bootinfo.c revision 85376 
1/*-
2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: head/sys/boot/i386/libi386/bootinfo.c 85376 2001-10-23 20:27:48Z jlemon $
27 */
28
29#include <stand.h>
30#include <sys/param.h>
31#include <sys/reboot.h>
32#include <sys/linker.h>
33#include <machine/bootinfo.h>
34#include "bootstrap.h"
35#include "libi386.h"
36#include "btxv86.h"
37
38static struct bootinfo	bi;
39
40/*
41 * Return a 'boothowto' value corresponding to the kernel arguments in
42 * (kargs) and any relevant environment variables.
43 */
44static struct
45{
46    const char	*ev;
47    int		mask;
48} howto_names[] = {
49    {"boot_askname",	RB_ASKNAME},
50    {"boot_cdrom",	RB_CDROM},
51    {"boot_userconfig",	RB_CONFIG},
52    {"boot_ddb",	RB_KDB},
53    {"boot_gdb",	RB_GDB},
54    {"boot_single",	RB_SINGLE},
55    {"boot_verbose",	RB_VERBOSE},
56    {NULL,	0}
57};
58
59vm_offset_t	bi_copymodules(vm_offset_t addr);
60
61int
62bi_getboothowto(char *kargs)
63{
64    char	*cp;
65    int		howto;
66    int		active;
67    int		i;
68
69    /* Parse kargs */
70    howto = 0;
71    if (kargs  != NULL) {
72	cp = kargs;
73	active = 0;
74	while (*cp != 0) {
75	    if (!active && (*cp == '-')) {
76		active = 1;
77	    } else if (active)
78		switch (*cp) {
79		case 'a':
80		    howto |= RB_ASKNAME;
81		    break;
82		case 'c':
83		    howto |= RB_CONFIG;
84		    break;
85		case 'C':
86		    howto |= RB_CDROM;
87		    break;
88		case 'd':
89		    howto |= RB_KDB;
90		    break;
91		case 'D':
92		    howto |= RB_MULTIPLE;
93		    break;
94		case 'm':
95		    howto |= RB_MUTE;
96		    break;
97		case 'g':
98		    howto |= RB_GDB;
99		    break;
100		case 'h':
101		    howto |= RB_SERIAL;
102		    break;
103		case 'r':
104		    howto |= RB_DFLTROOT;
105		    break;
106		case 's':
107		    howto |= RB_SINGLE;
108		    break;
109		case 'v':
110		    howto |= RB_VERBOSE;
111		    break;
112		default:
113		    active = 0;
114		    break;
115		}
116	    cp++;
117	}
118    }
119    /* get equivalents from the environment */
120    for (i = 0; howto_names[i].ev != NULL; i++)
121	if (getenv(howto_names[i].ev) != NULL)
122	    howto |= howto_names[i].mask;
123    if (!strcmp(getenv("console"), "comconsole"))
124	howto |= RB_SERIAL;
125    if (!strcmp(getenv("console"), "nullconsole"))
126	howto |= RB_MUTE;
127    return(howto);
128}
129
130/*
131 * Copy the environment into the load area starting at (addr).
132 * Each variable is formatted as <name>=<value>, with a single nul
133 * separating each variable, and a double nul terminating the environment.
134 */
135vm_offset_t
136bi_copyenv(vm_offset_t addr)
137{
138    struct env_var	*ep;
139
140    /* traverse the environment */
141    for (ep = environ; ep != NULL; ep = ep->ev_next) {
142	i386_copyin(ep->ev_name, addr, strlen(ep->ev_name));
143	addr += strlen(ep->ev_name);
144	i386_copyin("=", addr, 1);
145	addr++;
146	if (ep->ev_value != NULL) {
147	    i386_copyin(ep->ev_value, addr, strlen(ep->ev_value));
148	    addr += strlen(ep->ev_value);
149	}
150	i386_copyin("", addr, 1);
151	addr++;
152    }
153    i386_copyin("", addr, 1);
154    addr++;
155    return(addr);
156}
157
158/*
159 * Copy module-related data into the load area, where it can be
160 * used as a directory for loaded modules.
