locore2.c revision 1.36 
1/*	$NetBSD: locore2.c,v 1.36 2009/11/26 00:19:23 matt 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 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33__KERNEL_RCSID(0, "$NetBSD: locore2.c,v 1.36 2009/11/26 00:19:23 matt Exp $");
34
35#include "opt_ddb.h"
36
37#include <sys/param.h>
38#include <sys/systm.h>
39#include <sys/proc.h>
40#include <sys/reboot.h>
41#define ELFSIZE 32
42#include <sys/exec_elf.h>
43
44#include <uvm/uvm_extern.h>
45
46#include <machine/cpu.h>
47#include <machine/db_machdep.h>
48#include <machine/dvma.h>
49#include <machine/idprom.h>
50#include <machine/leds.h>
51#include <machine/mon.h>
52#include <machine/pmap.h>
53#include <machine/pte.h>
54
55#include <sun3/sun3/interreg.h>
56#include <sun3/sun3/machdep.h>
57#include <sun68k/sun68k/vector.h>
58
59/* This is defined in locore.s */
60extern char kernel_text[];
61
62/* These are defined by the linker */
63extern char etext[], edata[], end[];
64int nsym;
65char *ssym, *esym;
66
67/*
68 * XXX: m68k common code needs these...
69 * ... but this port does not need to deal with anything except
70 * an mc68030, so these two variables are always ignored.
71 */
72int cputype = CPU_68030;
73int mmutype = MMU_68030;
74
75/*
76 * Now our own stuff.
77 */
78
79extern struct pcb *curpcb;
80
81/* First C code called by locore.s */
82void _bootstrap(void);
83
84static void _vm_init(void);
85
86#if defined(DDB)
87static void _save_symtab(void);
88
89/*
90 * Preserve DDB symbols and strings by setting esym.
91 */
92static void
93_save_symtab(void)
94{
95	int i;
96	Elf_Ehdr *ehdr;
97	Elf_Shdr *shp;
98	vaddr_t minsym, maxsym;
99
100	/*
101	 * Check the ELF headers.
102	 */
103
104	ehdr = (void *)end;
105	if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG) != 0 ||
106	    ehdr->e_ident[EI_CLASS] != ELFCLASS32) {
107		mon_printf("_save_symtab: bad ELF magic\n");
108		return;
109	}
110
111	/*
112	 * Find the end of the symbols and strings.
113	 */
114
115	maxsym = 0;
116	minsym = ~maxsym;
117	shp = (Elf_Shdr *)(end + ehdr->e_shoff);
118	for (i = 0; i < ehdr->e_shnum; i++) {
119		if (shp[i].sh_type != SHT_SYMTAB &&
120		    shp[i].sh_type != SHT_STRTAB) {
121			continue;
122		}
123		minsym = min(minsym, (vaddr_t)end + shp[i].sh_offset);
124		maxsym = max(maxsym, (vaddr_t)end + shp[i].sh_offset +
125			     shp[i].sh_size);
126	}
127	nsym = 1;
128	ssym = (char *)ehdr;
129	esym = (char *)maxsym;
130}
131#endif	/* DDB */
132
133/*
134 * This function is called from _bootstrap() to initialize
135 * pre-vm-sytem virtual memory.  All this really does is to
136 * set virtual_avail to the first page following preloaded
137 * data (i.e. the kernel and its symbol table) and special
138 * things that may be needed very early (lwp0 upages).
139 * Once that is done, pmap_bootstrap() is called to do the
140 * usual preparations for our use of the MMU.
141 */
142static void
143_vm_init(void)
144{
145	vaddr_t nextva;
146
147	/*
148	 * First preserve our symbol table, which might have been
149	 * loaded after our BSS area by the boot loader.  However,
150	 * if DDB is not part of this kernel, ignore the symbols.
151	 */
152	esym = end + 4;
153#if defined(DDB)
154	/* This will advance esym past the symbols. */
155	_save_symtab();
156#endif
157
158	/*
159	 * Steal some special-purpose, already mapped pages.
160	 * Note: msgbuf is setup in machdep.c:cpu_startup()
161	 */
162	nextva = m68k_round_page(esym);
163
164	/*
165	 * Setup the u-area pages (stack, etc.) for lwp0.
166	 * This is done very early (here) to make sure the
167	 * fault handler works in case we hit an early bug.
168	 * (The fault handler may reference lwp0 stuff.)
169	 */
170	lwp0.l_addr = (struct user *) nextva;
171	nextva += USPACE;
172	memset(lwp0.l_addr, 0, USPACE);
173
174	/*
175	 * Now that lwp0 exists, make it the "current" one.
176	 */
177	curlwp = &lwp0;
178	curpcb = &lwp0.l_addr->u_pcb;
179
180	/* This does most of the real work. */
181	pmap_bootstrap(nextva);
182}
183
184/*
185 * This is called from locore.s just after the kernel is remapped
186 * to its proper address, but before the call to main().  The work
187 * done here corresponds to various things done in locore.s on the
188 * hp300 port (and other m68k) but which we prefer to do in C code.
189 * Also do setup specific to the Sun PROM monitor and IDPROM here.
190 */
191void
192_bootstrap(void)
193{
194
195	/* First, Clear BSS. */
196	memset(edata, 0, end - edata);
197
198	/* Set v_handler, get boothowto. */
199	sunmon_init();
200
201	/* Handle kernel mapping, pmap_bootstrap(), etc. */
202	_vm_init();
203
204	/*
205	 * Find and save OBIO mappings needed early,
206	 * and call some init functions.
207	 */
208	obio_init();
209
210	/*
211	 * Point interrupts/exceptions to our vector table.
212	 * (Until now, we use the one setup by the PROM.)
213	 *
214	 * This is done after obio_init() / intreg_init() finds
215	 * the interrupt register and disables the NMI clock so
216	 * it will not cause "spurrious level 7" complaints.
217	 * Done after _vm_init so the PROM can debug that.
218	 */
219	setvbr((void **)vector_table);
220	/* Interrupts are enabled later, after autoconfig. */
221
222	/*
223	 * Find the IDPROM and copy it to memory.
224	 * Needs obio_init and setvbr earlier.
225	 */
226	idprom_init();
227
228	/*
229	 * Turn on the LEDs so we know power is on.
230	 * Needs idprom_init and obio_init earlier.
231	 */
232	leds_init();
233}
234