gptboot.c revision 41013
1260067Skargl/*
2260067Skargl * Copyright (c) 1998 Robert Nordier
3260067Skargl * All rights reserved.
4260067Skargl *
5260067Skargl * Redistribution and use in source and binary forms are freely
6260067Skargl * permitted provided that the above copyright notice and this
7260067Skargl * paragraph and the following disclaimer are duplicated in all
8260067Skargl * such forms.
9260067Skargl *
10260067Skargl * This software is provided "AS IS" and without any express or
11260067Skargl * implied warranties, including, without limitation, the implied
12260067Skargl * warranties of merchantability and fitness for a particular
13260067Skargl * purpose.
14260067Skargl */
15260067Skargl
16260067Skargl/*
17260067Skargl *	$Id: boot2.c,v 1.15 1998/11/08 18:29:29 rnordier Exp $
18260067Skargl */
19260067Skargl
20260067Skargl#include <sys/param.h>
21260067Skargl#include <sys/reboot.h>
22260067Skargl#include <sys/diskslice.h>
23260067Skargl#include <sys/disklabel.h>
24260067Skargl#include <sys/dirent.h>
25260067Skargl#include <machine/bootinfo.h>
26260067Skargl
27260067Skargl#include <ufs/ffs/fs.h>
28260067Skargl#include <ufs/ufs/dinode.h>
29260067Skargl
30260067Skargl#include <stdarg.h>
31260067Skargl
32260067Skargl#include <a.out.h>
33260067Skargl#include <elf.h>
34260067Skargl
35260067Skargl#include <btxv86.h>
36260067Skargl
37260067Skargl#include "lib.h"
38260067Skargl
39260067Skargl#define RBX_ASKNAME	0x0	/* -a */
40260067Skargl#define RBX_SINGLE	0x1	/* -s */
41260067Skargl#define RBX_DFLTROOT	0x5	/* -r */
42260067Skargl#define RBX_KDB 	0x6	/* -d */
43260067Skargl#define RBX_CONFIG	0xa	/* -c */
44260067Skargl#define RBX_VERBOSE	0xb	/* -v */
45260067Skargl#define RBX_SERIAL	0xc	/* -h */
46260067Skargl#define RBX_CDROM	0xd	/* -C */
47260067Skargl#define RBX_GDB 	0xf	/* -g */
48260067Skargl#define RBX_DUAL	0x1d	/* -D */
49260067Skargl#define RBX_PROBEKBD	0x1e	/* -P */
50260067Skargl
51260067Skargl#define RBX_MASK	0xffff
52260067Skargl
53260067Skargl#define PATH_CONFIG	"/boot.config"
54260067Skargl#define PATH_BOOT3	"/boot/loader"
55260067Skargl#define PATH_KERNEL	"/kernel"
56260067Skargl#define PATH_HELP	"boot.help"
57260067Skargl
58260067Skargl#define ARGS		0x800
59260067Skargl#define NOPT		11
60260067Skargl#define BSIZEMAX	8192
61260067Skargl#define NDEV		5
62260067Skargl#define MEM_BASE	0x12
63260067Skargl#define MEM_EXT 	0x15
64260067Skargl#define V86_CY(x)	((x) & 1)
65260067Skargl#define V86_ZR(x)	((x) & 0x40)
66260067Skargl
67260067Skargl#define DRV_HARD	0x80
68260067Skargl#define DRV_MASK	0x7f
69260067Skargl
70260067Skargl#define MAJ_WD		0
71260067Skargl#define MAJ_WFD 	1
72260067Skargl#define MAJ_FD		2
73260067Skargl#define MAJ_DA		4
74260067Skargl
75260067Skarglextern uint32_t _end;
76260067Skargl
77260067Skarglstatic const char optstr[NOPT] = "DhaCcdgPrsv";
78260067Skarglstatic const unsigned char flags[NOPT] = {
79260067Skargl    RBX_DUAL,
80260145Skargl    RBX_SERIAL,
