boot2.c revision 214257 
1/*-
2 * Copyright (c) 2008-2009 TAKAHASHI Yoshihiro
3 * Copyright (c) 1998 Robert Nordier
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms are freely
7 * permitted provided that the above copyright notice and this
8 * paragraph and the following disclaimer are duplicated in all
9 * such forms.
10 *
11 * This software is provided "AS IS" and without any express or
12 * implied warranties, including, without limitation, the implied
13 * warranties of merchantability and fitness for a particular
14 * purpose.
15 */
16
17#include <sys/cdefs.h>
18__FBSDID("$FreeBSD: head/sys/boot/pc98/boot2/boot2.c 214257 2010-10-24 02:59:02Z nyan $");
19
20#include <sys/param.h>
21#include <sys/disklabel.h>
22#include <sys/diskpc98.h>
23#include <sys/dirent.h>
24#include <sys/reboot.h>
25
26#include <machine/bootinfo.h>
27#include <machine/cpufunc.h>
28#include <machine/elf.h>
29#include <machine/psl.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 IO_KEYBOARD	1
41#define IO_SERIAL	2
42
43#define SECOND		1	/* Circa that many ticks in a second. */
44
45#define RBX_ASKNAME	0x0	/* -a */
46#define RBX_SINGLE	0x1	/* -s */
47/* 0x2 is reserved for log2(RB_NOSYNC). */
48/* 0x3 is reserved for log2(RB_HALT). */
49/* 0x4 is reserved for log2(RB_INITNAME). */
50#define RBX_DFLTROOT	0x5	/* -r */
51#define RBX_KDB 	0x6	/* -d */
52/* 0x7 is reserved for log2(RB_RDONLY). */
53/* 0x8 is reserved for log2(RB_DUMP). */
54/* 0x9 is reserved for log2(RB_MINIROOT). */
55#define RBX_CONFIG	0xa	/* -c */
56#define RBX_VERBOSE	0xb	/* -v */
57#define RBX_SERIAL	0xc	/* -h */
58#define RBX_CDROM	0xd	/* -C */
59/* 0xe is reserved for log2(RB_POWEROFF). */
60#define RBX_GDB 	0xf	/* -g */
61#define RBX_MUTE	0x10	/* -m */
62/* 0x11 is reserved for log2(RB_SELFTEST). */
63/* 0x12 is reserved for boot programs. */
64/* 0x13 is reserved for boot programs. */
65#define RBX_PAUSE	0x14	/* -p */
66#define RBX_QUIET	0x15	/* -q */
67#define RBX_NOINTR	0x1c	/* -n */
68/* 0x1d is reserved for log2(RB_MULTIPLE) and is just misnamed here. */
69#define RBX_DUAL	0x1d	/* -D */
70/* 0x1f is reserved for log2(RB_BOOTINFO). */
71
72/* pass: -a, -s, -r, -d, -c, -v, -h, -C, -g, -m, -p, -D */
73#define RBX_MASK	(OPT_SET(RBX_ASKNAME) | OPT_SET(RBX_SINGLE) | \
74			OPT_SET(RBX_DFLTROOT) | OPT_SET(RBX_KDB ) | \
75			OPT_SET(RBX_CONFIG) | OPT_SET(RBX_VERBOSE) | \
76			OPT_SET(RBX_SERIAL) | OPT_SET(RBX_CDROM) | \
77			OPT_SET(RBX_GDB ) | OPT_SET(RBX_MUTE) | \
78			OPT_SET(RBX_PAUSE) | OPT_SET(RBX_DUAL))
79
80#define PATH_CONFIG	"/boot.config"
81#define PATH_BOOT3	"/boot/loader"
82#define PATH_KERNEL	"/boot/kernel/kernel"
83
84#define ARGS		0x900
85#define NOPT		14
86#define NDEV		3
87#define V86_CY(x)	((x) & PSL_C)
88#define V86_ZR(x)	((x) & PSL_Z)
89
90#define DRV_DISK	0xf0
91#define DRV_UNIT	0x0f
92
93#define TYPE_AD		0
94#define TYPE_DA		1
95#define TYPE_FD		2
96
97#define OPT_SET(opt)	(1 << (opt))
98#define OPT_CHECK(opt)	((opts) & OPT_SET(opt))
99
100extern uint32_t _end;
