xref: /freebsd/sys/dev/ofw/ofw_standard.c (revision f4b37ed0f8b307b1f3f0f630ca725d68f1dff30d)
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 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 
138 	{ 0, 0 }
139 };
140 
141 static ofw_def_t ofw_std = {
142 	OFW_STD_DIRECT,
143 	ofw_std_methods,
144 	0
145 };
146 OFW_DEF(ofw_std);
147 
148 static int (*openfirmware)(void *);
149 
150 /* Initializer */
151 
152 static int
153 ofw_std_init(ofw_t ofw, void *openfirm)
154 {
155 
156 	openfirmware = (int (*)(void *))openfirm;
157 	return (0);
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 	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, cell_t *returns)
188 {
189 	struct {
190 		cell_t name;
191 		cell_t nargs;
192 		cell_t nreturns;
193 		cell_t slot[16];
194 	} args = {
195 		(cell_t)"interpret",
196 		1,
197 	};
198 	cell_t status;
199 	int i = 0, j = 0;
200 
201 	args.nreturns = ++nreturns;
202 	args.slot[i++] = (cell_t)cmd;
203 	if (openfirmware(&args) == -1)
204 		return (-1);
205 	status = args.slot[i++];
206 	while (i < 1 + nreturns)
207 		returns[j++] = args.slot[i++];
208 	return (status);
209 }
210 
211 /*
212  * Device tree functions
213  */
214 
215 /* Return the next sibling of this node or 0. */
216 static phandle_t
217 ofw_std_peer(ofw_t ofw, phandle_t node)
218 {
219 	struct {
220 		cell_t name;
221 		cell_t nargs;
222 		cell_t nreturns;
223 		cell_t node;
224 		cell_t next;
225 	} args = {
226 		(cell_t)"peer",
227 		1,
228 		1,
229 	};
230 
231 	args.node = node;
232 	if (openfirmware(&args) == -1)
233 		return (-1);
234 	return (args.next);
235 }
236 
237 /* Return the first child of this node or 0. */
238 static phandle_t
239 ofw_std_child(ofw_t ofw, phandle_t node)
240 {
241 	struct {
242 		cell_t name;
243 		cell_t nargs;
244 		cell_t nreturns;
245 		cell_t node;
246 		cell_t child;
247 	} args = {
248 		(cell_t)"child",
249 		1,
250 		1,
251 	};
252 
253 	args.node = node;
254 	if (openfirmware(&args) == -1)
255 		return (-1);
256 	return (args.child);
257 }
258 
259 /* Return the parent of this node or 0. */
260 static phandle_t
261 ofw_std_parent(ofw_t ofw, phandle_t node)
262 {
263 	struct {
264 		cell_t name;
265 		cell_t nargs;
266 		cell_t nreturns;
267 		cell_t node;
268 		cell_t parent;
269 	} args = {
270 		(cell_t)"parent",
271 		1,
272 		1,
273 	};
274 
275 	args.node = node;
276 	if (openfirmware(&args) == -1)
277 		return (-1);
278 	return (args.parent);
279 }
280 
281 /* Return the package handle that corresponds to an instance handle. */
282 static phandle_t
283 ofw_std_instance_to_package(ofw_t ofw, ihandle_t instance)
284 {
285 	struct {
286 		cell_t name;
287 		cell_t nargs;
288 		cell_t nreturns;
289 		cell_t instance;
290 		cell_t package;
291 	} args = {
292 		(cell_t)"instance-to-package",
293 		1,
294 		1,
295 	};
296 
297 	args.instance = instance;
298 	if (openfirmware(&args) == -1)
299 		return (-1);
300 	return (args.package);
301 }
302 
303 /* Get the length of a property of a package. */
304 static ssize_t
305 ofw_std_getproplen(ofw_t ofw, phandle_t package, const char *propname)
306 {
307 	struct {
308 		cell_t name;