81260067Skargl    RBX_ASKNAME,
82260067Skargl    RBX_CDROM,
83260067Skargl    RBX_CONFIG,
84260067Skargl    RBX_KDB,
85260067Skargl    RBX_GDB,
86260067Skargl    RBX_PROBEKBD,
87260067Skargl    RBX_DFLTROOT,
88260067Skargl    RBX_SINGLE,
89260067Skargl    RBX_VERBOSE
90260067Skargl};
91260067Skargl
92260067Skarglstatic const char *const dev_nm[] = {"wd", "  ", "fd", "  ", "da"};
93260067Skargl
94260067Skarglstatic struct dsk {
95260067Skargl    unsigned drive;
96260067Skargl    unsigned type;
97260067Skargl    unsigned unit;
98260067Skargl    unsigned slice;
99260067Skargl    unsigned part;
100260067Skargl    unsigned start;
101260067Skargl    int init;
102260067Skargl    int meta;
103260067Skargl} dsk;
104260067Skarglstatic char cmd[512];
105260067Skarglstatic char kname[1024];
106260067Skarglstatic char help[2048];
107260067Skarglstatic uint32_t opts;
108260067Skarglstatic struct bootinfo bootinfo;
109260067Skarglstatic int ls;
110260067Skarglstatic uint32_t fs_off;
111260067Skarglstatic uint8_t ioctrl = 0x1;
112260067Skargl
113260067Skarglvoid exit(int);
114260067Skarglstatic void load(const char *);
115260067Skarglstatic int parse(char *);
116260067Skarglstatic void readfile(const char *, void *, size_t);
117260067Skarglstatic ino_t lookup(const char *);
118260067Skarglstatic int fsfind(const char *, ino_t *);
119260067Skarglstatic int xfsread(ino_t, void *, size_t);
120260067Skarglstatic ssize_t fsread(ino_t, void *, size_t);
121260067Skarglstatic int dskread(void *, unsigned, unsigned);
122260067Skarglstatic int printf(const char *,...);
123260067Skarglstatic void getstr(char *, int);
124260067Skarglstatic int putchar(int);
125260067Skarglstatic int getchar(void);
126260067Skarglstatic void *memcpy(void *, const void *, size_t);
127260067Skarglstatic int strcmp(const char *, const char *);
128260067Skarglstatic void *malloc(size_t);
129260067Skarglstatic uint32_t memsize(int);
130260067Skarglstatic uint32_t drvinfo(int);
131260067Skarglstatic int drvread(void *, unsigned, unsigned);
132static int keyhit(unsigned);
133static int xputc(int);
134static int xgetc(int);
135static void putc(int);
136static int getc(int);
137
138int
139main(void)
140{
141    int autoboot, helpon, i;
142
143    v86.ctl = V86_FLAGS;
144    dsk.drive = *(uint8_t *)PTOV(ARGS);
145    dsk.type = dsk.drive & DRV_HARD ? MAJ_WD : MAJ_FD;
146    dsk.unit = dsk.drive & DRV_MASK;
147    dsk.slice = *(uint8_t *)PTOV(ARGS + 1) + 1;
148    bootinfo.bi_version = BOOTINFO_VERSION;
149    bootinfo.bi_size = sizeof(bootinfo);
150    bootinfo.bi_basemem = memsize(MEM_BASE);
151    bootinfo.bi_extmem = memsize(MEM_EXT);
152    bootinfo.bi_memsizes_valid++;
153    for (i = 0; i < N_BIOS_GEOM; i++)
154	bootinfo.bi_bios_geom[i] = drvinfo(i);
155    autoboot = 2;
156    helpon = 1;
157    readfile(PATH_HELP, help, sizeof(help));
158    readfile(PATH_CONFIG, cmd, sizeof(cmd));
159    if (*cmd) {
