xref: /freebsd/sys/dev/ofw/ofw_standard.c (revision edf8578117e8844e02c0121147f45e4609b30680)
1 /*	$NetBSD: Locore.c,v 1.7 2000/08/20 07:04:59 tsubai Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-4-Clause AND BSD-2-Clause
5  *
6  * Copyright (C) 1995, 1996 Wolfgang Solfrank.
7  * Copyright (C) 1995, 1996 TooLs GmbH.
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by TooLs GmbH.
21  * 4. The name of TooLs GmbH may not be used to endorse or promote products
22  *    derived from this software without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
25  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
29  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
30  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
31  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
32  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
33  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 /*-
36  * Copyright (C) 2000 Benno Rice.
37  * All rights reserved.
38  *
39  * Redistribution and use in source and binary forms, with or without
40  * modification, are permitted provided that the following conditions
41  * are met:
42  * 1. Redistributions of source code must retain the above copyright
43  *    notice, this list of conditions and the following disclaimer.
44  * 2. Redistributions in binary form must reproduce the above copyright
45  *    notice, this list of conditions and the following disclaimer in the
46  *    documentation and/or other materials provided with the distribution.
47  *
48  * THIS SOFTWARE IS PROVIDED BY Benno Rice ``AS IS'' AND ANY EXPRESS OR
49  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
50  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
51  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
52  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
53  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
54  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
55  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
56  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
57  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
58  */
59 
60 #include <sys/cdefs.h>
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 int 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     cell_t *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, cell_t *args_and_returns);
98 static ihandle_t ofw_std_open(ofw_t ofw, const char *device);
99 static void ofw_std_close(ofw_t ofw, ihandle_t instance);
100 static ssize_t ofw_std_read(ofw_t ofw, ihandle_t instance, void *addr,
101     size_t len);
102 static ssize_t ofw_std_write(ofw_t ofw, ihandle_t instance, const void *addr,
103     size_t len);
104 static int ofw_std_seek(ofw_t ofw, ihandle_t instance, uint64_t pos);
105 static caddr_t ofw_std_claim(ofw_t ofw, void *virt, size_t size, u_int align);
106 static void ofw_std_release(ofw_t ofw, void *virt, size_t size);
107 static void ofw_std_enter(ofw_t ofw);
108 static void ofw_std_exit(ofw_t ofw);
109 
110 static ofw_method_t ofw_std_methods[] = {
111 	OFWMETHOD(ofw_init,			ofw_std_init),
112 	OFWMETHOD(ofw_peer,			ofw_std_peer),
113 	OFWMETHOD(ofw_child,			ofw_std_child),
114 	OFWMETHOD(ofw_parent,			ofw_std_parent),
115 	OFWMETHOD(ofw_instance_to_package,	ofw_std_instance_to_package),
116 	OFWMETHOD(ofw_getproplen,		ofw_std_getproplen),
117 	OFWMETHOD(ofw_getprop,			ofw_std_getprop),
118 	OFWMETHOD(ofw_nextprop,			ofw_std_nextprop),
