return (-1);
301 	return (args.package);
302 }
303 
304 /* Get the length of a property of a package. */
305 static ssize_t
306 ofw_std_getproplen(ofw_t ofw, phandle_t package, const char *propname)
307 {
308 	static struct {
309 		cell_t name;
310 		cell_t nargs;
311 		cell_t nreturns;
312 		cell_t package;
313 		cell_t propname;
314 		cell_t proplen;
315 	} args = {
316 		(cell_t)"getproplen",
317 		2,
318 		1,
319 	};
320 
321 	args.package = package;
322 	args.propname = (cell_t)propname;
323 	if (openfirmware(&args) == -1)
324 		return (-1);
325 	return (args.proplen);
326 }
327 
328 /* Get the value of a property of a package. */
329 static ssize_t
330 ofw_std_getprop(ofw_t ofw, phandle_t package, const char *propname, void *buf,
331     size_t buflen)
332 {
333 	static struct {
334 		cell_t name;
335 		cell_t nargs;
336 		cell_t nreturns;
337 		cell_t package;
338 		cell_t propname;
339 		cell_t buf;
340 		cell_t buflen;
341 		cell_t size;
342 	} args = {
343 		(cell_t)"getprop",
344 		4,
345 		1,
346 	};
347 
348 	args.package = package;
349 	args.propname = (cell_t)propname;
350 	args.buf = (cell_t)buf;
351 	args.buflen = buflen;
352 	if (openfirmware(&args) == -1)
353 		return (-1);
354 	return (args.size);
355 }
356 
357 /* Get the next property of a package. */
358 static int
359 ofw_std_nextprop(ofw_t ofw, phandle_t package, const char *previous, char *buf,
360     size_t size)
361 {
362 	static struct {
363 		cell_t name;
364 		cell_t nargs;
365 		cell_t nreturns;
366 		cell_t package;
367 		cell_t previous;
368 		cell_t buf;
369 		cell_t flag;
370 	} args = {
371 		(cell_t)"nextprop",
372 		3,
373 		1,
374 	};
375 
376 	args.package = package;
377 	args.previous = (cell_t)previous;
378 	args.buf = (cell_t)buf;
379 	if (openfirmware(&args) == -1)
380 		return (-1);
381 	return (args.flag);
382 }
383 
384 /* Set the value of a property of a package. */
385 /* XXX Has a bug on FirePower */
386 static int
387 ofw_std_setprop(ofw_t ofw, phandle_t package, const char *propname,
388     const void *buf, size_t len)
389 {
390 	static struct {
391 		cell_t name;
392 		cell_t nargs;
393 		cell_t nreturns;
394 		cell_t package;
395 		cell_t propname;
396 		cell_t buf;
397 		cell_t len;
398 		cell_t size;
399 	} args = {
400 		(cell_t)"setprop",
401 		4,
402 		1,
403 	};
404 
405 	args.package = package;
406 	args.propname = (cell_t)propname;
407 	args.buf = (cell_t)buf;
408 	args.len = len;
409 	if (openfirmware(&args) == -1)
410 		return (-1);
411 	return (args.size);
412 }
413 
414 /* Convert a device specifier to a fully qualified pathname. */
415 static ssize_t
416 ofw_std_canon(ofw_t ofw, const char *device, char *buf, size_t len)
417 {
418 	static struct {
419 		cell_t name;
420 		cell_t nargs;
421 		cell_t nreturns;
422 		cell_t device;
423 		cell_t buf;
424 		cell_t len;
425 		cell_t size;
426 	} args = {
427 		(cell_t)"canon",
428 		3,
429 		1,
430 	};
431 
432 	args.device = (cell_t)device;
433 	args.buf = (cell_t)buf;
434 	args.len = len;
435 	if (openfirmware(&args) == -1)
436 		return (-1);
437 	return (args.size);
438 }
439 
440 /* Return a package handle for the specified device. */
441 static phandle_t
442 ofw_std_finddevice(ofw_t ofw, const char *device)
443 {
444 	static struct {
445 		cell_t name;
446 		cell_t nargs;
447 		cell_t nreturns;
