/*      $NetBSD: boot.c,v 1.9 2020/08/19 02:19:07 msaitoh Exp $ */

/*-
* Copyright (c) 1998 Michael Smith <[email protected]>
* 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: src/sys/boot/common/boot.c,v 1.29 2003/08/25 23:30:41 obrien Exp $"); */


/*
* Loading modules, booting the system
*/

#include <lib/libsa/stand.h>
#include <lib/libsa/loadfile.h>
#include <lib/libkern/libkern.h>

#include "bootstrap.h"

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

/* List of kernel names to try */
static const char *default_bootfiles = "netbsd";

static int autoboot_tried;

/*
* The user wants us to boot.
*/

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) {
           command_seterr("can't boot '%s', kernel module already loaded",
               argv[1]);
           return(CMD_ERROR);
       }

       /* find/load the kernel module */
       if (file_loadkernel(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_seterr("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 */
   command_seterr("%s", strerror(file_formats[fp->f_loader]->l_exec(fp)));
   return(CMD_ERROR);
}


/*
* Autoboot after a delay
*/

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) {
           command_seterr("bad delay '%s'", argv[1]);
           return(CMD_ERROR);
       }
       /* FALLTHROUGH */
   case 1:
       return(autoboot(howlong, prompt));
   }

   command_seterr("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_seterr("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 = alloc(len + 1);
       strncpy(name, spec, len);
       name[len] = 0;
   }
   if (name && name[0] == 0) {
       free(name);
       name = NULL;
   }
   else {
     setenv("kernelname", name, 1);
   }

   return(name);
}

/*
* Try to find the /etc/fstab file on the filesystem (rootdev),
* which should 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);

   snprintf(lbuf, sizeof(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 != '/') || !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 */
       snprintf(lbuf, sizeof(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 (file_loadkernel(cp, argc - 1, argv + 1) != 0)
                       printf("can't load '%s'\n", cp);
               else
                       return 1;
       return 0;
}