160	printf("%s: %s", PATH_CONFIG, cmd);
161	if (parse(cmd))
162	    autoboot = 0;
163	*cmd = 0;
164    }
165    if (autoboot && !*kname) {
166	if (autoboot == 2) {
167	    memcpy(kname, PATH_BOOT3, sizeof(PATH_BOOT3));
168	    if (!keyhit(0x37)) {
169		load(kname);
170		autoboot = 1;
171	    }
172	}
173	if (autoboot == 1)
174	    memcpy(kname, PATH_KERNEL, sizeof(PATH_KERNEL));
175    }
176    for (;;) {
177	printf(" \n>> FreeBSD/i386 BOOT\n"
178	       "Default: %u:%s(%u,%c)%s\n"
179	       "%s"
180	       "boot: ",
181	       dsk.drive & DRV_MASK, dev_nm[dsk.type], dsk.unit,
182	       'a' + dsk.part, kname, helpon ? help : "");
183	if (ioctrl & 0x2)
184	    sio_flush();
185	if (!autoboot || keyhit(0x5a))
186	    getstr(cmd, sizeof(cmd));
187	else
188	    putchar('\n');
189	autoboot = helpon = 0;
190	if (parse(cmd))
191	    helpon = 1;
192	else
193	    load(kname);
194    }
195}
196
197void
198exit(int x)
199{
200}
201
202static void
203load(const char *fname)
204{
205    union {
206	struct exec ex;
207	Elf32_Ehdr eh;
208    } hdr;
209    Elf32_Phdr ep[2];
210    Elf32_Shdr es[2];
211    caddr_t p;
212    ino_t ino;
213    uint32_t addr, x;
214    int fmt, i, j;
215
216    if (!(ino = lookup(fname))) {
217	if (!ls)
218	    printf("No %s\n", fname);
219	return;
220    }
221    if (xfsread(ino, &hdr, sizeof(hdr)))
222	return;
223    if (N_GETMAGIC(hdr.ex) == ZMAGIC)
224	fmt = 0;
225    else if (IS_ELF(hdr.eh))
226	fmt = 1;
227    else {
228	printf("Invalid %s\n", "format");
229	return;
230    }
231    if (fmt == 0) {
232	addr = hdr.ex.a_entry & 0xffffff;
233	p = PTOV(addr);
234	fs_off = PAGE_SIZE;
235	if (xfsread(ino, p, hdr.ex.a_text))
236	    return;
237	p += roundup2(hdr.ex.a_text, PAGE_SIZE);
238	if (xfsread(ino, p, hdr.ex.a_data))
239	    return;
240	p += hdr.ex.a_data + roundup2(hdr.ex.a_bss, PAGE_SIZE);
241	bootinfo.bi_symtab = VTOP(p);
242	memcpy(p, &hdr.ex.a_syms, sizeof(hdr.ex.a_syms));
243	p += sizeof(hdr.ex.a_syms);
244	if (hdr.ex.a_syms) {
245	    if (xfsread(ino, p, hdr.ex.a_syms))
246		return;
247	    p += hdr.ex.a_syms;
248	    if (xfsread(ino, p, sizeof(int)))
249		return;
250	    x = *(uint32_t *)p;
251	    p += sizeof(int);
252	    x -= sizeof(int);
253	    if (xfsread(ino, p, x))
254		return;
255	    p += x;
256	}
257    } else {
258	fs_off = hdr.eh.e_phoff;
259	for (j = i = 0; i < hdr.eh.e_phoff && j < 2; i++) {
260	    if (xfsread(ino, ep + j, sizeof(ep[0])))
261		return;
262	    if (ep[j].p_type == PT_LOAD)
263		j++;
264	}
265	for (i = 0; i < 2; i++) {
266	    p = PTOV(ep[i].p_paddr & 0xffffff);
267	    fs_off = ep[i].p_offset;
268	    if (xfsread(ino, p, ep[i].p_filesz))
269		return;
270	}
271	p += roundup2(ep[1].p_memsz, PAGE_SIZE);
272	bootinfo.bi_symtab = VTOP(p);
273	if (hdr.eh.e_shnum == hdr.eh.e_shstrndx + 3) {
274	    fs_off = hdr.eh.e_shoff + sizeof(es[0]) *
275		(hdr.eh.e_shstrndx + 1);
276	    if (xfsread(ino, &es, sizeof(es)))
277		return;
278	    for (i = 0; i < 2; i++) {
