xref: /freebsd/stand/i386/isoboot/isoboot.c (revision cab6a39d7b343596a5823e65c0f7b426551ec22d)
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/gpt.h>
21 #include <sys/dirent.h>
22 #include <sys/reboot.h>
23 
24 #include <machine/bootinfo.h>
25 #include <machine/elf.h>
26 #include <machine/pc/bios.h>
27 #include <machine/psl.h>
28 
29 #include <stdarg.h>
30 
31 #include <a.out.h>
32 
33 #include <btxv86.h>
34 
35 #include "stand.h"
36 
37 #include "bootargs.h"
38 #include "lib.h"
39 #include "rbx.h"
40 #include "drv.h"
41 #include "cons.h"
42 #include "gpt.h"
43 #include "paths.h"
44 
45 #define ARGS		0x900
46 #define NOPT		14
47 #define NDEV		3
48 #define MEM_BASE	0x12
49 #define MEM_EXT 	0x15
50 
51 #define DRV_HARD	0x80
52 #define DRV_MASK	0x7f
53 
54 #define TYPE_AD		0
55 #define TYPE_DA		1
56 #define TYPE_MAXHARD	TYPE_DA
57 #define TYPE_FD		2
58 
59 extern uint32_t _end;
60 
61 static const char optstr[NOPT] = "DhaCcdgmnpqrsv"; /* Also 'P', 'S' */
62 static const unsigned char flags[NOPT] = {
63 	RBX_DUAL,
64 	RBX_SERIAL,
65 	RBX_ASKNAME,
66 	RBX_CDROM,
67 	RBX_CONFIG,
68 	RBX_KDB,
69 	RBX_GDB,
70 	RBX_MUTE,
71 	RBX_NOINTR,
72 	RBX_PAUSE,
73 	RBX_QUIET,
74 	RBX_DFLTROOT,
75 	RBX_SINGLE,
76 	RBX_VERBOSE
77 };
78 uint32_t opts;
79 
80 static const char *const dev_nm[NDEV] = {"ad", "da", "fd"};
81 static const unsigned char dev_maj[NDEV] = {30, 4, 2};
82 
83 static struct dsk dsk;
84 static char kname[1024];
85 static int comspeed = SIOSPD;
86 static struct bootinfo bootinfo;
87 
88 static vm_offset_t	high_heap_base;
89 static uint32_t		bios_basemem, bios_extmem, high_heap_size;
90 
91 static struct bios_smap smap;
92 
93 /*
94  * The minimum amount of memory to reserve in bios_extmem for the heap.
95  */
96 #define	HEAP_MIN	(3 * 1024 * 1024)
97 
98 static char *heap_next;
99 static char *heap_end;
100 
101 int main(void);
102 
103 static void load(void);
104 static int parse_cmds(char *, int *);
105 
106 static uint8_t ls, dsk_meta;
107 static uint32_t fs_off;
108 
109 #include "cd9660read.c"
110 
111 static inline int
112 xfsread(uint64_t inode, void *buf, size_t nbyte)
113 {
114 
115 	if ((size_t)cd9660_fsread(inode, buf, nbyte) != nbyte) {
116 		printf("Invalid %s\n", "format");
117 		return (-1);
118 	}
119 	return (0);
120 }
121 
122 static void
123 bios_getmem(void)
124 {
125 	uint64_t size;
126 
127 	/* Parse system memory map */
128 	v86.ebx = 0;
129 	do {
130 		v86.ctl = V86_FLAGS;
131 		v86.addr = MEM_EXT;		/* int 0x15 function 0xe820*/
132 		v86.eax = 0xe820;
133 		v86.ecx = sizeof(struct bios_smap);
134 		v86.edx = SMAP_SIG;
135 		v86.es = VTOPSEG(&smap);
136 		v86.edi = VTOPOFF(&smap);
137 		v86int();
138 		if ((v86.efl & 1) || (v86.eax != SMAP_SIG))
139 			break;
140 		/* look for a low-memory segment that's large enough */
141 		if ((smap.type == SMAP_TYPE_MEMORY) && (smap.base == 0) &&
142 		    (smap.length >= (512 * 1024)))
143 			bios_basemem = smap.length;
144 		/* look for the first segment in 'extended' memory */
145 		if ((smap.type == SMAP_TYPE_MEMORY) &&
146 		    (smap.base == 0x100000)) {
147 			bios_extmem = smap.length;
148 		}
149 
150 		/*
151 		 * Look for the largest segment in 'extended' memory beyond
152 		 * 1MB but below 4GB.
153 		 */
154 		if ((smap.type == SMAP_TYPE_MEMORY) &&
155 		    (smap.base > 0x100000) && (smap.base < 0x100000000ull)) {
156 			size = smap.length;
157 
158 			/*
159 			 * If this segment crosses the 4GB boundary,
160 			 * truncate it.
