xref: /freebsd/sys/dev/ofw/ofw_standard.c (revision f5463265955b829775bbb32e1fd0bc11dafc36ce)
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/param.h>
61 #include <sys/kernel.h>
62 #include <sys/malloc.h>
63 #include <sys/systm.h>
64 
65 #include <machine/stdarg.h>
66 
67 #include <dev/ofw/ofwvar.h>
68 #include <dev/ofw/openfirm.h>
69 
70 #include "ofw_if.h"
71 
72 static int ofw_std_init(ofw_t ofw, void *openfirm);
73 static int ofw_std_test(ofw_t ofw, const char *name);
74 static int ofw_std_interpret(ofw_t ofw, const char *cmd, int nreturns,
75     cell_t *returns);
76 static phandle_t ofw_std_peer(ofw_t ofw, phandle_t node);
77 static phandle_t ofw_std_child(ofw_t ofw, phandle_t node);
78 static phandle_t ofw_std_parent(ofw_t ofw, phandle_t node);
79 static phandle_t ofw_std_instance_to_package(ofw_t ofw, ihandle_t instance);
80 static ssize_t ofw_std_getproplen(ofw_t ofw, phandle_t package,
81     const char *propname);
82 static ssize_t ofw_std_getprop(ofw_t ofw, phandle_t package,
83     const char *propname, void *buf, size_t buflen);
84 static int ofw_std_nextprop(ofw_t ofw, phandle_t package, const char *previous,
85     char *buf, size_t);
86 static int ofw_std_setprop(ofw_t ofw, phandle_t package, const char *propname,
87     const void *buf, size_t len);
88 static ssize_t ofw_std_canon(ofw_t ofw, const char *device, char *buf,
89     size_t len);
90 static phandle_t ofw_std_finddevice(ofw_t ofw, const char *device);
91 static ssize_t ofw_std_instance_to_path(ofw_t ofw, ihandle_t instance,
92     char *buf, size_t len);
93 static ssize_t ofw_std_package_to_path(ofw_t ofw, phandle_t package, char *buf,
94     size_t len);
95 static int ofw_std_call_method(ofw_t ofw, ihandle_t instance,
96     const char *method, int nargs, int nreturns, cell_t *args_and_returns);
97 static ihandle_t ofw_std_open(ofw_t ofw, const char *device);
98 static void ofw_std_close(ofw_t ofw, ihandle_t instance);
99 static ssize_t ofw_std_read(ofw_t ofw, ihandle_t instance, void *addr,
100     size_t len);
101 static ssize_t ofw_std_write(ofw_t ofw, ihandle_t instance, const void *addr,
102     size_t len);
103 static int ofw_std_seek(ofw_t ofw, ihandle_t instance, uint64_t pos);
104 static caddr_t ofw_std_claim(ofw_t ofw, void *virt, size_t size, u_int align);
105 static void ofw_std_release(ofw_t ofw, void *virt, size_t size);
106 static void ofw_std_enter(ofw_t ofw);
107 static void ofw_std_exit(ofw_t ofw);
108 
109 static ofw_method_t ofw_std_methods[] = {
110 	OFWMETHOD(ofw_init,			ofw_std_init),
111 	OFWMETHOD(ofw_peer,			ofw_std_peer),
112 	OFWMETHOD(ofw_child,			ofw_std_child),
113 	OFWMETHOD(ofw_parent,			ofw_std_parent),
114 	OFWMETHOD(ofw_instance_to_package,	ofw_std_instance_to_package),
115 	OFWMETHOD(ofw_getproplen,		ofw_std_getproplen),
116 	OFWMETHOD(ofw_getprop,			ofw_std_getprop),
117 	OFWMETHOD(ofw_nextprop,			ofw_std_nextprop),
118 	OFWMETHOD(ofw_setprop,			ofw_std_setprop),
119 	OFWMETHOD(ofw_canon,			ofw_std_canon),
120 	OFWMETHOD(ofw_finddevice,		ofw_std_finddevice),
121 	OFWMETHOD(ofw_instance_to_path,		ofw_std_instance_to_path),
122 	OFWMETHOD(ofw_package_to_path,		ofw_std_package_to_path),
123 
124 	OFWMETHOD(ofw_test,			ofw_std_test),
125 	OFWMETHOD(ofw_call_method,		ofw_std_call_method),
126 	OFWMETHOD(ofw_interpret,		ofw_std_interpret),