279		memcpy(p, &es[i].sh_size, sizeof(es[i].sh_size));
280		p += sizeof(es[i].sh_size);
281		fs_off = es[i].sh_offset;
282		if (xfsread(ino, p, es[i].sh_size))
283		    return;
284		p += es[i].sh_size;
285	    }
286	}
287	addr = hdr.eh.e_entry & 0xffffff;
288    }
289    bootinfo.bi_esymtab = VTOP(p);
290    bootinfo.bi_kernelname = VTOP(fname);
291    __exec((caddr_t)addr, RB_BOOTINFO | (opts & RBX_MASK),
292	   MAKEBOOTDEV(dsk.type, 0, dsk.slice, dsk.unit, dsk.part),
293	   0, 0, 0, VTOP(&bootinfo));
294}
295
296static int
297parse(char *arg)
298{
299    char *p, *q;
300    int drv, c, i;
301
302    while ((c = *arg++)) {
303	if (c == ' ')
304	    continue;
305	for (p = arg; *p && *p != '\n' && *p != ' '; p++);
306	if (*p)
307	    *p++ = 0;
308	if (c == '-') {
309	    while ((c = *arg++)) {
310		for (i = 0; c != optstr[i]; i++)
311		    if (i == NOPT - 1)
312			return -1;
313		opts ^= 1 << flags[i];
314	    }
315	    if (opts & 1 << RBX_PROBEKBD) {
316		i = *(uint8_t *)PTOV(0x496) & 0x10;
317		printf("Keyboard: %s\n", i ? "yes" : "no");
318		if (!i)
319		    opts |= 1 << RBX_DUAL | 1 << RBX_SERIAL;
320		opts &= ~(1 << RBX_PROBEKBD);
321	    }
322	    ioctrl = opts & 1 << RBX_DUAL ? 0x3 :
323		     opts & 1 << RBX_SERIAL ? 0x2 : 0x1;
324	    if (ioctrl & 0x2)
325	        sio_init();
326	} else {
327	    for (q = arg--; *q && *q != '('; q++);
328	    if (*q) {
329		drv = -1;
330		if (arg[1] == ':') {
331		    if (*arg < '0' || *arg > '9')
332			return -1;
333		    drv = *arg - '0';
334		    arg += 2;
335		}
336		if (q - arg != 2)
337		    return -1;
338		for (i = 0; arg[0] != dev_nm[i][0] ||
339			    arg[1] != dev_nm[i][1]; i++)
340		    if (i == NDEV - 1)
341			return -1;
342		dsk.type = i;
343		arg += 3;
344		if (arg[1] != ',' || *arg < '0' || *arg > '9')
345		    return -1;
346		dsk.unit = *arg - '0';
347		arg += 2;
348		dsk.slice = WHOLE_DISK_SLICE;
349		if (arg[1] == ',') {
350		    if (*arg < '0' || *arg > '0' + NDOSPART)
351			return -1;
352		    if ((dsk.slice = *arg - '0'))
353			dsk.slice++;
354		    arg += 2;
355		}
356		if (arg[1] != ')' || *arg < 'a' || *arg > 'p')
357		    return -1;
358		dsk.part = *arg - 'a';
359		arg += 2;
360		if (drv == -1)
361		    drv = dsk.unit;
362		dsk.drive = (dsk.type == MAJ_WD ||
363			     dsk.type == MAJ_DA ? DRV_HARD : 0) + drv;
364		dsk.meta = 0;
365		fsread(0, NULL, 0);
366	    }
367	    if ((i = p - arg - !*(p - 1))) {
368		if (i >= sizeof(kname))
369		    return -1;
370		memcpy(kname, arg, i + 1);
371	    }
372	}
373	arg = p;
374    }
375    return 0;
376}
377
378static void
379readfile(const char *fname, void *buf, size_t size)
380{
381    ino_t ino;
382
383    if ((ino = lookup(fname)))
384	fsread(ino, buf, size);
385}
386
387static ino_t
388lookup(const char *path)
389{
390    char name[MAXNAMLEN + 1];
391    const char *s;
392    ino_t ino;
393    ssize_t n;
394    int dt;
395
396    ino = ROOTINO;
397    dt = DT_DIR;