309 		cell_t nargs;
310 		cell_t nreturns;
311 		cell_t package;
312 		cell_t propname;
313 		cell_t proplen;
314 	} args = {
315 		(cell_t)"getproplen",
316 		2,
317 		1,
318 	};
319 
320 	args.package = package;
321 	args.propname = (cell_t)propname;
322 	if (openfirmware(&args) == -1)
323 		return (-1);
324 	return (args.proplen);
325 }
326 
327 /* Get the value of a property of a package. */
328 static ssize_t
329 ofw_std_getprop(ofw_t ofw, phandle_t package, const char *propname, void *buf,
330     size_t buflen)
331 {
332 	struct {
333 		cell_t name;
334 		cell_t nargs;
335 		cell_t nreturns;
336 		cell_t package;
337 		cell_t propname;
338 		cell_t buf;
339 		cell_t buflen;
340 		cell_t size;
341 	} args = {
342 		(cell_t)"getprop",
343 		4,
344 		1,
345 	};
346 
347 	args.package = package;
348 	args.propname = (cell_t)propname;
349 	args.buf = (cell_t)buf;
350 	args.buflen = buflen;
351 	if (openfirmware(&args) == -1)
352 		return (-1);
353 	return (args.size);
354 }
355 
356 /* Get the next property of a package. */
357 static int
358 ofw_std_nextprop(ofw_t ofw, phandle_t package, const char *previous, char *buf,
359     size_t size)
360 {
361 	struct {
362 		cell_t name;
363 		cell_t nargs;
364 		cell_t nreturns;
365 		cell_t package;
366 		cell_t previous;
367 		cell_t buf;
368 		cell_t flag;
369 	} args = {
370 		(cell_t)"nextprop",
371 		3,
372 		1,
373 	};
374 
375 	args.package = package;
376 	args.previous = (cell_t)previous;
377 	args.buf = (cell_t)buf;
378 	if (openfirmware(&args) == -1)
379 		return (-1);
380 	return (args.flag);
381 }
382 
383 /* Set the value of a property of a package. */
384 /* XXX Has a bug on FirePower */
385 static int
386 ofw_std_setprop(ofw_t ofw, phandle_t package, const char *propname,
387     const void *buf, size_t len)
388 {
389 	struct {
390 		cell_t name;
391 		cell_t nargs;
392 		cell_t nreturns;
393 		cell_t package;
394 		cell_t propname;
395 		cell_t buf;
396 		cell_t len;
397 		cell_t size;
398 	} args = {
399 		(cell_t)"setprop",
400 		4,
401 		1,
402 	};
403 
404 	args.package = package;
405 	args.propname = (cell_t)propname;
406 	args.buf = (cell_t)buf;
407 	args.len = len;
408 	if (openfirmware(&args) == -1)
409 		return (-1);
410 	return (args.size);
411 }
412 
413 /* Convert a device specifier to a fully qualified pathname. */
414 static ssize_t
415 ofw_std_canon(ofw_t ofw, const char *device, char *buf, size_t len)
416 {
417 	struct {
418 		cell_t name;
419 		cell_t nargs;
420 		cell_t nreturns;
421 		cell_t device;
422 		cell_t buf;
423 		cell_t len;
424 		cell_t size;
425 	} args = {
426 		(cell_t)"canon",
427 		3,
428 		1,
429 	};
430 
431 	args.device = (cell_t)device;
432 	args.buf = (cell_t)buf;
433 	args.len = len;
434 	if (openfirmware(&args) == -1)
435 		return (-1);
436 	return (args.size);
437 }
438 
439 /* Return a package handle for the specified device. */
440 static phandle_t
441 ofw_std_finddevice(ofw_t ofw, const char *device)
442 {
443 	struct {
444 		cell_t name;
445 		cell_t nargs;
446 		cell_t nreturns;
447 		cell_t device;
448 		cell_t package;
449 	} args = {
450 		(cell_t)"finddevice",
