cpu.c revision 1.55
1/*	$NetBSD: cpu.c,v 1.55 2004/02/13 11:36:10 wiz Exp $	*/
2
3/*
4 * Copyright (c) 1995 Mark Brinicombe.
5 * Copyright (c) 1995 Brini.
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 Brini.
19 * 4. The name of the company nor the name of the author may be used to
20 *    endorse or promote products derived from this software without specific
21 *    prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED
24 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
27 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
28 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
29 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * RiscBSD kernel project
36 *
37 * cpu.c
38 *
39 * Probing and configuration for the master CPU
40 *
41 * Created      : 10/10/95
42 */
43
44#include "opt_armfpe.h"
45#include "opt_multiprocessor.h"
46
47#include <sys/param.h>
48
49__KERNEL_RCSID(0, "$NetBSD: cpu.c,v 1.55 2004/02/13 11:36:10 wiz Exp $");
50
51#include <sys/systm.h>
52#include <sys/malloc.h>
53#include <sys/device.h>
54#include <sys/proc.h>
55#include <sys/conf.h>
56#include <uvm/uvm_extern.h>
57#include <machine/cpu.h>
58
59#include <arm/cpuconf.h>
60#include <arm/undefined.h>
61
62#ifdef ARMFPE
63#include <machine/bootconfig.h> /* For boot args */
64#include <arm/fpe-arm/armfpe.h>
65#endif
66
67char cpu_model[256];
68
69/* Prototypes */
70void identify_arm_cpu(struct device *dv, struct cpu_info *);
71
72/*
73 * Identify the master (boot) CPU
74 */
75
76void
77cpu_attach(struct device *dv)
78{
79	int usearmfpe;
80
81	usearmfpe = 1;	/* when compiled in, its enabled by default */
82
83	curcpu()->ci_dev = dv;
84
85	evcnt_attach_dynamic(&curcpu()->ci_arm700bugcount, EVCNT_TYPE_MISC,
86	    NULL, dv->dv_xname, "arm700swibug");
87
88	/* Get the CPU ID from coprocessor 15 */
89
90	curcpu()->ci_arm_cpuid = cpu_id();
91	curcpu()->ci_arm_cputype = curcpu()->ci_arm_cpuid & CPU_ID_CPU_MASK;
92	curcpu()->ci_arm_cpurev =
93	    curcpu()->ci_arm_cpuid & CPU_ID_REVISION_MASK;
94
95	identify_arm_cpu(dv, curcpu());
96
97	if (curcpu()->ci_arm_cputype == CPU_ID_SA110 &&
98	    curcpu()->ci_arm_cpurev < 3) {
99		aprint_normal("%s: SA-110 with bugged STM^ instruction\n",
100		       dv->dv_xname);
101	}
102
103#ifdef CPU_ARM8
104	if ((curcpu()->ci_arm_cpuid & CPU_ID_CPU_MASK) == CPU_ID_ARM810) {
105		int clock = arm8_clock_config(0, 0);
106		char *fclk;
107		aprint_normal("%s: ARM810 cp15=%02x", dv->dv_xname, clock);
108		aprint_normal(" clock:%s", (clock & 1) ? " dynamic" : "");
109		aprint_normal("%s", (clock & 2) ? " sync" : "");
110		switch ((clock >> 2) & 3) {
111		case 0:
112			fclk = "bus clock";
113			break;
114		case 1:
115			fclk = "ref clock";
116			break;
117		case 3:
118			fclk = "pll";
119			break;
120		default:
121			fclk = "illegal";
122			break;
123		}
124		aprint_normal(" fclk source=%s\n", fclk);
125 	}
126#endif
127
128#ifdef ARMFPE
129	/*
130	 * Ok now we test for an FPA
131	 * At this point no floating point emulator has been installed.
132	 * This means any FP instruction will cause undefined exception.
133	 * We install a temporay coproc 1 handler which will modify
134	 * undefined_test if it is called.
135	 * We then try to read the FP status register. If undefined_test
136	 * has been decremented then the instruction was not handled by
137	 * an FPA so we know the FPA is missing. If undefined_test is
138	 * still 1 then we know the instruction was handled by an FPA.
139	 * We then remove our test handler and look at the
140	 * FP status register for identification.