161 			 */
162 			if (smap.base + size > 0x100000000ull)
163 				size = 0x100000000ull - smap.base;
164 
165 			if (size > high_heap_size) {
166 				high_heap_size = size;
167 				high_heap_base = smap.base;
168 			}
169 		}
170 	} while (v86.ebx != 0);
171 
172 	/* Fall back to the old compatibility function for base memory */
173 	if (bios_basemem == 0) {
174 		v86.ctl = 0;
175 		v86.addr = 0x12;		/* int 0x12 */
176 		v86int();
177 
178 		bios_basemem = (v86.eax & 0xffff) * 1024;
179 	}
180 
181 	/*
182 	 * Fall back through several compatibility functions for extended
183 	 * memory
184 	 */
185 	if (bios_extmem == 0) {
186 		v86.ctl = V86_FLAGS;
187 		v86.addr = 0x15;		/* int 0x15 function 0xe801*/
188 		v86.eax = 0xe801;
189 		v86int();
190 		if (!(v86.efl & 1)) {
191 			bios_extmem = ((v86.ecx & 0xffff) +
192 			    ((v86.edx & 0xffff) * 64)) * 1024;
193 		}
194 	}
195 	if (bios_extmem == 0) {
196 		v86.ctl = 0;
197 		v86.addr = 0x15;		/* int 0x15 function 0x88*/
198 		v86.eax = 0x8800;
199 		v86int();
200 		bios_extmem = (v86.eax & 0xffff) * 1024;
201 	}
202 
203 	/*
204 	 * If we have extended memory and did not find a suitable heap
205 	 * region in the SMAP, use the last 3MB of 'extended' memory as a
206 	 * high heap candidate.
207 	 */
208 	if (bios_extmem >= HEAP_MIN && high_heap_size < HEAP_MIN) {
209 		high_heap_size = HEAP_MIN;
210 		high_heap_base = bios_extmem + 0x100000 - HEAP_MIN;
211 	}
212 }
213 
214 int
215 main(void)
216 {
217 	char cmd[512], cmdtmp[512];
218 	ssize_t sz;
219 	int autoboot, dskupdated;
220 	uint64_t ino;
221 
222 	bios_getmem();
223 
224 	if (high_heap_size > 0) {
225 		heap_end = PTOV(high_heap_base + high_heap_size);
226 		heap_next = PTOV(high_heap_base);
227 	} else {
228 		heap_next = (char *)
229 		    (roundup2(__base + (int32_t)&_end, 0x10000) - __base);
230 		heap_end = (char *)PTOV(bios_basemem);
231 	}
232 	setheap(heap_next, heap_end);
233 
234 	v86.ctl = V86_FLAGS;
235 	v86.efl = PSL_RESERVED_DEFAULT | PSL_I;
236 	dsk.drive = *(uint8_t *)PTOV(ARGS);
237 	dsk.type = dsk.drive & DRV_HARD ? TYPE_AD : TYPE_FD;
238 	dsk.unit = dsk.drive & DRV_MASK;
239 	dsk.part = -1;
240 	dsk.start = 0;
241 	bootinfo.bi_version = BOOTINFO_VERSION;
242 	bootinfo.bi_size = sizeof(bootinfo);
243 	bootinfo.bi_basemem = bios_basemem / 1024;
244 	bootinfo.bi_extmem = bios_extmem / 1024;
245 	bootinfo.bi_memsizes_valid++;
246 	bootinfo.bi_bios_dev = dsk.drive;
247 
248 	autoboot = 1;
249 	*cmd = '\0';
250 
251 	for (;;) {
252 		*kname = '\0';
253 		if ((ino = cd9660_lookup(PATH_CONFIG)) ||
254 		    (ino = cd9660_lookup(PATH_DOTCONFIG))) {
255 			sz = cd9660_fsread(ino, cmd, sizeof(cmd) - 1);
256 			cmd[(sz < 0) ? 0 : sz] = '\0';
257 		}
258 		if (*cmd != '\0') {
259 			memcpy(cmdtmp, cmd, sizeof(cmdtmp));
260 			if (parse_cmds(cmdtmp, &dskupdated))
261 				break;
262 			if (!OPT_CHECK(RBX_QUIET))
263 				printf("%s: %s", PATH_CONFIG, cmd);
264 			*cmd = '\0';
265 		}
266 
267 		if (autoboot && keyhit(3)) {
268 			if (*kname == '\0')
269 				memcpy(kname, PATH_LOADER, sizeof(PATH_LOADER));
270 			break;
271 		}
272 		autoboot = 0;
273 
274 		/*
275 		 * Try to exec stage 3 boot loader. If interrupted by a
276 		 * keypress, or in case of failure, try to load a kernel
277 		 * directly instead.