161 *
162 * Module data is presented in a self-describing format.  Each datum
163 * is preceded by a 32-bit identifier and a 32-bit size field.
164 *
165 * Currently, the following data are saved:
166 *
167 * MOD_NAME	(variable)		module name (string)
168 * MOD_TYPE	(variable)		module type (string)
169 * MOD_ARGS	(variable)		module parameters (string)
170 * MOD_ADDR	sizeof(vm_offset_t)	module load address
171 * MOD_SIZE	sizeof(size_t)		module size
172 * MOD_METADATA	(variable)		type-specific metadata
173 */
174#define COPY32(v, a) {				\
175    u_int32_t	x = (v);			\
176    i386_copyin(&x, a, sizeof(x));		\
177    a += sizeof(x);				\
178}
179
180#define MOD_STR(t, a, s) {			\
181    COPY32(t, a);				\
182    COPY32(strlen(s) + 1, a);			\
183    i386_copyin(s, a, strlen(s) + 1);		\
184    a += roundup(strlen(s) + 1, sizeof(u_long));\
185}
186
187#define MOD_NAME(a, s)	MOD_STR(MODINFO_NAME, a, s)
188#define MOD_TYPE(a, s)	MOD_STR(MODINFO_TYPE, a, s)
189#define MOD_ARGS(a, s)	MOD_STR(MODINFO_ARGS, a, s)
190
191#define MOD_VAR(t, a, s) {			\
192    COPY32(t, a);				\
193    COPY32(sizeof(s), a);			\
194    i386_copyin(&s, a, sizeof(s));		\
195    a += roundup(sizeof(s), sizeof(u_long));	\
196}
197
198#define MOD_ADDR(a, s)	MOD_VAR(MODINFO_ADDR, a, s)
199#define MOD_SIZE(a, s)	MOD_VAR(MODINFO_SIZE, a, s)
200
201#define MOD_METADATA(a, mm) {			\
202    COPY32(MODINFO_METADATA | mm->md_type, a);	\
203    COPY32(mm->md_size, a);			\
204    i386_copyin(mm->md_data, a, mm->md_size);	\
205    a += roundup(mm->md_size, sizeof(u_long));\
206}
207
208#define MOD_END(a) {				\
209    COPY32(MODINFO_END, a);			\
210    COPY32(0, a);				\
211}
212
213vm_offset_t
214bi_copymodules(vm_offset_t addr)
215{
216    struct preloaded_file	*fp;
217    struct file_metadata	*md;
218
219    /* start with the first module on the list, should be the kernel */
220    for (fp = file_findfile(NULL, NULL); fp != NULL; fp = fp->f_next) {
221
222	MOD_NAME(addr, fp->f_name);	/* this field must come first */
223	MOD_TYPE(addr, fp->f_type);
224	if (fp->f_args)
225	    MOD_ARGS(addr, fp->f_args);
226	MOD_ADDR(addr, fp->f_addr);
227	MOD_SIZE(addr, fp->f_size);
228	for (md = fp->f_metadata; md != NULL; md = md->md_next)
229	    if (!(md->md_type & MODINFOMD_NOCOPY))
230		MOD_METADATA(addr, md);
231    }
232    MOD_END(addr);
233    return(addr);
234}
235
236/*
237 * Load the information expected by an i386 kernel.
238 *
239 * - The 'boothowto' argument is constructed
240 * - The 'bootdev' argument is constructed
241 * - The 'bootinfo' struct is constructed, and copied into the kernel space.
242 * - The kernel environment is copied into kernel space.
243 * - Module metadata are formatted and placed in kernel space.