141	 */
142
143	/*
144	 * Ok if ARMFPE is defined and the boot options request the
145	 * ARM FPE then it will be installed as the FPE.
146	 * This is just while I work on integrating the new FPE.
147	 * It means the new FPE gets installed if compiled int (ARMFPE
148	 * defined) and also gives me a on/off option when I boot in
149	 * case the new FPE is causing panics.
150	 */
151
152
153	if (boot_args)
154		get_bootconf_option(boot_args, "armfpe",
155		    BOOTOPT_TYPE_BOOLEAN, &usearmfpe);
156	if (usearmfpe)
157		initialise_arm_fpe();
158#endif
159}
160
161enum cpu_class {
162	CPU_CLASS_NONE,
163	CPU_CLASS_ARM2,
164	CPU_CLASS_ARM2AS,
165	CPU_CLASS_ARM3,
166	CPU_CLASS_ARM6,
167	CPU_CLASS_ARM7,
168	CPU_CLASS_ARM7TDMI,
169	CPU_CLASS_ARM8,
170	CPU_CLASS_ARM9TDMI,
171	CPU_CLASS_ARM9ES,
172	CPU_CLASS_ARM10E,
173	CPU_CLASS_SA1,
174	CPU_CLASS_XSCALE
175};
176
177static const char * const generic_steppings[16] = {
178	"rev 0",	"rev 1",	"rev 2",	"rev 3",
179	"rev 4",	"rev 5",	"rev 6",	"rev 7",
180	"rev 8",	"rev 9",	"rev 10",	"rev 11",
181	"rev 12",	"rev 13",	"rev 14",	"rev 15",
182};
183
184static const char * const sa110_steppings[16] = {
185	"rev 0",	"step J",	"step K",	"step S",
186	"step T",	"rev 5",	"rev 6",	"rev 7",
187	"rev 8",	"rev 9",	"rev 10",	"rev 11",
188	"rev 12",	"rev 13",	"rev 14",	"rev 15",
189};
190
191static const char * const sa1100_steppings[16] = {
192	"rev 0",	"step B",	"step C",	"rev 3",
193	"rev 4",	"rev 5",	"rev 6",	"rev 7",
194	"step D",	"step E",	"rev 10"	"step G",
195	"rev 12",	"rev 13",	"rev 14",	"rev 15",
196};
197
198static const char * const sa1110_steppings[16] = {
199	"step A-0",	"rev 1",	"rev 2",	"rev 3",
200	"step B-0",	"step B-1",	"step B-2",	"step B-3",
201	"step B-4",	"step B-5",	"rev 10",	"rev 11",
202	"rev 12",	"rev 13",	"rev 14",	"rev 15",
203};
204
205static const char * const ixp12x0_steppings[16] = {
206	"(IXP1200 step A)",		"(IXP1200 step B)",
207	"rev 2",			"(IXP1200 step C)",
208	"(IXP1200 step D)",		"(IXP1240/1250 step A)",
209	"(IXP1240 step B)",		"(IXP1250 step B)",
210	"rev 8",	"rev 9",	"rev 10",	"rev 11",
211	"rev 12",	"rev 13",	"rev 14",	"rev 15",
212};
213
214static const char * const xscale_steppings[16] = {
215	"step A-0",	"step A-1",	"step B-0",	"step C-0",
216	"step D-0",	"rev 5",	"rev 6",	"rev 7",
217	"rev 8",	"rev 9",	"rev 10",	"rev 11",
218	"rev 12",	"rev 13",	"rev 14",	"rev 15",
219};
220
221static const char * const i80321_steppings[16] = {
222	"step A-0",	"step B-0",	"rev 2",	"rev 3",
223	"rev 4",	"rev 5",	"rev 6",	"rev 7",
224	"rev 8",	"rev 9",	"rev 10",	"rev 11",
225	"rev 12",	"rev 13",	"rev 14",	"rev 15",
226};
227