101
102static const char optstr[NOPT] = "DhaCcdgmnpqrsv"; /* Also 'P', 'S' */
103static const unsigned char flags[NOPT] = {
104    RBX_DUAL,
105    RBX_SERIAL,
106    RBX_ASKNAME,
107    RBX_CDROM,
108    RBX_CONFIG,
109    RBX_KDB,
110    RBX_GDB,
111    RBX_MUTE,
112    RBX_NOINTR,
113    RBX_PAUSE,
114    RBX_QUIET,
115    RBX_DFLTROOT,
116    RBX_SINGLE,
117    RBX_VERBOSE
118};
119
120static const char *const dev_nm[NDEV] = {"ad", "da", "fd"};
121static const unsigned char dev_maj[NDEV] = {30, 4, 2};
122static const unsigned char dev_daua[NDEV] = {0x80, 0xa0, 0x90};
123
124static struct dsk {
125    unsigned daua;
126    unsigned type;
127    unsigned disk;
128    unsigned unit;
129    unsigned head;
130    unsigned sec;
131    unsigned slice;
132    unsigned part;
133    unsigned start;
134} dsk;
135static char cmd[512], cmddup[512];
136static char kname[1024];
137static uint32_t opts;
138static int comspeed = SIOSPD;
139static struct bootinfo bootinfo;
140static uint8_t ioctrl = IO_KEYBOARD;
141
142void exit(int);
143static void load(void);
144static int parse(void);
145static int xfsread(ino_t, void *, size_t);
146static int dskread(void *, unsigned, unsigned);
147static void printf(const char *,...);
148static void putchar(int);
149static uint32_t memsize(void);
150static int drvread(void *, unsigned);
151static int keyhit(unsigned);
152static int xputc(int);
153static int xgetc(int);
154static int getc(int);
155
156static void memcpy(void *, const void *, int);
157static void
158memcpy(void *dst, const void *src, int len)
159{
160    const char *s = src;
161    char *d = dst;
162
163    while (len--)
164        *d++ = *s++;
165}
166
167static inline int
168strcmp(const char *s1, const char *s2)
169{
170    for (; *s1 == *s2 && *s1; s1++, s2++);
171    return (unsigned char)*s1 - (unsigned char)*s2;
172}
173
174#define	UFS_SMALL_CGBASE
175#include "ufsread.c"
176
177static inline int
178xfsread(ino_t inode, void *buf, size_t nbyte)
179{
180    if ((size_t)fsread(inode, buf, nbyte) != nbyte) {
181	printf("Invalid %s\n", "format");
182	return -1;
183    }
184    return 0;
185}
186
187static inline uint32_t
188memsize(void)
189{
190    return (*(u_char *)PTOV(0x401) * 128 * 1024 +
191	*(uint16_t *)PTOV(0x594) * 1024 * 1024);
192}
193
194static inline void
195getstr(void)
196{
197    char *s;
198    int c;
199
200    s = cmd;
201    for (;;) {
202	switch (c = xgetc(0)) {
203	case 0:
204	    break;
205	case '\177':
206	case '\b':
207	    if (s > cmd) {
208		s--;
209		printf("\b \b");
210	    }
211	    break;
212	case '\n':
213	case '\r':
214	    *s = 0;
215	    return;
216	default:
217	    if (s - cmd < sizeof(cmd) - 1)
218		*s++ = c;
219	    putchar(c);
220	}
221    }
222}
223
224static inline void
225putc(int c)
226{
227
228    v86.ctl = V86_ADDR | V86_CALLF | V86_FLAGS;
229    v86.addr = PUTCORG;		/* call to putc in boot1 */
230    v86.eax = c;
231    v86int();
232    v86.ctl = V86_FLAGS;
233}
234
235static inline int
236is_scsi_hd(void)