244 */
245int
246bi_load(char *args, int *howtop, int *bootdevp, vm_offset_t *bip)
247{
248    struct preloaded_file	*xp;
249    struct i386_devdesc		*rootdev;
250    vm_offset_t			addr;
251    char			*rootdevname;
252    int				bootdevnr, i;
253    u_int			pad;
254    char			*kernelname;
255    const char			*kernelpath;
256
257    *howtop = bi_getboothowto(args);
258
259    /*
260     * Allow the environment variable 'rootdev' to override the supplied device
261     * This should perhaps go to MI code and/or have $rootdev tested/set by
262     * MI code before launching the kernel.
263     */
264    rootdevname = getenv("rootdev");
265    i386_getdev((void **)(&rootdev), rootdevname, NULL);
266    if (rootdev == NULL) {		/* bad $rootdev/$currdev */
267	printf("can't determine root device\n");
268	return(EINVAL);
269    }
270
271    /* Try reading the /etc/fstab file to select the root device */
272    getrootmount(i386_fmtdev((void *)rootdev));
273
274    /* Do legacy rootdev guessing */
275
276    /* XXX - use a default bootdev of 0.  Is this ok??? */
277    bootdevnr = 0;
278
279    switch(rootdev->d_type) {
280    case DEVT_DISK:
281	/* pass in the BIOS device number of the current disk */
282	bi.bi_bios_dev = bd_unit2bios(rootdev->d_kind.biosdisk.unit);
283	bootdevnr = bd_getdev(rootdev);
284	if (bootdevnr != -1)
285	    break;
286	printf("root device %s invalid\n", i386_fmtdev(rootdev));
287	return(EINVAL);
288
289    case DEVT_NET:
290	    break;
291
292    default:
293	printf("WARNING - don't know how to boot from device type %d\n", rootdev->d_type);
294    }
295    free(rootdev);
296    *bootdevp = bootdevnr;
297
298    /* legacy bootinfo structure */
299    bi.bi_version = BOOTINFO_VERSION;
300    bi.bi_kernelname = 0;		/* XXX char * -> kernel name */
301    bi.bi_nfs_diskless = 0;		/* struct nfs_diskless * */
302    bi.bi_n_bios_used = 0;		/* XXX would have to hook biosdisk driver for these */
303    for (i = 0; i < N_BIOS_GEOM; i++)
304        bi.bi_bios_geom[i] = bd_getbigeom(i);
305    bi.bi_size = sizeof(bi);
306    bi.bi_memsizes_valid = 1;
307    bi.bi_basemem = bios_basemem / 1024;
308    bi.bi_extmem = bios_extmem / 1024;
309
310    /* find the last module in the chain */
311    addr = 0;
312    for (xp = file_findfile(NULL, NULL); xp != NULL; xp = xp->f_next) {
313	if (addr < (xp->f_addr + xp->f_size))
314	    addr = xp->f_addr + xp->f_size;
315    }
316    /* pad to a page boundary */
317    pad = (u_int)addr & PAGE_MASK;
318    if (pad != 0) {
319	pad = PAGE_SIZE - pad;
320	addr += pad;
321    }
322
323    /* copy our environment */
324    bi.bi_envp = addr;
325    addr = bi_copyenv(addr);
326
327    /* pad to a page boundary */
328    pad = (u_int)addr & PAGE_MASK;
329    if (pad != 0) {
330	pad = PAGE_SIZE - pad;
331	addr += pad;
332    }
333    /* copy module list and metadata */
334    bi.bi_modulep = addr;
335    addr = bi_copymodules(addr);
336
337    /* all done copying stuff in, save end of loaded object space */
338    bi.bi_kernend = addr;
339
340    *howtop |= RB_BOOTINFO;		/* it's there now */
341
342    /*
343     * Get the kernel name, strip off any device prefix.
344     */
345    kernelname = getenv("kernelname");
346    i386_getdev(NULL, kernelname, &kernelpath);
347    bi.bi_kernelname = VTOP(kernelpath);
348    *bip = VTOP(&bi);
349
350    return(0);
351}
352