xref: /netbsd-src/sys/arch/atari/stand/installboot/installboot.c (revision aad9773e38ed2370a628a6416e098f9008fc10a7)
1 /*	$NetBSD: installboot.c,v 1.34 2014/11/24 08:08:23 tsutsui Exp $	*/
2 
3 /*
4  * Copyright (c) 1995 Waldi Ravens
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *        This product includes software developed by Waldi Ravens.
18  * 4. The name of the author may not be used to endorse or promote products
19  *    derived from this software without specific prior written permission
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include <sys/types.h>
34 #include <sys/param.h>
35 #include <sys/sysctl.h>
36 #include <sys/ioctl.h>
37 #include <unistd.h>
38 #include <string.h>
39 #include <stdlib.h>
40 #include <stdio.h>
41 #include <paths.h>
42 #include <fcntl.h>
43 #include <errno.h>
44 #include <err.h>
45 #include <limits.h>
46 #include <nlist.h>
47 #include <kvm.h>
48 
49 #define	DKTYPENAMES
50 #define	FSTYPENAMES
51 #include <sys/disklabel.h>
52 #include <machine/ahdilabel.h>
53 
54 #include "installboot.h"
55 
56 static void	usage(void);
57 #ifdef CHECK_OS_BOOTVERSION
58 static void	oscheck(void);
59 #endif
60 static u_int	abcksum(void *);
61 static void	setNVpref(void);
62 static void	setIDEpar(u_int8_t *, size_t);
63 static void	mkahdiboot(struct ahdi_root *, char *,
64 						char *, u_int32_t);
65 static void	mkbootblock(struct bootblock *, char *,
66 				char *, struct disklabel *, u_int);
67 static void	install_fd(char *, struct disklabel *);
68 static void	install_sd(char *, struct disklabel *);
69 static void	install_wd(char *, struct disklabel *);
70 
71 static struct bootblock	bootarea;
72 static struct ahdi_root ahdiboot;
73 static const char	mdecpath[] = PATH_MDEC;
74 static const char	stdpath[] = PATH_STD;
75 static const char	milanpath[] = PATH_MILAN;
76 static int		nowrite = 0;
77 static int		verbose = 0;
78 static int		trackpercyl = 0;
79 static int		secpertrack = 0;
80 static int		milan = 0;
81 
82 static void
83 usage(void)
84 {
85 	fprintf(stderr,
86 		"usage: installboot [options] device\n"
87 		"where options are:\n"
88 		"\t-N  do not actually write anything on the disk\n"
89 		"\t-m  use Milan boot blocks\n"
90 		"\t-t  number of tracks per cylinder (IDE disk)\n"
91 		"\t-u  number of sectors per track (IDE disk)\n"
92 		"\t-v  verbose mode\n");
93 	exit(EXIT_FAILURE);
94 }
95 
96 int
97 main(int argc, char *argv[])
98 {
99 	struct disklabel dl;
100 	char		 *dn;
101 	char		 *devchr;
102 	int		 fd, c;
103 
104 #ifdef CHECK_OS_BOOTVERSION
105 	/* check OS bootversion */
106 	oscheck();
107 #endif
108 
109 	/* parse options */
110 	while ((c = getopt(argc, argv, "Nmt:u:v")) != -1) {
111 		switch (c) {
112 		  case 'N':
113 			nowrite = 1;
114 			break;
115 		  case 'm':
116 			milan = 1;
117 			break;
118 		  case 't':
119 			trackpercyl = atoi(optarg);
120 			break;