237{
238
239    if ((*(u_char *)PTOV(0x482) >> dsk.unit) & 0x01)
240	return 1;
241
242    return 0;
243}
244
245static inline void
246fix_sector_size(void)
247{
248    u_char *p;
249
250    p = (u_char *)PTOV(0x460 + dsk.unit * 4);	/* SCSI equipment parameter */
251
252    if ((p[0] & 0x1f) == 7) {		/* SCSI MO */
253	if (!(p[3] & 0x30)) {		/* 256B / sector */
254	    p[3] |= 0x10;		/* forced set 512B / sector */
255	    p[3 + 0xa1000] |= 0x10;
256	}
257    }
258}
259
260static inline uint32_t
261get_diskinfo(void)
262{
263
264    if (dsk.disk == 0x30) {				/* 1440KB FD */
265	/* 80 cylinders, 2 heads, 18 sectors */
266	return (80 << 16) | (2 << 8) | 18;
267    } else if (dsk.disk == 0x90) {			/* 1200KB FD */
268	/* 80 cylinders, 2 heads, 15 sectors */
269	return (80 << 16) | (2 << 8) | 15;
270    } else if (dsk.disk == 0x80 || is_scsi_hd()) {	/* IDE or SCSI HDD */
271	v86.addr = 0x1b;
272	v86.eax = 0x8400 | dsk.daua;
273	v86int();
274	return (v86.ecx << 16) | v86.edx;
275    }
276
277    /* SCSI MO or CD */
278    fix_sector_size();	/* SCSI MO */
279
280    /* other SCSI devices */
281    return (65535 << 16) | (8 << 8) | 32;
282}
283
284static void
285set_dsk(void)
286{
287    uint32_t di;
288
289    di = get_diskinfo();
290
291    dsk.head = (di >> 8) & 0xff;
292    dsk.sec = di & 0xff;
293    dsk.start = 0;
294}
295
296#ifdef GET_BIOSGEOM
297static uint32_t
298bd_getbigeom(int bunit)
299{
300    int hds = 0;
301    int unit = 0x80;		/* IDE HDD */
302    u_int addr = 0x55d;
303
304    while (unit < 0xa7) {
305	if (*(u_char *)PTOV(addr) & (1 << (unit & 0x0f)))
306	    if (hds++ == bunit)
307		break;
308
309	if (unit >= 0xA0) {
310	    int media = ((unsigned *)PTOV(0x460))[unit & 0x0F] & 0x1F;
311
312	    if (media == 7 && hds++ == bunit)	/* SCSI MO */
313		return(0xFFFE0820); /* C:65535 H:8 S:32 */
314	}
315	if (++unit == 0x84) {
316	    unit = 0xA0;	/* SCSI HDD */
317	    addr = 0x482;
318	}
319    }
320    if (unit == 0xa7)
321	return 0x4F020F;	/* 1200KB FD C:80 H:2 S:15 */
322    v86.addr = 0x1b;
323    v86.eax = 0x8400 | unit;
324    v86int();
325    if (v86.efl & 0x1)
326	return 0x4F020F;	/* 1200KB FD C:80 H:2 S:15 */
327    return ((v86.ecx & 0xffff) << 16) | (v86.edx & 0xffff);
328}
329#endif
330
331static int
332check_slice(void)
333{
334    struct pc98_partition *dp;
335    char *sec;
336    unsigned i, cyl;
337
338    sec = dmadat->secbuf;
339    cyl = *(uint16_t *)PTOV(ARGS);
340    set_dsk();
341
342    if (dsk.type == TYPE_FD)
343	return (WHOLE_DISK_SLICE);
344    if (drvread(sec, DOSBBSECTOR + 1))
345	return (WHOLE_DISK_SLICE);	/* Read error */
346    dp = (void *)(sec + DOSPARTOFF);
347    for (i = 0; i < NDOSPART; i++) {
348	if (dp[i].dp_mid == DOSMID_386BSD) {
349	    if (dp[i].dp_scyl <= cyl && cyl <= dp[i].dp_ecyl)
350		return (BASE_SLICE + i);
351	}
352    }
353
354    return (WHOLE_DISK_SLICE);
355}
356
357int
358main(void)
359{
360#ifdef GET_BIOSGEOM
361    int i;
362#endif
363    int autoboot;
364    ino_t ino;