278 		 */
279 		if (*kname != '\0')
280 			load();
281 		memcpy(kname, PATH_LOADER, sizeof(PATH_LOADER));
282 		load();
283 		memcpy(kname, PATH_KERNEL, sizeof(PATH_KERNEL));
284 		load();
285 		dsk_meta = 0;
286 	}
287 
288 	/* Present the user with the boot2 prompt. */
289 
290 	for (;;) {
291 		if (!OPT_CHECK(RBX_QUIET)) {
292 			printf("\nFreeBSD/x86 boot\n"
293 			    "Default: %u:%s(%up%u)%s\n"
294 			    "boot: ",
295 			    dsk.drive & DRV_MASK, dev_nm[dsk.type], dsk.unit,
296 			    dsk.part, kname);
297 		}
298 		if (ioctrl & IO_SERIAL)
299 			sio_flush();
300 		*cmd = '\0';
301 		if (keyhit(0))
302 			getstr(cmd, sizeof(cmd));
303 		else if (!OPT_CHECK(RBX_QUIET))
304 			putchar('\n');
305 		if (parse_cmds(cmd, &dskupdated)) {
306 			putchar('\a');
307 			continue;
308 		}
309 		load();
310 	}
311 	/* NOTREACHED */
312 }
313 
314 /* Needed so btxld can link us properly; do not remove. */
315 void
316 exit(int x)
317 {
318 
319 	while (1);
320 	__unreachable();
321 }
322 
323 static void
324 load(void)
325 {
326 	union {
327 		struct exec ex;
328 		Elf32_Ehdr eh;
329 	} hdr;
330 	static Elf32_Phdr ep[2];
331 	static Elf32_Shdr es[2];
332 	caddr_t p;
333 	uint64_t ino;
334 	uint32_t addr, x;
335 	int fmt, i, j;
336 
337 	if (!(ino = cd9660_lookup(kname))) {
338 		if (!ls) {
339 			printf("%s: No %s on %u:%s(%up%u)\n", BOOTPROG,
340 			    kname, dsk.drive & DRV_MASK, dev_nm[dsk.type],
341 			    dsk.unit,
342 			    dsk.part);
343 		}
344 		return;
345 	}
346 	if (xfsread(ino, &hdr, sizeof(hdr)))
347 		return;
348 	if (N_GETMAGIC(hdr.ex) == ZMAGIC)
349 		fmt = 0;
350 	else if (IS_ELF(hdr.eh))
351 		fmt = 1;
352 	else {
353 		printf("Invalid %s\n", "format");
354 		return;
355 	}
356 	if (fmt == 0) {
357 		addr = hdr.ex.a_entry & 0xffffff;
358 		p = PTOV(addr);
359 		fs_off = PAGE_SIZE;
360 		if (xfsread(ino, p, hdr.ex.a_text))
361 			return;
362 		p += roundup2(hdr.ex.a_text, PAGE_SIZE);
363 		if (xfsread(ino, p, hdr.ex.a_data))
364 			return;
365 		p += hdr.ex.a_data + roundup2(hdr.ex.a_bss, PAGE_SIZE);
366 		bootinfo.bi_symtab = VTOP(p);
367 		memcpy(p, &hdr.ex.a_syms, sizeof(hdr.ex.a_syms));
368 		p += sizeof(hdr.ex.a_syms);
369 		if (hdr.ex.a_syms) {
370 			if (xfsread(ino, p, hdr.ex.a_syms))
371 				return;
372 			p += hdr.ex.a_syms;
373 			if (xfsread(ino, p, sizeof(int)))
374 				return;
375 			x = *(uint32_t *)p;
376 			p += sizeof(int);
377 			x -= sizeof(int);
378 			if (xfsread(ino, p, x))
379 				return;
380 			p += x;
381 		}
382 	} else {
383 		fs_off = hdr.eh.e_phoff;
384 		for (j = i = 0; i < hdr.eh.e_phnum && j < 2; i++) {
385 			if (xfsread(ino, ep + j, sizeof(ep[0])))
386 				return;
387 			if (ep[j].p_type == PT_LOAD)
388 				j++;
389 		}
390 		for (i = 0; i < 2; i++) {
391 			p = PTOV(ep[i].p_paddr & 0xffffff);
392 			fs_off = ep[i].p_offset;
393 			if (xfsread(ino, p, ep[i].p_filesz))
394 				return;
395 		}
396 		p += roundup2(ep[1].p_memsz, PAGE_SIZE);
397 		bootinfo.bi_symtab = VTOP(p);
398 		if (hdr.eh.e_shnum == hdr.eh.e_shstrndx + 3) {
399 			fs_off = hdr.eh.e_shoff + sizeof(es[0]) *
400 			    (hdr.eh.e_shstrndx + 1);
401 			if (xfsread(ino, &es, sizeof(es)))
402 				return;