451 		1,
452 		1,
453 	};
454 
455 	args.device = (cell_t)device;
456 	if (openfirmware(&args) == -1)
457 		return (-1);
458 	return (args.package);
459 }
460 
461 /* Return the fully qualified pathname corresponding to an instance. */
462 static ssize_t
463 ofw_std_instance_to_path(ofw_t ofw, ihandle_t instance, char *buf, size_t len)
464 {
465 	struct {
466 		cell_t name;
467 		cell_t nargs;
468 		cell_t nreturns;
469 		cell_t instance;
470 		cell_t buf;
471 		cell_t len;
472 		cell_t size;
473 	} args = {
474 		(cell_t)"instance-to-path",
475 		3,
476 		1,
477 	};
478 
479 	args.instance = instance;
480 	args.buf = (cell_t)buf;
481 	args.len = len;
482 	if (openfirmware(&args) == -1)
483 		return (-1);
484 	return (args.size);
485 }
486 
487 /* Return the fully qualified pathname corresponding to a package. */
488 static ssize_t
489 ofw_std_package_to_path(ofw_t ofw, phandle_t package, char *buf, size_t len)
490 {
491 	struct {
492 		cell_t name;
493 		cell_t nargs;
494 		cell_t nreturns;
495 		cell_t package;
496 		cell_t buf;
497 		cell_t len;
498 		cell_t size;
499 	} args = {
500 		(cell_t)"package-to-path",
501 		3,
502 		1,
503 	};
504 
505 	args.package = package;
506 	args.buf = (cell_t)buf;
507 	args.len = len;
508 	if (openfirmware(&args) == -1)
509 		return (-1);
510 	return (args.size);
511 }
512 
513 /*  Call the method in the scope of a given instance. */
514 static int
515 ofw_std_call_method(ofw_t ofw, ihandle_t instance, const char *method,
516     int nargs, int nreturns, cell_t *args_and_returns)
517 {
518 	struct {
519 		cell_t name;
520 		cell_t nargs;
521 		cell_t nreturns;
522 		cell_t method;
523 		cell_t instance;
524 		cell_t args_n_results[12];
525 	} args = {
526 		(cell_t)"call-method",
527 		2,
528 		1,
529 	};
530 	cell_t *ap, *cp;
531 	int n;
532 
533 	if (nargs > 6)
534 		return (-1);
535 	args.nargs = nargs + 2;
536 	args.nreturns = nreturns + 1;
537 	args.method = (cell_t)method;
538 	args.instance = instance;
539 
540 	ap = args_and_returns;
541 	for (cp = args.args_n_results + (n = nargs); --n >= 0;)
542 		*--cp = *(ap++);
543 	if (openfirmware(&args) == -1)
544 		return (-1);
545 	if (args.args_n_results[nargs])
546 		return (args.args_n_results[nargs]);
547 	for (cp = args.args_n_results + nargs + (n = args.nreturns); --n > 0;)
548 		*(ap++) = *--cp;
549 	return (0);
550 }
551 
552 /*
553  * Device I/O functions
554  */
555 
556 /* Open an instance for a device. */
557 static ihandle_t
558 ofw_std_open(ofw_t ofw, const char *device)
559 {
560 	struct {
561 		cell_t name;
562 		cell_t nargs;
563 		cell_t nreturns;
564 		cell_t device;
565 		cell_t instance;
566 	} args = {
567 		(cell_t)"open",
568 		1,
569 		1,
570 	};
571 
572 	args.device = (cell_t)device;
573 	if (openfirmware(&args) == -1 || args.instance == 0)
574 		return (-1);
575 	return (args.instance);
576 }
577 
578 /* Close an instance. */
579 static void
580 ofw_std_close(ofw_t ofw, ihandle_t instance)
581 {
582 	struct {
583 		cell_t name;
584 		cell_t nargs;
585 		cell_t nreturns;
586 		cell_t instance;
587 	} args = {
588 		(cell_t)"close",
589 		1,
590 		0,
591 	};
592 