121 		  case 'u':
122 			secpertrack = atoi(optarg);
123 			break;
124 		  case 'v':
125 			verbose = 1;
126 			break;
127 		  default:
128 			usage();
129 		}
130 	}
131 	argv += optind;
132 	argc -= optind;
133 	if (argc != 1)
134 		usage();
135 
136 	/* get disk label */
137 	size_t dnlen = sizeof(_PATH_DEV) + strlen(argv[0]) + 8;
138 	dn = alloca(dnlen);
139 	if (!strchr(argv[0], '/')) {
140 		snprintf(dn, dnlen, "%sr%s%c", _PATH_DEV, argv[0],
141 		    RAW_PART + 'a');
142 		fd = open(dn, O_RDONLY);
143 		if (fd < 0 && errno == ENOENT) {
144 			snprintf(dn, dnlen, "%sr%s", _PATH_DEV, argv[0]);
145 			fd = open(dn, O_RDONLY);
146 		}
147 	} else {
148 		snprintf(dn, dnlen, "%s", argv[0]);
149 		fd = open(dn, O_RDONLY);
150 	}
151 	if (fd < 0)
152 		err(EXIT_FAILURE, "%s", dn);
153 	if (ioctl(fd, DIOCGDINFO, &dl))
154 		err(EXIT_FAILURE, "%s: DIOCGDINFO", dn);
155 	if (close(fd))
156 		err(EXIT_FAILURE, "%s", dn);
157 
158 	/* Eg: in /dev/fd0c, set devchr to point to the 'f' */
159 	devchr = strrchr(dn, '/') + 1;
160 	if (*devchr == 'r')
161 		++devchr;
162 
163 	switch (*devchr) {
164 		case 'f': /* fd */
165 			install_fd(dn, &dl);
166 			break;
167 		case 'w': /* wd */
168 			install_wd(dn, &dl);
169 			setNVpref();
170 			break;
171 		case 's': /* sd */
172 			install_sd(dn, &dl);
173 			setNVpref();
174 			break;
175 		default:
176 			errx(EXIT_FAILURE,
177 			     "%s: '%c': Device type not supported.",
178 			     dn, *devchr);
179 	}
180 
181 	return(EXIT_SUCCESS);
182 }
183 
184 #ifdef CHECK_OS_BOOTVERSION
185 static void
186 oscheck(void)
187 {
188 	struct nlist kbv[] = {
189 		{ .n_name = "_bootversion" },
190 		{ .n_name = NULL }
191 	};
192 	kvm_t		*kd_kern;
193 	char		errbuf[_POSIX2_LINE_MAX];
194 	u_short		kvers;
195 	struct stat	sb;
196 
197 	if (stat(_PATH_UNIX, &sb) < 0) {
198 		warnx("Cannot stat %s, no bootversion check done", _PATH_UNIX);
199 		return;
200 	}
201 
202 	kd_kern = kvm_openfiles(NULL, NULL, NULL, O_RDONLY, errbuf);
203 	if (kd_kern == NULL)
204 		errx(EXIT_FAILURE, "kvm_openfiles: %s", errbuf);
205 	if (kvm_nlist(kd_kern, kbv) == -1)
206 		errx(EXIT_FAILURE, "kvm_nlist: %s", kvm_geterr(kd_kern));
207 	if (kbv[0].n_value == 0)
208 		errx(EXIT_FAILURE, "%s not in namelist", kbv[0].n_name);
209 	if (kvm_read(kd_kern, kbv[0].n_value, &kvers, sizeof(kvers)) == -1)
210 		errx(EXIT_FAILURE, "kvm_read: %s", kvm_geterr(kd_kern));
211 	kvm_close(kd_kern);
212 	if (kvers != BOOTVERSION)
213 		errx(EXIT_FAILURE, "Kern bootversion: %d, expected: %d",
214 		    kvers, BOOTVERSION);
215 }
216 #endif
217 
218 static void
219 install_fd(char *devnm, struct disklabel *label)
220 {
221 	const char	 *machpath;
222 	char		 *xxboot, *bootxx;
223 	struct partition *rootpart;
224 
225 	if (label->d_secsize != 512)
226 		errx(EXIT_FAILURE,
227 		     "%s: %u: Block size not supported.", devnm,
