xref: /freebsd-11-stable/stand/common/boot.c

/*-
 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD: stable/11/stand/common/boot.c 344378 2019-02-20 19:19:24Z kevans $");

/*
 * Loading modules, booting the system
 */

#include <stand.h>
#include <sys/reboot.h>
#include <sys/boot.h>
#include <string.h>

#include "bootstrap.h"

static int	autoboot(int timeout, char *prompt);
static char	*getbootfile(int try);
static int	loadakernel(int try, int argc, char* argv[]);

/* List of kernel names to try (may be overwritten by boot.config) XXX should move from here? */
static const char *default_bootfiles = "kernel";

static int autoboot_tried;

/*
 * The user wants us to boot.
 */
COMMAND_SET(boot, "boot", "boot a file or loaded kernel", command_boot);

static int
command_boot(int argc, char *argv[])
{
	struct preloaded_file	*fp;

	/*
	 * See if the user has specified an explicit kernel to boot.
	 */
	if ((argc > 1) && (argv[1][0] != '-')) {

		/* XXX maybe we should discard everything and start again? */
		if (file_findfile(NULL, NULL) != NULL) {
			snprintf(command_errbuf, sizeof(command_errbuf),
			    "can't boot '%s', kernel module already loaded", argv[1]);
			return(CMD_ERROR);
		}

		/* find/load the kernel module */
		if (mod_loadkld(argv[1], argc - 2, argv + 2) != 0)
			return(CMD_ERROR);
		/* we have consumed all arguments */
		argc = 1;
	}

	/*
	 * See if there is a kernel module already loaded
	 */
	if (file_findfile(NULL, NULL) == NULL)
		if (loadakernel(0, argc - 1, argv + 1))
			/* we have consumed all arguments */
			argc = 1;

	/*
	 * Loaded anything yet?
	 */
	if ((fp = file_findfile(NULL, NULL)) == NULL) {
		command_errmsg = "no bootable kernel";
		return(CMD_ERROR);
	}

	/*
	 * If we were given arguments, discard any previous.
	 * XXX should we merge arguments?  Hard to DWIM.
	 */
	if (argc > 1) {
		if (fp->f_args != NULL)
			free(fp->f_args);
		fp->f_args = unargv(argc - 1, argv + 1);
	}

	/* Hook for platform-specific autoloading of modules */
	if (archsw.arch_autoload() != 0)
		return(CMD_ERROR);

	/* Call the exec handler from the loader matching the kernel */
	file_formats[fp->f_loader]->l_exec(fp);
	return(CMD_ERROR);
}


/*
 * Autoboot after a delay
 */

COMMAND_SET(autoboot, "autoboot", "boot automatically after a delay", command_autoboot);

static int
command_autoboot(int argc, char *argv[])
{
	int		howlong;
	char	*cp, *prompt;

	prompt = NULL;
	howlong = -1;
	switch(argc) {
	case 3:
		prompt = argv[2];
		/* FALLTHROUGH */
	case 2:
		howlong = strtol(argv[1], &cp, 0);
		if (*cp != 0) {
			snprintf(command_errbuf, sizeof(command_errbuf),
			    "bad delay '%s'", argv[1]);
			return(CMD_ERROR);
		}
		/* FALLTHROUGH */
	case 1:
		return(autoboot(howlong, prompt));
	}

	command_errmsg = "too many arguments";
	return(CMD_ERROR);
}

/*
 * Called before we go interactive.  If we think we can autoboot, and
 * we haven't tried already, try now.
 */
void
autoboot_maybe()
{
	char	*cp;

	cp = getenv("autoboot_delay");
	if ((autoboot_tried == 0) && ((cp == NULL) || strcasecmp(cp, "NO")))
		autoboot(-1, NULL);		/* try to boot automatically */
}

static int
autoboot(int timeout, char *prompt)
{
	time_t	when, otime, ntime;
	int		c, yes;
	char	*argv[2], *cp, *ep;
	char	*kernelname;
#ifdef BOOT_PROMPT_123
	const char	*seq = "123", *p = seq;
#endif

	autoboot_tried = 1;

	if (timeout == -1) {
		timeout = 10;
		/* try to get a delay from the environment */
		if ((cp = getenv("autoboot_delay"))) {
			timeout = strtol(cp, &ep, 0);
			if (cp == ep)
				timeout = 10;		/* Unparseable? Set default! */
		}
	}

	kernelname = getenv("kernelname");
	if (kernelname == NULL) {
		argv[0] = NULL;
		loadakernel(0, 0, argv);
		kernelname = getenv("kernelname");
		if (kernelname == NULL) {
			command_errmsg = "no valid kernel found";
			return(CMD_ERROR);
		}
	}

	if (timeout >= 0) {
		otime = time(NULL);
		when = otime + timeout;	/* when to boot */

		yes = 0;