228static const char * const pxa2x0_steppings[16] = {
229	"step A-0",	"step A-1",	"step B-0",	"step B-1",
230	"step B-2",	"step C-0",	"rev 6",	"rev 7",
231	"rev 8",	"rev 9",	"rev 10",	"rev 11",
232	"rev 12",	"rev 13",	"rev 14",	"rev 15",
233};
234
235static const char * const ixp425_steppings[16] = {
236	"step 0",	"rev 1",	"rev 2",	"rev 3",
237	"rev 4",	"rev 5",	"rev 6",	"rev 7",
238	"rev 8",	"rev 9",	"rev 10",	"rev 11",
239	"rev 12",	"rev 13",	"rev 14",	"rev 15",
240};
241
242struct cpuidtab {
243	u_int32_t	cpuid;
244	enum		cpu_class cpu_class;
245	const char	*cpu_name;
246	const char * const *cpu_steppings;
247};
248
249const struct cpuidtab cpuids[] = {
250	{ CPU_ID_ARM2,		CPU_CLASS_ARM2,		"ARM2",
251	  generic_steppings },
252	{ CPU_ID_ARM250,	CPU_CLASS_ARM2AS,	"ARM250",
253	  generic_steppings },
254
255	{ CPU_ID_ARM3,		CPU_CLASS_ARM3,		"ARM3",
256	  generic_steppings },
257
258	{ CPU_ID_ARM600,	CPU_CLASS_ARM6,		"ARM600",
259	  generic_steppings },
260	{ CPU_ID_ARM610,	CPU_CLASS_ARM6,		"ARM610",
261	  generic_steppings },
262	{ CPU_ID_ARM620,	CPU_CLASS_ARM6,		"ARM620",
263	  generic_steppings },
264
265	{ CPU_ID_ARM700,	CPU_CLASS_ARM7,		"ARM700",
266	  generic_steppings },
267	{ CPU_ID_ARM710,	CPU_CLASS_ARM7,		"ARM710",
268	  generic_steppings },
269	{ CPU_ID_ARM7500,	CPU_CLASS_ARM7,		"ARM7500",
270	  generic_steppings },
271	{ CPU_ID_ARM710A,	CPU_CLASS_ARM7,		"ARM710a",
272	  generic_steppings },
273	{ CPU_ID_ARM7500FE,	CPU_CLASS_ARM7,		"ARM7500FE",
274	  generic_steppings },
275	{ CPU_ID_ARM710T,	CPU_CLASS_ARM7TDMI,	"ARM710T",
276	  generic_steppings },
277	{ CPU_ID_ARM720T,	CPU_CLASS_ARM7TDMI,	"ARM720T",
278	  generic_steppings },
279	{ CPU_ID_ARM740T8K,	CPU_CLASS_ARM7TDMI, "ARM740T (8 KB cache)",
280	  generic_steppings },
281	{ CPU_ID_ARM740T4K,	CPU_CLASS_ARM7TDMI, "ARM740T (4 KB cache)",
282	  generic_steppings },
283
284	{ CPU_ID_ARM810,	CPU_CLASS_ARM8,		"ARM810",
285	  generic_steppings },
286
287	{ CPU_ID_ARM920T,	CPU_CLASS_ARM9TDMI,	"ARM920T",
288	  generic_steppings },
289	{ CPU_ID_ARM922T,	CPU_CLASS_ARM9TDMI,	"ARM922T",
290	  generic_steppings },
291	{ CPU_ID_ARM940T,	CPU_CLASS_ARM9TDMI,	"ARM940T",
292	  generic_steppings },
293	{ CPU_ID_ARM946ES,	CPU_CLASS_ARM9ES,	"ARM946E-S",
294	  generic_steppings },
295	{ CPU_ID_ARM966ES,	CPU_CLASS_ARM9ES,	"ARM966E-S",
296	  generic_steppings },
297	{ CPU_ID_ARM966ESR1,	CPU_CLASS_ARM9ES,	"ARM966E-S",
298	  generic_steppings },
299	{ CPU_ID_TI925T,	CPU_CLASS_ARM9TDMI,	"TI ARM925T",
300	  generic_steppings },
301
302	{ CPU_ID_ARM1020E,	CPU_CLASS_ARM10E,	"ARM1020E",
303	  generic_steppings },
304	{ CPU_ID_ARM1022ES,	CPU_CLASS_ARM10E,	"ARM1022E-S",
