Initial import from FreeBSD RELENG_4:
[dragonfly.git] / sys / boot / pc32 / boot2 / boot2.c
CommitLineData
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MD
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 * $FreeBSD: src/sys/boot/i386/boot2/boot2.c,v 1.28.2.7 2002/10/10 15:53:24 iwasaki 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#include <machine/elf.h>
27
28#include <ufs/ffs/fs.h>
29#include <ufs/ufs/dinode.h>
30
31#include <stdarg.h>
32
33#include <a.out.h>
34
35#include <btxv86.h>
36
37#include "boot2.h"
38#include "lib.h"
39
40#define RBX_ASKNAME 0x0 /* -a */
41#define RBX_SINGLE 0x1 /* -s */
42#define RBX_DFLTROOT 0x5 /* -r */
43#define RBX_KDB 0x6 /* -d */
44#define RBX_CONFIG 0xa /* -c */
45#define RBX_VERBOSE 0xb /* -v */
46#define RBX_SERIAL 0xc /* -h */
47#define RBX_CDROM 0xd /* -C */
48#define RBX_GDB 0xf /* -g */
49#define RBX_DUAL 0x1d /* -D */
50#define RBX_PROBEKBD 0x1e /* -P */
51#define RBX_NOINTR 0x1f /* -n */
52
53#define RBX_MASK 0xffff
54
55#define PATH_CONFIG "/boot.config"
56#define PATH_BOOT3 "/boot/loader"
57#define PATH_KERNEL "/kernel"
58
59#define ARGS 0x900
60#define NOPT 12
61#define BSIZEMAX 16384
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 TYPE_AD 0
72#define TYPE_WD 1
73#define TYPE_WFD 2
74#define TYPE_FD 3
75#define TYPE_DA 4
76
77extern uint32_t _end;
78
79static const char optstr[NOPT] = "DhaCcdgnPrsv";
80static const unsigned char flags[NOPT] = {
81 RBX_DUAL,
82 RBX_SERIAL,
83 RBX_ASKNAME,
84 RBX_CDROM,
85 RBX_CONFIG,
86 RBX_KDB,
87 RBX_GDB,
88 RBX_NOINTR,
89 RBX_PROBEKBD,
90 RBX_DFLTROOT,
91 RBX_SINGLE,
92 RBX_VERBOSE
93};
94
95static const char *const dev_nm[] = {"ad", "wd", " ", "fd", "da"};
96static const unsigned dev_maj[] = {30, 0, 1, 2, 4};
97
98static struct dsk {
99 unsigned drive;
100 unsigned type;
101 unsigned unit;
102 unsigned slice;
103 unsigned part;
104 unsigned start;
105 int init;
106 int meta;
107} dsk;
108static char cmd[512];
109static char kname[1024];
110static uint32_t opts;
111static struct bootinfo bootinfo;
112static int ls;
113static uint32_t fs_off;
114static uint8_t ioctrl = 0x1;
115
116void exit(int);
117static void load(const char *);
118static int parse(char *);
119static ino_t lookup(const char *);
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 int putchar(int);
125static void *memcpy(void *, const void *, size_t);
126static void *malloc(size_t);
127static uint32_t memsize(int);
128static int drvread(void *, unsigned, unsigned);
129static int keyhit(unsigned);
130static int xputc(int);
131static int xgetc(int);
132static int getc(int);
133
134static inline void
135readfile(const char *fname, void *buf, size_t size)
136{
137 ino_t ino;
138
139 if ((ino = lookup(fname)))
140 fsread(ino, buf, size);
141}
142
143static inline int
144strcmp(const char *s1, const char *s2)
145{
146 for (; *s1 == *s2 && *s1; s1++, s2++);
