locore2.c revision 1.9
1/*	$NetBSD: locore2.c,v 1.9 1997/02/11 00:58:32 gwr Exp $	*/
2
3/*-
4 * Copyright (c) 1996 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Gordon W. Ross and Jeremy Cooper.
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 the NetBSD
21 *        Foundation, Inc. and its contributors.
22 * 4. Neither the name of The NetBSD Foundation nor the names of its
23 *    contributors may be used to endorse or promote products derived
24 *    from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39#include <sys/param.h>
40#include <sys/systm.h>
41#include <sys/proc.h>
42#include <sys/reboot.h>
43#include <sys/user.h>
44#include <sys/exec_aout.h>
45
46#include <vm/vm.h>
47
48#include <machine/cpu.h>
49#include <machine/db_machdep.h>
50#include <machine/dvma.h>
51#include <machine/mon.h>
52#include <machine/pte.h>
53#include <machine/pmap.h>
54#include <machine/idprom.h>
55#include <machine/obio.h>
56#include <machine/machdep.h>
57
58#include <sun3/sun3/interreg.h>
59#include <sun3/sun3/vector.h>
60
61/* This is defined in locore.s */
62extern char kernel_text[];
63
64/* These are defined by the linker */
65extern char etext[], edata[], end[];
66char *esym;	/* DDB */
67
68/*
69 * XXX: m68k common code needs these...
70 * ... but this port does not need to deal with anything except
71 * an mc68030, so these two variables are always ignored.
72 * XXX: Need to do something about <m68k/include/cpu.h>
73 */
74int cputype =  1;	/* CPU_68030 */
75int mmutype = -1;	/* MMU_68030 */
76
77/*
78 * Now our own stuff.
79 */
80int boothowto = RB_KDB; 	/* XXX - For now... */
81int cold = 1;
82
83unsigned char cpu_machine_id = 0;
84char *cpu_string = NULL;
85int cpu_has_vme = 0;
86int has_iocache = 0;
87
88int msgbufmapped = 0;
89struct msgbuf *msgbufp = NULL;
90
91struct user *proc0paddr;	/* proc[0] pcb address (u-area VA) */
92extern struct pcb *curpcb;
93
94/* First C code called by locore.s */
95void _bootstrap __P((struct exec));
96
97static void _verify_hardware __P((void));
98static void _vm_init __P((struct exec *kehp));
99
100
101#if defined(DDB) && !defined(SYMTAB_SPACE)
102static void _save_symtab __P((struct exec *kehp));
103
104/*
105 * Preserve DDB symbols and strings by setting esym.
106 */
107static void
108_save_symtab(kehp)
109	struct exec *kehp;	/* kernel exec header */
110{
111	int x, *symsz, *strsz;
112	char *endp;
113	char *errdesc = "?";
114
115	/*
116	 * First, sanity-check the exec header.
117	 */
118	mon_printf("_save_symtab: ");
119	if ((kehp->a_midmag & 0xFFF0) != 0x0100) {
120		errdesc = "magic";
121		goto err;
122	}
123	/* Boundary between text and data varries a little. */
124	x = kehp->a_text + kehp->a_data;
125	if (x != (edata - kernel_text)) {
126		errdesc = "a_text+a_data";
127		goto err;
128	}
129	if (kehp->a_bss != (end - edata)) {
130		errdesc = "a_bss";
131		goto err;
132	}
133	if (kehp->a_entry != (int)kernel_text) {
134		errdesc = "a_entry";
135		goto err;
136	}
137	if (kehp->a_trsize || kehp->a_drsize) {
138		errdesc = "a_Xrsize";
139		goto err;
140	}
141	/* The exec header looks OK... */
142
143	/* Check the symtab length word. */
144	endp = end;
145	symsz = (int*)endp;
146	if (kehp->a_syms != *symsz) {
147		errdesc = "a_syms";
148		goto err;
149	}
150	endp += sizeof(int);	/* past length word */
151	endp += *symsz;			/* past nlist array */
152
153	/* Check the string table length. */
154	strsz = (int*)endp;
155	if ((*strsz < 4) || (*strsz > 0x80000)) {
156		errdesc = "strsize";
157		goto err;
158	}
159
160	/* Success!  We have a valid symbol table! */
161	endp += *strsz;			/* past strings */
162	esym = endp;
163	mon_printf(" found %d + %d\n", *symsz, *strsz);
164	return;
165
166 err:
167	mon_printf(" no symbols (bad %s)\n", errdesc);
168}
169#endif	/* DDB && !SYMTAB_SPACE */
170
171/*
172 * This function is called from _bootstrap() to initialize
173 * pre-vm-sytem virtual memory.  All this really does is to
174 * set virtual_avail to the first page following preloaded
175 * data (i.e. the kernel and its symbol table) and special
176 * things that may be needed very early (proc0 upages).