228 							  label->d_secsize);
229 	if (label->d_ntracks != 2)
230 		errx(EXIT_FAILURE,
231 		     "%s: Single sided floppy not supported.", devnm);
232 
233 	if (milan)
234 		machpath = milanpath;
235 	else
236 		machpath = stdpath;
237 	size_t xxbootlen = strlen(mdecpath) + strlen(machpath) + 8;
238 	xxboot = alloca(xxbootlen);
239 	snprintf(xxboot, xxbootlen, "%s%sfdboot", mdecpath, machpath);
240 	bootxx = alloca(xxbootlen);
241 	snprintf(bootxx, xxbootlen, "%s%sbootxx", mdecpath, machpath);
242 
243 	/* first used partition (a, b or c) */		/* XXX */
244 	for (rootpart = label->d_partitions; ; ++rootpart) {
245 		if (rootpart->p_size)
246 			break;
247 	}
248 	if (rootpart != label->d_partitions) {		/* XXX */
249 		*(label->d_partitions) = *rootpart;
250 		memset(rootpart, 0, sizeof(*rootpart));
251 	}
252 	label->d_partitions->p_fstype = FS_BSDFFS;	/* XXX */
253 	label->d_npartitions = 1;
254 	label->d_checksum = 0;
255 	label->d_checksum = dkcksum(label);
256 
257 	trackpercyl = secpertrack = 0;
258 	mkbootblock(&bootarea, xxboot, bootxx, label, 0);
259 
260 	if (!nowrite) {
261 		int	fd;
262 		if ((fd = open(devnm, O_WRONLY)) < 0)
263 			err(EXIT_FAILURE, "%s", devnm);
264 		if (write(fd, &bootarea, sizeof(bootarea)) != sizeof(bootarea))
265 			err(EXIT_FAILURE, "%s", devnm);
266 		if (close(fd))
267 			err(EXIT_FAILURE, "%s", devnm);
268 		if (verbose)
269 			printf("Boot block installed on %s\n", devnm);
270 	}
271 }
272 
273 static void
274 install_sd(char *devnm, struct disklabel *label)
275 {
276 	const char	 *machpath;
277 	char		 *xxb00t, *xxboot, *bootxx;
278 	struct disklabel rawlabel;
279 	u_int32_t	 bbsec;
280 	u_int		 magic;
281 
282 	if (label->d_partitions[0].p_size == 0)
283 		errx(EXIT_FAILURE, "%s: No root-filesystem.", devnm);
284 	if (label->d_partitions[0].p_fstype != FS_BSDFFS)
285 		errx(EXIT_FAILURE, "%s: %s: Illegal root-filesystem type.",
286 		     devnm, fstypenames[label->d_partitions[0].p_fstype]);
287 
288 	bbsec = readdisklabel(devnm, &rawlabel);
289 	if (bbsec == NO_BOOT_BLOCK)
290 		errx(EXIT_FAILURE, "%s: No NetBSD boot block.", devnm);
291 	if (memcmp(label, &rawlabel, sizeof(*label)))
292 		errx(EXIT_FAILURE, "%s: Invalid NetBSD boot block.", devnm);
293 
294 	if (milan)
295 		machpath = milanpath;
296 	else
297 		machpath = stdpath;
298 	if (bbsec) {
299 		size_t xxb00tlen = strlen(mdecpath) + strlen(machpath) + 14;
300 		xxb00t = alloca(xxb00tlen);
301 		snprintf(xxb00t, xxb00tlen, "%s%ssdb00t.ahdi", mdecpath, machpath);
302 		xxboot = alloca(xxb00tlen);
303 		snprintf(xxboot, xxb00tlen, "%s%sxxboot.ahdi", mdecpath, machpath);
304 		magic = AHDIMAGIC;
305 	} else {
306 		size_t xxbootlen = strlen(mdecpath) + strlen(machpath) + 8;
307 		xxb00t = NULL;
308 		xxboot = alloca(xxbootlen);
309 		snprintf(xxboot, xxbootlen, "%s%ssdboot", mdecpath, machpath);
310 		magic = NBDAMAGIC;
311 	}