147 return (u_char)*s1 - (u_char)*s2;
148}
149
150static inline int
151fsfind(const char *name, ino_t * ino)
152{
153 char buf[DEV_BSIZE];
154 struct dirent *d;
155 char *s;
156 ssize_t n;
157
158 fs_off = 0;
159 while ((n = fsread(*ino, buf, DEV_BSIZE)) > 0)
160 for (s = buf; s < buf + DEV_BSIZE;) {
161 d = (void *)s;
162 if (ls)
163 printf("%s ", d->d_name);
164 else if (!strcmp(name, d->d_name)) {
165 *ino = d->d_fileno;
166 return d->d_type;
167 }
168 s += d->d_reclen;
169 }
170 if (n != -1 && ls)
171 putchar('\n');
172 return 0;
173}
174
175static inline int
176getchar(void)
177{
178 int c;
179
180 c = xgetc(0);
181 if (c == '\r')
182 c = '\n';
183 return c;
184}
185
186static inline void
187getstr(char *str, int size)
188{
189 char *s;
190 int c;
191
192 s = str;
193 do {
194 switch (c = getchar()) {
195 case 0:
196 break;
197 case '\b':
198 case '\177':
199 if (s > str) {
200 s--;
201 putchar('\b');
202 putchar(' ');
203 } else
204 c = 0;
205 break;
206 case '\n':
207 *s = 0;
208 break;
209 default:
210 if (s - str < size - 1)
211 *s++ = c;
212 }
213 if (c)
214 putchar(c);
215 } while (c != '\n');
216}
217
218static inline uint32_t
219drvinfo(int drive)
220{
221 v86.addr = 0x13;
222 v86.eax = 0x800;
223 v86.edx = DRV_HARD + drive;
224 v86int();
225 if (V86_CY(v86.efl))
226 return 0x4f010f;
227 return ((v86.ecx & 0xc0) << 18) | ((v86.ecx & 0xff00) << 8) |
228 (v86.edx & 0xff00) | (v86.ecx & 0x3f);
229}
230
231static inline void
232putc(int c)
233{
234 v86.addr = 0x10;
235 v86.eax = 0xe00 | (c & 0xff);
236 v86.ebx = 0x7;
237 v86int();
238}
239
240int
241main(void)
242{
243 int autoboot, i;
244
245 v86.ctl = V86_FLAGS;
246 dsk.drive = *(uint8_t *)PTOV(ARGS);
247 dsk.type = dsk.drive & DRV_HARD ? TYPE_AD : TYPE_FD;
248 dsk.unit = dsk.drive & DRV_MASK;
249 dsk.slice = *(uint8_t *)PTOV(ARGS + 1) + 1;
250 bootinfo.bi_version = BOOTINFO_VERSION;
251 bootinfo.bi_size = sizeof(bootinfo);
252 bootinfo.bi_basemem = 0; /* XXX will be filled by loader or kernel */
253 bootinfo.bi_extmem = memsize(MEM_EXT);
254 bootinfo.bi_memsizes_valid++;
255 for (i = 0; i < N_BIOS_GEOM; i++)
256 bootinfo.bi_bios_geom[i] = drvinfo(i);
257 autoboot = 2;
258 readfile(PATH_CONFIG, cmd, sizeof(cmd));
259 if (*cmd) {
260 printf("%s: %s", PATH_CONFIG, cmd);
261 if (parse(cmd))
262 autoboot = 0;
263 *cmd = 0;
264 }
265 if (autoboot && !*kname) {
266 if (autoboot == 2) {
267 memcpy(kname, PATH_BOOT3, sizeof(PATH_BOOT3));
268 if (!keyhit(0x37)) {
269 load(kname);
270 autoboot = 1;
271 }
272 }
273 if (autoboot == 1)
274 memcpy(kname, PATH_KERNEL, sizeof(PATH_KERNEL));
275 }
276 for (;;) {
277 printf(" \n>> FreeBSD/i386 BOOT\n"
278 "Default: %u:%s(%u,%c)%s\n"
279 "boot: ",
280 dsk.drive & DRV_MASK, dev_nm[dsk.type], dsk.unit,
281 'a' + dsk.part, kname);
282 if (ioctrl & 0x2)
283 sio_flush();
284 if (!autoboot || keyhit(0x5a))
285 getstr(cmd, sizeof(cmd));
286 else
