gptboot.c revision 40404 
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/*
17 *	$Id: boot2.c,v 1.6 1998/10/13 23:43:38 rnordier Exp $
18 */
19
20#include <sys/param.h>
21#include <sys/reboot.h>
22#include <sys/diskslice.h>
23#include <sys/disklabel.h>
24#include <sys/dirent.h>
25#include <machine/bootinfo.h>
26
27#include <ufs/ffs/fs.h>
28#include <ufs/ufs/dinode.h>
29
30#include <stdarg.h>
31
32#include <a.out.h>
33#include <elf.h>
34
35#include <btxv86.h>
36
37#include "lib.h"
38
39#define RBX_ASKNAME	0x0	/* -a */
40#define RBX_SINGLE	0x1	/* -s */
41#define RBX_DFLTROOT	0x5	/* -r */
42#define RBX_KDB 	0x6	/* -d */
43#define RBX_CONFIG	0xa	/* -c */
44#define RBX_VERBOSE	0xb	/* -v */
45#define RBX_SERIAL	0xc	/* -h */
46#define RBX_CDROM	0xd	/* -C */
47#define RBX_GDB 	0xf	/* -g */
48#define RBX_DUAL	0x1d	/* -D */
49#define RBX_PROBEKBD	0x1e	/* -P */
50
51#define RBX_MASK	0xffff
52
53#define PATH_CONFIG	"/boot.config"
54#define PATH_BOOT3	"/boot/loader"
55#define PATH_KERNEL	"/kernel"
56#define PATH_HELP	"boot.help"
57
58#define ARGS		0x800
59#define NOPT		11
60#define XOPT		2
61#define BSIZEMAX	8192
62#define NDEV		5
63#define MEM_BASE	0x12
64#define MEM_EXT 	0x15
65#define V86_CY(x)	((x) & 1)
66#define V86_ZR(x)	((x) & 0x40)
67
68#define DRV_HARD	0x80
69#define DRV_MASK	0x7f
70
71#define MAJ_WD		0
72#define MAJ_WFD 	1
73#define MAJ_FD		2
74#define MAJ_DA		4
75
76extern uint32_t _end;
77
78static const char optstr[NOPT] = "DhaCcdgPrsv";
79static const unsigned char flags[NOPT] = {
80    RBX_DUAL,
81    RBX_SERIAL,
82    RBX_ASKNAME,
83    RBX_CDROM,
84    RBX_CONFIG,
85    RBX_KDB,
86    RBX_GDB,
87    RBX_PROBEKBD,
88    RBX_DFLTROOT,
89    RBX_SINGLE,
90    RBX_VERBOSE
91};
92
93static const char *const dev_nm[] = {"wd", "  ", "fd", "  ", "da"};
94
95static struct dsk {
96    unsigned drive;
97    unsigned type;
98    unsigned unit;
99    unsigned slice;
100    unsigned part;
101    unsigned start;
102    int init;
103    int meta;
104} dsk;
105static char cmd[512];
106static char kname[1024];
107static char help[2048];
108static uint32_t opts;
109static struct bootinfo bootinfo;
110static int ls;
111static uint32_t fs_off;
112static uint8_t ioctrl = 0x1;
113
114void exit(int);
115static void load(const char *);
116static int parse(char *);
117static void readfile(const char *, void *, size_t);
118static ino_t lookup(const char *);
119static int fsfind(const char *, ino_t *);
120static int xfsread(ino_t, void *, size_t);
121static ssize_t fsread(ino_t, void *, size_t);
122static int dskread(void *, unsigned, unsigned);
123static int printf(const char *,...);
124static void getstr(char *, int);
125static int putchar(int);
126static int getchar(void);
127static void *memcpy(void *, const void *, size_t);
128static int strcmp(const char *, const char *);
129static void *malloc(size_t);
130static uint32_t memsize(int);
131static uint32_t drvinfo(int);
132static int drvread(void *, unsigned, unsigned);