305	  generic_steppings },
306
307	{ CPU_ID_SA110,		CPU_CLASS_SA1,		"SA-110",
308	  sa110_steppings },
309	{ CPU_ID_SA1100,	CPU_CLASS_SA1,		"SA-1100",
310	  sa1100_steppings },
311	{ CPU_ID_SA1110,	CPU_CLASS_SA1,		"SA-1110",
312	  sa1110_steppings },
313
314	{ CPU_ID_IXP1200,	CPU_CLASS_SA1,		"IXP1200",
315	  ixp12x0_steppings },
316
317	{ CPU_ID_80200,		CPU_CLASS_XSCALE,	"i80200",
318	  xscale_steppings },
319
320	{ CPU_ID_80321_400,	CPU_CLASS_XSCALE,	"i80321 400MHz",
321	  i80321_steppings },
322	{ CPU_ID_80321_600,	CPU_CLASS_XSCALE,	"i80321 600MHz",
323	  i80321_steppings },
324	{ CPU_ID_80321_400_B0,	CPU_CLASS_XSCALE,	"i80321 400MHz",
325	  i80321_steppings },
326	{ CPU_ID_80321_600_B0,	CPU_CLASS_XSCALE,	"i80321 600MHz",
327	  i80321_steppings },
328
329	{ CPU_ID_PXA250A,	CPU_CLASS_XSCALE,	"PXA250",
330	  pxa2x0_steppings },
331	{ CPU_ID_PXA210A,	CPU_CLASS_XSCALE,	"PXA210",
332	  pxa2x0_steppings },
333	{ CPU_ID_PXA250B,	CPU_CLASS_XSCALE,	"PXA250",
334	  pxa2x0_steppings },
335	{ CPU_ID_PXA210B,	CPU_CLASS_XSCALE,	"PXA210",
336	  pxa2x0_steppings },
337	{ CPU_ID_PXA250C, 	CPU_CLASS_XSCALE,	"PXA250",
338	  pxa2x0_steppings },
339	{ CPU_ID_PXA210C, 	CPU_CLASS_XSCALE,	"PXA210",
340	  pxa2x0_steppings },
341
342	{ CPU_ID_IXP425_533,	CPU_CLASS_XSCALE,	"IXP425 533MHz",
343	  ixp425_steppings },
344	{ CPU_ID_IXP425_400,	CPU_CLASS_XSCALE,	"IXP425 400MHz",
345	  ixp425_steppings },
346	{ CPU_ID_IXP425_266,	CPU_CLASS_XSCALE,	"IXP425 266MHz",
347	  ixp425_steppings },
348
349	{ 0, CPU_CLASS_NONE, NULL, NULL }
350};
351
352struct cpu_classtab {
353	const char	*class_name;
354	const char	*class_option;
355};
356
357const struct cpu_classtab cpu_classes[] = {
358	{ "unknown",	NULL },			/* CPU_CLASS_NONE */
359	{ "ARM2",	"CPU_ARM2" },		/* CPU_CLASS_ARM2 */
360	{ "ARM2as",	"CPU_ARM250" },		/* CPU_CLASS_ARM2AS */
361	{ "ARM3",	"CPU_ARM3" },		/* CPU_CLASS_ARM3 */
362	{ "ARM6",	"CPU_ARM6" },		/* CPU_CLASS_ARM6 */
363	{ "ARM7",	"CPU_ARM7" },		/* CPU_CLASS_ARM7 */
364	{ "ARM7TDMI",	"CPU_ARM7TDMI" },	/* CPU_CLASS_ARM7TDMI */
365	{ "ARM8",	"CPU_ARM8" },		/* CPU_CLASS_ARM8 */
366	{ "ARM9TDMI",	NULL },			/* CPU_CLASS_ARM9TDMI */
367	{ "ARM9E-S",	NULL },			/* CPU_CLASS_ARM9ES */
368	{ "ARM10E",	"CPU_ARM10" },		/* CPU_CLASS_ARM10E */
369	{ "SA-1",	"CPU_SA110" },		/* CPU_CLASS_SA1 */
370	{ "XScale",	"CPU_XSCALE_..." },	/* CPU_CLASS_XSCALE */
371};
372
373/*
374 * Report the type of the specified arm processor. This uses the generic and
375 * arm specific information in the CPU structure to identify the processor.
376 * The remaining fields in the CPU structure are filled in appropriately.
