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//==========================================================================

//

//      misc.cxx

//

//      Fileio miscellaneous functions

//

//==========================================================================

// ####ECOSGPLCOPYRIGHTBEGIN####                                            

// -------------------------------------------                              

// This file is part of eCos, the Embedded Configurable Operating System.   

// Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.

//

// eCos 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; either version 2 or (at your option) any later      

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//

// eCos 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 eCos; if not, write to the Free Software Foundation, Inc.,    

// 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.            

//

// As a special exception, if other files instantiate templates or use      

// macros or inline functions from this file, or you compile this file      

// and link it with other works to produce a work based on this file,       

// this file does not by itself cause the resulting work to be covered by   

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// must still be made available in accordance with section (3) of the GNU   

// General Public License v2.                                               

//

// This exception does not invalidate any other reasons why a work based    

// on this file might be covered by the GNU General Public License.         

// -------------------------------------------                              

// ####ECOSGPLCOPYRIGHTEND####                                              

//==========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):           nickg

// Contributors:        nickg

// Date:                2000-05-25

// Purpose:             Fileio miscellaneous functions

// Description:         This file contains various miscellaneous functions

//                      for use with the fileio system. These include startup,

//                      table management, and other service routines.

//

//####DESCRIPTIONEND####

//

//==========================================================================

#include <pkgconf/system.h>

#include <pkgconf/hal.h>

#include <pkgconf/io_fileio.h>

#ifdef CYGPKG_LIBC_TIME

#include <pkgconf/libc_time.h>

#endif

#include <cyg/infra/cyg_trac.h>        // tracing macros

#include <cyg/infra/cyg_ass.h>         // assertion macros

#include <string.h>                    // strcmp()

#include <time.h>                      // time()

#ifdef CYGPKG_IO_WALLCLOCK

# include <cyg/io/wallclock.hxx>       // Wallclock class

#endif

#ifdef CYGPKG_KERNEL

#include <pkgconf/kernel.h>

#include <cyg/kernel/ktypes.h>         // base kernel types

#include <cyg/kernel/clock.inl>         // Clock inlines

#endif

#include "fio.h"                       // Private header

//==========================================================================

// forward definitions

static void cyg_mtab_init();

__externC int chdir( const char *path );

//==========================================================================

// Filesystem tables

// -------------------------------------------------------------------------

// Filesystem table.

// This array contains entries for all filesystem that are installed in

// the system.

__externC cyg_fstab_entry cyg_fstab[];

CYG_HAL_TABLE_BEGIN( cyg_fstab, fstab );

// end of filesystem table, set in linker script.

__externC cyg_fstab_entry cyg_fstab_end;

CYG_HAL_TABLE_END( cyg_fstab_end, fstab );

#ifdef CYGPKG_KERNEL

// Array of mutexes for locking the fstab entries

static Cyg_Mutex fstab_lock[CYGNUM_FILEIO_FSTAB_MAX] CYGBLD_ATTRIB_INIT_PRI(CYG_INIT_IO_FS);

#endif

// -------------------------------------------------------------------------

// Mount table.

// This array contains entries for all valid running filesystems.

__externC cyg_mtab_entry cyg_mtab[];

CYG_HAL_TABLE_BEGIN( cyg_mtab, mtab );

// Extra entries at end of mtab for dynamic mount points.

#if CYGNUM_FILEIO_MTAB_EXTRA > 0

cyg_mtab_entry cyg_mtab_extra[CYGNUM_FILEIO_MTAB_EXTRA] CYG_HAL_TABLE_EXTRA(mtab) = { { NULL } };

#endif

// End of mount table, set in the linker script.

__externC cyg_mtab_entry cyg_mtab_end;

CYG_HAL_TABLE_END( cyg_mtab_end, mtab );

#ifdef CYGPKG_KERNEL

// Array of mutexes for locking the mtab entries

static Cyg_Mutex mtab_lock[CYGNUM_FILEIO_MTAB_MAX] CYGBLD_ATTRIB_INIT_PRI(CYG_INIT_IO_FS);

#endif

//==========================================================================

// Current directory

cyg_mtab_entry *cyg_cdir_mtab_entry = NULL;

cyg_dir cyg_cdir_dir = CYG_DIR_NULL;

//==========================================================================

// Initialization object

class Cyg_Fileio_Init_Class

{

public:

    Cyg_Fileio_Init_Class();

};

static Cyg_Fileio_Init_Class fileio_initializer CYGBLD_ATTRIB_INIT_PRI(CYG_INIT_IO_FS);

Cyg_Fileio_Init_Class::Cyg_Fileio_Init_Class()

{

    cyg_fd_init();

    cyg_mtab_init();

    chdir("/");