365
366    dmadat = (void *)(roundup2(__base + (int32_t)&_end, 0x10000) - __base);
367    v86.ctl = V86_FLAGS;
368    v86.efl = PSL_RESERVED_DEFAULT | PSL_I;
369    dsk.daua = *(uint8_t *)PTOV(0x584);
370    dsk.disk = dsk.daua & DRV_DISK;
371    dsk.unit = dsk.daua & DRV_UNIT;
372    if (dsk.disk == 0x80)
373        dsk.type = TYPE_AD;
374    else if (dsk.disk == 0xa0)
375        dsk.type = TYPE_DA;
376    else /* if (dsk.disk == 0x30 || dsk.disk == 0x90) */
377        dsk.type = TYPE_FD;
378    dsk.slice = check_slice();
379#ifdef GET_BIOSGEOM
380    for (i = 0; i < N_BIOS_GEOM; i++)
381	bootinfo.bi_bios_geom[i] = bd_getbigeom(i);
382#endif
383    bootinfo.bi_version = BOOTINFO_VERSION;
384    bootinfo.bi_size = sizeof(bootinfo);
385    bootinfo.bi_basemem = 0;	/* XXX will be filled by loader or kernel */
386    bootinfo.bi_extmem = memsize();
387    bootinfo.bi_memsizes_valid++;
388
389    /* Process configuration file */
390
391    autoboot = 1;
392
393    if ((ino = lookup(PATH_CONFIG)))
394	fsread(ino, cmd, sizeof(cmd));
395
396    if (*cmd) {
397	memcpy(cmddup, cmd, sizeof(cmd));
398	if (parse())
399	    autoboot = 0;
400	if (!OPT_CHECK(RBX_QUIET))
401	    printf("%s: %s", PATH_CONFIG, cmddup);
402	/* Do not process this command twice */
403	*cmd = 0;
404    }
405
406    /*
407     * Try to exec stage 3 boot loader. If interrupted by a keypress,
408     * or in case of failure, try to load a kernel directly instead.
409     */
410
411    if (autoboot && !*kname) {
412	memcpy(kname, PATH_BOOT3, sizeof(PATH_BOOT3));
413	if (!keyhit(3*SECOND)) {
414	    load();
415	    memcpy(kname, PATH_KERNEL, sizeof(PATH_KERNEL));
416	}
417    }
418
419    /* Present the user with the boot2 prompt. */
420
421    for (;;) {
422	if (!autoboot || !OPT_CHECK(RBX_QUIET))
423	    printf("\nFreeBSD/pc98 boot\n"
424		   "Default: %u:%s(%u,%c)%s\n"
425		   "boot: ",
426		   dsk.unit, dev_nm[dsk.type], dsk.unit,
427		   'a' + dsk.part, kname);
428	if (ioctrl & IO_SERIAL)
429	    sio_flush();
430	if (!autoboot || keyhit(5*SECOND))
431	    getstr();
432	else if (!autoboot || !OPT_CHECK(RBX_QUIET))
433	    putchar('\n');
434	autoboot = 0;
435	if (parse())
436	    putchar('\a');
437	else
438	    load();
439    }
440}
441
442/* XXX - Needed for btxld to link the boot2 binary; do not remove. */
443void
444exit(int x)
445{
446}
447
448static void
449load(void)
450{
451    union {
452	struct exec ex;
453	Elf32_Ehdr eh;
454    } hdr;
455    static Elf32_Phdr ep[2];
456    static Elf32_Shdr es[2];
457    caddr_t p;
458    ino_t ino;
459    uint32_t addr, x;
460    int fmt, i, j;
461
462    if (!(ino = lookup(kname))) {
463	if (!ls)
464	    printf("No %s\n", kname);
465	return;
466    }
467    if (xfsread(ino, &hdr, sizeof(hdr)))
468	return;
469    if (N_GETMAGIC(hdr.ex) == ZMAGIC)
470	fmt = 0;
471    else if (IS_ELF(hdr.eh))
472	fmt = 1;
473    else {
474	printf("Invalid %s\n", "format");
475	return;
476    }
477    if (fmt == 0) {
478	addr = hdr.ex.a_entry & 0xffffff;