287 putchar('\n');
288 autoboot = 0;
289 if (parse(cmd))
290 putchar('\a');
291 else
292 load(kname);
293 }
294}
295
296/* XXX - Needed for btxld to link the boot2 binary; do not remove. */
297void
298exit(int x)
299{
300}
301
302static void
303load(const char *fname)
304{
305 union {
306 struct exec ex;
307 Elf32_Ehdr eh;
308 } hdr;
309 Elf32_Phdr ep[2];
310 Elf32_Shdr es[2];
311 caddr_t p;
312 ino_t ino;
313 uint32_t addr, x;
314 int fmt, i, j;
315
316 if (!(ino = lookup(fname))) {
317 if (!ls)
318 printf("No %s\n", fname);
319 return;
320 }
321 if (xfsread(ino, &hdr, sizeof(hdr)))
322 return;
323 if (N_GETMAGIC(hdr.ex) == ZMAGIC)
324 fmt = 0;
325 else if (IS_ELF(hdr.eh))
326 fmt = 1;
327 else {
328 printf("Invalid %s\n", "format");
329 return;
330 }
331 if (fmt == 0) {
332 addr = hdr.ex.a_entry & 0xffffff;
333 p = PTOV(addr);
334 fs_off = PAGE_SIZE;
335 if (xfsread(ino, p, hdr.ex.a_text))
336 return;
337 p += roundup2(hdr.ex.a_text, PAGE_SIZE);
338 if (xfsread(ino, p, hdr.ex.a_data))
339 return;
340 p += hdr.ex.a_data + roundup2(hdr.ex.a_bss, PAGE_SIZE);
341 bootinfo.bi_symtab = VTOP(p);
342 memcpy(p, &hdr.ex.a_syms, sizeof(hdr.ex.a_syms));
343 p += sizeof(hdr.ex.a_syms);
344 if (hdr.ex.a_syms) {
345 if (xfsread(ino, p, hdr.ex.a_syms))
346 return;
347 p += hdr.ex.a_syms;
348 if (xfsread(ino, p, sizeof(int)))
349 return;
350 x = *(uint32_t *)p;
351 p += sizeof(int);
352 x -= sizeof(int);
353 if (xfsread(ino, p, x))
354 return;
355 p += x;
356 }
357 } else {
358 fs_off = hdr.eh.e_phoff;
359 for (j = i = 0; i < hdr.eh.e_phnum && j < 2; i++) {
360 if (xfsread(ino, ep + j, sizeof(ep[0])))
361 return;
362 if (ep[j].p_type == PT_LOAD)
363 j++;
364 }
365 for (i = 0; i < 2; i++) {
366 p = PTOV(ep[i].p_paddr & 0xffffff);
367 fs_off = ep[i].p_offset;
368 if (xfsread(ino, p, ep[i].p_filesz))
369 return;
370 }
371 p += roundup2(ep[1].p_memsz, PAGE_SIZE);
372 bootinfo.bi_symtab = VTOP(p);
373 if (hdr.eh.e_shnum == hdr.eh.e_shstrndx + 3) {
374 fs_off = hdr.eh.e_shoff + sizeof(es[0]) *
375 (hdr.eh.e_shstrndx + 1);
376 if (xfsread(ino, &es, sizeof(es)))
377 return;
378 for (i = 0; i < 2; i++) {
379 memcpy(p, &es[i].sh_size, sizeof(es[i].sh_size));
380 p += sizeof(es[i].sh_size);
381 fs_off = es[i].sh_offset;
382 if (xfsread(ino, p, es[i].sh_size))
383 return;
384 p += es[i].sh_size;
385 }
386 }
387 addr = hdr.eh.e_entry & 0xffffff;
388 }
389 bootinfo.bi_esymtab = VTOP(p);
390 bootinfo.bi_kernelname = VTOP(fname);
391 bootinfo.bi_bios_dev = dsk.drive;
392 __exec((caddr_t)addr, RB_BOOTINFO | (opts & RBX_MASK),
393 MAKEBOOTDEV(dev_maj[dsk.type], 0, dsk.slice, dsk.unit, dsk.part),
394 0, 0, 0, VTOP(&bootinfo));
395}
396
397static int
398parse(char *arg)
399{
400 char *p, *q;
401 int drv, c, i;
402
403 while ((c = *arg++)) {
404 if (c == ' ' || c == '\t' || c == '\n')
405 continue;
406 for (p = arg; *p && *p != '\n' && *p != ' ' && *p != '\t'; p++);
