xref: /freebsd-11-stable/stand/i386/boot2/boot2.c

/*-
 * Copyright (c) 1998 Robert Nordier
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are freely
 * permitted provided that the above copyright notice and this
 * paragraph and the following disclaimer are duplicated in all
 * such forms.
 *
 * This software is provided "AS IS" and without any express or
 * implied warranties, including, without limitation, the implied
 * warranties of merchantability and fitness for a particular
 * purpose.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD: stable/11/stand/i386/boot2/boot2.c 332130 2018-04-06 18:55:02Z kevans $");

#include <sys/param.h>
#include <sys/disklabel.h>
#include <sys/diskmbr.h>
#include <sys/dirent.h>
#include <sys/reboot.h>

#include <machine/bootinfo.h>
#include <machine/elf.h>

#include <stdarg.h>

#include <a.out.h>

#include <btxv86.h>

#include "boot2.h"
#include "lib.h"
#include "paths.h"
#include "rbx.h"

/* Define to 0 to omit serial support */
#ifndef SERIAL
#define SERIAL 1
#endif

#define IO_KEYBOARD	1
#define IO_SERIAL	2

#if SERIAL
#define DO_KBD (ioctrl & IO_KEYBOARD)
#define DO_SIO (ioctrl & IO_SERIAL)
#else
#define DO_KBD (1)
#define DO_SIO (0)
#endif

#define SECOND		18	/* Circa that many ticks in a second. */

#define ARGS		0x900
#define NOPT		14
#define NDEV		3
#define MEM_BASE	0x12
#define MEM_EXT 	0x15

#define DRV_HARD	0x80
#define DRV_MASK	0x7f

#define TYPE_AD		0
#define TYPE_DA		1
#define TYPE_MAXHARD	TYPE_DA
#define TYPE_FD		2

extern uint32_t _end;

static const char optstr[NOPT] = "DhaCcdgmnpqrsv"; /* Also 'P', 'S' */
static const unsigned char flags[NOPT] = {
	RBX_DUAL,
	RBX_SERIAL,
	RBX_ASKNAME,
	RBX_CDROM,
	RBX_CONFIG,
	RBX_KDB,
	RBX_GDB,
	RBX_MUTE,
	RBX_NOINTR,
	RBX_PAUSE,
	RBX_QUIET,
	RBX_DFLTROOT,
	RBX_SINGLE,
	RBX_VERBOSE
};

static const char *const dev_nm[NDEV] = {"ad", "da", "fd"};
static const unsigned char dev_maj[NDEV] = {30, 4, 2};

static struct dsk {
	unsigned drive;
	unsigned type;
	unsigned unit;
	uint8_t slice;
	uint8_t part;
	unsigned start;
	int init;
} dsk;
static char cmd[512], cmddup[512], knamebuf[1024];
static const char *kname;
uint32_t opts;
static struct bootinfo bootinfo;
#if SERIAL
static int comspeed = SIOSPD;
static uint8_t ioctrl = IO_KEYBOARD;
#endif

int main(void);
void exit(int);
static void load(void);
static int parse(void);
static int dskread(void *, unsigned, unsigned);
static void printf(const char *,...);
static void putchar(int);
static int drvread(void *, unsigned, unsigned);
static int keyhit(unsigned);
static int xputc(int);
static int xgetc(int);
static inline int getc(int);

static void memcpy(void *, const void *, int);
static void
memcpy(void *dst, const void *src, int len)
{
	const char *s;
	char *d;

	s = src;
	d = dst;

	while (len--)
		*d++ = *s++;
}

static inline int
strcmp(const char *s1, const char *s2)
{

	for (; *s1 == *s2 && *s1; s1++, s2++);
	return ((unsigned char)*s1 - (unsigned char)*s2);
}

#define	UFS_SMALL_CGBASE
#include "ufsread.c"

static int
xfsread(ufs_ino_t inode, void *buf, size_t nbyte)
{

	if ((size_t)fsread(inode, buf, nbyte) != nbyte) {
		printf("Invalid %s\n", "format");
		return (-1);
	}
	return (0);
}

static inline void
getstr(void)
{
	char *s;
	int c;

	s = cmd;
	for (;;) {
		switch (c = xgetc(0)) {
		case 0:
			break;
		case '\177':
		case '\b':
			if (s > cmd) {
				s--;
				printf("\b \b");
			}
			break;
		case '\n':
		case '\r':
			*s = 0;
			return;
		default:
			if (s - cmd < sizeof(cmd) - 1)
				*s++ = c;
			putchar(c);
		}
	}
}