479	p = PTOV(addr);
480	fs_off = PAGE_SIZE;
481	if (xfsread(ino, p, hdr.ex.a_text))
482	    return;
483	p += roundup2(hdr.ex.a_text, PAGE_SIZE);
484	if (xfsread(ino, p, hdr.ex.a_data))
485	    return;
486	p += hdr.ex.a_data + roundup2(hdr.ex.a_bss, PAGE_SIZE);
487	bootinfo.bi_symtab = VTOP(p);
488	*(uint32_t*)p = hdr.ex.a_syms;
489	p += sizeof(hdr.ex.a_syms);
490	if (hdr.ex.a_syms) {
491	    if (xfsread(ino, p, hdr.ex.a_syms))
492		return;
493	    p += hdr.ex.a_syms;
494	    if (xfsread(ino, p, sizeof(int)))
495		return;
496	    x = *(uint32_t *)p;
497	    p += sizeof(int);
498	    x -= sizeof(int);
499	    if (xfsread(ino, p, x))
500		return;
501	    p += x;
502	}
503    } else {
504	fs_off = hdr.eh.e_phoff;
505	for (j = i = 0; i < hdr.eh.e_phnum && j < 2; i++) {
506	    if (xfsread(ino, ep + j, sizeof(ep[0])))
507		return;
508	    if (ep[j].p_type == PT_LOAD)
509		j++;
510	}
511	for (i = 0; i < 2; i++) {
512	    p = PTOV(ep[i].p_paddr & 0xffffff);
513	    fs_off = ep[i].p_offset;
514	    if (xfsread(ino, p, ep[i].p_filesz))
515		return;
516	}
517	p += roundup2(ep[1].p_memsz, PAGE_SIZE);
518	bootinfo.bi_symtab = VTOP(p);
519	if (hdr.eh.e_shnum == hdr.eh.e_shstrndx + 3) {
520	    fs_off = hdr.eh.e_shoff + sizeof(es[0]) *
521		(hdr.eh.e_shstrndx + 1);
522	    if (xfsread(ino, &es, sizeof(es)))
523		return;
524	    for (i = 0; i < 2; i++) {
525		*(Elf32_Word *)p = es[i].sh_size;
526		p += sizeof(es[i].sh_size);
527		fs_off = es[i].sh_offset;
528		if (xfsread(ino, p, es[i].sh_size))
529		    return;
530		p += es[i].sh_size;
531	    }
532	}
533	addr = hdr.eh.e_entry & 0xffffff;
534    }
535    bootinfo.bi_esymtab = VTOP(p);
536    bootinfo.bi_kernelname = VTOP(kname);
537    bootinfo.bi_bios_dev = dsk.daua;
538    __exec((caddr_t)addr, RB_BOOTINFO | (opts & RBX_MASK),
539	   MAKEBOOTDEV(dev_maj[dsk.type], dsk.slice, dsk.unit, dsk.part),
540	   0, 0, 0, VTOP(&bootinfo));
541}
542
543static int
544parse()
545{
546    char *arg = cmd;
547    char *ep, *p, *q;
548    const char *cp;
549    unsigned int drv;
550    int c, i, j;
551
552    while ((c = *arg++)) {
553	if (c == ' ' || c == '\t' || c == '\n')
554	    continue;
555	for (p = arg; *p && *p != '\n' && *p != ' ' && *p != '\t'; p++);
556	ep = p;
557	if (*p)
558	    *p++ = 0;
559	if (c == '-') {
560	    while ((c = *arg++)) {
561		if (c == 'P') {
562		    if (*(uint8_t *)PTOV(0x481) & 0x48) {
563			cp = "yes";
564		    } else {
565			opts |= OPT_SET(RBX_DUAL) | OPT_SET(RBX_SERIAL);
566			cp = "no";
567		    }
568		    printf("Keyboard: %s\n", cp);
569		    continue;
570		} else if (c == 'S') {
571		    j = 0;
572		    while ((unsigned int)(i = *arg++ - '0') <= 9)
573			j = j * 10 + i;
574		    if (j > 0 && i == -'0') {
575			comspeed = j;
576			break;
577		    }
578		    /* Fall through to error below ('S' not in optstr[]). */
579		}
580		for (i = 0; c != optstr[i]; i++)
581		    if (i == NOPT - 1)
582			return -1;
583		opts ^= OPT_SET(flags[i]);
584	    }
585	    ioctrl = OPT_CHECK(RBX_DUAL) ? (IO_SERIAL|IO_KEYBOARD) :