407 if (*p)
408 *p++ = 0;
409 if (c == '-') {
410 while ((c = *arg++)) {
411 for (i = 0; c != optstr[i]; i++)
412 if (i == NOPT - 1)
413 return -1;
414 opts ^= 1 << flags[i];
415 }
416 if (opts & 1 << RBX_PROBEKBD) {
417 i = *(uint8_t *)PTOV(0x496) & 0x10;
418 printf("Keyboard: %s\n", i ? "yes" : "no");
419 if (!i)
420 opts |= 1 << RBX_DUAL | 1 << RBX_SERIAL;
421 opts &= ~(1 << RBX_PROBEKBD);
422 }
423 ioctrl = opts & 1 << RBX_DUAL ? 0x3 :
424 opts & 1 << RBX_SERIAL ? 0x2 : 0x1;
425 if (ioctrl & 0x2)
426 sio_init();
427 } else {
428 for (q = arg--; *q && *q != '('; q++);
429 if (*q) {
430 drv = -1;
431 if (arg[1] == ':') {
432 if (*arg < '0' || *arg > '9')
433 return -1;
434 drv = *arg - '0';
435 arg += 2;
436 }
437 if (q - arg != 2)
438 return -1;
439 for (i = 0; arg[0] != dev_nm[i][0] ||
440 arg[1] != dev_nm[i][1]; i++)
441 if (i == NDEV - 1)
442 return -1;
443 dsk.type = i;
444 arg += 3;
445 if (arg[1] != ',' || *arg < '0' || *arg > '9')
446 return -1;
447 dsk.unit = *arg - '0';
448 arg += 2;
449 dsk.slice = WHOLE_DISK_SLICE;
450 if (arg[1] == ',') {
451 if (*arg < '0' || *arg > '0' + NDOSPART)
452 return -1;
453 if ((dsk.slice = *arg - '0'))
454 dsk.slice++;
455 arg += 2;
456 }
457 if (arg[1] != ')' || *arg < 'a' || *arg > 'p')
458 return -1;
459 dsk.part = *arg - 'a';
460 arg += 2;
461 if (drv == -1)
462 drv = dsk.unit;
463 dsk.drive = (dsk.type == TYPE_WD ||
464 dsk.type == TYPE_AD ||
465 dsk.type == TYPE_DA ? DRV_HARD : 0) + drv;
466 dsk.meta = 0;
467 fsread(0, NULL, 0);
468 }
469 if ((i = p - arg - !*(p - 1))) {
470 if (i >= sizeof(kname))
471 return -1;
472 memcpy(kname, arg, i + 1);
473 }
474 }
475 arg = p;
476 }
477 return 0;
478}
479
480static ino_t
481lookup(const char *path)
482{
483 char name[MAXNAMLEN + 1];
484 const char *s;
485 ino_t ino;
486 ssize_t n;
487 int dt;
488
489 ino = ROOTINO;
490 dt = DT_DIR;
491 for (;;) {
492 if (*path == '/')
493 path++;
494 if (!*path)
495 break;
496 for (s = path; *s && *s != '/'; s++);
497 if ((n = s - path) > MAXNAMLEN)
498 return 0;
499 ls = *path == '?' && n == 1 && !*s;
500 memcpy(name, path, n);
501 name[n] = 0;
502 if ((dt = fsfind(name, &ino)) <= 0)
503 break;
504 path = s;
505 }
506 return dt == DT_REG ? ino : 0;
507}
508static int
509xfsread(ino_t inode, void *buf, size_t nbyte)
510{
511 if (fsread(inode, buf, nbyte) != nbyte) {
512 printf("Invalid %s\n", "format");
513 return -1;
514 }
515 return 0;
516}
517
518static ssize_t
519fsread(ino_t inode, void *buf, size_t nbyte)
520{
521 static struct fs fs;
522 static struct dinode din;
523 static char *blkbuf;
524 static ufs_daddr_t *indbuf;
525 static ino_t inomap;
526 static ufs_daddr_t blkmap, indmap;
527 static unsigned fsblks;
528 char *s;
529 ufs_daddr_t lbn, addr;
530 size_t n, nb, off;
531
532 if (!dsk.meta) {
533 if (!blkbuf)
534 blkbuf = malloc(BSIZEMAX);
535 inomap = 0;
536 if (dskread(blkbuf, SBOFF / DEV_BSIZE, SBSIZE / DEV_BSIZE))