static inline void
putc(int c)
{

	v86.addr = 0x10;
	v86.eax = 0xe00 | (c & 0xff);
	v86.ebx = 0x7;
	v86int();
}

int
main(void)
{
	uint8_t autoboot;
	ufs_ino_t ino;
	size_t nbyte;

	dmadat = (void *)(roundup2(__base + (int32_t)&_end, 0x10000) - __base);
	v86.ctl = V86_FLAGS;
	v86.efl = PSL_RESERVED_DEFAULT | PSL_I;
	dsk.drive = *(uint8_t *)PTOV(ARGS);
	dsk.type = dsk.drive & DRV_HARD ? TYPE_AD : TYPE_FD;
	dsk.unit = dsk.drive & DRV_MASK;
	dsk.slice = *(uint8_t *)PTOV(ARGS + 1) + 1;
	bootinfo.bi_version = BOOTINFO_VERSION;
	bootinfo.bi_size = sizeof(bootinfo);

	/* Process configuration file */

	autoboot = 1;

	if ((ino = lookup(PATH_CONFIG)) ||
	    (ino = lookup(PATH_DOTCONFIG))) {
		nbyte = fsread(ino, cmd, sizeof(cmd) - 1);
		cmd[nbyte] = '\0';
	}

	if (*cmd) {
		memcpy(cmddup, cmd, sizeof(cmd));
		if (parse())
			autoboot = 0;
		if (!OPT_CHECK(RBX_QUIET))
			printf("%s: %s", PATH_CONFIG, cmddup);
		/* Do not process this command twice */
		*cmd = 0;
	}

	/*
	 * Try to exec stage 3 boot loader. If interrupted by a keypress,
	 * or in case of failure, try to load a kernel directly instead.
	 */

	if (!kname) {
		kname = PATH_LOADER;
		if (autoboot && !keyhit(3*SECOND)) {
			load();
			kname = PATH_KERNEL;
		}
	}

	/* Present the user with the boot2 prompt. */

	for (;;) {
		if (!autoboot || !OPT_CHECK(RBX_QUIET))
			printf("\nFreeBSD/x86 boot\n"
				 "Default: %u:%s(%u,%c)%s\n"
				 "boot: ",
			    dsk.drive & DRV_MASK, dev_nm[dsk.type], dsk.unit,
			    'a' + dsk.part, kname);
		if (DO_SIO)
			sio_flush();
		if (!autoboot || keyhit(3*SECOND))
			getstr();
		else if (!autoboot || !OPT_CHECK(RBX_QUIET))
			putchar('\n');
		autoboot = 0;
		if (parse())
			putchar('\a');
		else
			load();
	}
}

/* XXX - Needed for btxld to link the boot2 binary; do not remove. */
void
exit(int x)
{

}

static void
load(void)
{
	union {
		struct exec ex;
		Elf32_Ehdr eh;
	} hdr;
	static Elf32_Phdr ep[2];
	static Elf32_Shdr es[2];
	caddr_t p;
	ufs_ino_t ino;
	uint32_t addr;
	int k;
	uint8_t i, j;

	if (!(ino = lookup(kname))) {
		if (!ls)
			printf("No %s\n", kname);
		return;
	}
	if (xfsread(ino, &hdr, sizeof(hdr)))
		return;

	if (N_GETMAGIC(hdr.ex) == ZMAGIC) {
		addr = hdr.ex.a_entry & 0xffffff;
		p = PTOV(addr);
		fs_off = PAGE_SIZE;
		if (xfsread(ino, p, hdr.ex.a_text))
			return;
		p += roundup2(hdr.ex.a_text, PAGE_SIZE);
		if (xfsread(ino, p, hdr.ex.a_data))
			return;
	} else if (IS_ELF(hdr.eh)) {
		fs_off = hdr.eh.e_phoff;
		for (j = k = 0; k < hdr.eh.e_phnum && j < 2; k++) {
			if (xfsread(ino, ep + j, sizeof(ep[0])))
				return;
			if (ep[j].p_type == PT_LOAD)
				j++;
		}
		for (i = 0; i < 2; i++) {
			p = PTOV(ep[i].p_paddr & 0xffffff);
			fs_off = ep[i].p_offset;
			if (xfsread(ino, p, ep[i].p_filesz))
				return;
		}
		p += roundup2(ep[1].p_memsz, PAGE_SIZE);
		bootinfo.bi_symtab = VTOP(p);
		if (hdr.eh.e_shnum == hdr.eh.e_shstrndx + 3) {
			fs_off = hdr.eh.e_shoff + sizeof(es[0]) *
			    (hdr.eh.e_shstrndx + 1);
			if (xfsread(ino, &es, sizeof(es)))
				return;
			for (i = 0; i < 2; i++) {
				*(Elf32_Word *)p = es[i].sh_size;
				p += sizeof(es[i].sh_size);
				fs_off = es[i].sh_offset;
				if (xfsread(ino, p, es[i].sh_size))
					return;
				p += es[i].sh_size;
			}
		}
		addr = hdr.eh.e_entry & 0xffffff;
		bootinfo.bi_esymtab = VTOP(p);
	} else {
		printf("Invalid %s\n", "format");
		return;
	}