119 	OFWMETHOD(ofw_setprop,			ofw_std_setprop),
120 	OFWMETHOD(ofw_canon,			ofw_std_canon),
121 	OFWMETHOD(ofw_finddevice,		ofw_std_finddevice),
122 	OFWMETHOD(ofw_instance_to_path,		ofw_std_instance_to_path),
123 	OFWMETHOD(ofw_package_to_path,		ofw_std_package_to_path),
124 
125 	OFWMETHOD(ofw_test,			ofw_std_test),
126 	OFWMETHOD(ofw_call_method,		ofw_std_call_method),
127 	OFWMETHOD(ofw_interpret,		ofw_std_interpret),
128 	OFWMETHOD(ofw_open,			ofw_std_open),
129 	OFWMETHOD(ofw_close,			ofw_std_close),
130 	OFWMETHOD(ofw_read,			ofw_std_read),
131 	OFWMETHOD(ofw_write,			ofw_std_write),
132 	OFWMETHOD(ofw_seek,			ofw_std_seek),
133 	OFWMETHOD(ofw_claim,			ofw_std_claim),
134 	OFWMETHOD(ofw_release,			ofw_std_release),
135 	OFWMETHOD(ofw_enter,			ofw_std_enter),
136 	OFWMETHOD(ofw_exit,			ofw_std_exit),
137 	{ 0, 0 }
138 };
139 
140 static ofw_def_t ofw_std = {
141 	OFW_STD_DIRECT,
142 	ofw_std_methods,
143 	0
144 };
145 OFW_DEF(ofw_std);
146 
147 static int (*openfirmware)(void *);
148 
149 /* Initializer */
150 
151 static int
152 ofw_std_init(ofw_t ofw, void *openfirm)
153 {
154 
155 	openfirmware = (int (*)(void *))openfirm;
156 	return (0);
157 }
158 
159 /*
160  * Generic functions
161  */
162 
163 /* Test to see if a service exists. */
164 static int
165 ofw_std_test(ofw_t ofw, const char *name)
166 {
167 	struct {
168 		cell_t name;
169 		cell_t nargs;
170 		cell_t nreturns;
171 		cell_t service;
172 		cell_t missing;
173 	} args = {
174 		(cell_t)"test",
175 		1,
176 		1,
177 	};
178 
179 	args.service = (cell_t)name;
180 	if (openfirmware(&args) == -1)
181 		return (-1);
182 	return (args.missing);
183 }
184 
185 static int
186 ofw_std_interpret(ofw_t ofw, const char *cmd, int nreturns, cell_t *returns)
187 {
188 	struct {
189 		cell_t name;
190 		cell_t nargs;
191 		cell_t nreturns;
192 		cell_t slot[16];
193 	} args = {
194 		(cell_t)"interpret",
195 		1,
196 	};
197 	cell_t status;
198 	int i = 0, j = 0;
199 
200 	args.nreturns = ++nreturns;
201 	args.slot[i++] = (cell_t)cmd;
202 	if (openfirmware(&args) == -1)
203 		return (-1);
204 	status = args.slot[i++];
205 	while (i < 1 + nreturns)
206 		returns[j++] = args.slot[i++];
207 	return (status);
208 }
209 
210 /*
211  * Device tree functions
212  */
213 
214 /* Return the next sibling of this node or 0. */
215 static phandle_t
216 ofw_std_peer(ofw_t ofw, phandle_t node)
217 {
218 	struct {
219 		cell_t name;
220 		cell_t nargs;
221 		cell_t nreturns;
222 		cell_t node;
223 		cell_t next;
224 	} args = {
225 		(cell_t)"peer",
226 		1,
227 		1,
228 	};
229 
230 	args.node = node;
231 	if (openfirmware(&args) == -1)
232 		return (0);
233 	return (args.next);
234 }
235 
236 /* Return the first child of this node or 0. */
237 static phandle_t
238 ofw_std_child(ofw_t ofw, phandle_t node)
239 {
240 	struct {
241 		cell_t name;
242 		cell_t nargs;
243 		cell_t nreturns;
244 		cell_t node;
245 		cell_t child;
246 	} args = {
247 		(cell_t)"child",
248 		1,
249 		1,
250 	};
251 
252 	args.node = node;
253 	if (openfirmware(&args) == -1)
254 		return (0);
255 	return (args.child);
256 }
257 
258 /* Return the parent of this node or 0. */
259 static phandle_t
260 ofw_std_parent(ofw_t ofw, phandle_t node)
261 {
262 	struct {
263 		cell_t name;
264 		cell_t nargs;
265 		cell_t nreturns;
266 		cell_t node;
267 		cell_t parent;
268 	} args = {
269 		(cell_t)"parent",
270 		1,
271 		1,
272 	};
273 
274 	args.node = node;
275 	if (openfirmware(&args) == -1)