586		     OPT_CHECK(RBX_SERIAL) ? IO_SERIAL : IO_KEYBOARD;
587	    if (ioctrl & IO_SERIAL)
588	        sio_init(115200 / comspeed);
589	} else {
590	    for (q = arg--; *q && *q != '('; q++);
591	    if (*q) {
592		drv = -1;
593		if (arg[1] == ':') {
594		    drv = *arg - '0';
595		    if (drv > 9)
596			return (-1);
597		    arg += 2;
598		}
599		if (q - arg != 2)
600		    return -1;
601		for (i = 0; arg[0] != dev_nm[i][0] ||
602			    arg[1] != dev_nm[i][1]; i++)
603		    if (i == NDEV - 1)
604			return -1;
605		dsk.type = i;
606		arg += 3;
607		dsk.unit = *arg - '0';
608		if (arg[1] != ',' || dsk.unit > 9)
609		    return -1;
610		arg += 2;
611		dsk.slice = WHOLE_DISK_SLICE;
612		if (arg[1] == ',') {
613		    dsk.slice = *arg - '0' + 1;
614		    if (dsk.slice > NDOSPART + 1)
615			return -1;
616		    arg += 2;
617		}
618		if (arg[1] != ')')
619		    return -1;
620		dsk.part = *arg - 'a';
621		if (dsk.part > 7)
622		    return (-1);
623		arg += 2;
624		if (drv == -1)
625		    drv = dsk.unit;
626		dsk.disk = dev_daua[dsk.type];
627		dsk.daua = dsk.disk | dsk.unit;
628		dsk_meta = 0;
629	    }
630	    if ((i = ep - arg)) {
631		if ((size_t)i >= sizeof(kname))
632		    return -1;
633		memcpy(kname, arg, i + 1);
634	    }
635	}
636	arg = p;
637    }
638    return 0;
639}
640
641static int
642dskread(void *buf, unsigned lba, unsigned nblk)
643{
644    struct pc98_partition *dp;
645    struct disklabel *d;
646    char *sec;
647    unsigned sl, i;
648    u_char *p;
649
650    if (!dsk_meta) {
651	sec = dmadat->secbuf;
652	set_dsk();
653	if (dsk.type == TYPE_FD)
654	    goto unsliced;
655	if (drvread(sec, DOSBBSECTOR + 1))
656	    return -1;
657	dp = (void *)(sec + DOSPARTOFF);
658	sl = dsk.slice;
659	if (sl < BASE_SLICE) {
660	    for (i = 0; i < NDOSPART; i++)
661		if (dp[i].dp_mid == DOSMID_386BSD) {
662		    sl = BASE_SLICE + i;
663		    break;
664		}
665	    dsk.slice = sl;
666	}
667	if (sl != WHOLE_DISK_SLICE) {
668	    dp += sl - BASE_SLICE;
669	    if (dp->dp_mid != DOSMID_386BSD) {
670		printf("Invalid %s\n", "slice");
671		return -1;
672	    }
673	    dsk.start = dp->dp_scyl * dsk.head * dsk.sec +
674		dp->dp_shd * dsk.sec + dp->dp_ssect;
675	}
676	if (drvread(sec, dsk.start + LABELSECTOR))
677		return -1;
678	d = (void *)(sec + LABELOFFSET);
679	if (d->d_magic != DISKMAGIC || d->d_magic2 != DISKMAGIC) {
680	    if (dsk.part != RAW_PART) {
681		printf("Invalid %s\n", "label");
682		return -1;
683	    }
684	} else {
685	    if (dsk.part >= d->d_npartitions ||
686		!d->d_partitions[dsk.part].p_size) {
687		printf("Invalid %s\n", "partition");
688		return -1;
689	    }
690	    dsk.start += d->d_partitions[dsk.part].p_offset;
691	    dsk.start -= d->d_partitions[RAW_PART].p_offset;
692	}
693    unsliced: ;
694    }
695    for (p = buf; nblk; p += 512, lba++, nblk--) {
696	if ((i = drvread(p, dsk.start + lba)))
697	    return i;
698    }
699    return 0;
700}
701
702static void
703printf(const char *fmt,...)