133static int keyhit(unsigned);
134static int xputc(int);
135static int xgetc(int);
136static void putc(int);
137static int getc(int);
138
139int
140main(void)
141{
142    int autoboot, helpon, i;
143
144    v86.ctl = V86_FLAGS;
145    dsk.drive = *(uint8_t *)PTOV(ARGS);
146    dsk.type = dsk.drive & DRV_HARD ? MAJ_WD : MAJ_FD;
147    dsk.unit = dsk.drive & DRV_MASK;
148    dsk.slice = *(uint8_t *)PTOV(ARGS + 1) + 1;
149    bootinfo.bi_version = BOOTINFO_VERSION;
150    bootinfo.bi_size = sizeof(bootinfo);
151    bootinfo.bi_basemem = memsize(MEM_BASE);
152    bootinfo.bi_extmem = memsize(MEM_EXT);
153    bootinfo.bi_memsizes_valid++;
154    for (i = 0; i < N_BIOS_GEOM; i++)
155	bootinfo.bi_bios_geom[i] = drvinfo(i);
156    autoboot = 2;
157    helpon = 1;
158    readfile(PATH_CONFIG, cmd, sizeof(cmd));
159    if (parse(cmd))
160	autoboot = 0;
161    else if (!*kname) {
162	if (autoboot == 2) {
163	    memcpy(kname, PATH_BOOT3, sizeof(PATH_BOOT3));
164	    if (!keyhit(0x37)) {
165		load(kname);
166		autoboot = 1;
167	    }
168	}
169	if (autoboot == 1)
170	    memcpy(kname, PATH_KERNEL, sizeof(PATH_KERNEL));
171    }
172    readfile(PATH_HELP, help, sizeof(help));
173    for (;;) {
174	printf(" \n>> FreeBSD/i386 BOOT\n"
175	       "Default: %u:%s(%u,%c)%s\n"
176	       "%s"
177	       "boot: ",
178	       dsk.drive & DRV_MASK, dev_nm[dsk.type], dsk.unit,
179	       'a' + dsk.part, kname, helpon ? help : "");
180	if (ioctrl & 0x2)
181	    sio_flush();
182	if (!autoboot || keyhit(0x5a))
183	    getstr(cmd, sizeof(cmd));
184	autoboot = helpon = 0;
185	if (parse(cmd))
186	    helpon = 1;
187	else
188	    load(kname);
189    }
190}
191
192void
193exit(int x)
194{
195}
196
197static void
198load(const char *fname)
199{
200    union {
201	struct exec ex;
202	Elf32_Ehdr eh;
203    } hdr;
204    Elf32_Phdr ep[2];
205    Elf32_Shdr es[2];
206    caddr_t p;
207    ino_t ino;
208    uint32_t addr, x;
209    int fmt, i, j;
210
211    if (!(ino = lookup(fname))) {
212	if (!ls)
213	    printf("No %s\n", fname);
214	return;
215    }
216    if (xfsread(ino, &hdr, sizeof(hdr)))
217	return;
218    if (N_GETMAGIC(hdr.ex) == ZMAGIC)
219	fmt = 0;
220    else if (IS_ELF(hdr.eh))
221	fmt = 1;
222    else {
223	printf("Invalid %s\n", "format");
224	return;
225    }
226    if (fmt == 0) {
227	addr = hdr.ex.a_entry & 0xffffff;
228	p = PTOV(addr);
229	printf("%s=0x%x ", "text", (unsigned)hdr.ex.a_text);
230	fs_off = PAGE_SIZE;
231	if (xfsread(ino, p, hdr.ex.a_text))
232	    return;
233	p += roundup2(hdr.ex.a_text, PAGE_SIZE);
234	printf("%s=0x%x ", "data", (unsigned)hdr.ex.a_data);
235	if (xfsread(ino, p, hdr.ex.a_data))
236	    return;
237	p += hdr.ex.a_data;
238	printf("%s=0x%x ", "bss", (unsigned)hdr.ex.a_bss);
239	p += roundup2(hdr.ex.a_bss, PAGE_SIZE);
240	bootinfo.bi_symtab = VTOP(p);
241	memcpy(p, &hdr.ex.a_syms, sizeof(hdr.ex.a_syms));
242	p += sizeof(hdr.ex.a_syms);
243	printf("symbols=[");
244	printf("+0x%x", (unsigned)hdr.ex.a_syms);