276 		return (0);
277 	return (args.parent);
278 }
279 
280 /* Return the package handle that corresponds to an instance handle. */
281 static phandle_t
282 ofw_std_instance_to_package(ofw_t ofw, ihandle_t instance)
283 {
284 	struct {
285 		cell_t name;
286 		cell_t nargs;
287 		cell_t nreturns;
288 		cell_t instance;
289 		cell_t package;
290 	} args = {
291 		(cell_t)"instance-to-package",
292 		1,
293 		1,
294 	};
295 
296 	args.instance = instance;
297 	if (openfirmware(&args) == -1)
298 		return (-1);
299 	return (args.package);
300 }
301 
302 /* Get the length of a property of a package. */
303 static ssize_t
304 ofw_std_getproplen(ofw_t ofw, phandle_t package, const char *propname)
305 {
306 	struct {
307 		cell_t name;
308 		cell_t nargs;
309 		cell_t nreturns;
310 		cell_t package;
311 		cell_t propname;
312 		cell_t proplen;
313 	} args = {
314 		(cell_t)"getproplen",
315 		2,
316 		1,
317 	};
318 
319 	args.package = package;
320 	args.propname = (cell_t)propname;
321 	if (openfirmware(&args) == -1)
322 		return (-1);
323 	return (args.proplen);
324 }
325 
326 /* Get the value of a property of a package. */
327 static ssize_t
328 ofw_std_getprop(ofw_t ofw, phandle_t package, const char *propname, void *buf,
329     size_t buflen)
330 {
331 	struct {
332 		cell_t name;
333 		cell_t nargs;
334 		cell_t nreturns;
335 		cell_t package;
336 		cell_t propname;
337 		cell_t buf;
338 		cell_t buflen;
339 		cell_t size;
340 	} args = {
341 		(cell_t)"getprop",
342 		4,
343 		1,
344 	};
345 
346 	args.package = package;
347 	args.propname = (cell_t)propname;
348 	args.buf = (cell_t)buf;
349 	args.buflen = buflen;
350 	if (openfirmware(&args) == -1)
351 		return (-1);
352 	return (args.size);
353 }
354 
355 /* Get the next property of a package. */
356 static int
357 ofw_std_nextprop(ofw_t ofw, phandle_t package, const char *previous, char *buf,
358     size_t size)
359 {
360 	struct {
361 		cell_t name;
362 		cell_t nargs;
363 		cell_t nreturns;
364 		cell_t package;
365 		cell_t previous;
366 		cell_t buf;
367 		cell_t flag;
368 	} args = {
369 		(cell_t)"nextprop",
370 		3,
371 		1,
372 	};
373 
374 	args.package = package;
375 	args.previous = (cell_t)previous;
376 	args.buf = (cell_t)buf;
377 	if (openfirmware(&args) == -1)
378 		return (-1);
379 	return (args.flag);
380 }
381 
382 /* Set the value of a property of a package. */
383 /* XXX Has a bug on FirePower */
384 static int
385 ofw_std_setprop(ofw_t ofw, phandle_t package, const char *propname,
386     const void *buf, size_t len)
387 {
388 	struct {
389 		cell_t name;
390 		cell_t nargs;
391 		cell_t nreturns;
392 		cell_t package;
393 		cell_t propname;
394 		cell_t buf;
395 		cell_t len;
396 		cell_t size;
397 	} args = {
398 		(cell_t)"setprop",
399 		4,
400 		1,
401 	};
402 
403 	args.package = package;
404 	args.propname = (cell_t)propname;
405 	args.buf = (cell_t)buf;
406 	args.len = len;
407 	if (openfirmware(&args) == -1)
408 		return (-1);
409 	return (args.size);
410 }
411 
412 /* Convert a device specifier to a fully qualified pathname. */
413 static ssize_t
414 ofw_std_canon(ofw_t ofw, const char *device, char *buf, size_t len)
415 {
416 	struct {
417 		cell_t name;
418 		cell_t nargs;
419 		cell_t nreturns;
420 		cell_t device;
421 		cell_t buf;
422 		cell_t len;
423 		cell_t size;
424 	} args = {
425 		(cell_t)"canon",
426 		3,
427 		1,
428 	};
429 
430 	args.device = (cell_t)device;
431 	args.buf = (cell_t)buf;