398    for (;;) {
399	if (*path == '/')
400	    path++;
401	if (!*path)
402	    break;
403	for (s = path; *s && *s != '/'; s++);
404	if ((n = s - path) > MAXNAMLEN)
405	    return 0;
406	ls = *path == '?' && n == 1 && !*s;
407	memcpy(name, path, n);
408	name[n] = 0;
409	if ((dt = fsfind(name, &ino)) <= 0)
410	    break;
411	path = s;
412    }
413    return dt == DT_REG ? ino : 0;
414}
415
416static int
417fsfind(const char *name, ino_t * ino)
418{
419    char buf[DEV_BSIZE];
420    struct dirent *d;
421    char *s;
422    ssize_t n;
423
424    fs_off = 0;
425    while ((n = fsread(*ino, buf, DEV_BSIZE)) > 0)
426	for (s = buf; s < buf + DEV_BSIZE;) {
427	    d = (void *)s;
428	    if (ls)
429		printf("%s ", d->d_name);
430	    else if (!strcmp(name, d->d_name)) {
431		*ino = d->d_fileno;
432		return d->d_type;
433	    }
434	    s += d->d_reclen;
435	}
436    if (n != -1 && ls)
437	putchar('\n');
438    return 0;
439}
440
441static int
442xfsread(ino_t inode, void *buf, size_t nbyte)
443{
444    if (fsread(inode, buf, nbyte) != nbyte) {
445	printf("Invalid %s\n", "format");
446	return -1;
447    }
448    return 0;
449}
450
451static ssize_t
452fsread(ino_t inode, void *buf, size_t nbyte)
453{
454    static struct fs fs;
455    static struct dinode din;
456    static char *blkbuf;
457    static ufs_daddr_t *indbuf;
458    static ino_t inomap;
459    static ufs_daddr_t blkmap, indmap;
460    static unsigned fsblks;
461    char *s;
462    ufs_daddr_t lbn, addr;
463    size_t n, nb, off;
464
465    if (!dsk.meta) {
466	if (!blkbuf)
467	    blkbuf = malloc(BSIZEMAX);
468	inomap = 0;
469	if (dskread(blkbuf, SBOFF / DEV_BSIZE, SBSIZE / DEV_BSIZE))
470	    return -1;
471	memcpy(&fs, blkbuf, sizeof(fs));
472	if (fs.fs_magic != FS_MAGIC) {
473	    printf("Not ufs\n");
474	    return -1;
475	}
476	fsblks = fs.fs_bsize >> DEV_BSHIFT;
477	dsk.meta++;
478    }
479    if (!inode)
480	return 0;
481    if (inomap != inode) {
482	if (dskread(blkbuf, fsbtodb(&fs, ino_to_fsba(&fs, inode)),
483		    fsblks))
484	    return -1;
485	din = ((struct dinode *)blkbuf)[inode % INOPB(&fs)];
486	inomap = inode;
487	fs_off = 0;
488	blkmap = indmap = 0;
489    }
490    s = buf;
491    if (nbyte > (n = din.di_size - fs_off))
492	nbyte = n;
493    nb = nbyte;
494    while (nb) {
495	lbn = lblkno(&fs, fs_off);
496	if (lbn < NDADDR)
497	    addr = din.di_db[lbn];
498	else {
499	    if (indmap != din.di_ib[0]) {
500		if (!indbuf)
501		    indbuf = malloc(BSIZEMAX);
502		if (dskread(indbuf, fsbtodb(&fs, din.di_ib[0]),
503			    fsblks))
504		    return -1;
505		indmap = din.di_ib[0];
506	    }
507	    addr = indbuf[(lbn - NDADDR) % NINDIR(&fs)];
508	}
509	n = dblksize(&fs, &din, lbn);
510	if (blkmap != addr) {
511	    if (dskread(blkbuf, fsbtodb(&fs, addr), n >> DEV_BSHIFT))
512		return -1;
513	    blkmap = addr;
514	}
515	off = blkoff(&fs, fs_off);
516	n -= off;
517	if (n > nb)
518	    n = nb;
519	memcpy(s, blkbuf + off, n);