	bootinfo.bi_kernelname = VTOP(kname);
	bootinfo.bi_bios_dev = dsk.drive;
	__exec((caddr_t)addr, RB_BOOTINFO | (opts & RBX_MASK),
	    MAKEBOOTDEV(dev_maj[dsk.type], dsk.slice, dsk.unit, dsk.part),
	    0, 0, 0, VTOP(&bootinfo));
}

static int
parse()
{
	char *arg, *ep, *p, *q;
	const char *cp;
	unsigned int drv;
	int c, i, j;
	size_t k;

	arg = cmd;

	while ((c = *arg++)) {
		if (c == ' ' || c == '\t' || c == '\n')
			continue;
		for (p = arg; *p && *p != '\n' && *p != ' ' && *p != '\t'; p++);
		ep = p;
		if (*p)
			*p++ = 0;
		if (c == '-') {
			while ((c = *arg++)) {
				if (c == 'P') {
					if (*(uint8_t *)PTOV(0x496) & 0x10) {
						cp = "yes";
					} else {
						opts |= OPT_SET(RBX_DUAL) |
						    OPT_SET(RBX_SERIAL);
						cp = "no";
					}
					printf("Keyboard: %s\n", cp);
					continue;
#if SERIAL
				} else if (c == 'S') {
					j = 0;
					while ((u_int)(i = *arg++ - '0') <= 9)
						j = j * 10 + i;
					if (j > 0 && i == -'0') {
						comspeed = j;
						break;
					}
					/*
					 * Fall through to error below
					 * ('S' not in optstr[]).
					 */
#endif
				}
				for (i = 0; c != optstr[i]; i++)
					if (i == NOPT - 1)
						return (-1);
				opts ^= OPT_SET(flags[i]);
			}
#if SERIAL
			ioctrl = OPT_CHECK(RBX_DUAL) ? (IO_SERIAL|IO_KEYBOARD) :
			    OPT_CHECK(RBX_SERIAL) ? IO_SERIAL : IO_KEYBOARD;
			if (DO_SIO) {
				if (sio_init(115200 / comspeed) != 0)
					ioctrl &= ~IO_SERIAL;
			}
#endif
		} else {
			for (q = arg--; *q && *q != '('; q++);
			if (*q) {
				drv = -1;
				if (arg[1] == ':') {
					drv = *arg - '0';
					if (drv > 9)
						return (-1);
					arg += 2;
				}
				if (q - arg != 2)
					return (-1);
				for (i = 0; arg[0] != dev_nm[i][0] ||
				    arg[1] != dev_nm[i][1]; i++)
					if (i == NDEV - 1)
						return (-1);
				dsk.type = i;
				arg += 3;
				dsk.unit = *arg - '0';
				if (arg[1] != ',' || dsk.unit > 9)
					return (-1);
				arg += 2;
				dsk.slice = WHOLE_DISK_SLICE;
				if (arg[1] == ',') {
					dsk.slice = *arg - '0' + 1;
					if (dsk.slice > NDOSPART + 1)
						return (-1);
					arg += 2;
				}
				if (arg[1] != ')')
					return (-1);
				dsk.part = *arg - 'a';
				if (dsk.part > 7)
					return (-1);
				arg += 2;
				if (drv == -1)
					drv = dsk.unit;
				dsk.drive = (dsk.type <= TYPE_MAXHARD
				    ? DRV_HARD : 0) + drv;
				dsk_meta = 0;
			}
			k = ep - arg;
			if (k > 0) {
				if (k >= sizeof(knamebuf))
					return (-1);
				memcpy(knamebuf, arg, k + 1);
				kname = knamebuf;
			}
		}
		arg = p;
	}
	return (0);
}

static int
dskread(void *buf, unsigned lba, unsigned nblk)
{
	struct dos_partition *dp;
	struct disklabel *d;
	char *sec;
	unsigned i;
	uint8_t sl;
	const char *reason;