312 	size_t bootxxlen = strlen(mdecpath) + strlen(machpath) + 8;
313 	bootxx = alloca(bootxxlen);
314 	snprintf(bootxx, bootxxlen, "%s%sbootxx", mdecpath, machpath);
315 
316 	trackpercyl = secpertrack = 0;
317 	if (xxb00t)
318 		mkahdiboot(&ahdiboot, xxb00t, devnm, bbsec);
319 	mkbootblock(&bootarea, xxboot, bootxx, label, magic);
320 
321 	if (!nowrite) {
322 		off_t	bbo = (off_t)bbsec * AHDI_BSIZE;
323 		int	fd;
324 
325 		if ((fd = open(devnm, O_WRONLY)) < 0)
326 			err(EXIT_FAILURE, "%s", devnm);
327 		if (lseek(fd, bbo, SEEK_SET) != bbo)
328 			err(EXIT_FAILURE, "%s", devnm);
329 		if (write(fd, &bootarea, sizeof(bootarea)) != sizeof(bootarea))
330 			err(EXIT_FAILURE, "%s", devnm);
331 		if (verbose)
332 			printf("Boot block installed on %s (sector %d)\n",
333 			    devnm, bbsec);
334 		if (xxb00t) {
335 			if (lseek(fd, (off_t)0, SEEK_SET) != 0)
336 				err(EXIT_FAILURE, "%s", devnm);
337 			if (write(fd, &ahdiboot, sizeof(ahdiboot)) !=
338 			    sizeof(ahdiboot))
339 				err(EXIT_FAILURE, "%s", devnm);
340 			if (verbose)
341 				printf("AHDI root  installed on %s (0)\n",
342 				    devnm);
343 		}
344 		if (close(fd))
345 			err(EXIT_FAILURE, "%s", devnm);
346 	}
347 }
348 
349 static void
350 install_wd(char *devnm, struct disklabel *label)
351 {
352 	const char	 *machpath;
353 	char		 *xxb00t, *xxboot, *bootxx;
354 	struct disklabel rawlabel;
355 	u_int32_t	 bbsec;
356 	u_int		 magic;
357 
358 	if (label->d_partitions[0].p_size == 0)
359 		errx(EXIT_FAILURE, "%s: No root-filesystem.", devnm);
360 	if (label->d_partitions[0].p_fstype != FS_BSDFFS)
361 		errx(EXIT_FAILURE, "%s: %s: Illegal root-filesystem type.",
362 		     devnm, fstypenames[label->d_partitions[0].p_fstype]);
363 
364 	bbsec = readdisklabel(devnm, &rawlabel);
365 	if (bbsec == NO_BOOT_BLOCK)
366 		errx(EXIT_FAILURE, "%s: No NetBSD boot block.", devnm);
367 	if (memcmp(label, &rawlabel, sizeof(*label)))
368 		errx(EXIT_FAILURE, "%s: Invalid NetBSD boot block.", devnm);
369 
370 	if (milan)
371 		machpath = milanpath;
372 	else
373 		machpath = stdpath;
374 	if (bbsec) {
375 		size_t xxb00tlen = strlen(mdecpath) + strlen(machpath) + 14;
376 		xxb00t = alloca(xxb00tlen);
377 		snprintf(xxb00t, xxb00tlen, "%s%swdb00t.ahdi", mdecpath, machpath);
378 		xxboot = alloca(xxb00tlen);
379 		snprintf(xxboot, xxb00tlen, "%s%sxxboot.ahdi", mdecpath, machpath);
380 		magic = AHDIMAGIC;
381 	} else {
382 		size_t xxbootlen = strlen(mdecpath) + strlen(machpath) + 8;
383 		xxb00t = NULL;
384 		xxboot = alloca(xxbootlen);
385 		snprintf(xxboot, xxbootlen, "%s%swdboot", mdecpath, machpath);
386 		magic = NBDAMAGIC;
387 	}
388 	size_t bootxxlen = strlen(mdecpath) + strlen(machpath) + 8;
389 	bootxx = alloca(bootxxlen);
390 	snprintf(bootxx, bootxxlen, "%s%sbootxx", mdecpath, machpath);
391 
392 	if (xxb00t)
393 		mkahdiboot(&ahdiboot, xxb00t, devnm, bbsec);