177 * Once that is done, pmap_bootstrap() is called to do the
178 * usual preparations for our use of the MMU.
179 */
180static void
181_vm_init(kehp)
182	struct exec *kehp;	/* kernel exec header */
183{
184	vm_offset_t nextva;
185
186	/*
187	 * First, reserve our symbol table which might have been
188	 * loaded after our BSS area by the boot loader.  However,
189	 * if DDB is not part of this kernel, ignore the symbols.
190	 */
191	esym = end;
192#if defined(DDB) && !defined(SYMTAB_SPACE)
193	/* This will advance esym past the symbols. */
194	_save_symtab(kehp);
195#endif
196
197	/*
198	 * Steal some special-purpose, already mapped pages.
199	 * Note: msgbuf is setup in machdep.c:cpu_startup()
200	 */
201	nextva = sun3x_round_page(esym);
202
203	/*
204	 * Setup the u-area pages (stack, etc.) for proc0.
205	 * This is done very early (here) to make sure the
206	 * fault handler works in case we hit an early bug.
207	 * (The fault handler may reference proc0 stuff.)
208	 */
209	proc0paddr = (struct user *) nextva;
210	nextva += USPACE;
211	bzero((caddr_t)proc0paddr, USPACE);
212	proc0.p_addr = proc0paddr;
213
214	/*
215	 * Now that proc0 exists, make it the "current" one.
216	 */
217	curproc = &proc0;
218	curpcb = &proc0paddr->u_pcb;
219
220	/*
221	 * Call pmap_bootstrap() so that we may begin using
222	 * pmap_enter_kernel() and pmap_bootstrap_alloc().
223	 */
224	pmap_bootstrap(nextva);
225}
226
227
228/*
229 * XXX - Should empirically estimate the divisor...
230 * Note that the value of delay_divisor is roughly
231 * 2048 / cpuclock	(where cpuclock is in MHz).
232 */
233int delay_divisor = 82;		/* assume the fastest (3/260) */
234
235static void
236_verify_hardware()
237{
238	unsigned char machtype;
239
240	machtype = identity_prom.idp_machtype;
241	if ((machtype & CPU_ARCH_MASK) != SUN3X_ARCH) {
242		mon_printf("not a sun3x?\n");
243		sunmon_abort();
244	}
245
246	cpu_machine_id = machtype & SUN3X_IMPL_MASK;
247	switch (cpu_machine_id) {
248
249	case SUN3X_MACH_80 :
250		cpu_string = "80";  	/* Hydra */
251		delay_divisor = 102;	/* 20 MHz ? XXX */
252		cpu_has_vme = FALSE;
253		break;
254
255	case SUN3X_MACH_470:
256		cpu_string = "470"; 	/* Pegasus */
257		delay_divisor = 82; 	/* 25 MHz ? XXX */
258		cpu_has_vme = TRUE;
259		break;
260
261	default:
262		mon_printf("unknown sun3x model\n");
263		sunmon_abort();
264	}
265}
266
267
268/*
269 * This is called from locore.s just after the kernel is remapped
270 * to its proper address, but before the call to main().  The work
271 * done here corresponds to various things done in locore.s on the
272 * hp300 port (and other m68k) but which we prefer to do in C code.
273 * Also do setup specific to the Sun PROM monitor and IDPROM here.
274 */
275void
276_bootstrap(keh)
277	struct exec keh;	/* kernel exec header */
278{
279
280	/* First, Clear BSS. */
281	bzero(edata, end - edata);
282
283	/* set v_handler, get boothowto */
284	sunmon_init();
285
286	/* Find devices we need early (like the IDPROM). */
287	obio_init();
288
289	/* Note: must come after obio_init (for IDPROM). */
290	_verify_hardware();	/* get CPU type, etc. */
291
292	/* handle kernel mapping, pmap_bootstrap(), etc. */
293	_vm_init(&keh);
294
295	/*
296	 * Point interrupts/exceptions to our vector table.
297	 * (Until now, we use the one setup by the PROM.)
298	 *
299	 * This is done after obio_init() / intreg_init() finds
300	 * the interrupt register and disables the NMI clock so
301	 * it will not cause "spurrious level 7" complaints.
302	 */
303	setvbr((void **)vector_table);
304
305	/* Interrupts are enabled later, after autoconfig. */
306}
307