xref: /freebsd/stand/i386/boot2/boot2.c (revision b9f654b163bce26de79705e77b872427c9f2afa1)
1 /*-
2  * Copyright (c) 1998 Robert Nordier
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms are freely
6  * permitted provided that the above copyright notice and this
7  * paragraph and the following disclaimer are duplicated in all
8  * such forms.
9  *
10  * This software is provided "AS IS" and without any express or
11  * implied warranties, including, without limitation, the implied
12  * warranties of merchantability and fitness for a particular
13  * purpose.
14  */
15 
16 #include <sys/cdefs.h>
17 __FBSDID("$FreeBSD$");
18 
19 #include <sys/param.h>
20 #include <sys/disklabel.h>
21 #include <sys/diskmbr.h>
22 #include <sys/dirent.h>
23 #include <sys/reboot.h>
24 
25 #include <machine/bootinfo.h>
26 #include <machine/elf.h>
27 
28 #include <stdarg.h>
29 
30 #include <a.out.h>
31 
32 #include <btxv86.h>
33 
34 #include "boot2.h"
35 #include "lib.h"
36 #include "paths.h"
37 #include "rbx.h"
38 
39 /* Define to 0 to omit serial support */
40 #ifndef SERIAL
41 #define SERIAL 1
42 #endif
43 
44 #define IO_KEYBOARD	1
45 #define IO_SERIAL	2
46 
47 #if SERIAL
48 #define DO_KBD (ioctrl & IO_KEYBOARD)
49 #define DO_SIO (ioctrl & IO_SERIAL)
50 #else
51 #define DO_KBD (1)
52 #define DO_SIO (0)
53 #endif
54 
55 #define SECOND		18	/* Circa that many ticks in a second. */
56 
57 #define ARGS		0x900
58 #define NOPT		14
59 #define NDEV		3
60 #define MEM_BASE	0x12
61 #define MEM_EXT 	0x15
62 
63 #define DRV_HARD	0x80
64 #define DRV_MASK	0x7f
65 
66 #define TYPE_AD		0
67 #define TYPE_DA		1
68 #define TYPE_MAXHARD	TYPE_DA
69 #define TYPE_FD		2
70 
71 extern uint32_t _end;
72 
73 static const char optstr[NOPT] = "DhaCcdgmnpqrsv"; /* Also 'P', 'S' */
74 static const unsigned char flags[NOPT] = {
75 	RBX_DUAL,
76 	RBX_SERIAL,
77 	RBX_ASKNAME,
78 	RBX_CDROM,
79 	RBX_CONFIG,
80 	RBX_KDB,
81 	RBX_GDB,
82 	RBX_MUTE,
83 	RBX_NOINTR,
84 	RBX_PAUSE,
85 	RBX_QUIET,
86 	RBX_DFLTROOT,
87 	RBX_SINGLE,
88 	RBX_VERBOSE
89 };
90 
91 static const char *const dev_nm[NDEV] = {"ad", "da", "fd"};
92 static const unsigned char dev_maj[NDEV] = {30, 4, 2};
93 
94 static struct dsk {
95 	unsigned drive;
96 	unsigned type;
97 	unsigned unit;
98 	uint8_t slice;
99 	uint8_t part;
100 	unsigned start;
101 	int init;
102 } dsk;
103 static char cmd[512], cmddup[512], knamebuf[1024];
104 static const char *kname;
105 uint32_t opts;
106 static struct bootinfo bootinfo;
107 #if SERIAL
108 static int comspeed = SIOSPD;
109 static uint8_t ioctrl = IO_KEYBOARD;
110 #endif
111 
112 int main(void);
113 void exit(int);
114 static void load(void);
115 static int parse(void);
116 static int dskread(void *, unsigned, unsigned);