432 	args.len = len;
433 	if (openfirmware(&args) == -1)
434 		return (-1);
435 	return (args.size);
436 }
437 
438 /* Return a package handle for the specified device. */
439 static phandle_t
440 ofw_std_finddevice(ofw_t ofw, const char *device)
441 {
442 	struct {
443 		cell_t name;
444 		cell_t nargs;
445 		cell_t nreturns;
446 		cell_t device;
447 		cell_t package;
448 	} args = {
449 		(cell_t)"finddevice",
450 		1,
451 		1,
452 	};
453 
454 	args.device = (cell_t)device;
455 	if (openfirmware(&args) == -1)
456 		return (-1);
457 	return (args.package);
458 }
459 
460 /* Return the fully qualified pathname corresponding to an instance. */
461 static ssize_t
462 ofw_std_instance_to_path(ofw_t ofw, ihandle_t instance, char *buf, size_t len)
463 {
464 	struct {
465 		cell_t name;
466 		cell_t nargs;
467 		cell_t nreturns;
468 		cell_t instance;
469 		cell_t buf;
470 		cell_t len;
471 		cell_t size;
472 	} args = {
473 		(cell_t)"instance-to-path",
474 		3,
475 		1,
476 	};
477 
478 	args.instance = instance;
479 	args.buf = (cell_t)buf;
480 	args.len = len;
481 	if (openfirmware(&args) == -1)
482 		return (-1);
483 	return (args.size);
484 }
485 
486 /* Return the fully qualified pathname corresponding to a package. */
487 static ssize_t
488 ofw_std_package_to_path(ofw_t ofw, phandle_t package, char *buf, size_t len)
489 {
490 	struct {
491 		cell_t name;
492 		cell_t nargs;
493 		cell_t nreturns;
494 		cell_t package;
495 		cell_t buf;
496 		cell_t len;
497 		cell_t size;
498 	} args = {
499 		(cell_t)"package-to-path",
500 		3,
501 		1,
502 	};
503 
504 	args.package = package;
505 	args.buf = (cell_t)buf;
506 	args.len = len;
507 	if (openfirmware(&args) == -1)
508 		return (-1);
509 	return (args.size);
510 }
511 
512 /*  Call the method in the scope of a given instance. */
513 static int
514 ofw_std_call_method(ofw_t ofw, ihandle_t instance, const char *method,
515     int nargs, int nreturns, cell_t *args_and_returns)
516 {
517 	struct {
518 		cell_t name;
519 		cell_t nargs;
520 		cell_t nreturns;
521 		cell_t method;
522 		cell_t instance;
523 		cell_t args_n_results[12];
524 	} args = {
525 		(cell_t)"call-method",
526 		2,
527 		1,
528 	};
529 	cell_t *ap, *cp;
530 	int n;
531 
532 	if (nargs > 6)
533 		return (-1);
534 	args.nargs = nargs + 2;
535 	args.nreturns = nreturns + 1;
536 	args.method = (cell_t)method;
537 	args.instance = instance;
538 
539 	ap = args_and_returns;
540 	for (cp = args.args_n_results + (n = nargs); --n >= 0;)
541 		*--cp = *(ap++);
542 	if (openfirmware(&args) == -1)
543 		return (-1);
544 	if (args.args_n_results[nargs])
545 		return (args.args_n_results[nargs]);
546 	for (cp = args.args_n_results + nargs + (n = args.nreturns); --n > 0;)
547 		*(ap++) = *--cp;
548 	return (0);
549 }
550 
551 /*
552  * Device I/O functions
553  */
554 
555 /* Open an instance for a device. */
556 static ihandle_t
557 ofw_std_open(ofw_t ofw, const char *device)
558 {
559 	struct {
560 		cell_t name;
561 		cell_t nargs;
562 		cell_t nreturns;
563 		cell_t device;
564 		cell_t instance;
565 	} args = {
566 		(cell_t)"open",
567 		1,
568 		1,
569 	};
570 
571 	args.device = (cell_t)device;
572 	if (openfirmware(&args) == -1 || args.instance == 0)
573 		return (-1);
574 	return (args.instance);
575 }
576 
577 /* Close an instance. */
578 static void
579 ofw_std_close(ofw_t ofw, ihandle_t instance)
580 {
581 	struct {
582 		cell_t name;
583 		cell_t nargs;
584 		cell_t nreturns;
