locore2.c revision 1.12
1/*	$NetBSD: locore2.c,v 1.12 1997/03/13 17:40:36 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_SINGLE | RB_KDB; 	/* XXX - For now... */
81
82unsigned char cpu_machine_id = 0;
83char *cpu_string = NULL;
84int cpu_has_vme = 0;
85int has_iocache = 0;
86
87int msgbufmapped = 0;
88struct msgbuf *msgbufp = NULL;
89
90struct user *proc0paddr;	/* proc[0] pcb address (u-area VA) */
91extern struct pcb *curpcb;
92
93/* First C code called by locore.s */
94void _bootstrap __P((struct exec));
95
96static void _verify_hardware __P((void));
97static void _vm_init __P((struct exec *kehp));
98
99
100#if defined(DDB) && !defined(SYMTAB_SPACE)
101static void _save_symtab __P((struct exec *kehp));
102
103/*
104 * Preserve DDB symbols and strings by setting esym.
105 */
106static void
107_save_symtab(kehp)
108	struct exec *kehp;	/* kernel exec header */
109{
110	int x, *symsz, *strsz;
111	char *endp;
112	char *errdesc = "?";
113
114	/*
115	 * First, sanity-check the exec header.
116	 */
117	mon_printf("_save_symtab: ");
118	if ((kehp->a_midmag & 0xFFF0) != 0x0100) {
119		errdesc = "magic";
120		goto err;
121	}
122	/* Boundary between text and data varries a little. */
123	x = kehp->a_text + kehp->a_data;
124	if (x != (edata - kernel_text)) {
125		errdesc = "a_text+a_data";
126		goto err;
127	}
128	if (kehp->a_bss != (end - edata)) {
129		errdesc = "a_bss";
130		goto err;
131	}
132	if (kehp->a_entry != (int)kernel_text) {
133		errdesc = "a_entry";
134		goto err;
135	}
136	if (kehp->a_trsize || kehp->a_drsize) {
137		errdesc = "a_Xrsize";
138		goto err;
139	}
140	/* The exec header looks OK... */
141
142	/* Check the symtab length word. */
143	endp = end;
144	symsz = (int*)endp;
145	if (kehp->a_syms != *symsz) {
146		errdesc = "a_syms";
147		goto err;
148	}
149	endp += sizeof(int);	/* past length word */
150	endp += *symsz;			/* past nlist array */
151
152	/* Check the string table length. */
153	strsz = (int*)endp;
154	if ((*strsz < 4) || (*strsz > 0x80000)) {
155		errdesc = "strsize";
156		goto err;
157	}
158
159	/* Success!  We have a valid symbol table! */
160	endp += *strsz;			/* past strings */
161	esym = endp;
162	mon_printf(" found %d + %d\n", *symsz, *strsz);
163	return;
164
165 err:
166	mon_printf(" no symbols (bad %s)\n", errdesc);
167}
168#endif	/* DDB && !SYMTAB_SPACE */
169
170/*
171 * This function is called from _bootstrap() to initialize
172 * pre-vm-sytem virtual memory.  All this really does is to
173 * set virtual_avail to the first page following preloaded
174 * data (i.e. the kernel and its symbol table) and special
175 * things that may be needed very early (proc0 upages).
176 * Once that is done, pmap_bootstrap() is called to do the
177 * usual preparations for our use of the MMU.
178 */
179static void
180_vm_init(kehp)
181	struct exec *kehp;	/* kernel exec header */
182{
183	vm_offset_t nextva;
184
185	/*
186	 * First, reserve our symbol table which might have been
187	 * loaded after our BSS area by the boot loader.  However,
188	 * if DDB is not part of this kernel, ignore the symbols.
189	 */
190	esym = end;
191#if defined(DDB) && !defined(SYMTAB_SPACE)
192	/* This will advance esym past the symbols. */
193	_save_symtab(kehp);
194#endif
195
196	/*
197	 * Steal some special-purpose, already mapped pages.
198	 * Note: msgbuf is setup in machdep.c:cpu_startup()
199	 */
200	nextva = _round_page(esym);
201
202	/*
203	 * Setup the u-area pages (stack, etc.) for proc0.
204	 * This is done very early (here) to make sure the
205	 * fault handler works in case we hit an early bug.
206	 * (The fault handler may reference proc0 stuff.)
207	 */
208	proc0paddr = (struct user *) nextva;
209	nextva += USPACE;
210	bzero((caddr_t)proc0paddr, USPACE);
211	proc0.p_addr = proc0paddr;
212
213	/*
214	 * Now that proc0 exists, make it the "current" one.
215	 */
216	curproc = &proc0;
217	curpcb = &proc0paddr->u_pcb;
218
219	/*
220	 * Call pmap_bootstrap() so that we may begin using
221	 * pmap_enter_kernel() and pmap_bootstrap_alloc().
222	 */
223	pmap_bootstrap(nextva);
224}
225
226
227/*
228 * XXX - Should empirically estimate the divisor...
229 * Note that the value of delay_divisor is roughly
230 * 2048 / cpuclock	(where cpuclock is in MHz).
231 */
232int delay_divisor = 82;		/* assume the fastest (3/260) */
233
234static void
235_verify_hardware()
236{
237	unsigned char machtype;
238
239	machtype = identity_prom.idp_machtype;
240	if ((machtype & CPU_ARCH_MASK) != SUN3X_ARCH) {
241		mon_printf("not a sun3x?\n");
242		sunmon_abort();
243	}
244
245	cpu_machine_id = machtype & SUN3X_IMPL_MASK;
246	switch (cpu_machine_id) {
247
248	case SUN3X_MACH_80 :
249		cpu_string = "80";  	/* Hydra */
250		delay_divisor = 102;	/* 20 MHz ? XXX */
251		cpu_has_vme = FALSE;
252		break;
253
254	case SUN3X_MACH_470:
255		cpu_string = "470"; 	/* Pegasus */
256		delay_divisor = 82; 	/* 25 MHz ? XXX */
257		cpu_has_vme = TRUE;
258		break;
259
260	default:
261		mon_printf("unknown sun3x model\n");
262		sunmon_abort();
263	}
264}
265
266
267/*
268 * This is called from locore.s just after the kernel is remapped
269 * to its proper address, but before the call to main().  The work
270 * done here corresponds to various things done in locore.s on the
271 * hp300 port (and other m68k) but which we prefer to do in C code.
272 * Also do setup specific to the Sun PROM monitor and IDPROM here.
273 */
274void
275_bootstrap(keh)
276	struct exec keh;	/* kernel exec header */
277{
278
279	/* First, Clear BSS. */
280	bzero(edata, end - edata);
281
282	/* set v_handler, get boothowto */
283	sunmon_init();
284
285	/* Find devices we need early (like the IDPROM). */
286	obio_init();
287
288	/* Note: must come after obio_init (for IDPROM). */
289	_verify_hardware();	/* get CPU type, etc. */
290
291	/* handle kernel mapping, pmap_bootstrap(), etc. */
292	_vm_init(&keh);
293
294	/*
295	 * Point interrupts/exceptions to our vector table.
296	 * (Until now, we use the one setup by the PROM.)
297	 *
298	 * This is done after obio_init() / intreg_init() finds
299	 * the interrupt register and disables the NMI clock so
300	 * it will not cause "spurrious level 7" complaints.
301	 */
302	setvbr((void **)vector_table);
303
304	/* Interrupts are enabled later, after autoconfig. */
305}
306