127 	OFWMETHOD(ofw_open,			ofw_std_open),
128 	OFWMETHOD(ofw_close,			ofw_std_close),
129 	OFWMETHOD(ofw_read,			ofw_std_read),
130 	OFWMETHOD(ofw_write,			ofw_std_write),
131 	OFWMETHOD(ofw_seek,			ofw_std_seek),
132 	OFWMETHOD(ofw_claim,			ofw_std_claim),
133 	OFWMETHOD(ofw_release,			ofw_std_release),
134 	OFWMETHOD(ofw_enter,			ofw_std_enter),
135 	OFWMETHOD(ofw_exit,			ofw_std_exit),
136 	{ 0, 0 }
137 };
138 
139 static ofw_def_t ofw_std = {
140 	OFW_STD_DIRECT,
141 	ofw_std_methods,
142 	0
143 };
144 OFW_DEF(ofw_std);
145 
146 static int (*openfirmware)(void *);
147 
148 /* Initializer */
149 
150 static int
151 ofw_std_init(ofw_t ofw, void *openfirm)
152 {
153 
154 	openfirmware = (int (*)(void *))openfirm;
155 	return (0);
156 }
157 
158 /*
159  * Generic functions
160  */
161 
162 /* Test to see if a service exists. */
163 static int
164 ofw_std_test(ofw_t ofw, const char *name)
165 {
166 	struct {
167 		cell_t name;
168 		cell_t nargs;
169 		cell_t nreturns;
170 		cell_t service;
171 		cell_t missing;
172 	} args = {
173 		(cell_t)"test",
174 		1,
175 		1,
176 	};
177 
178 	args.service = (cell_t)name;
179 	if (openfirmware(&args) == -1)
180 		return (-1);
181 	return (args.missing);
182 }
183 
184 static int
185 ofw_std_interpret(ofw_t ofw, const char *cmd, int nreturns, cell_t *returns)
186 {
187 	struct {
188 		cell_t name;
189 		cell_t nargs;
190 		cell_t nreturns;
191 		cell_t slot[16];
192 	} args = {
193 		(cell_t)"interpret",
194 		1,
195 	};
196 	cell_t status;
197 	int i = 0, j = 0;
198 
199 	args.nreturns = ++nreturns;
200 	args.slot[i++] = (cell_t)cmd;
201 	if (openfirmware(&args) == -1)
202 		return (-1);
203 	status = args.slot[i++];
204 	while (i < 1 + nreturns)
205 		returns[j++] = args.slot[i++];
206 	return (status);
207 }
208 
209 /*
210  * Device tree functions
211  */
212 
213 /* Return the next sibling of this node or 0. */
214 static phandle_t
215 ofw_std_peer(ofw_t ofw, phandle_t node)
216 {
217 	struct {
218 		cell_t name;
219 		cell_t nargs;
220 		cell_t nreturns;
221 		cell_t node;
222 		cell_t next;
223 	} args = {
224 		(cell_t)"peer",
225 		1,
226 		1,
227 	};
228 
229 	args.node = node;
230 	if (openfirmware(&args) == -1)
231 		return (0);
232 	return (args.next);
233 }
234 
235 /* Return the first child of this node or 0. */
236 static phandle_t
237 ofw_std_child(ofw_t ofw, phandle_t node)
238 {
239 	struct {
240 		cell_t name;
241 		cell_t nargs;
242 		cell_t nreturns;
243 		cell_t node;
244 		cell_t child;
245 	} args = {
246 		(cell_t)"child",
247 		1,
248 		1,
249 	};
250 
251 	args.node = node;
252 	if (openfirmware(&args) == -1)
253 		return (0);
254 	return (args.child);
255 }
256 
257 /* Return the parent of this node or 0. */
258 static phandle_t
259 ofw_std_parent(ofw_t ofw, phandle_t node)
260 {
261 	struct {
262 		cell_t name;
263 		cell_t nargs;
264 		cell_t nreturns;
265 		cell_t node;
266 		cell_t parent;
267 	} args = {
268 		(cell_t)"parent",
269 		1,
270 		1,
271 	};
272 
273 	args.node = node;
274 	if (openfirmware(&args) == -1)
275 		return (0);
276 	return (args.parent);
277 }
278 
279 /* Return the package handle that corresponds to an instance handle. */
280 static phandle_t
281 ofw_std_instance_to_package(ofw_t ofw, ihandle_t instance)
282 {
283 	struct {
284 		cell_t name;
285 		cell_t nargs;