#ifdef BOOT_PROMPT_123
		printf("%s\n", (prompt == NULL) ? "Hit [Enter] to boot immediately, or "
		    "1 2 3 sequence for command prompt." : prompt);
#else
		printf("%s\n", (prompt == NULL) ? "Hit [Enter] to boot immediately, or any other key for command prompt." : prompt);
#endif

		for (;;) {
			if (ischar()) {
				c = getchar();
#ifdef BOOT_PROMPT_123
				if ((c == '\r') || (c == '\n')) {
					yes = 1;
					break;
				} else if (c != *p++)
					p = seq;
				if (*p == 0)
					break;
#else
				if ((c == '\r') || (c == '\n'))
					yes = 1;
				break;
#endif
			}
			ntime = time(NULL);
			if (ntime >= when) {
				yes = 1;
				break;
			}

			if (ntime != otime) {
				printf("\rBooting [%s] in %d second%s... ",
				    kernelname, (int)(when - ntime),
				    (when-ntime)==1?"":"s");
				otime = ntime;
			}
		}
	} else {
		yes = 1;
	}

	if (yes)
		printf("\rBooting [%s]...               ", kernelname);
	putchar('\n');
	if (yes) {
		argv[0] = "boot";
		argv[1] = NULL;
		return(command_boot(1, argv));
	}
	return(CMD_OK);
}

/*
 * Scrounge for the name of the (try)'th file we will try to boot.
 */
static char *
getbootfile(int try)
{
	static char *name = NULL;
	const char	*spec, *ep;
	size_t	len;

	/* we use dynamic storage */
	if (name != NULL) {
		free(name);
		name = NULL;
	}

	/*
	 * Try $bootfile, then try our builtin default
	 */
	if ((spec = getenv("bootfile")) == NULL)
		spec = default_bootfiles;

	while ((try > 0) && (spec != NULL)) {
		spec = strchr(spec, ';');
		if (spec)
			spec++;	/* skip over the leading ';' */
		try--;
	}
	if (spec != NULL) {
		if ((ep = strchr(spec, ';')) != NULL) {
			len = ep - spec;
		} else {
			len = strlen(spec);
		}
		name = malloc(len + 1);
		strncpy(name, spec, len);
		name[len] = 0;
	}
	if (name && name[0] == 0) {
		free(name);
		name = NULL;
	}
	return(name);
}

/*
 * Try to find the /etc/fstab file on the filesystem (rootdev),
 * which should be be the root filesystem, and parse it to find
 * out what the kernel ought to think the root filesystem is.
 *
 * If we're successful, set vfs.root.mountfrom to <vfstype>:<path>
 * so that the kernel can tell both which VFS and which node to use
 * to mount the device.  If this variable's already set, don't
 * overwrite it.
 */
int
getrootmount(char *rootdev)
{
	char	lbuf[128], *cp, *ep, *dev, *fstyp, *options;
	int		fd, error;

	if (getenv("vfs.root.mountfrom") != NULL)
		return(0);

	error = 1;
	sprintf(lbuf, "%s/etc/fstab", rootdev);
	if ((fd = open(lbuf, O_RDONLY)) < 0)
		goto notfound;

	/* loop reading lines from /etc/fstab    What was that about sscanf again? */
	fstyp = NULL;
	dev = NULL;
	while (fgetstr(lbuf, sizeof(lbuf), fd) >= 0) {
		if ((lbuf[0] == 0) || (lbuf[0] == '#'))
			continue;

		/* skip device name */
		for (cp = lbuf; (*cp != 0) && !isspace(*cp); cp++)
			;
		if (*cp == 0)		/* misformatted */
			continue;
		/* delimit and save */
		*cp++ = 0;
		free(dev);
		dev = strdup(lbuf);

		/* skip whitespace up to mountpoint */
		while ((*cp != 0) && isspace(*cp))
			cp++;
		/* must have /<space> to be root */
		if ((*cp == 0) || (*cp != '/') || !isspace(*(cp + 1)))
			continue;
		/* skip whitespace up to fstype */
		cp += 2;
		while ((*cp != 0) && isspace(*cp))
			cp++;
		if (*cp == 0)		/* misformatted */
			continue;
		/* skip text to end of fstype and delimit */
		ep = cp;
		while ((*cp != 0) && !isspace(*cp))
			cp++;
		*cp = 0;
		free(fstyp);
		fstyp = strdup(ep);

		/* skip whitespace up to mount options */
		cp += 1;
		while ((*cp != 0) && isspace(*cp))
			cp++;
		if (*cp == 0)           /* misformatted */
			continue;
		/* skip text to end of mount options and delimit */
		ep = cp;
		while ((*cp != 0) && !isspace(*cp))
			cp++;
		*cp = 0;
		options = strdup(ep);
		/* Build the <fstype>:<device> and save it in vfs.root.mountfrom */
		sprintf(lbuf, "%s:%s", fstyp, dev);
		setenv("vfs.root.mountfrom", lbuf, 0);

		/* Don't override vfs.root.mountfrom.options if it is already set */
		if (getenv("vfs.root.mountfrom.options") == NULL) {
			/* save mount options */
			setenv("vfs.root.mountfrom.options", options, 0);
		}
		free(options);
		error = 0;
		break;
	}
	close(fd);
	free(dev);
	free(fstyp);

notfound:
	if (error) {
		const char *currdev;

		currdev = getenv("currdev");
		if (currdev != NULL && strncmp("zfs:", currdev, 4) == 0) {
			cp = strdup(currdev);
			cp[strlen(cp) - 1] = '\0';
			setenv("vfs.root.mountfrom", cp, 0);
			error = 0;
			free(cp);
		}
	}

	return(error);
}

static int
loadakernel(int try, int argc, char* argv[])
{
	char *cp;

	for (try = 0; (cp = getbootfile(try)) != NULL; try++)
		if (mod_loadkld(cp, argc - 1, argv + 1) != 0)
			printf("can't load '%s'\n", cp);
		else
			return 1;
	return 0;
}