	if (!dsk_meta) {
		sec = dmadat->secbuf;
		dsk.start = 0;
		if (drvread(sec, DOSBBSECTOR, 1))
			return (-1);
		dp = (void *)(sec + DOSPARTOFF);
		sl = dsk.slice;
		if (sl < BASE_SLICE) {
			for (i = 0; i < NDOSPART; i++)
				if (dp[i].dp_typ == DOSPTYP_386BSD &&
				    (dp[i].dp_flag & 0x80 || sl < BASE_SLICE)) {
					sl = BASE_SLICE + i;
					if (dp[i].dp_flag & 0x80 ||
					    dsk.slice == COMPATIBILITY_SLICE)
						break;
				}
			if (dsk.slice == WHOLE_DISK_SLICE)
				dsk.slice = sl;
		}
		if (sl != WHOLE_DISK_SLICE) {
			if (sl != COMPATIBILITY_SLICE)
				dp += sl - BASE_SLICE;
			if (dp->dp_typ != DOSPTYP_386BSD) {
				reason = "slice";
				goto error;
			}
			dsk.start = dp->dp_start;
		}
		if (drvread(sec, dsk.start + LABELSECTOR, 1))
			return (-1);
		d = (void *)(sec + LABELOFFSET);
		if (d->d_magic != DISKMAGIC || d->d_magic2 != DISKMAGIC) {
			if (dsk.part != RAW_PART) {
				reason = "label";
				goto error;
			}
		} else {
			if (!dsk.init) {
				if (d->d_type == DTYPE_SCSI)
					dsk.type = TYPE_DA;
				dsk.init++;
			}
			if (dsk.part >= d->d_npartitions ||
			    !d->d_partitions[dsk.part].p_size) {
				reason = "partition";
				goto error;
			}
			dsk.start += d->d_partitions[dsk.part].p_offset;
			dsk.start -= d->d_partitions[RAW_PART].p_offset;
		}
	}
	return (drvread(buf, dsk.start + lba, nblk));
error:
	printf("Invalid %s\n", reason);
	return (-1);
}

static void
printf(const char *fmt,...)
{
	va_list ap;
	static char buf[10];
	char *s;
	unsigned u;
	int c;

	va_start(ap, fmt);
	while ((c = *fmt++)) {
		if (c == '%') {
			c = *fmt++;
			switch (c) {
			case 'c':
				putchar(va_arg(ap, int));
				continue;
			case 's':
				for (s = va_arg(ap, char *); *s; s++)
					putchar(*s);
				continue;
			case 'u':
				u = va_arg(ap, unsigned);
				s = buf;
				do
					*s++ = '0' + u % 10U;
				while (u /= 10U);
				while (--s >= buf)
					putchar(*s);
				continue;
			}
		}
		putchar(c);
	}
	va_end(ap);
	return;
}

static void
putchar(int c)
{

	if (c == '\n')
		xputc('\r');
	xputc(c);
}

static int
drvread(void *buf, unsigned lba, unsigned nblk)
{
	static unsigned c = 0x2d5c7c2f;

	if (!OPT_CHECK(RBX_QUIET)) {
		xputc(c = c << 8 | c >> 24);
		xputc('\b');
	}
	v86.ctl = V86_ADDR | V86_CALLF | V86_FLAGS;
	v86.addr = XREADORG;		/* call to xread in boot1 */
	v86.es = VTOPSEG(buf);
	v86.eax = lba;
	v86.ebx = VTOPOFF(buf);
	v86.ecx = lba >> 16;
	v86.edx = nblk << 8 | dsk.drive;
	v86int();
	v86.ctl = V86_FLAGS;
	if (V86_CY(v86.efl)) {
		printf("error %u lba %u\n", v86.eax >> 8 & 0xff, lba);
		return (-1);
	}
	return (0);
}

static int
keyhit(unsigned ticks)
{
	uint32_t t0, t1;

	if (OPT_CHECK(RBX_NOINTR))
		return (0);
	t0 = 0;
	for (;;) {
		if (xgetc(1))
			return (1);
		t1 = *(uint32_t *)PTOV(0x46c);
		if (!t0)
			t0 = t1;
		if ((uint32_t)(t1 - t0) >= ticks)
			return (0);
	}
}

static int
xputc(int c)
{

	if (DO_KBD)
		putc(c);
	if (DO_SIO)
		sio_putc(c);
	return (c);
}

static int
getc(int fn)
{

	v86.addr = 0x16;
	v86.eax = fn << 8;
	v86int();
	return (fn == 0 ? v86.eax & 0xff : !V86_ZR(v86.efl));
}

static int
xgetc(int fn)
{

	if (OPT_CHECK(RBX_NOINTR))
		return (0);
	for (;;) {
		if (DO_KBD && getc(1))
			return (fn ? 1 : getc(0));
		if (DO_SIO && sio_ischar())
			return (fn ? 1 : sio_getc());
		if (fn)
			return (0);
	}
}