286 		cell_t nreturns;
287 		cell_t instance;
288 		cell_t package;
289 	} args = {
290 		(cell_t)"instance-to-package",
291 		1,
292 		1,
293 	};
294 
295 	args.instance = instance;
296 	if (openfirmware(&args) == -1)
297 		return (-1);
298 	return (args.package);
299 }
300 
301 /* Get the length of a property of a package. */
302 static ssize_t
303 ofw_std_getproplen(ofw_t ofw, phandle_t package, const char *propname)
304 {
305 	struct {
306 		cell_t name;
307 		cell_t nargs;
308 		cell_t nreturns;
309 		cell_t package;
310 		cell_t propname;
311 		cell_t proplen;
312 	} args = {
313 		(cell_t)"getproplen",
314 		2,
315 		1,
316 	};
317 
318 	args.package = package;
319 	args.propname = (cell_t)propname;
320 	if (openfirmware(&args) == -1)
321 		return (-1);
322 	return (args.proplen);
323 }
324 
325 /* Get the value of a property of a package. */
326 static ssize_t
327 ofw_std_getprop(ofw_t ofw, phandle_t package, const char *propname, void *buf,
328     size_t buflen)
329 {
330 	struct {
331 		cell_t name;
332 		cell_t nargs;
333 		cell_t nreturns;
334 		cell_t package;
335 		cell_t propname;
336 		cell_t buf;
337 		cell_t buflen;
338 		cell_t size;
339 	} args = {
340 		(cell_t)"getprop",
341 		4,
342 		1,
343 	};
344 
345 	args.package = package;
346 	args.propname = (cell_t)propname;
347 	args.buf = (cell_t)buf;
348 	args.buflen = buflen;
349 	if (openfirmware(&args) == -1)
350 		return (-1);
351 	return (args.size);
352 }
353 
354 /* Get the next property of a package. */
355 static int
356 ofw_std_nextprop(ofw_t ofw, phandle_t package, const char *previous, char *buf,
357     size_t size)
358 {
359 	struct {
360 		cell_t name;
361 		cell_t nargs;
362 		cell_t nreturns;
363 		cell_t package;
364 		cell_t previous;
365 		cell_t buf;
366 		cell_t flag;
367 	} args = {
368 		(cell_t)"nextprop",
369 		3,
370 		1,
371 	};
372 
373 	args.package = package;
374 	args.previous = (cell_t)previous;
375 	args.buf = (cell_t)buf;
376 	if (openfirmware(&args) == -1)
377 		return (-1);
378 	return (args.flag);
379 }
380 
381 /* Set the value of a property of a package. */
382 /* XXX Has a bug on FirePower */
383 static int
384 ofw_std_setprop(ofw_t ofw, phandle_t package, const char *propname,
385     const void *buf, size_t len)
386 {
387 	struct {
388 		cell_t name;
389 		cell_t nargs;
390 		cell_t nreturns;
391 		cell_t package;
392 		cell_t propname;
393 		cell_t buf;
394 		cell_t len;
395 		cell_t size;
396 	} args = {
397 		(cell_t)"setprop",
398 		4,
399 		1,
400 	};
401 
402 	args.package = package;
403 	args.propname = (cell_t)propname;
404 	args.buf = (cell_t)buf;
405 	args.len = len;
406 	if (openfirmware(&args) == -1)
407 		return (-1);
408 	return (args.size);
409 }
410 
411 /* Convert a device specifier to a fully qualified pathname. */
412 static ssize_t
413 ofw_std_canon(ofw_t ofw, const char *device, char *buf, size_t len)
414 {
415 	struct {
416 		cell_t name;
417 		cell_t nargs;
418 		cell_t nreturns;
419 		cell_t device;
420 		cell_t buf;
421 		cell_t len;
422 		cell_t size;
423 	} args = {
424 		(cell_t)"canon",
425 		3,
426 		1,
427 	};
428 
429 	args.device = (cell_t)device;
430 	args.buf = (cell_t)buf;
431 	args.len = len;
432 	if (openfirmware(&args) == -1)
433 		return (-1);
434 	return (args.size);
435 }
436 