117 static void printf(const char *,...);
118 static void putchar(int);
119 static int drvread(void *, unsigned, unsigned);
120 static int keyhit(unsigned);
121 static int xputc(int);
122 static int xgetc(int);
123 static inline int getc(int);
124 
125 static void memcpy(void *, const void *, int);
126 static void
127 memcpy(void *dst, const void *src, int len)
128 {
129 	const char *s;
130 	char *d;
131 
132 	s = src;
133 	d = dst;
134 
135 	while (len--)
136 		*d++ = *s++;
137 }
138 
139 static inline int
140 strcmp(const char *s1, const char *s2)
141 {
142 
143 	for (; *s1 == *s2 && *s1; s1++, s2++);
144 	return ((unsigned char)*s1 - (unsigned char)*s2);
145 }
146 
147 #define	UFS_SMALL_CGBASE
148 #include "ufsread.c"
149 
150 static int
151 xfsread(ufs_ino_t inode, void *buf, size_t nbyte)
152 {
153 
154 	if ((size_t)fsread(inode, buf, nbyte) != nbyte) {
155 		printf("Invalid %s\n", "format");
156 		return (-1);
157 	}
158 	return (0);
159 }
160 
161 static inline void
162 getstr(void)
163 {
164 	char *s;
165 	int c;
166 
167 	s = cmd;
168 	for (;;) {
169 		switch (c = xgetc(0)) {
170 		case 0:
171 			break;
172 		case '\177':
173 		case '\b':
174 			if (s > cmd) {
175 				s--;
176 				printf("\b \b");
177 			}
178 			break;
179 		case '\n':
180 		case '\r':
181 			*s = 0;
182 			return;
183 		default:
184 			if (s - cmd < sizeof(cmd) - 1)
185 				*s++ = c;
186 			putchar(c);
187 		}
188 	}
189 }
190 
191 static inline void
192 putc(int c)
193 {
194 
195 	v86.addr = 0x10;
196 	v86.eax = 0xe00 | (c & 0xff);
197 	v86.ebx = 0x7;
198 	v86int();
199 }
200 
201 int
202 main(void)
203 {
204 	uint8_t autoboot;
205 	ufs_ino_t ino;
206 	size_t nbyte;
207 
208 	dmadat = (void *)(roundup2(__base + (int32_t)&_end, 0x10000) - __base);
209 	v86.ctl = V86_FLAGS;
210 	v86.efl = PSL_RESERVED_DEFAULT | PSL_I;
211 	dsk.drive = *(uint8_t *)PTOV(ARGS);
212 	dsk.type = dsk.drive & DRV_HARD ? TYPE_AD : TYPE_FD;
213 	dsk.unit = dsk.drive & DRV_MASK;
214 	dsk.slice = *(uint8_t *)PTOV(ARGS + 1) + 1;
215 	bootinfo.bi_version = BOOTINFO_VERSION;
216 	bootinfo.bi_size = sizeof(bootinfo);
217 
218 	/* Process configuration file */
219 
220 	autoboot = 1;
221 
222 	if ((ino = lookup(PATH_CONFIG)) ||
223 	    (ino = lookup(PATH_DOTCONFIG))) {
224 		nbyte = fsread(ino, cmd, sizeof(cmd) - 1);
225 		cmd[nbyte] = '\0';
226 	}
227 
228 	if (*cmd) {
229 		memcpy(cmddup, cmd, sizeof(cmd));
230 		if (parse())
231 			autoboot = 0;
232 		if (!OPT_CHECK(RBX_QUIET))
233 			printf("%s: %s", PATH_CONFIG, cmddup);
234 		/* Do not process this command twice */
235 		*cmd = 0;
236 	}
237 
238 	/*
239 	 * Try to exec stage 3 boot loader. If interrupted by a keypress,
240 	 * or in case of failure, try to load a kernel directly instead.
