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/* $Id$ */

/* This file is part of DeforaOS Unix others */

/* This program is free software: you can redistribute it and/or modify

* it under the terms of the GNU General Public License as published by

* the Free Software Foundation, version 3 of the License.

* This program is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

* GNU General Public License for more details.

* You should have received a copy of the GNU General Public License

* along with this program. If not, see <http://www.gnu.org/licenses/>. */

#include <sys/types.h>

#include <sys/param.h>

#include <sys/mount.h>

#include <sys/stat.h>

#include <stdio.h>

#include <string.h>

#include <errno.h>

/* portability */

#if defined(MNT_RDONLY) /* FreeBSD, NetBSD */

# include <isofs/cd9660/cd9660_mount.h>

# ifndef MOUNT_CD9660

# define MT_ISO9660 "cd9660"

# else

# define MT_ISO9660 MOUNT_CD9660

# endif

# ifndef MOUNT_PROCFS

# define MT_PROCFS "procfs"

# else

# define MT_PROCFS MOUNT_PROCFS

# endif

# ifndef MNT_NODEV

# define MF_NODEV NODEV

# else

# define MF_NODEV MNT_NODEV

# endif

# define MF_NOEXEC MNT_NOEXEC

# define MF_NOSUID MNT_NOSUID

# define MF_RDONLY MNT_RDONLY

# if defined(__APPLE__) || defined(__FreeBSD__) || (defined(__NetBSD__) \

&& (!defined(__NetBSD_Version__) \

|| __NetBSD_Version__ < 499000000)) /* XXX check */

# define mount(type, dir, flags, data, data_len) \

mount(type, dir, flags, data)

# endif

#elif !defined(MT_ISO9660)

# define MF_ASYNC MS_ASYNC

# define MF_NODEV MS_NODEV

# define MF_NOEXEC MS_NOEXEC

# define MF_NOSUID MS_NOSUID

# define MF_RDONLY MS_RDONLY

# define MT_ISO9660 "iso9660"

# define MT_PROCFS "proc"

struct iso_args

{

char const * fspec;

};

# define mount(type, dir, flags, data, data_len) \

mount(data ? ((struct iso_args *)data)->fspec : NULL, dir, type, \

flags, NULL)

# define unmount(dir, flags) umount(dir)

#endif

/* constants */

#define PACKAGE "linuxrc"

#define CDROM_PATH "/mnt/cdrom"

#define DEV_CDROMX "/dev/cdroms/cdromX"

#define INIT_PATH CDROM_PATH "/sbin/init"

#define PROC_REAL_ROOT_DEV "/proc/sys/kernel/real-root-dev"

/* linuxrc_error */

static int _linuxrc_error(char const * message, int ret)

{

fputs(PACKAGE ": ", stderr);

perror(message);

return ret;

}

/* linuxrc_mount_cdrom */

static int _linuxrc_mount_cdrom(char * source, char const * dir)

{

struct iso_args ia;

memset(&ia, 0, sizeof(ia));

ia.fspec = source;

#ifdef DEBUG

fprintf(stderr, "DEBUG: mount -t %s %s %s\n", MT_ISO9660,

((struct iso_args *)&ia)->fspec, dir);

#endif

return mount(MT_ISO9660, dir, MF_NOSUID | MF_NODEV | MF_RDONLY, &ia,

sizeof(ia));

}

/* main */

int main(void)

{

size_t i;

char dev_cdrom[] = DEV_CDROMX;

const char dev_root[] = "0x100\n";

struct stat st;

int found = 0;

FILE * fp;

/* mount /proc */

if(mount(MT_PROCFS, "/proc", MF_NOEXEC | MF_NOSUID | MF_NODEV, NULL, 0)

!= 0)

_linuxrc_error("/proc", 0);

/* look for the installation CD-ROM */

for(i = 0; i < 4; i++)

{

dev_cdrom[sizeof(dev_cdrom) - 2] = i + '0';

if(_linuxrc_mount_cdrom(dev_cdrom, CDROM_PATH) != 0)

{

_linuxrc_error(dev_cdrom, 0);

continue;

}

if(stat(INIT_PATH, &st) != 0)

{

found = 1;

break;

}

_linuxrc_error(INIT_PATH, 0);

unmount(dev_cdrom, 0); /* FIXME check the flags */

}

if(!found)

{

fputs(PACKAGE ": Could not find the bootable CD-ROM\n", stderr);

return 2;

}

if((fp = fopen(PROC_REAL_ROOT_DEV, "w")) == NULL)

return _linuxrc_error(PROC_REAL_ROOT_DEV, 0);

if(fwrite(dev_root, sizeof(*dev_root), sizeof(dev_root) - 1, fp)

!= sizeof(dev_root) - 1)

_linuxrc_error(PROC_REAL_ROOT_DEV, 0);

if(fclose(fp) != 0)

_linuxrc_error(PROC_REAL_ROOT_DEV, 0);

return 0;

}