394 	mkbootblock(&bootarea, xxboot, bootxx, label, magic);
395 
396 	if (!nowrite) {
397 		int	fd;
398 		off_t	bbo;
399 
400 		bbo = (off_t)bbsec * AHDI_BSIZE;
401 		if ((fd = open(devnm, O_WRONLY)) < 0)
402 			err(EXIT_FAILURE, "%s", devnm);
403 		if (lseek(fd, bbo, SEEK_SET) != bbo)
404 			err(EXIT_FAILURE, "%s", devnm);
405 		if (write(fd, &bootarea, sizeof(bootarea)) != sizeof(bootarea))
406 			err(EXIT_FAILURE, "%s", devnm);
407 		if (verbose)
408 			printf("Boot block installed on %s (sector %d)\n",
409 			    devnm, bbsec);
410 		if (xxb00t) {
411 			if (lseek(fd, (off_t)0, SEEK_SET) != 0)
412 				err(EXIT_FAILURE, "%s", devnm);
413 			if (write(fd, &ahdiboot, sizeof(ahdiboot))
414 							!= sizeof(ahdiboot))
415 				err(EXIT_FAILURE, "%s", devnm);
416 			if (verbose)
417 				printf("AHDI root installed on %s (sector 0)\n",
418 				    devnm);
419 		}
420 		if (close(fd))
421 			err(EXIT_FAILURE, "%s", devnm);
422 	}
423 }
424 
425 static void
426 mkahdiboot(struct ahdi_root *newroot, char *xxb00t, char *devnm,
427     u_int32_t bbsec)
428 {
429 	struct ahdi_root tmproot;
430 	struct ahdi_part *pd;
431 	int		 fd;
432 
433 	/* read prototype root-sector */
434 	if ((fd = open(xxb00t, O_RDONLY)) < 0)
435 		err(EXIT_FAILURE, "%s", xxb00t);
436 	if (read(fd, &tmproot, sizeof(tmproot)) != sizeof(tmproot))
437 		err(EXIT_FAILURE, "%s", xxb00t);
438 	if (close(fd))
439 		err(EXIT_FAILURE, "%s", xxb00t);
440 
441 	/* set tracks/cylinder and sectors/track */
442 	setIDEpar(tmproot.ar_fill, sizeof(tmproot.ar_fill));
443 
444 	/* read current root-sector */
445 	if ((fd = open(devnm, O_RDONLY)) < 0)
446 		err(EXIT_FAILURE, "%s", devnm);
447 	if (read(fd, newroot, sizeof(*newroot)) != sizeof(*newroot))
448 		err(EXIT_FAILURE, "%s", devnm);
449 	if (close(fd))
450 		err(EXIT_FAILURE, "%s", devnm);
451 
452 	/* set bootflags */
453 	for (pd = newroot->ar_parts; pd-newroot->ar_parts < AHDI_MAXRPD; ++pd) {
454 		if (pd->ap_st == bbsec) {
455 			pd->ap_flg = 0x21;	/* bootable, pref = NetBSD */
456 			goto gotit;
457 		}
458 	}
459 	errx(EXIT_FAILURE,
460 	     "%s: NetBSD boot block not on primary AHDI partition.", devnm);
461 
462 gotit:	/* copy code from prototype and set new checksum */
463 	memcpy(newroot->ar_fill, tmproot.ar_fill, sizeof(tmproot.ar_fill));
464 	newroot->ar_checksum = 0;
465 	newroot->ar_checksum = 0x1234 - abcksum(newroot);
466 
467 	if (verbose)
468 		printf("AHDI      boot loader: %s\n", xxb00t);
469 }
470 
471 static void
472 mkbootblock(struct bootblock *bb, char *xxb, char *bxx,
473     struct disklabel *label, u_int magic)
474 {
475 	int		 fd;
476 
477 	memset(bb, 0, sizeof(*bb));
478 
479 	/* set boot block magic */
480 	bb->bb_magic = magic;
481 
482 	/* set disk pack label */
483 	BBSETLABEL(bb, label);
484 
485 	/* set second-stage boot loader */
486 	if ((fd = open(bxx, O_RDONLY)) < 0)