537 return -1;
538 memcpy(&fs, blkbuf, sizeof(fs));
539 if (fs.fs_magic != FS_MAGIC) {
540 printf("Not ufs\n");
541 return -1;
542 }
543 fsblks = fs.fs_bsize >> DEV_BSHIFT;
544 dsk.meta++;
545 }
546 if (!inode)
547 return 0;
548 if (inomap != inode) {
549 if (dskread(blkbuf, fsbtodb(&fs, ino_to_fsba(&fs, inode)),
550 fsblks))
551 return -1;
552 din = ((struct dinode *)blkbuf)[inode % INOPB(&fs)];
553 inomap = inode;
554 fs_off = 0;
555 blkmap = indmap = 0;
556 }
557 s = buf;
558 if (nbyte > (n = din.di_size - fs_off))
559 nbyte = n;
560 nb = nbyte;
561 while (nb) {
562 lbn = lblkno(&fs, fs_off);
563 if (lbn < NDADDR)
564 addr = din.di_db[lbn];
565 else {
566 if (indmap != din.di_ib[0]) {
567 if (!indbuf)
568 indbuf = malloc(BSIZEMAX);
569 if (dskread(indbuf, fsbtodb(&fs, din.di_ib[0]),
570 fsblks))
571 return -1;
572 indmap = din.di_ib[0];
573 }
574 addr = indbuf[(lbn - NDADDR) % NINDIR(&fs)];
575 }
576 n = dblksize(&fs, &din, lbn);
577 if (blkmap != addr) {
578 if (dskread(blkbuf, fsbtodb(&fs, addr), n >> DEV_BSHIFT))
579 return -1;
580 blkmap = addr;
581 }
582 off = blkoff(&fs, fs_off);
583 n -= off;
584 if (n > nb)
585 n = nb;
586 memcpy(s, blkbuf + off, n);
587 s += n;
588 fs_off += n;
589 nb -= n;
590 }
591 return nbyte;
592}
593
594static int
595dskread(void *buf, unsigned lba, unsigned nblk)
596{
597 static char *sec;
598 struct dos_partition *dp;
599 struct disklabel *d;
600 unsigned sl, i;
601
602 if (!dsk.meta) {
603 if (!sec)
604 sec = malloc(DEV_BSIZE);
605 dsk.start = 0;
606 if (drvread(sec, DOSBBSECTOR, 1))
607 return -1;
608 dp = (void *)(sec + DOSPARTOFF);
609 sl = dsk.slice;
610 if (sl < BASE_SLICE) {
611 for (i = 0; i < NDOSPART; i++)
612 if (dp[i].dp_typ == DOSPTYP_386BSD &&
613 (dp[i].dp_flag & 0x80 || sl < BASE_SLICE)) {
614 sl = BASE_SLICE + i;
615 if (dp[i].dp_flag & 0x80 ||
616 dsk.slice == COMPATIBILITY_SLICE)
617 break;
618 }
619 if (dsk.slice == WHOLE_DISK_SLICE)
620 dsk.slice = sl;
621 }
622 if (sl != WHOLE_DISK_SLICE) {
623 if (sl != COMPATIBILITY_SLICE)
624 dp += sl - BASE_SLICE;
625 if (dp->dp_typ != DOSPTYP_386BSD) {
626 printf("Invalid %s\n", "slice");
627 return -1;
628 }
629 dsk.start = dp->dp_start;
630 }
631 if (drvread(sec, dsk.start + LABELSECTOR, 1))
632 return -1;
633 d = (void *)(sec + LABELOFFSET);
634 if (d->d_magic != DISKMAGIC || d->d_magic2 != DISKMAGIC) {
635 if (dsk.part != RAW_PART) {
636 printf("Invalid %s\n", "label");
637 return -1;
638 }
639 } else {
640 if (!dsk.init) {
641 if (d->d_type == DTYPE_SCSI)
642 dsk.type = TYPE_DA;
643 dsk.init++;
644 }
645 if (dsk.part >= d->d_npartitions ||
646 !d->d_partitions[dsk.part].p_size) {
647 printf("Invalid %s\n", "partition");
648 return -1;
649 }
650 dsk.start = d->d_partitions[dsk.part].p_offset;
651 }
652 }
653 return drvread(buf, dsk.start + lba, nblk);
654}
655
656static int
657printf(const char *fmt,...)