245	if (hdr.ex.a_syms) {
246	    if (xfsread(ino, p, hdr.ex.a_syms))
247		return;
248	    p += hdr.ex.a_syms;
249	    if (xfsread(ino, p, sizeof(int)))
250		return;
251	    x = *(uint32_t *)p;
252	    p += sizeof(int);
253	    x -= sizeof(int);
254	    printf("+0x%x", x);
255	    if (xfsread(ino, p, x))
256		return;
257	    p += x;
258	}
259    } else {
260	fs_off = hdr.eh.e_phoff;
261	for (j = i = 0; i < hdr.eh.e_phoff && j < 2; i++) {
262	    if (xfsread(ino, ep + j, sizeof(ep[0])))
263		return;
264	    if (ep[j].p_type == PT_LOAD)
265		j++;
266	}
267	for (i = 0; i < 2; i++) {
268	    p = PTOV(ep[i].p_paddr & 0xffffff);
269	    printf("%s=0x%x ", !i ? "text" : "data", ep[i].p_filesz);
270	    fs_off = ep[i].p_offset;
271	    if (xfsread(ino, p, ep[i].p_filesz))
272		return;
273	}
274	printf("%s=0x%x ", "bss", ep[1].p_memsz - ep[1].p_filesz);
275	p += roundup2(ep[1].p_memsz, PAGE_SIZE);
276	bootinfo.bi_symtab = VTOP(p);
277	printf("symbols=[");
278	if (hdr.eh.e_shnum == hdr.eh.e_shstrndx + 3) {
279	    fs_off = hdr.eh.e_shoff + sizeof(es[0]) *
280		(hdr.eh.e_shstrndx + 1);
281	    if (xfsread(ino, &es, sizeof(es)))
282		return;
283	    for (i = 0; i < 2; i++) {
284		memcpy(p, &es[i].sh_size, sizeof(es[i].sh_size));
285		p += sizeof(es[i].sh_size);
286		printf("+0x%x", es[i].sh_size);
287		fs_off = es[i].sh_offset;
288		if (xfsread(ino, p, es[i].sh_size))
289		    return;
290		p += es[i].sh_size;
291	    }
292	}
293	addr = hdr.eh.e_entry & 0xffffff;
294    }
295    bootinfo.bi_esymtab = VTOP(p);
296    printf("]\nentry=0x%x\n", addr);
297    bootinfo.bi_kernelname = VTOP(fname);
298    __exec((caddr_t)addr, RB_BOOTINFO | (opts & RBX_MASK),
299	   MAKEBOOTDEV(dsk.type, 0, dsk.slice, dsk.unit, dsk.part),
300	   0, 0, 0, VTOP(&bootinfo));
301}
302
303static int
304parse(char *arg)
305{
306    char *p, *q;
307    int drv, c, i;
308
309    while ((c = *arg++)) {
310	if (c == ' ')
311	    continue;
312	for (p = arg; *p && *p != '\n' && *p != ' '; p++);
313	if (*p)
314	    *p++ = 0;
315	if (c == '-') {
316	    while ((c = *arg++)) {
317		for (i = 0; c != optstr[i]; i++)
318		    if (i == NOPT - 1)
319			return -1;
320		if (i < XOPT)
321		    opts ^= 1 << flags[i];
322		else
323		    opts |= 1 << flags[i];
324	    }
325	    if (opts & 1 << RBX_PROBEKBD) {
326		i = *(uint8_t *)PTOV(0x496) & 0x10;
327		printf("Keyboard: %s\n", i ? "yes" : "no");
328		if (!i)
329		    opts |= 1 << RBX_DUAL | 1 << RBX_SERIAL;
330	    }
331	    ioctrl = opts & 1 << RBX_DUAL ? 0x3 :
332		     opts & 1 << RBX_SERIAL ? 0x2 : 0x1;
333	    if (ioctrl & 0x2)
334	        sio_init();
335	} else {
336	    for (q = arg--; *q && *q != '('; q++);
337	    if (*q) {
338		drv = -1;
339		if (arg[1] == ':') {
340		    if (*arg < '0' || *arg > '9')
341			return -1;
342		    drv = *arg - '0';
343		    arg += 2;
344		}
345		if (q - arg != 2)
346		    return -1;
347		for (i = 0; arg[0] != dev_nm[i][0] ||
348			    arg[1] != dev_nm[i][1]; i++)
349		    if (i == NDEV - 1)