}

//==========================================================================

// Mount table initializer

static void cyg_mtab_init()

{

    cyg_mtab_entry *m;

    for( m = &cyg_mtab[0]; m != &cyg_mtab_end; m++ )

    {

        const char *fsname = m->fsname;

        cyg_fstab_entry *f;

        // Ignore empty entries

        if( m->name == NULL )

            continue;

        // stop if there are more than the configured maximum

        if( m-&cyg_mtab[0] >= CYGNUM_FILEIO_MTAB_MAX )

            break;

        for( f = &cyg_fstab[0]; f != &cyg_fstab_end; f++ )

        {

            // stop if there are more than the configured maximum

            if( f-&cyg_fstab[0] >= CYGNUM_FILEIO_FSTAB_MAX )

                break;

            if( strcmp( fsname, f->name) == 0 )

            {

                // We have a match.

                if( f->mount( f, m ) == 0 )

                {

                    m->valid    = true;

                    m->fs       = f;

                    // m->root installed by fs.

                }

                else

                {

                    m->valid = false;

                }

                break;

            }

        }

    }

}

//==========================================================================

// Mount table matching

// -------------------------------------------------------------------------

// matchlen() compares two strings and returns the number of bytes by which

// they match.

static int matchlen( const char *s1, const char *s2 )

{

    int len = 0;

    while( s1[len] == s2[len] && s1[len] && s2[len] ) len++;

    // Return length only if s2 is an initial substring of s1,

    // and it terminates in s1 at end-of-string or a '/'.

    // Special case for s2 == "/"

    if( len == 1 && s2[0] == '/' && s2[1] == 0 )

        return len;

    if( (s2[len] == 0) && (s1[len] == 0 || s1[len] == '/'))

         return len;

    else return 0;

}

// -------------------------------------------------------------------------

// Simple strlen implementation

static int my_strlen(const char *c)

{

    int l = 0;

    while (*c++) l++;

    return l;

}

// -------------------------------------------------------------------------

// Search the mtab for the entry that matches the longest substring of

// **name. 

__externC int cyg_mtab_lookup( cyg_dir *dir, const char **name, cyg_mtab_entry **mte)

{

    cyg_mtab_entry *m, *best = NULL;

    int best_len = 0;

    // Unrooted file names start from current dir

    if( **name != '/' ) {

        int cwd_len;

        if (*mte == (cyg_mtab_entry *)NULL) {

            // No known current directory

            return -1;

        }

        best = *mte;

        cwd_len = my_strlen((*mte)->name);

        // current dir is not the correct mte if the relative path crosses

        // mount points -  search for best matching mount point

        for( m = &cyg_mtab[0]; m != &cyg_mtab_end; m++ )

        {

            if( m->name != NULL && m->valid )

            {

                int len = matchlen(m->name, (*mte)->name);

                // mount point under cwd?

                if (len == cwd_len)

                {

                    if (m->name[len] == '/')

                        len++;

                    len = matchlen(*name, &m->name[len]);

                    if (len > best_len)

                        best = m, best_len = len;

                }

            }

        }

        // did we find a better match?

        if (best != *mte)

          *dir = best->root;

    }

    else

    {

        // Otherwise search the mount table.

        for( m = &cyg_mtab[0]; m != &cyg_mtab_end; m++ )

        {

            if( m->name != NULL && m->valid )

            {

                int len = matchlen(*name,m->name);

                if( len > best_len )

                    best = m, best_len = len;

            }

        }

        // No match found, bad path name...

        if( best_len == 0 ) return -1;

        *dir = best->root;

    }

    *name += best_len;

    if( **name == '/' )

        (*name)++;

    *mte = best;

    return 0;

}

//==========================================================================

// mount filesystem

__externC int mount( const char *devname,

                     const char *dir,

                     const char *fsname)

{

    FILEIO_ENTRY();

    cyg_mtab_entry *m;

    cyg_fstab_entry *f;

    int result = ENOERR;

    // Search the mount table for an empty entry

    for( m = &cyg_mtab[0]; m != &cyg_mtab_end; m++ )

    {

        // stop if there are more than the configured maximum

        if( m-&cyg_mtab[0] >= CYGNUM_FILEIO_MTAB_MAX )

        {

            m = &cyg_mtab_end;

            break;

        }

         if( m->name == NULL ) break;

    }

    if( m == &cyg_mtab_end )

        FILEIO_RETURN(ENOMEM);

    // Now search the fstab for the filesystem implementation

    for( f = &cyg_fstab[0]; f != &cyg_fstab_end; f++ )

    {

        // stop if there are more than the configured maximum

        if( f-&cyg_fstab[0] >= CYGNUM_FILEIO_FSTAB_MAX )

            break;

        if( strcmp( fsname, f->name) == 0 )

            break;

    }

    if( f == &cyg_fstab_end )

        FILEIO_RETURN(ENODEV);

    // We have a match.

    m->name = dir;

    m->fsname = fsname;

    m->devname = devname;

    if( (result = f->mount( f, m )) == 0 )

    {

        m->valid    = true;

        m->fs       = f;

        // m->root installed by fs.