437 /* Return a package handle for the specified device. */
438 static phandle_t
439 ofw_std_finddevice(ofw_t ofw, const char *device)
440 {
441 	struct {
442 		cell_t name;
443 		cell_t nargs;
444 		cell_t nreturns;
445 		cell_t device;
446 		cell_t package;
447 	} args = {
448 		(cell_t)"finddevice",
449 		1,
450 		1,
451 	};
452 
453 	args.device = (cell_t)device;
454 	if (openfirmware(&args) == -1)
455 		return (-1);
456 	return (args.package);
457 }
458 
459 /* Return the fully qualified pathname corresponding to an instance. */
460 static ssize_t
461 ofw_std_instance_to_path(ofw_t ofw, ihandle_t instance, char *buf, size_t len)
462 {
463 	struct {
464 		cell_t name;
465 		cell_t nargs;
466 		cell_t nreturns;
467 		cell_t instance;
468 		cell_t buf;
469 		cell_t len;
470 		cell_t size;
471 	} args = {
472 		(cell_t)"instance-to-path",
473 		3,
474 		1,
475 	};
476 
477 	args.instance = instance;
478 	args.buf = (cell_t)buf;
479 	args.len = len;
480 	if (openfirmware(&args) == -1)
481 		return (-1);
482 	return (args.size);
483 }
484 
485 /* Return the fully qualified pathname corresponding to a package. */
486 static ssize_t
487 ofw_std_package_to_path(ofw_t ofw, phandle_t package, char *buf, size_t len)
488 {
489 	struct {
490 		cell_t name;
491 		cell_t nargs;
492 		cell_t nreturns;
493 		cell_t package;
494 		cell_t buf;
495 		cell_t len;
496 		cell_t size;
497 	} args = {
498 		(cell_t)"package-to-path",
499 		3,
500 		1,
501 	};
502 
503 	args.package = package;
504 	args.buf = (cell_t)buf;
505 	args.len = len;
506 	if (openfirmware(&args) == -1)
507 		return (-1);
508 	return (args.size);
509 }
510 
511 /*  Call the method in the scope of a given instance. */
512 static int
513 ofw_std_call_method(ofw_t ofw, ihandle_t instance, const char *method,
514     int nargs, int nreturns, cell_t *args_and_returns)
515 {
516 	struct {
517 		cell_t name;
518 		cell_t nargs;
519 		cell_t nreturns;
520 		cell_t method;
521 		cell_t instance;
522 		cell_t args_n_results[12];
523 	} args = {
524 		(cell_t)"call-method",
525 		2,
526 		1,
527 	};
528 	cell_t *ap, *cp;
529 	int n;
530 
531 	if (nargs > 6)
532 		return (-1);
533 	args.nargs = nargs + 2;
534 	args.nreturns = nreturns + 1;
535 	args.method = (cell_t)method;
536 	args.instance = instance;
537 
538 	ap = args_and_returns;
539 	for (cp = args.args_n_results + (n = nargs); --n >= 0;)
540 		*--cp = *(ap++);
541 	if (openfirmware(&args) == -1)
542 		return (-1);
543 	if (args.args_n_results[nargs])
544 		return (args.args_n_results[nargs]);
545 	for (cp = args.args_n_results + nargs + (n = args.nreturns); --n > 0;)
546 		*(ap++) = *--cp;
547 	return (0);
548 }
549 
550 /*
551  * Device I/O functions
552  */
553 
554 /* Open an instance for a device. */
555 static ihandle_t
556 ofw_std_open(ofw_t ofw, const char *device)
557 {
558 	struct {
559 		cell_t name;
560 		cell_t nargs;
561 		cell_t nreturns;
562 		cell_t device;
563 		cell_t instance;
564 	} args = {
565 		(cell_t)"open",
566 		1,
567 		1,
568 	};
569 
570 	args.device = (cell_t)device;
571 	if (openfirmware(&args) == -1 || args.instance == 0)
572 		return (-1);
573 	return (args.instance);
574 }
575 
576 /* Close an instance. */
577 static void
578 ofw_std_close(ofw_t ofw, ihandle_t instance)
579 {
580 	struct {
581 		cell_t name;
582 		cell_t nargs;
583 		cell_t nreturns;