448 		cell_t device;
449 		cell_t package;
450 	} args = {
451 		(cell_t)"finddevice",
452 		1,
453 		1,
454 	};
455 
456 	args.device = (cell_t)device;
457 	if (openfirmware(&args) == -1)
458 		return (-1);
459 	return (args.package);
460 }
461 
462 /* Return the fully qualified pathname corresponding to an instance. */
463 static ssize_t
464 ofw_std_instance_to_path(ofw_t ofw, ihandle_t instance, char *buf, size_t len)
465 {
466 	static struct {
467 		cell_t name;
468 		cell_t nargs;
469 		cell_t nreturns;
470 		cell_t instance;
471 		cell_t buf;
472 		cell_t len;
473 		cell_t size;
474 	} args = {
475 		(cell_t)"instance-to-path",
476 		3,
477 		1,
478 	};
479 
480 	args.instance = instance;
481 	args.buf = (cell_t)buf;
482 	args.len = len;
483 	if (openfirmware(&args) == -1)
484 		return (-1);
485 	return (args.size);
486 }
487 
488 /* Return the fully qualified pathname corresponding to a package. */
489 static ssize_t
490 ofw_std_package_to_path(ofw_t ofw, phandle_t package, char *buf, size_t len)
491 {
492 	static struct {
493 		cell_t name;
494 		cell_t nargs;
495 		cell_t nreturns;
496 		cell_t package;
497 		cell_t buf;
498 		cell_t len;
499 		cell_t size;
500 	} args = {
501 		(cell_t)"package-to-path",
502 		3,
503 		1,
504 	};
505 
506 	args.package = package;
507 	args.buf = (cell_t)buf;
508 	args.len = len;
509 	if (openfirmware(&args) == -1)
510 		return (-1);
511 	return (args.size);
512 }
513 
514 /*  Call the method in the scope of a given instance. */
515 static int
516 ofw_std_call_method(ofw_t ofw, ihandle_t instance, const char *method,
517     int nargs, int nreturns, unsigned long *args_and_returns)
518 {
519 	static struct {
520 		cell_t name;
521 		cell_t nargs;
522 		cell_t nreturns;
523 		cell_t method;
524 		cell_t instance;
525 		cell_t args_n_results[12];
526 	} args = {
527 		(cell_t)"call-method",
528 		2,
529 		1,
530 	};
531 	cell_t *cp;
532 	unsigned long *ap;
533 	int n;
534 
535 	if (nargs > 6)
536 		return (-1);
537 	args.nargs = nargs + 2;
538 	args.nreturns = nreturns + 1;
539 	args.method = (cell_t)method;
540 	args.instance = instance;
541 
542 	ap = args_and_returns;
543 	for (cp = args.args_n_results + (n = nargs); --n >= 0;)
544 		*--cp = *(ap++);
545 	if (openfirmware(&args) == -1)
546 		return (-1);
547 	if (args.args_n_results[nargs])
548 		return (args.args_n_results[nargs]);
549 	for (cp = args.args_n_results + nargs + (n = args.nreturns); --n > 0;)
550 		*(ap++) = *--cp;
551 	return (0);
552 }
553 
554 /*
555  * Device I/O functions
556  */
557 
558 /* Open an instance for a device. */
559 static ihandle_t
560 ofw_std_open(ofw_t ofw, const char *device)
561 {
562 	static struct {
563 		cell_t name;
564 		cell_t nargs;
565 		cell_t nreturns;
566 		cell_t device;
567 		cell_t instance;
568 	} args = {
569 		(cell_t)"open",
570 		1,
571 		1,
572 	};
573 
574 	args.device = (cell_t)device;
575 	if (openfirmware(&args) == -1 || args.instance == 0)
576 		return (-1);
577 	return (args.instance);
578 }
579 
580 /* Close an instance. */
581 static void
582 ofw_std_close(ofw_t ofw, ihandle_t instance)
583 {
584 	static struct {
585 		cell_t name;
586 		cell_t nargs;
587 		cell_t nreturns;
588 		cell_t instance;
589 	} args = {
590 		(cell_t)"close",
591 		1,
592 	};
593 
594 	args.instance = instance;
595 	openfirmware(&args);