241 	 */
242 
243 	if (!kname) {
244 		kname = PATH_LOADER;
245 		if (autoboot && !keyhit(3*SECOND)) {
246 			load();
247 			kname = PATH_KERNEL;
248 		}
249 	}
250 
251 	/* Present the user with the boot2 prompt. */
252 
253 	for (;;) {
254 		if (!autoboot || !OPT_CHECK(RBX_QUIET))
255 			printf("\nFreeBSD/x86 boot\n"
256 				 "Default: %u:%s(%u,%c)%s\n"
257 				 "boot: ",
258 			    dsk.drive & DRV_MASK, dev_nm[dsk.type], dsk.unit,
259 			    'a' + dsk.part, kname);
260 		if (DO_SIO)
261 			sio_flush();
262 		if (!autoboot || keyhit(3*SECOND))
263 			getstr();
264 		else if (!autoboot || !OPT_CHECK(RBX_QUIET))
265 			putchar('\n');
266 		autoboot = 0;
267 		if (parse())
268 			putchar('\a');
269 		else
270 			load();
271 	}
272 }
273 
274 /* XXX - Needed for btxld to link the boot2 binary; do not remove. */
275 void
276 exit(int x)
277 {
278 
279 }
280 
281 static void
282 load(void)
283 {
284 	union {
285 		struct exec ex;
286 		Elf32_Ehdr eh;
287 	} hdr;
288 	static Elf32_Phdr ep[2];
289 	static Elf32_Shdr es[2];
290 	caddr_t p;
291 	ufs_ino_t ino;
292 	uint32_t addr;
293 	int k;
294 	uint8_t i, j;
295 
296 	if (!(ino = lookup(kname))) {
297 		if (!ls)
298 			printf("No %s\n", kname);
299 		return;
300 	}
301 	if (xfsread(ino, &hdr, sizeof(hdr)))
302 		return;
303 
304 	if (N_GETMAGIC(hdr.ex) == ZMAGIC) {
305 		addr = hdr.ex.a_entry & 0xffffff;
306 		p = PTOV(addr);
307 		fs_off = PAGE_SIZE;
308 		if (xfsread(ino, p, hdr.ex.a_text))
309 			return;
310 		p += roundup2(hdr.ex.a_text, PAGE_SIZE);
311 		if (xfsread(ino, p, hdr.ex.a_data))
312 			return;
313 	} else if (IS_ELF(hdr.eh)) {
314 		fs_off = hdr.eh.e_phoff;
315 		for (j = k = 0; k < hdr.eh.e_phnum && j < 2; k++) {
316 			if (xfsread(ino, ep + j, sizeof(ep[0])))
317 				return;
318 			if (ep[j].p_type == PT_LOAD)
319 				j++;
320 		}
321 		for (i = 0; i < 2; i++) {
322 			p = PTOV(ep[i].p_paddr & 0xffffff);
323 			fs_off = ep[i].p_offset;
324 			if (xfsread(ino, p, ep[i].p_filesz))
325 				return;
326 		}
327 		p += roundup2(ep[1].p_memsz, PAGE_SIZE);
328 		bootinfo.bi_symtab = VTOP(p);
329 		if (hdr.eh.e_shnum == hdr.eh.e_shstrndx + 3) {
330 			fs_off = hdr.eh.e_shoff + sizeof(es[0]) *
331 			    (hdr.eh.e_shstrndx + 1);
332 			if (xfsread(ino, &es, sizeof(es)))
333 				return;
334 			for (i = 0; i < 2; i++) {
335 				*(Elf32_Word *)p = es[i].sh_size;
336 				p += sizeof(es[i].sh_size);
337 				fs_off = es[i].sh_offset;
338 				if (xfsread(ino, p, es[i].sh_size))
339 					return;
340 				p += es[i].sh_size;
341 			}
342 		}
343 		addr = hdr.eh.e_entry & 0xffffff;
344 		bootinfo.bi_esymtab = VTOP(p);
345 	} else {
346 		printf("Invalid %s\n", "format");
347 		return;
348 	}
349 
350 	bootinfo.bi_kernelname = VTOP(kname);
351 	bootinfo.bi_bios_dev = dsk.drive;
352 	__exec((caddr_t)addr, RB_BOOTINFO | (opts & RBX_MASK),
353 	    MAKEBOOTDEV(dev_maj[dsk.type], dsk.slice, dsk.unit, dsk.part),
354 	    0, 0, 0, VTOP(&bootinfo));
355 }
356 
357 static int
358 parse()
359 {
360 	char *arg, *ep, *p, *q;
361 	const char *cp;
362 	unsigned int drv;
363 	int c, i, j;
364 	size_t k;
365 
366 	arg = cmd;
367 
368 	while ((c = *arg++)) {
369 		if (c == ' ' || c == '\t' || c == '\n')
370 			continue;
371 		for (p = arg; *p && *p != '\n' && *p != ' ' && *p != '\t'; p++);
372 		ep = p;
373 		if (*p)
374 			*p++ = 0;
375 		if (c == '-') {
376 			while ((c = *arg++)) {
377 				if (c == 'P') {
378 					if (*(uint8_t *)PTOV(0x496) & 0x10) {
379 						cp = "yes";
380 					} else {
381 						opts |= OPT_SET(RBX_DUAL) |
382 						    OPT_SET(RBX_SERIAL);
383 						cp = "no";
384 					}
385 					printf("Keyboard: %s\n", cp);
386 					continue;
387 #if SERIAL
388 				} else if (c == 'S') {
389 					j = 0;
390 					while ((u_int)(i = *arg++ - '0') <= 9)
391 						j = j * 10 + i;
392 					if (j > 0 && i == -'0') {
393 						comspeed = j;
394 						break;
395 					}
396 					/*
397 					 * Fall through to error below
398 					 * ('S' not in optstr[]).