403 			for (i = 0; i < 2; i++) {
404 				memcpy(p, &es[i].sh_size,
405 				    sizeof(es[i].sh_size));
406 				p += sizeof(es[i].sh_size);
407 				fs_off = es[i].sh_offset;
408 				if (xfsread(ino, p, es[i].sh_size))
409 					return;
410 				p += es[i].sh_size;
411 			}
412 		}
413 		addr = hdr.eh.e_entry & 0xffffff;
414 	}
415 	bootinfo.bi_esymtab = VTOP(p);
416 	bootinfo.bi_kernelname = VTOP(kname);
417 	bootinfo.bi_bios_dev = dsk.drive;
418 	__exec((caddr_t)addr, RB_BOOTINFO | (opts & RBX_MASK),
419 	    MAKEBOOTDEV(dev_maj[dsk.type], 0, dsk.unit, 0),
420 	    0, 0, 0, VTOP(&bootinfo));
421 }
422 
423 static int
424 parse_cmds(char *cmdstr, int *dskupdated)
425 {
426 	char *arg;
427 	char *ep, *p, *q;
428 	const char *cp;
429 	unsigned int drv;
430 	int c, i, j;
431 
432 	arg = cmdstr;
433 	*dskupdated = 0;
434 	while ((c = *arg++)) {
435 		if (c == ' ' || c == '\t' || c == '\n')
436 			continue;
437 		for (p = arg; *p && *p != '\n' && *p != ' ' && *p != '\t'; p++);
438 		ep = p;
439 		if (*p)
440 			*p++ = 0;
441 		if (c == '-') {
442 			while ((c = *arg++)) {
443 				if (c == 'P') {
444 					if (*(uint8_t *)PTOV(0x496) & 0x10) {
445 						cp = "yes";
446 					} else {
447 						opts |= OPT_SET(RBX_DUAL) |
448 						    OPT_SET(RBX_SERIAL);
449 						cp = "no";
450 					}
451 					printf("Keyboard: %s\n", cp);
452 					continue;
453 				} else if (c == 'S') {
454 					j = 0;
455 					while ((unsigned int)(i = *arg++ - '0')
456 					    <= 9)
457 						j = j * 10 + i;
458 					if (j > 0 && i == -'0') {
459 						comspeed = j;
460 						break;
461 					}
462 					/*
463 					 * Fall through to error below
464 					 * ('S' not in optstr[]).
465 					 */
466 				}
467 				for (i = 0; c != optstr[i]; i++)
468 					if (i == NOPT - 1)
469 						return (-1);
470 				opts ^= OPT_SET(flags[i]);
471 			}
472 			ioctrl = OPT_CHECK(RBX_DUAL) ? (IO_SERIAL|IO_KEYBOARD) :
473 			    OPT_CHECK(RBX_SERIAL) ? IO_SERIAL : IO_KEYBOARD;
474 			if (ioctrl & IO_SERIAL) {
475 				if (sio_init(115200 / comspeed) != 0)
476 					ioctrl &= ~IO_SERIAL;
477 			}
478 		} else {
479 			for (q = arg--; *q && *q != '('; q++);
480 			if (*q) {
481 				drv = -1;
482 				if (arg[1] == ':') {
483 					drv = *arg - '0';
484 					if (drv > 9)
485 						return (-1);
486 					arg += 2;
487 				}
488 				if (q - arg != 2)
489 					return (-1);
490 				for (i = 0; arg[0] != dev_nm[i][0] ||
491 				    arg[1] != dev_nm[i][1]; i++)
492 					if (i == NDEV - 1)
493 						return (-1);
494 				dsk.type = i;
495 				arg += 3;
496 				dsk.unit = *arg - '0';
497 				if (arg[1] != 'p' || dsk.unit > 9)
498 					return (-1);
499 				arg += 2;
500 				dsk.part = *arg - '0';
501 				if (dsk.part < 1 || dsk.part > 9)
502 					return (-1);
503 				arg++;
504 				if (arg[0] != ')')
505 					return (-1);
506 				arg++;
507 				if (drv == -1)
508 					drv = dsk.unit;
509 				dsk.drive = (dsk.type <= TYPE_MAXHARD
510 				    ? DRV_HARD : 0) + drv;
511 				*dskupdated = 1;
512 			}
513 			if ((i = ep - arg)) {
514 				if ((size_t)i >= sizeof(kname))
515 					return (-1);
516 				memcpy(kname, arg, i + 1);
517 			}
518 		}
519 		arg = p;
520 	}
521 	return (0);
522 }
523