487 		err(EXIT_FAILURE, "%s", bxx);
488 	if (read(fd, bb->bb_bootxx, sizeof(bb->bb_bootxx))
489 					!= sizeof(bb->bb_bootxx))
490 		err(EXIT_FAILURE, "%s", bxx);
491 	if (close(fd))
492 		err(EXIT_FAILURE, "%s", bxx);
493 
494 	/* set first-stage bootloader */
495 	if ((fd = open(xxb, O_RDONLY)) < 0)
496 		err(EXIT_FAILURE, "%s", xxb);
497 	if (read(fd, bb->bb_xxboot, sizeof(bb->bb_xxboot))
498 					!= sizeof(bb->bb_xxboot))
499 		err(EXIT_FAILURE, "%s", xxb);
500 	if (close(fd))
501 		err(EXIT_FAILURE, "%s", xxb);
502 
503 	/* set tracks/cylinder and sectors/track */
504 	setIDEpar(bb->bb_xxboot, sizeof(bb->bb_xxboot));
505 
506 	/* set AHDI checksum */
507 	*((u_int16_t *)bb->bb_xxboot + 255) = 0;
508 	*((u_int16_t *)bb->bb_xxboot + 255) = 0x1234 - abcksum(bb->bb_xxboot);
509 
510 	if (verbose) {
511 		printf("Primary   boot loader: %s\n", xxb);
512 		printf("Secondary boot loader: %s\n", bxx);
513 	}
514 }
515 
516 static void
517 setIDEpar (u_int8_t *start, size_t size)
518 {
519 	static const u_int8_t	mark[] = { 'N', 'e', 't', 'B', 'S', 'D' };
520 
521 	if ((u_int)trackpercyl > 255)
522 		errx(EXIT_FAILURE,
523 		     "%d: Illegal tracks/cylinder value (1..255)", trackpercyl);
524 	if ((u_int)secpertrack > 255)
525 		errx(EXIT_FAILURE,
526 		     "%d: Illegal sectors/track value (1..255)", secpertrack);
527 
528 	if (trackpercyl || secpertrack) {
529 		u_int8_t *p;
530 
531 		if (!trackpercyl)
532 			errx(EXIT_FAILURE, "Need tracks/cylinder too.");
533 		if (!secpertrack)
534 			errx(EXIT_FAILURE, "Need sectors/track too.");
535 
536 		start += 2;
537 		size  -= sizeof(mark) + 2;
538 		for (p = start + size; p >= start; --p) {
539 			if (*p != *mark)
540 				continue;
541 			if (!memcmp(p, mark, sizeof(mark)))
542 				break;
543 		}
544 		if (p < start)
545 			errx(EXIT_FAILURE,
546 			     "Malformatted xxboot prototype.");
547 
548 		*--p = secpertrack;
549 		*--p = trackpercyl;
550 
551 		if (verbose) {
552 			printf("sectors/track  : %d\n", secpertrack);
553 			printf("tracks/cylinder: %d\n", trackpercyl);
554 		}
555 	}
556 }
557 
558 static void
559 setNVpref(void)
560 {
561 	static const u_char	bootpref = BOOTPREF_NETBSD;
562 	static const char	nvrdev[] = PATH_NVRAM;
563 
564 	if (!nowrite) {
565 		int	fd;
566 
567 		if ((fd = open(nvrdev, O_RDWR)) < 0)
568 			err(EXIT_FAILURE, "%s", nvrdev);
569 		if (lseek(fd, (off_t)1, SEEK_SET) != 1)
570 			err(EXIT_FAILURE, "%s", nvrdev);
571 		if (write(fd, &bootpref, (size_t)1) != 1)
572 			err(EXIT_FAILURE, "%s", nvrdev);
573 		if (close(fd))
574 			err(EXIT_FAILURE, "%s", nvrdev);
575 		if (verbose)
576 			printf("Boot preference set to NetBSD.\n");
577 	}
578 }
579 
580 static u_int
581 abcksum (void *bs)
582 {
583 	u_int16_t sum  = 0,
584 		  *st  = (u_int16_t *)bs,
585 		  *end = (u_int16_t *)bs + 256;
586 
587 	while (st < end)
588 		sum += *st++;
589 	return(sum);
590 }
591