/*-
 * 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.
 *
 * $FreeBSD: src/sys/boot/common/boot.c,v 1.29 2003/08/25 23:30:41 obrien Exp $
 */

/*
 * Loading modules, booting the system
 */

#include <stand.h>
#include <string.h>

#include "bootstrap.h"

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;
    char *local_module_path;
    char *exported_module_path;

    /*
     * 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);

    /*
     * Exec the kernel.  We have to shift our exported_module_path
     * (which has the correct /boot prefix for the kernel) over to
     * module_path.  If the exec fails we switch it back.
     */
    exported_module_path = getenv("exported_module_path");
    if (exported_module_path) {
            exported_module_path = strdup(exported_module_path);
            local_module_path = getenv("module_path");
            if (local_module_path)
                local_module_path = strdup(local_module_path);
            setenv("module_path", exported_module_path, 1);
            unsetenv("exported_module_path");
    }

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

    if (exported_module_path) {
            if (local_module_path) {
                setenv("module_path", local_module_path, 1);
                free(local_module_path);
            } else {
                unsetenv("module_path");
            }
            setenv("exported_module_path", exported_module_path, 1);
            free(exported_module_path);
    }
    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(void)
{
    char        *cp;

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

int
autoboot(int timeout, char *prompt)
{
    time_t      when, otime, ntime;
    int         c, yes;
    char        *argv[2], *cp, *ep;
    char        *kernelname;

    autoboot_tried = 1;

    if (timeout == -1) {
        /* try to get a delay from the environment */
        if ((cp = getenv("autoboot_delay"))) {
            timeout = strtol(cp, &ep, 0);
            if (cp == ep)
                timeout = -1;
        }
    }
    if (timeout == -1)          /* all else fails */
        timeout = 10;

    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);
        }
    }

    otime = time(NULL);
    when = otime + timeout;     /* when to boot */
    yes = 0;

    printf("%s\n", (prompt == NULL) ? "Hit [Enter] to boot immediately, or any other key for command prompt." : prompt);

    for (;;) {
        if (ischar()) {
            c = getchar();
            if ((c == '\r') || (c == '\n'))
                yes = 1;
            break;
        }
        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;
        }
    }
    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;
    int         fd, error;

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

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

    /* loop reading lines from /etc/fstab    What was that about sscanf again? */
    error = 1;
    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;
        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;
        fstyp = strdup(ep);

        /* build the final result and save it */
        sprintf(lbuf, "%s:%s", fstyp, dev);
        free(dev);
        free(fstyp);
        setenv("vfs.root.mountfrom", lbuf, 0);
        error = 0;
        break;
    }
    close(fd);
    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;
}