377 */
378
379static const char * const wtnames[] = {
380	"write-through",
381	"write-back",
382	"write-back",
383	"**unknown 3**",
384	"**unknown 4**",
385	"write-back-locking",		/* XXX XScale-specific? */
386	"write-back-locking-A",
387	"write-back-locking-B",
388	"**unknown 8**",
389	"**unknown 9**",
390	"**unknown 10**",
391	"**unknown 11**",
392	"**unknown 12**",
393	"**unknown 13**",
394	"**unknown 14**",
395	"**unknown 15**",
396};
397
398void
399identify_arm_cpu(struct device *dv, struct cpu_info *ci)
400{
401	u_int cpuid;
402	enum cpu_class cpu_class = CPU_CLASS_NONE;
403	int i;
404
405	cpuid = ci->ci_arm_cpuid;
406
407	if (cpuid == 0) {
408		aprint_error("Processor failed probe - no CPU ID\n");
409		return;
410	}
411
412	for (i = 0; cpuids[i].cpuid != 0; i++)
413		if (cpuids[i].cpuid == (cpuid & CPU_ID_CPU_MASK)) {
414			cpu_class = cpuids[i].cpu_class;
415			sprintf(cpu_model, "%s %s (%s core)",
416			    cpuids[i].cpu_name,
417			    cpuids[i].cpu_steppings[cpuid &
418						    CPU_ID_REVISION_MASK],
419			    cpu_classes[cpu_class].class_name);
420			break;
421		}
422
423	if (cpuids[i].cpuid == 0)
424		sprintf(cpu_model, "unknown CPU (ID = 0x%x)", cpuid);
425
426	aprint_naive(": %s\n", cpu_model);
427	aprint_normal(": %s\n", cpu_model);
428
429	aprint_normal("%s:", dv->dv_xname);
430
431	switch (cpu_class) {
432	case CPU_CLASS_ARM6:
433	case CPU_CLASS_ARM7:
434	case CPU_CLASS_ARM7TDMI:
435	case CPU_CLASS_ARM8:
436		if ((ci->ci_ctrl & CPU_CONTROL_IDC_ENABLE) == 0)
437			aprint_normal(" IDC disabled");
438		else
439			aprint_normal(" IDC enabled");
440		break;
441	case CPU_CLASS_ARM9TDMI:
442	case CPU_CLASS_ARM10E:
443	case CPU_CLASS_SA1:
444	case CPU_CLASS_XSCALE:
445		if ((ci->ci_ctrl & CPU_CONTROL_DC_ENABLE) == 0)
446			aprint_normal(" DC disabled");
447		else
448			aprint_normal(" DC enabled");
449		if ((ci->ci_ctrl & CPU_CONTROL_IC_ENABLE) == 0)
450			aprint_normal(" IC disabled");
451		else
452			aprint_normal(" IC enabled");
453		break;
454	default:
455		break;
456	}
457	if ((ci->ci_ctrl & CPU_CONTROL_WBUF_ENABLE) == 0)
458		aprint_normal(" WB disabled");
459	else
460		aprint_normal(" WB enabled");
461
462	if (ci->ci_ctrl & CPU_CONTROL_LABT_ENABLE)
463		aprint_normal(" LABT");
464	else
465		aprint_normal(" EABT");
466
467	if (ci->ci_ctrl & CPU_CONTROL_BPRD_ENABLE)
468		aprint_normal(" branch prediction enabled");
469
470	aprint_normal("\n");
471
472	/* Print cache info. */
473	if (arm_picache_line_size == 0 && arm_pdcache_line_size == 0)
474		goto skip_pcache;
475
476	if (arm_pcache_unified) {
477		aprint_normal("%s: %dKB/%dB %d-way %s unified cache\n",
478		    dv->dv_xname, arm_pdcache_size / 1024,
479		    arm_pdcache_line_size, arm_pdcache_ways,
480		    wtnames[arm_pcache_type]);
481	} else {
482		aprint_normal("%s: %dKB/%dB %d-way Instruction cache\n",
483		    dv->dv_xname, arm_picache_size / 1024,
484		    arm_picache_line_size, arm_picache_ways);
485		aprint_normal("%s: %dKB/%dB %d-way %s Data cache\n",