399 					 */
400 #endif
401 				}
402 				for (i = 0; c != optstr[i]; i++)
403 					if (i == NOPT - 1)
404 						return (-1);
405 				opts ^= OPT_SET(flags[i]);
406 			}
407 #if SERIAL
408 			ioctrl = OPT_CHECK(RBX_DUAL) ? (IO_SERIAL|IO_KEYBOARD) :
409 			    OPT_CHECK(RBX_SERIAL) ? IO_SERIAL : IO_KEYBOARD;
410 			if (DO_SIO) {
411 				if (sio_init(115200 / comspeed) != 0)
412 					ioctrl &= ~IO_SERIAL;
413 			}
414 #endif
415 		} else {
416 			for (q = arg--; *q && *q != '('; q++);
417 			if (*q) {
418 				drv = -1;
419 				if (arg[1] == ':') {
420 					drv = *arg - '0';
421 					if (drv > 9)
422 						return (-1);
423 					arg += 2;
424 				}
425 				if (q - arg != 2)
426 					return (-1);
427 				for (i = 0; arg[0] != dev_nm[i][0] ||
428 				    arg[1] != dev_nm[i][1]; i++)
429 					if (i == NDEV - 1)
430 						return (-1);
431 				dsk.type = i;
432 				arg += 3;
433 				dsk.unit = *arg - '0';
434 				if (arg[1] != ',' || dsk.unit > 9)
435 					return (-1);
436 				arg += 2;
437 				dsk.slice = WHOLE_DISK_SLICE;
438 				if (arg[1] == ',') {
439 					dsk.slice = *arg - '0' + 1;
440 					if (dsk.slice > NDOSPART + 1)
441 						return (-1);
442 					arg += 2;
443 				}
444 				if (arg[1] != ')')
445 					return (-1);
446 				dsk.part = *arg - 'a';
447 				if (dsk.part > 7)
448 					return (-1);
449 				arg += 2;
450 				if (drv == -1)
451 					drv = dsk.unit;
452 				dsk.drive = (dsk.type <= TYPE_MAXHARD
453 				    ? DRV_HARD : 0) + drv;
454 				dsk_meta = 0;
455 			}
456 			k = ep - arg;
457 			if (k > 0) {
458 				if (k >= sizeof(knamebuf))
459 					return (-1);
460 				memcpy(knamebuf, arg, k + 1);
461 				kname = knamebuf;
462 			}
463 		}
464 		arg = p;
465 	}
466 	return (0);
467 }
468 
469 static int
470 dskread(void *buf, unsigned lba, unsigned nblk)
471 {
472 	struct dos_partition *dp;
473 	struct disklabel *d;
474 	char *sec;
475 	unsigned i;
476 	uint8_t sl;
477 	const char *reason;
478 
479 	if (!dsk_meta) {
480 		sec = dmadat->secbuf;
481 		dsk.start = 0;
482 		if (drvread(sec, DOSBBSECTOR, 1))
483 			return (-1);
484 		dp = (void *)(sec + DOSPARTOFF);
485 		sl = dsk.slice;
486 		if (sl < BASE_SLICE) {
487 			for (i = 0; i < NDOSPART; i++)
488 				if (dp[i].dp_typ == DOSPTYP_386BSD &&
489 				    (dp[i].dp_flag & 0x80 || sl < BASE_SLICE)) {
490 					sl = BASE_SLICE + i;
491 					if (dp[i].dp_flag & 0x80 ||
492 					    dsk.slice == COMPATIBILITY_SLICE)
493 						break;
494 				}
495 			if (dsk.slice == WHOLE_DISK_SLICE)
496 				dsk.slice = sl;
497 		}
498 		if (sl != WHOLE_DISK_SLICE) {
499 			if (sl != COMPATIBILITY_SLICE)
500 				dp += sl - BASE_SLICE;
501 			if (dp->dp_typ != DOSPTYP_386BSD) {
502 				reason = "slice";
503 				goto error;
504 			}
505 			dsk.start = dp->dp_start;
506 		}
507 		if (drvread(sec, dsk.start + LABELSECTOR, 1))
508 			return (-1);
509 		d = (void *)(sec + LABELOFFSET);
510 		if (d->d_magic != DISKMAGIC || d->d_magic2 != DISKMAGIC) {
511 			if (dsk.part != RAW_PART) {
512 				reason = "label";
513 				goto error;
514 			}
515 		} else {
516 			if (!dsk.init) {
517 				if (d->d_type == DTYPE_SCSI)
518 					dsk.type = TYPE_DA;
519 				dsk.init++;
520 			}
521 			if (dsk.part >= d->d_npartitions ||
522 			    !d->d_partitions[dsk.part].p_size) {
523 				reason = "partition";
524 				goto error;
525 			}
526 			dsk.start += d->d_partitions[dsk.part].p_offset;
527 			dsk.start -= d->d_partitions[RAW_PART].p_offset;
528 		}
529 	}
530 	return (drvread(buf, dsk.start + lba, nblk));
531 error:
532 	printf("Invalid %s\n", reason);
533 	return (-1);
534 }
535 
536 static void
537 printf(const char *fmt,...)