658{
659 static const char digits[16] = "0123456789abcdef";
660 va_list ap;
661 char buf[10];
662 char *s;
663 unsigned r, u;
664 int c;
665
666 va_start(ap, fmt);
667 while ((c = *fmt++)) {
668 if (c == '%') {
669 c = *fmt++;
670 switch (c) {
671 case 'c':
672 putchar(va_arg(ap, int));
673 continue;
674 case 's':
675 for (s = va_arg(ap, char *); *s; s++)
676 putchar(*s);
677 continue;
678 case 'u':
679 case 'x':
680 r = c == 'u' ? 10U : 16U;
681 u = va_arg(ap, unsigned);
682 s = buf;
683 do
684 *s++ = digits[u % r];
685 while (u /= r);
686 while (--s >= buf)
687 putchar(*s);
688 continue;
689 }
690 }
691 putchar(c);
692 }
693 va_end(ap);
694 return 0;
695}
696
697static int
698putchar(int c)
699{
700 if (c == '\n')
701 xputc('\r');
702 return xputc(c);
703}
704
705static void *
706memcpy(void *dst, const void *src, size_t size)
707{
708 const char *s;
709 char *d;
710
711 for (d = dst, s = src; size; size--)
712 *d++ = *s++;
713 return dst;
714}
715
716static void *
717malloc(size_t size)
718{
719 static uint32_t next;
720 void *p;
721
722 if (!next)
723 next = roundup2(__base + _end, 0x10000) - __base;
724 p = (void *)next;
725 next += size;
726 return p;
727}
728
729static uint32_t
730memsize(int type)
731{
732 v86.addr = type;
733 v86.eax = 0x8800;
734 v86int();
735 return v86.eax;
736}
737
738static int
739drvread(void *buf, unsigned lba, unsigned nblk)
740{
741 static unsigned c = 0x2d5c7c2f;
742
743 printf("%c\b", c = c << 8 | c >> 24);
744 v86.ctl = V86_ADDR | V86_CALLF | V86_FLAGS;
745 v86.addr = XREADORG; /* call to xread in boot1 */
746 v86.es = VTOPSEG(buf);
747 v86.eax = lba;
748 v86.ebx = VTOPOFF(buf);
749 v86.ecx = lba >> 16;
750 v86.edx = nblk << 8 | dsk.drive;
751 v86int();
752 v86.ctl = V86_FLAGS;
753 if (V86_CY(v86.efl)) {
754 printf("Disk error 0x%x (lba=0x%x)\n", v86.eax >> 8 & 0xff,
755 lba);
756 return -1;
757 }
758 return 0;
759}
760
761static int
762keyhit(unsigned ticks)
763{
764 uint32_t t0, t1;
765
766 if (opts & 1 << RBX_NOINTR)
767 return 0;
768 t0 = 0;
769 for (;;) {
770 if (xgetc(1))
771 return 1;
772 t1 = *(uint32_t *)PTOV(0x46c);
773 if (!t0)
774 t0 = t1;
775 if (t1 < t0 || t1 >= t0 + ticks)
776 return 0;
777 }
778}
779
780static int
781xputc(int c)
782{
783 if (ioctrl & 0x1)
784 putc(c);
785 if (ioctrl & 0x2)
786 sio_putc(c);
787 return c;
788}
789
790static int
791xgetc(int fn)
792{
793 if (opts & 1 << RBX_NOINTR)
794 return 0;
795 for (;;) {
796 if (ioctrl & 0x1 && getc(1))
797 return fn ? 1 : getc(0);
798 if (ioctrl & 0x2 && sio_ischar())
799 return fn ? 1 : sio_getc();
800 if (fn)
801 return 0;
802 }
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}