593 	args.instance = instance;
594 	openfirmware(&args);
595 }
596 
597 /* Read from an instance. */
598 static ssize_t
599 ofw_std_read(ofw_t ofw, ihandle_t instance, void *addr, size_t len)
600 {
601 	struct {
602 		cell_t name;
603 		cell_t nargs;
604 		cell_t nreturns;
605 		cell_t instance;
606 		cell_t addr;
607 		cell_t len;
608 		cell_t actual;
609 	} args = {
610 		(cell_t)"read",
611 		3,
612 		1,
613 	};
614 
615 	args.instance = instance;
616 	args.addr = (cell_t)addr;
617 	args.len = len;
618 	if (openfirmware(&args) == -1)
619 		return (-1);
620 
621 	return (args.actual);
622 }
623 
624 /* Write to an instance. */
625 static ssize_t
626 ofw_std_write(ofw_t ofw, ihandle_t instance, const void *addr, size_t len)
627 {
628 	struct {
629 		cell_t name;
630 		cell_t nargs;
631 		cell_t nreturns;
632 		cell_t instance;
633 		cell_t addr;
634 		cell_t len;
635 		cell_t actual;
636 	} args = {
637 		(cell_t)"write",
638 		3,
639 		1,
640 	};
641 
642 	args.instance = instance;
643 	args.addr = (cell_t)addr;
644 	args.len = len;
645 	if (openfirmware(&args) == -1)
646 		return (-1);
647 	return (args.actual);
648 }
649 
650 /* Seek to a position. */
651 static int
652 ofw_std_seek(ofw_t ofw, ihandle_t instance, uint64_t pos)
653 {
654 	struct {
655 		cell_t name;
656 		cell_t nargs;
657 		cell_t nreturns;
658 		cell_t instance;
659 		cell_t poshi;
660 		cell_t poslo;
661 		cell_t status;
662 	} args = {
663 		(cell_t)"seek",
664 		3,
665 		1,
666 	};
667 
668 	args.instance = instance;
669 	args.poshi = pos >> 32;
670 	args.poslo = pos;
671 	if (openfirmware(&args) == -1)
672 		return (-1);
673 	return (args.status);
674 }
675 
676 /*
677  * Memory functions
678  */
679 
680 /* Claim an area of memory. */
681 static caddr_t
682 ofw_std_claim(ofw_t ofw, void *virt, size_t size, u_int align)
683 {
684 	struct {
685 		cell_t name;
686 		cell_t nargs;
687 		cell_t nreturns;
688 		cell_t virt;
689 		cell_t size;
690 		cell_t align;
691 		cell_t baseaddr;
692 	} args = {
693 		(cell_t)"claim",
694 		3,
695 		1,
696 	};
697 
698 	args.virt = (cell_t)virt;
699 	args.size = size;
700 	args.align = align;
701 	if (openfirmware(&args) == -1)
702 		return ((void *)-1);
703 	return ((void *)args.baseaddr);
704 }
705 
706 /* Release an area of memory. */
707 static void
708 ofw_std_release(ofw_t ofw, void *virt, size_t size)
709 {
710 	struct {
711 		cell_t name;
712 		cell_t nargs;
713 		cell_t nreturns;
714 		cell_t virt;
715 		cell_t size;
716 	} args = {
717 		(cell_t)"release",
718 		2,
719 		0,
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 	struct {
736 		cell_t name;
737 		cell_t nargs;
738 		cell_t nreturns;
739 	} args = {
740 		(cell_t)"enter",
741 		0,
742 		0,
743 	};
744 
745 	openfirmware(&args);
746 	/* We may come back. */
747 }
748 
749 /* Shut down and drop back to the Open Firmware interface. */
750 static void
751 ofw_std_exit(ofw_t ofw)
752 {
753 	struct {
754 		cell_t name;
755 		cell_t nargs;
756 		cell_t nreturns;
757 	} args = {
758 		(cell_t)"exit",
759 		0,
760 		0,
761 	};
762 
763 	openfirmware(&args);
764 	for (;;)			/* just in case */
765 		;
766 }
767