596 }
597 
598 /* Read from an instance. */
599 static ssize_t
600 ofw_std_read(ofw_t ofw, ihandle_t instance, void *addr, size_t len)
601 {
602 	static struct {
603 		cell_t name;
604 		cell_t nargs;
605 		cell_t nreturns;
606 		cell_t instance;
607 		cell_t addr;
608 		cell_t len;
609 		cell_t actual;
610 	} args = {
611 		(cell_t)"read",
612 		3,
613 		1,
614 	};
615 
616 	args.instance = instance;
617 	args.addr = (cell_t)addr;
618 	args.len = len;
619 	if (openfirmware(&args) == -1)
620 		return (-1);
621 
622 	return (args.actual);
623 }
624 
625 /* Write to an instance. */
626 static ssize_t
627 ofw_std_write(ofw_t ofw, ihandle_t instance, const void *addr, size_t len)
628 {
629 	static struct {
630 		cell_t name;
631 		cell_t nargs;
632 		cell_t nreturns;
633 		cell_t instance;
634 		cell_t addr;
635 		cell_t len;
636 		cell_t actual;
637 	} args = {
638 		(cell_t)"write",
639 		3,
640 		1,
641 	};
642 
643 	args.instance = instance;
644 	args.addr = (cell_t)addr;
645 	args.len = len;
646 	if (openfirmware(&args) == -1)
647 		return (-1);
648 	return (args.actual);
649 }
650 
651 /* Seek to a position. */
652 static int
653 ofw_std_seek(ofw_t ofw, ihandle_t instance, uint64_t pos)
654 {
655 	static struct {
656 		cell_t name;
657 		cell_t nargs;
658 		cell_t nreturns;
659 		cell_t instance;
660 		cell_t poshi;
661 		cell_t poslo;
662 		cell_t status;
663 	} args = {
664 		(cell_t)"seek",
665 		3,
666 		1,
667 	};
668 
669 	args.instance = instance;
670 	args.poshi = pos >> 32;
671 	args.poslo = pos;
672 	if (openfirmware(&args) == -1)
673 		return (-1);
674 	return (args.status);
675 }
676 
677 /*
678  * Memory functions
679  */
680 
681 /* Claim an area of memory. */
682 static caddr_t
683 ofw_std_claim(ofw_t ofw, void *virt, size_t size, u_int align)
684 {
685 	static struct {
686 		cell_t name;
687 		cell_t nargs;
688 		cell_t nreturns;
689 		cell_t virt;
690 		cell_t size;
691 		cell_t align;
692 		cell_t baseaddr;
693 	} args = {
694 		(cell_t)"claim",
695 		3,
696 		1,
697 	};
698 
699 	args.virt = (cell_t)virt;
700 	args.size = size;
701 	args.align = align;
702 	if (openfirmware(&args) == -1)
703 		return ((void *)-1);
704 	return ((void *)args.baseaddr);
705 }
706 
707 /* Release an area of memory. */
708 static void
709 ofw_std_release(ofw_t ofw, void *virt, size_t size)
710 {
711 	static struct {
712 		cell_t name;
713 		cell_t nargs;
714 		cell_t nreturns;
715 		cell_t virt;
716 		cell_t size;
717 	} args = {
718 		(cell_t)"release",
719 		2,
720 	};
721 
722 	args.virt = (cell_t)virt;
723 	args.size = size;
724 	openfirmware(&args);
725 }
726 
727 /*
728  * Control transfer functions
729  */
730 
731 /* Suspend and drop back to the Open Firmware interface. */
732 static void
733 ofw_std_enter(ofw_t ofw)
734 {
735 	static struct {
736 		cell_t name;
737 		cell_t nargs;
738 		cell_t nreturns;
739 	} args = {
740 		(cell_t)"enter",
741 	};
742 
743 	openfirmware(&args);
744 	/* We may come back. */
745 }
746 
747 /* Shut down and drop back to the Open Firmware interface. */
748 static void
749 ofw_std_exit(ofw_t ofw)
750 {
751 	static struct {
752 		cell_t name;
753 		cell_t nargs;
754 		cell_t nreturns;
755 	} args = {
756 		(cell_t)"exit",
757 	};
758 
759 	openfirmware(&args);
760 	for (;;)			/* just in case */
761 		;
762 }
763