520	s += n;
521	fs_off += n;
522	nb -= n;
523    }
524    return nbyte;
525}
526
527static int
528dskread(void *buf, unsigned lba, unsigned nblk)
529{
530    static char *sec;
531    struct dos_partition *dp;
532    struct disklabel *d;
533    unsigned sl, i;
534
535    if (!dsk.meta) {
536	if (!sec)
537	    sec = malloc(DEV_BSIZE);
538	dsk.start = 0;
539	if (drvread(sec, DOSBBSECTOR, 1))
540	    return -1;
541	dp = (void *)(sec + DOSPARTOFF);
542	sl = dsk.slice;
543	if (sl < BASE_SLICE) {
544	    for (i = 0; i < NDOSPART; i++)
545		if (dp[i].dp_typ == DOSPTYP_386BSD &&
546		    (dp[i].dp_flag & 0x80 || sl < BASE_SLICE)) {
547		    sl = BASE_SLICE + i;
548		    if (dp[i].dp_flag & 0x80 ||
549			dsk.slice == COMPATIBILITY_SLICE)
550			break;
551		}
552	    if (dsk.slice == WHOLE_DISK_SLICE)
553		dsk.slice = sl;
554	}
555	if (sl != WHOLE_DISK_SLICE) {
556	    if (sl != COMPATIBILITY_SLICE)
557		dp += sl - BASE_SLICE;
558	    if (dp->dp_typ != DOSPTYP_386BSD) {
559		printf("Invalid %s\n", "slice");
560		return -1;
561	    }
562	    dsk.start = dp->dp_start;
563	}
564	if (drvread(sec, dsk.start + LABELSECTOR, 1))
565		return -1;
566	d = (void *)(sec + LABELOFFSET);
567	if (d->d_magic != DISKMAGIC || d->d_magic2 != DISKMAGIC) {
568	    if (dsk.part != RAW_PART) {
569		printf("Invalid %s\n", "label");
570		return -1;
571	    }
572	} else {
573	    if (!dsk.init) {
574		if (d->d_type == DTYPE_SCSI)
575		    dsk.type = MAJ_DA;
576		dsk.init++;
577	    }
578	    if (dsk.part >= d->d_npartitions) {
579		printf("Invalid %s\n", "partition");
580		return -1;
581	    }
582	    dsk.start = d->d_partitions[dsk.part].p_offset;
583	}
584    }
585    return drvread(buf, dsk.start + lba, nblk);
586}
587
588static int
589printf(const char *fmt,...)
590{
591    static const char digits[16] = "0123456789abcdef";
592    va_list ap;
593    char buf[10];
594    char *s;
595    unsigned r, u;
596    int c;
597
598    va_start(ap, fmt);
599    while ((c = *fmt++)) {
600	if (c == '%') {
601	    c = *fmt++;
602	    switch (c) {
603	    case 'c':
604		putchar(va_arg(ap, int));
605		continue;
606	    case 's':
607		for (s = va_arg(ap, char *); *s; s++)
608		    putchar(*s);
609		continue;
610	    case 'u':
611	    case 'x':
612		r = c == 'u' ? 10U : 16U;
613		u = va_arg(ap, unsigned);
614		s = buf;
615		do
616		    *s++ = digits[u % r];
617		while (u /= r);
618		while (--s >= buf)
619		    putchar(*s);
620		continue;
621	    }
622	}
623	putchar(c);
624    }
625    va_end(ap);
626    return 0;
627}
628
629static void
630getstr(char *str, int size)
631{
632    char *s;
633    int c;
634
635    s = str;
636    do {
637	switch (c = getchar()) {
638	case 0:
639	    break;
640	case '\b':
641	    if (s > str) {
642		s--;
643		putchar(c);
644		putchar(' ');
645	    } else
646		c = 0;
647	    break;
648	case '\n':
649	    *s = 0;
650	    break;
651	default:
652	    if (s - str < size - 1)
653		*s++ = c;
654	}
655	if (c)