486		    dv->dv_xname, arm_pdcache_size / 1024,
487		    arm_pdcache_line_size, arm_pdcache_ways,
488		    wtnames[arm_pcache_type]);
489	}
490
491 skip_pcache:
492
493	switch (cpu_class) {
494#ifdef CPU_ARM2
495	case CPU_CLASS_ARM2:
496#endif
497#ifdef CPU_ARM250
498	case CPU_CLASS_ARM2AS:
499#endif
500#ifdef CPU_ARM3
501	case CPU_CLASS_ARM3:
502#endif
503#ifdef CPU_ARM6
504	case CPU_CLASS_ARM6:
505#endif
506#ifdef CPU_ARM7
507	case CPU_CLASS_ARM7:
508#endif
509#ifdef CPU_ARM7TDMI
510	case CPU_CLASS_ARM7TDMI:
511#endif
512#ifdef CPU_ARM8
513	case CPU_CLASS_ARM8:
514#endif
515#ifdef CPU_ARM9
516	case CPU_CLASS_ARM9TDMI:
517#endif
518#ifdef CPU_ARM10
519	case CPU_CLASS_ARM10E:
520#endif
521#if defined(CPU_SA110) || defined(CPU_SA1100) || \
522    defined(CPU_SA1110) || defined(CPU_IXP12X0)
523	case CPU_CLASS_SA1:
524#endif
525#if defined(CPU_XSCALE_80200) || defined(CPU_XSCALE_80321) || \
526    defined(CPU_XSCALE_PXA2X0) || defined(CPU_XSCALE_IXP425)
527	case CPU_CLASS_XSCALE:
528#endif
529		break;
530	default:
531		if (cpu_classes[cpu_class].class_option != NULL)
532			aprint_error("%s: %s does not fully support this CPU."
533			       "\n", dv->dv_xname, ostype);
534		else {
535			aprint_error("%s: This kernel does not fully support "
536			       "this CPU.\n", dv->dv_xname);
537			aprint_normal("%s: Recompile with \"options %s\" to "
538			       "correct this.\n", dv->dv_xname,
539			       cpu_classes[cpu_class].class_option);
540		}
541		break;
542	}
543
544}
545#ifdef MULTIPROCESSOR
546int
547cpu_alloc_idlepcb(struct cpu_info *ci)
548{
549	vaddr_t uaddr;
550	struct pcb *pcb;
551	struct trapframe *tf;
552	int error;
553
554	/*
555	 * Generate a kernel stack and PCB (in essence, a u-area) for the
556	 * new CPU.
557	 */
558	if (uvm_uarea_alloc(&uaddr)) {
559		error = uvm_fault_wire(kernel_map, uaddr, uaddr + USPACE,
560		    VM_FAULT_WIRE, VM_PROT_READ | VM_PROT_WRITE);
561		if (error)
562			return error;
563	}
564	ci->ci_idlepcb = pcb = (struct pcb *)uaddr;
565
566	/*
567	 * This code is largely derived from cpu_fork(), with which it
568	 * should perhaps be shared.
569	 */
570
571	/* Copy the pcb */
572	*pcb = proc0.p_addr->u_pcb;
573
574	/* Set up the undefined stack for the process. */
575	pcb->pcb_un.un_32.pcb32_und_sp = uaddr + USPACE_UNDEF_STACK_TOP;
576	pcb->pcb_un.un_32.pcb32_sp = uaddr + USPACE_SVC_STACK_TOP;
577
578#ifdef STACKCHECKS
579	/* Fill the undefined stack with a known pattern */
580	memset(((u_char *)uaddr) + USPACE_UNDEF_STACK_BOTTOM, 0xdd,
581	    (USPACE_UNDEF_STACK_TOP - USPACE_UNDEF_STACK_BOTTOM));
582	/* Fill the kernel stack with a known pattern */
583	memset(((u_char *)uaddr) + USPACE_SVC_STACK_BOTTOM, 0xdd,
584	    (USPACE_SVC_STACK_TOP - USPACE_SVC_STACK_BOTTOM));
585#endif	/* STACKCHECKS */
586
587	pcb->pcb_tf = tf =
588	    (struct trapframe *)pcb->pcb_un.un_32.pcb32_sp - 1;
589	*tf = *proc0.p_addr->u_pcb.pcb_tf;
590	return 0;
591}
592#endif /* MULTIPROCESSOR */
593
594/* End of cpu.c */
595