350			return -1;
351		dsk.type = i;
352		arg += 3;
353		if (arg[1] != ',' || *arg < '0' || *arg > '9')
354		    return -1;
355		dsk.unit = *arg - '0';
356		arg += 2;
357		dsk.slice = WHOLE_DISK_SLICE;
358		if (arg[1] == ',') {
359		    if (*arg < '0' || *arg > '0' + NDOSPART)
360			return -1;
361		    if ((dsk.slice = *arg - '0'))
362			dsk.slice++;
363		    arg += 2;
364		}
365		if (arg[1] != ')' || *arg < 'a' || *arg > 'p')
366		    return -1;
367		dsk.part = *arg - 'a';
368		arg += 2;
369		if (drv == -1)
370		    drv = dsk.unit;
371		dsk.drive = (dsk.type == MAJ_WD ||
372			     dsk.type == MAJ_DA ? DRV_HARD : 0) + drv;
373		dsk.meta = 0;
374		fsread(0, NULL, 0);
375	    }
376	    if ((i = p - arg - !*(p - 1))) {
377		if (i >= sizeof(kname))
378		    return -1;
379		memcpy(kname, arg, i + 1);
380	    }
381	}
382	arg = p;
383    }
384    return 0;
385}
386
387static void
388readfile(const char *fname, void *buf, size_t size)
389{
390    ino_t ino;
391
392    if ((ino = lookup(fname)))
393	fsread(ino, buf, size);
394}
395
396static ino_t
397lookup(const char *path)
398{
399    char name[MAXNAMLEN + 1];
400    const char *s;
401    ino_t ino;
402    ssize_t n;
403    int dt;
404
405    ino = ROOTINO;
406    dt = DT_DIR;
407    for (;;) {
408	if (*path == '/')
409	    path++;
410	if (!*path)
411	    break;
412	for (s = path; *s && *s != '/'; s++);
413	if ((n = s - path) > MAXNAMLEN)
414	    return 0;
415	ls = *path == '?' && n == 1 && !*s;
416	memcpy(name, path, n);
417	name[n] = 0;
418	if ((dt = fsfind(name, &ino)) <= 0)
419	    break;
420	path = s;
421    }
422    return dt == DT_REG ? ino : 0;
423}
424
425static int
426fsfind(const char *name, ino_t * ino)
427{
428    char buf[DEV_BSIZE];
429    struct dirent *d;
430    char *s;
431    ssize_t n;
432
433    fs_off = 0;
434    while ((n = fsread(*ino, buf, DEV_BSIZE)) > 0)
435	for (s = buf; s < buf + DEV_BSIZE;) {
436	    d = (void *)s;
437	    if (ls)
438		printf("%s ", d->d_name);
439	    else if (!strcmp(name, d->d_name)) {
440		*ino = d->d_fileno;
441		return d->d_type;
442	    }
443	    s += d->d_reclen;
444	}
445    if (n != -1 && ls)
446	putchar('\n');
447    return 0;
448}
449
450static int
451xfsread(ino_t inode, void *buf, size_t nbyte)
452{
453    if (fsread(inode, buf, nbyte) != nbyte) {
454	printf("Invalid %s\n", "format");
455	return -1;
456    }
457    return 0;
458}
459
460static ssize_t
461fsread(ino_t inode, void *buf, size_t nbyte)
462{
463    static struct fs fs;
464    static struct dinode din;
465    static char *blkbuf;
466    static ufs_daddr_t *indbuf;
467    static ino_t inomap;
468    static ufs_daddr_t blkmap, indmap;
469    static unsigned fsblks;
470    char *s;
471    ufs_daddr_t lbn, addr;
472    size_t n, nb, off;
473
474    if (!dsk.meta) {
475	if (!blkbuf)
476	    blkbuf = malloc(BSIZEMAX);
477	inomap = 0;
478	if (dskread(blkbuf, SBOFF / DEV_BSIZE, SBSIZE / DEV_BSIZE))
479	    return -1;
480	memcpy(&fs, blkbuf, sizeof(fs));