584 		cell_t instance;
585 	} args = {
586 		(cell_t)"close",
587 		1,
588 		0,
589 	};
590 
591 	args.instance = instance;
592 	openfirmware(&args);
593 }
594 
595 /* Read from an instance. */
596 static ssize_t
597 ofw_std_read(ofw_t ofw, ihandle_t instance, void *addr, size_t len)
598 {
599 	struct {
600 		cell_t name;
601 		cell_t nargs;
602 		cell_t nreturns;
603 		cell_t instance;
604 		cell_t addr;
605 		cell_t len;
606 		cell_t actual;
607 	} args = {
608 		(cell_t)"read",
609 		3,
610 		1,
611 	};
612 
613 	args.instance = instance;
614 	args.addr = (cell_t)addr;
615 	args.len = len;
616 	if (openfirmware(&args) == -1)
617 		return (-1);
618 
619 	return (args.actual);
620 }
621 
622 /* Write to an instance. */
623 static ssize_t
624 ofw_std_write(ofw_t ofw, ihandle_t instance, const void *addr, size_t len)
625 {
626 	struct {
627 		cell_t name;
628 		cell_t nargs;
629 		cell_t nreturns;
630 		cell_t instance;
631 		cell_t addr;
632 		cell_t len;
633 		cell_t actual;
634 	} args = {
635 		(cell_t)"write",
636 		3,
637 		1,
638 	};
639 
640 	args.instance = instance;
641 	args.addr = (cell_t)addr;
642 	args.len = len;
643 	if (openfirmware(&args) == -1)
644 		return (-1);
645 	return (args.actual);
646 }
647 
648 /* Seek to a position. */
649 static int
650 ofw_std_seek(ofw_t ofw, ihandle_t instance, uint64_t pos)
651 {
652 	struct {
653 		cell_t name;
654 		cell_t nargs;
655 		cell_t nreturns;
656 		cell_t instance;
657 		cell_t poshi;
658 		cell_t poslo;
659 		cell_t status;
660 	} args = {
661 		(cell_t)"seek",
662 		3,
663 		1,
664 	};
665 
666 	args.instance = instance;
667 	args.poshi = pos >> 32;
668 	args.poslo = pos;
669 	if (openfirmware(&args) == -1)
670 		return (-1);
671 	return (args.status);
672 }
673 
674 /*
675  * Memory functions
676  */
677 
678 /* Claim an area of memory. */
679 static caddr_t
680 ofw_std_claim(ofw_t ofw, void *virt, size_t size, u_int align)
681 {
682 	struct {
683 		cell_t name;
684 		cell_t nargs;
685 		cell_t nreturns;
686 		cell_t virt;
687 		cell_t size;
688 		cell_t align;
689 		cell_t baseaddr;
690 	} args = {
691 		(cell_t)"claim",
692 		3,
693 		1,
694 	};
695 
696 	args.virt = (cell_t)virt;
697 	args.size = size;
698 	args.align = align;
699 	if (openfirmware(&args) == -1)
700 		return ((void *)-1);
701 	return ((void *)args.baseaddr);
702 }
703 
704 /* Release an area of memory. */
705 static void
706 ofw_std_release(ofw_t ofw, void *virt, size_t size)
707 {
708 	struct {
709 		cell_t name;
710 		cell_t nargs;
711 		cell_t nreturns;
712 		cell_t virt;
713 		cell_t size;
714 	} args = {
715 		(cell_t)"release",
716 		2,
717 		0,
718 	};
719 
720 	args.virt = (cell_t)virt;
721 	args.size = size;
722 	openfirmware(&args);
723 }
724 
725 /*
726  * Control transfer functions
727  */
728 
729 /* Suspend and drop back to the Open Firmware interface. */
730 static void
731 ofw_std_enter(ofw_t ofw)
732 {
733 	struct {
734 		cell_t name;
735 		cell_t nargs;
736 		cell_t nreturns;
737 	} args = {
738 		(cell_t)"enter",
739 		0,
740 		0,
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 	struct {
752 		cell_t name;
753 		cell_t nargs;
754 		cell_t nreturns;
755 	} args = {
756 		(cell_t)"exit",
757 		0,
758 		0,
759 	};
760 
761 	openfirmware(&args);
762 	for (;;)			/* just in case */
763 		;
764 }
765