585 		cell_t instance;
586 	} args = {
587 		(cell_t)"close",
588 		1,
589 		0,
590 	};
591 
592 	args.instance = instance;
593 	openfirmware(&args);
594 }
595 
596 /* Read from an instance. */
597 static ssize_t
598 ofw_std_read(ofw_t ofw, ihandle_t instance, void *addr, size_t len)
599 {
600 	struct {
601 		cell_t name;
602 		cell_t nargs;
603 		cell_t nreturns;
604 		cell_t instance;
605 		cell_t addr;
606 		cell_t len;
607 		cell_t actual;
608 	} args = {
609 		(cell_t)"read",
610 		3,
611 		1,
612 	};
613 
614 	args.instance = instance;
615 	args.addr = (cell_t)addr;
616 	args.len = len;
617 	if (openfirmware(&args) == -1)
618 		return (-1);
619 
620 	return (args.actual);
621 }
622 
623 /* Write to an instance. */
624 static ssize_t
625 ofw_std_write(ofw_t ofw, ihandle_t instance, const void *addr, size_t len)
626 {
627 	struct {
628 		cell_t name;
629 		cell_t nargs;
630 		cell_t nreturns;
631 		cell_t instance;
632 		cell_t addr;
633 		cell_t len;
634 		cell_t actual;
635 	} args = {
636 		(cell_t)"write",
637 		3,
638 		1,
639 	};
640 
641 	args.instance = instance;
642 	args.addr = (cell_t)addr;
643 	args.len = len;
644 	if (openfirmware(&args) == -1)
645 		return (-1);
646 	return (args.actual);
647 }
648 
649 /* Seek to a position. */
650 static int
651 ofw_std_seek(ofw_t ofw, ihandle_t instance, uint64_t pos)
652 {
653 	struct {
654 		cell_t name;
655 		cell_t nargs;
656 		cell_t nreturns;
657 		cell_t instance;
658 		cell_t poshi;
659 		cell_t poslo;
660 		cell_t status;
661 	} args = {
662 		(cell_t)"seek",
663 		3,
664 		1,
665 	};
666 
667 	args.instance = instance;
668 	args.poshi = pos >> 32;
669 	args.poslo = pos;
670 	if (openfirmware(&args) == -1)
671 		return (-1);
672 	return (args.status);
673 }
674 
675 /*
676  * Memory functions
677  */
678 
679 /* Claim an area of memory. */
680 static caddr_t
681 ofw_std_claim(ofw_t ofw, void *virt, size_t size, u_int align)
682 {
683 	struct {
684 		cell_t name;
685 		cell_t nargs;
686 		cell_t nreturns;
687 		cell_t virt;
688 		cell_t size;
689 		cell_t align;
690 		cell_t baseaddr;
691 	} args = {
692 		(cell_t)"claim",
693 		3,
694 		1,
695 	};
696 
697 	args.virt = (cell_t)virt;
698 	args.size = size;
699 	args.align = align;
700 	if (openfirmware(&args) == -1)
701 		return ((void *)-1);
702 	return ((void *)args.baseaddr);
703 }
704 
705 /* Release an area of memory. */
706 static void
707 ofw_std_release(ofw_t ofw, void *virt, size_t size)
708 {
709 	struct {
710 		cell_t name;
711 		cell_t nargs;
712 		cell_t nreturns;
713 		cell_t virt;
714 		cell_t size;
715 	} args = {
716 		(cell_t)"release",
717 		2,
718 		0,
719 	};
720 
721 	args.virt = (cell_t)virt;
722 	args.size = size;
723 	openfirmware(&args);
724 }
725 
726 /*
727  * Control transfer functions
728  */
729 
730 /* Suspend and drop back to the Open Firmware interface. */
731 static void
732 ofw_std_enter(ofw_t ofw)
733 {
734 	struct {
735 		cell_t name;
736 		cell_t nargs;
737 		cell_t nreturns;
738 	} args = {
739 		(cell_t)"enter",
740 		0,
741 		0,
742 	};
743 
744 	openfirmware(&args);
745 	/* We may come back. */
746 }
747 
748 /* Shut down and drop back to the Open Firmware interface. */
749 static void
750 ofw_std_exit(ofw_t ofw)
751 {
752 	struct {
753 		cell_t name;
754 		cell_t nargs;
755 		cell_t nreturns;
756 	} args = {
757 		(cell_t)"exit",
758 		0,
759 		0,
760 	};
761 
762 	openfirmware(&args);
763 	for (;;)			/* just in case */
764 		;
765 }
766