481	if (fs.fs_magic != FS_MAGIC) {
482	    printf("Not ufs\n");
483	    return -1;
484	}
485	fsblks = fs.fs_bsize >> DEV_BSHIFT;
486	dsk.meta = 1;
487    }
488    if (!inode)
489	return 0;
490    if (inomap != inode) {
491	if (dskread(blkbuf, fsbtodb(&fs, ino_to_fsba(&fs, inode)),
492		    fsblks))
493	    return -1;
494	din = ((struct dinode *)blkbuf)[inode % INOPB(&fs)];
495	inomap = inode;
496	fs_off = 0;
497	blkmap = indmap = 0;
498    }
499    s = buf;
500    if (nbyte > (n = din.di_size - fs_off))
501	nbyte = n;
502    nb = nbyte;
503    while (nb) {
504	lbn = lblkno(&fs, fs_off);
505	if (lbn < NDADDR)
506	    addr = din.di_db[lbn];
507	else {
508	    if (indmap != din.di_ib[0]) {
509		if (!indbuf)
510		    indbuf = malloc(BSIZEMAX);
511		if (dskread(indbuf, fsbtodb(&fs, din.di_ib[0]),
512			    fsblks))
513		    return -1;
514		indmap = din.di_ib[0];
515	    }
516	    addr = indbuf[(lbn - NDADDR) % NINDIR(&fs)];
517	}
518	n = dblksize(&fs, &din, lbn);
519	if (blkmap != addr) {
520	    if (dskread(blkbuf, fsbtodb(&fs, addr), n >> DEV_BSHIFT))
521		return -1;
522	    blkmap = addr;
523	}
524	off = blkoff(&fs, fs_off);
525	n -= off;
526	if (n > nb)
527	    n = nb;
528	memcpy(s, blkbuf + off, n);
529	s += n;
530	fs_off += n;
531	nb -= n;
532    }
533    return nbyte;
534}
535
536static int
537dskread(void *buf, unsigned lba, unsigned nblk)
538{
539    static char *sec;
540    struct dos_partition *dp;
541    struct disklabel *d;
542    unsigned sl, i;
543
544    if (!dsk.meta) {
545	if (!sec)
546	    sec = malloc(DEV_BSIZE);
547	dsk.start = 0;
548	if (drvread(sec, DOSBBSECTOR, 1))
549	    return -1;
550	dp = (void *)(sec + DOSPARTOFF);
551	sl = dsk.slice;
552	if (sl < BASE_SLICE) {
553	    for (i = 0; i < NDOSPART; i++)
554		if (dp[i].dp_typ == DOSPTYP_386BSD &&
555		    (dp[i].dp_flag & 0x80 || sl < BASE_SLICE)) {
556		    sl = BASE_SLICE + i;
557		    if (dp[i].dp_flag & 0x80 ||
558			dsk.slice == COMPATIBILITY_SLICE)
559			break;
560		}
561	    if (dsk.slice == WHOLE_DISK_SLICE)
562		dsk.slice = sl;
563	}
564	if (sl != WHOLE_DISK_SLICE) {
565	    if (sl != COMPATIBILITY_SLICE)
566		dp += sl - BASE_SLICE;
567	    if (dp->dp_typ != DOSPTYP_386BSD) {
568		printf("Invalid %s\n", "slice");
569		return -1;
570	    }
571	    dsk.start = dp->dp_start;
572	}
573	if (drvread(sec, dsk.start + LABELSECTOR, 1))
574		return -1;
575	d = (void *)(sec + LABELOFFSET);
576	if (d->d_magic != DISKMAGIC || d->d_magic2 != DISKMAGIC) {
577	    if (dsk.part != RAW_PART) {
578		printf("Invalid %s\n", "label");
579		return -1;
580	    }
581	} else {
582	    if (!dsk.init) {
583		if (d->d_type == DTYPE_SCSI)
584		    dsk.type = MAJ_DA;
585		dsk.init++;
586	    }
587	    if (dsk.part >= d->d_npartitions) {
588		printf("Invalid %s\n", "partition");
589		return -1;
590	    }
591	    dsk.start = d->d_partitions[dsk.part].p_offset;
592	}
593    }
594    return drvread(buf, dsk.start + lba, nblk);
595}
596
597static int
598printf(const char *fmt,...)