656	    putchar(c);
657    } while (c != '\n');
658}
659
660static int
661putchar(int c)
662{
663    if (c == '\n')
664	xputc('\r');
665    return xputc(c);
666}
667
668static int
669getchar(void)
670{
671    int c;
672
673    c = xgetc(0);
674    if (c == '\r')
675	c = '\n';
676    return c;
677}
678
679static void *
680memcpy(void *dst, const void *src, size_t size)
681{
682    const char *s;
683    char *d;
684
685    for (d = dst, s = src; size; size--)
686	*d++ = *s++;
687    return dst;
688}
689
690static int
691strcmp(const char *s1, const char *s2)
692{
693    for (; *s1 == *s2 && *s1; s1++, s2++);
694    return (u_char)*s1 - (u_char)*s2;
695}
696
697static void *
698malloc(size_t size)
699{
700    static uint32_t next;
701    void *p;
702
703    if (!next)
704	next = roundup2(__base + _end, 0x10000) - __base;
705    p = (void *)next;
706    next += size;
707    return p;
708}
709
710static uint32_t
711memsize(int type)
712{
713    v86.addr = type;
714    v86.eax = 0x8800;
715    v86int();
716    return v86.eax;
717}
718
719static uint32_t
720drvinfo(int drive)
721{
722    v86.addr = 0x13;
723    v86.eax = 0x800;
724    v86.edx = DRV_HARD + drive;
725    v86int();
726    if (V86_CY(v86.efl))
727	return 0x4f010f;
728    return ((v86.ecx & 0xc0) << 18) | ((v86.ecx & 0xff00) << 8) |
729	   (v86.edx & 0xff00) | (v86.ecx & 0x3f);
730}
731
732static int
733drvread(void *buf, unsigned lba, unsigned nblk)
734{
735    static unsigned c = 0x2d5c7c2f;
736
737    printf("%c\b", c = c << 8 | c >> 24);
738    v86.ctl = V86_ADDR | V86_CALLF | V86_FLAGS;
739    v86.addr = 0x604;
740    v86.es = VTOPSEG(buf);
741    v86.eax = lba;
742    v86.ebx = VTOPOFF(buf);
743    v86.ecx = lba >> 16;
744    v86.edx = nblk << 8 | dsk.drive;
745    v86int();
746    v86.ctl = V86_FLAGS;
747    if (V86_CY(v86.efl)) {
748	printf("Disk error 0x%x (lba=0x%x)\n", v86.eax >> 8 & 0xff,
749	       lba);
750	return -1;
751    }
752    return 0;
753}
754
755static int
756keyhit(unsigned ticks)
757{
758    uint32_t t0, t1;
759
760    t0 = 0;
761    for (;;) {
762	if (xgetc(1))
763	    return 1;
764	t1 = *(uint32_t *)PTOV(0x46c);
765	if (!t0)
766	    t0 = t1;
767	if (t1 < t0 || t1 >= t0 + ticks)
768	    return 0;
769    }
770}
771
772static int
773xputc(int c)
774{
775    if (ioctrl & 0x1)
776	putc(c);
777    if (ioctrl & 0x2)
778	sio_putc(c);
779    return c;
780}
781
782static int
783xgetc(int fn)
784{
785    for (;;) {
786	if (ioctrl & 0x1 && getc(1))
787	    return fn ? 1 : getc(0);
788	if (ioctrl & 0x2 && sio_ischar())
789	    return fn ? 1 : sio_getc();
790	if (fn)
791	    return 0;
792    }
793}
794
795static void
796putc(int c)
797{
798    v86.addr = 0x10;
799    v86.eax = 0xe00 | (c & 0xff);
800    v86.ebx = 0x7;
801    v86int();
802}
803
804static int
805getc(int fn)
806{
807    v86.addr = 0x16;
808    v86.eax = fn << 8;
809    v86int();
810    return fn == 0 ? v86.eax & 0xff : !V86_ZR(v86.efl);
811}
812