538 {
539 	va_list ap;
540 	static char buf[10];
541 	char *s;
542 	unsigned u;
543 	int c;
544 
545 	va_start(ap, fmt);
546 	while ((c = *fmt++)) {
547 		if (c == '%') {
548 			c = *fmt++;
549 			switch (c) {
550 			case 'c':
551 				putchar(va_arg(ap, int));
552 				continue;
553 			case 's':
554 				for (s = va_arg(ap, char *); *s; s++)
555 					putchar(*s);
556 				continue;
557 			case 'u':
558 				u = va_arg(ap, unsigned);
559 				s = buf;
560 				do
561 					*s++ = '0' + u % 10U;
562 				while (u /= 10U);
563 				while (--s >= buf)
564 					putchar(*s);
565 				continue;
566 			}
567 		}
568 		putchar(c);
569 	}
570 	va_end(ap);
571 	return;
572 }
573 
574 static void
575 putchar(int c)
576 {
577 
578 	if (c == '\n')
579 		xputc('\r');
580 	xputc(c);
581 }
582 
583 static int
584 drvread(void *buf, unsigned lba, unsigned nblk)
585 {
586 	static unsigned c = 0x2d5c7c2f;
587 
588 	if (!OPT_CHECK(RBX_QUIET)) {
589 		xputc(c = c << 8 | c >> 24);
590 		xputc('\b');
591 	}
592 	v86.ctl = V86_ADDR | V86_CALLF | V86_FLAGS;
593 	v86.addr = XREADORG;		/* call to xread in boot1 */
594 	v86.es = VTOPSEG(buf);
595 	v86.eax = lba;
596 	v86.ebx = VTOPOFF(buf);
597 	v86.ecx = lba >> 16;
598 	v86.edx = nblk << 8 | dsk.drive;
599 	v86int();
600 	v86.ctl = V86_FLAGS;
601 	if (V86_CY(v86.efl)) {
602 		printf("error %u lba %u\n", v86.eax >> 8 & 0xff, lba);
603 		return (-1);
604 	}
605 	return (0);
606 }
607 
608 static int
609 keyhit(unsigned ticks)
610 {
611 	uint32_t t0, t1;
612 
613 	if (OPT_CHECK(RBX_NOINTR))
614 		return (0);
615 	t0 = 0;
616 	for (;;) {
617 		if (xgetc(1))
618 			return (1);
619 		t1 = *(uint32_t *)PTOV(0x46c);
620 		if (!t0)
621 			t0 = t1;
622 		if ((uint32_t)(t1 - t0) >= ticks)
623 			return (0);
624 	}
625 }
626 
627 static int
628 xputc(int c)
629 {
630 
631 	if (DO_KBD)
632 		putc(c);
633 	if (DO_SIO)
634 		sio_putc(c);
635 	return (c);
636 }
637 
638 static int
639 getc(int fn)
640 {
641 
642 	v86.addr = 0x16;
643 	v86.eax = fn << 8;
644 	v86int();
645 	return (fn == 0 ? v86.eax & 0xff : !V86_ZR(v86.efl));
646 }
647 
648 static int
649 xgetc(int fn)
650 {
651 
652 	if (OPT_CHECK(RBX_NOINTR))
653 		return (0);
654 	for (;;) {
655 		if (DO_KBD && getc(1))
656 			return (fn ? 1 : getc(0));
657 		if (DO_SIO && sio_ischar())
658 			return (fn ? 1 : sio_getc());
659 		if (fn)
660 			return (0);
661 	}
662 }
663