599{
600    static const char digits[16] = "0123456789abcdef";
601    va_list ap;
602    char buf[10];
603    char *s;
604    unsigned r, u;
605    int c;
606
607    va_start(ap, fmt);
608    while ((c = *fmt++)) {
609	if (c == '%') {
610	    c = *fmt++;
611	    switch (c) {
612	    case 'c':
613		putchar(va_arg(ap, int));
614		continue;
615	    case 's':
616		for (s = va_arg(ap, char *); *s; s++)
617		    putchar(*s);
618		continue;
619	    case 'u':
620	    case 'x':
621		r = c == 'u' ? 10U : 16U;
622		u = va_arg(ap, unsigned);
623		s = buf;
624		do
625		    *s++ = digits[u % r];
626		while (u /= r);
627		while (--s >= buf)
628		    putchar(*s);
629		continue;
630	    }
631	}
632	putchar(c);
633    }
634    va_end(ap);
635    return 0;
636}
637
638static void
639getstr(char *str, int size)
640{
641    char *s;
642    int c;
643
644    s = str;
645    do {
646	switch (c = getchar()) {
647	case '\b':
648	    if (s > str)
649		s--;
650	    break;
651	case '\n':
652	    *s = 0;
653	    break;
654	default:
655	    if (s - str < size - 1)
656		*s++ = c;
657	}
658	putchar(c);
659    } while (c != '\n');
660}
661
662static int
663putchar(int c)
664{
665    if (c == '\n')
666	xputc('\r');
667    return xputc(c);
668}
669
670static int
671getchar(void)
672{
673    int c;
674
675    c = xgetc(0);
676    if (c == '\r')
677	c = '\n';
678    return c;
679}
680
681static void *
682memcpy(void *dst, const void *src, size_t size)
683{
684    const char *s;
685    char *d;
686
687    for (d = dst, s = src; size; size--)
688	*d++ = *s++;
689    return dst;
690}
691
692static int
693strcmp(const char *s1, const char *s2)
694{
695    for (; *s1 == *s2 && *s1; s1++, s2++);
696    return (u_char)*s1 - (u_char)*s2;
697}
698
699static void *
700malloc(size_t size)
701{
702    static uint32_t next;
703    void *p;
704
705    if (!next)
706	next = roundup2(__base + _end, 0x10000) - __base;
707    p = (void *)next;
708    next += size;
709    return p;
710}
711
712static uint32_t
713memsize(int type)
714{
715    v86.addr = type;
716    v86.eax = 0x8800;
717    v86int();
718    return v86.eax;
719}
720
721static uint32_t
722drvinfo(int drive)
723{
724    v86.addr = 0x13;
725    v86.eax = 0x800;
726    v86.edx = DRV_HARD + drive;
727    v86int();
728    if (V86_CY(v86.efl))
729	return 0x4f010f;
730    return ((v86.ecx & 0xc0) << 18) | ((v86.ecx & 0xff00) << 8) |
731	   (v86.edx & 0xff00) | (v86.ecx & 0x3f);
732}
733
734static int
735drvread(void *buf, unsigned lba, unsigned nblk)
736{
737    static unsigned c = 0x2d5c7c2f;
738
739    printf("%c\b", c = c << 8 | c >> 24);
740    v86.ctl = V86_ADDR | V86_CALLF | V86_FLAGS;
741    v86.addr = 0x604;
742    v86.eax = nblk;
743    v86.ebx = VTOPSEG(buf) << 16 | VTOPOFF(buf);
744    v86.ecx = lba;
745    v86.edx = 0x100 | dsk.drive;
746    v86int();
747    v86.ctl = V86_FLAGS;
748    if (V86_CY(v86.efl)) {
749	printf("Disk error 0x%x (lba=0x%x)\n", v86.eax >> 8 & 0xff,
750	       lba);
751	return -1;
752    }
753    return 0;
754}
755
756static int
757keyhit(unsigned ticks)
758{
759    uint32_t t0, t1;
760
761    t0 = 0;
762    for (;;) {
763	if (xgetc(1))
764	    return 1;
765	t1 = *(uint32_t *)PTOV(0x46c);
766	if (!t0)
767	    t0 = t1;
768	if (t1 < t0 || t1 >= t0 + ticks)
769	    return 0;
770    }
771}
772
773static int
774xputc(int c)
775{
776    if (ioctrl & 0x1)
777	putc(c);
778    if (ioctrl & 0x2)
779	sio_putc(c);
780    return c;
781}
782
783static int
784xgetc(int fn)
785{
786    for (;;) {
787	if (ioctrl & 0x1 && getc(1))
788	    return fn ? 1 : getc(0);
789	if (ioctrl & 0x2 && sio_ischar())
790	    return fn ? 1 : sio_getc();
791	if (fn)
792	    return 0;
793    }
794}
795
796static void
797putc(int c)
798{
799    v86.addr = 0x10;
800    v86.eax = 0xe00 | (c & 0xff);
801    v86.ebx = 0x7;
802    v86int();
803}
804
805static int
806getc(int fn)
807{
808    v86.addr = 0x16;
809    v86.eax = fn << 8;
810    v86int();
811    return fn == 0 ? v86.eax & 0xff : !V86_ZR(v86.efl);
812}
813