704{
705    va_list ap;
706    char buf[10];
707    char *s;
708    unsigned u;
709    int c;
710
711    va_start(ap, fmt);
712    while ((c = *fmt++)) {
713	if (c == '%') {
714	    c = *fmt++;
715	    switch (c) {
716	    case 'c':
717		putchar(va_arg(ap, int));
718		continue;
719	    case 's':
720		for (s = va_arg(ap, char *); *s; s++)
721		    putchar(*s);
722		continue;
723	    case 'u':
724		u = va_arg(ap, unsigned);
725		s = buf;
726		do
727		    *s++ = '0' + u % 10U;
728		while (u /= 10U);
729		while (--s >= buf)
730		    putchar(*s);
731		continue;
732	    }
733	}
734	putchar(c);
735    }
736    va_end(ap);
737    return;
738}
739
740static void
741putchar(int c)
742{
743    if (c == '\n')
744	xputc('\r');
745    xputc(c);
746}
747
748static int
749drvread(void *buf, unsigned lba)
750{
751    static unsigned c = 0x2d5c7c2f;
752    unsigned bpc, x, cyl, head, sec;
753
754    bpc = dsk.sec * dsk.head;
755    cyl = lba / bpc;
756    x = lba % bpc;
757    head = x / dsk.sec;
758    sec = x % dsk.sec;
759
760    if (!OPT_CHECK(RBX_QUIET))
761	printf("%c\b", c = c << 8 | c >> 24);
762    v86.ctl = V86_ADDR | V86_CALLF | V86_FLAGS;
763    v86.addr = READORG;		/* call to read in boot1 */
764    v86.ecx = cyl;
765    v86.edx = (head << 8) | sec;
766    v86.edi = lba;
767    v86.ebx = 512;
768    v86.es = VTOPSEG(buf);
769    v86.ebp = VTOPOFF(buf);
770    v86int();
771    v86.ctl = V86_FLAGS;
772    if (V86_CY(v86.efl)) {
773	printf("error %u c/h/s %u/%u/%u lba %u\n", v86.eax >> 8 & 0xff,
774	       cyl, head, sec, lba);
775	return -1;
776    }
777    return 0;
778}
779
780static inline void
781delay(void)
782{
783    int i;
784
785    i = 800;
786    do {
787	outb(0x5f, 0);	/* about 600ns */
788    } while (--i >= 0);
789}
790
791static int
792keyhit(unsigned sec)
793{
794    unsigned i;
795
796    if (OPT_CHECK(RBX_NOINTR))
797	return 0;
798    for (i = 0; i < sec * 1000; i++) {
799	if (xgetc(1))
800	    return 1;
801	delay();
802    }
803    return 0;
804}
805
806static int
807xputc(int c)
808{
809    if (ioctrl & IO_KEYBOARD)
810	putc(c);
811    if (ioctrl & IO_SERIAL)
812	sio_putc(c);
813    return c;
814}
815
816static int
817xgetc(int fn)
818{
819    if (OPT_CHECK(RBX_NOINTR))
820	return 0;
821    for (;;) {
822	if (ioctrl & IO_KEYBOARD && getc(1))
823	    return fn ? 1 : getc(0);
824	if (ioctrl & IO_SERIAL && sio_ischar())
825	    return fn ? 1 : sio_getc();
826	if (fn)
827	    return 0;
828    }
829}
830
831static int
832getc(int fn)
833{
834    v86.addr = 0x18;
835    v86.eax = fn << 8;
836    v86int();
837    if (fn)
838	return (v86.ebx >> 8) & 0x01;
839    else
840	return v86.eax & 0xff;
841}
842