    }

    else

    {

        m->valid = false;

        m->name = NULL;

    }

    // Make sure that there is something to search (for open)

    if (cyg_cdir_mtab_entry == (cyg_mtab_entry *)NULL) {

        cyg_cdir_mtab_entry = m;

    }

    FILEIO_RETURN(result);

}

//==========================================================================

// unmount filesystem

__externC int umount( const char *name)

{

    int err = ENOERR;

    FILEIO_ENTRY();

    cyg_mtab_entry *m;

    // Search the mount table for a matching entry

    for( m = &cyg_mtab[0]; m != &cyg_mtab_end; m++ )

    {

        // stop if there are more than the configured maximum

        if( m-&cyg_mtab[0] >= CYGNUM_FILEIO_MTAB_MAX )

        {

            m = &cyg_mtab_end;

            break;

        }

        // Ignore empty or invalid entries

         if( m->name == NULL || !m->valid ) continue;

         // match names.

         if( strcmp(name,m->name) == 0 ) break;

         // Match device name too?

    }

    if( m == &cyg_mtab_end )

        FILEIO_RETURN(EINVAL);

    // We have a match, call the umount function

    err = m->fs->umount( m );

    if( err == ENOERR )

    {

        m->valid        = false;

        m->name         = NULL;

    }

    FILEIO_RETURN(err);

}

//==========================================================================

// Implement filesystem locking protocol. 

void cyg_fs_lock( cyg_mtab_entry *mte, cyg_uint32 syncmode )

{

    CYG_ASSERT(mte != NULL, "Bad mount table entry");

    if( syncmode & CYG_SYNCMODE_FILE_FILESYSTEM ) {

        CYG_ASSERT(mte->fs-&cyg_fstab[0] < CYGNUM_FILEIO_FSTAB_MAX, "Bad file system");

        FILEIO_MUTEX_LOCK( fstab_lock[mte->fs-&cyg_fstab[0]] );

    }

    if( syncmode & CYG_SYNCMODE_FILE_MOUNTPOINT ) {

        CYG_ASSERT(mte-&cyg_mtab[0] < CYGNUM_FILEIO_MTAB_MAX, "Bad mount point");

        FILEIO_MUTEX_LOCK( mtab_lock[mte-&cyg_mtab[0]] );

    }

}

void cyg_fs_unlock( cyg_mtab_entry *mte, cyg_uint32 syncmode )

{

    CYG_ASSERT(mte != NULL, "Bad mount table entry");

    if( syncmode & CYG_SYNCMODE_FILE_FILESYSTEM ) {

        CYG_ASSERT(mte->fs-&cyg_fstab[0] < CYGNUM_FILEIO_FSTAB_MAX, "Bad file system");

        FILEIO_MUTEX_UNLOCK( fstab_lock[mte->fs-&cyg_fstab[0]] );

    }

    if( syncmode & CYG_SYNCMODE_FILE_MOUNTPOINT ) {

        CYG_ASSERT(mte-&cyg_mtab[0] < CYGNUM_FILEIO_MTAB_MAX, "Bad mount point");

        FILEIO_MUTEX_UNLOCK( mtab_lock[mte-&cyg_mtab[0]] );

    }

}

//==========================================================================

// Search mount table for a filesystems root. 

__externC cyg_mtab_entry * cyg_fs_root_lookup( cyg_dir *root )

{

     cyg_mtab_entry *m;

     for( m = &cyg_mtab[0]; m != &cyg_mtab_end; m++ )

     {

          if( (cyg_dir *)m->root == root )

          {

               return m;

          }

     }

     return NULL;

}

//==========================================================================

// Timestamp support

// This provides access to the current time/date, expressed as a

// time_t.  It uses a number of mechanisms to do this, selecting

// whichever is available in the current configuration.

__externC time_t cyg_timestamp()

{

#if defined(CYGPKG_IO_WALLCLOCK)

    // First, try to get the time from the wallclock device.

    return (time_t) Cyg_WallClock::wallclock->get_current_time();

#elif defined(CYGINT_ISO_POSIX_TIMERS)

    // If POSIX is present, use the current value of the realtime

    // clock.

    struct timespec tp;

    clock_gettime( CLOCK_REALTIME, &tp );

    return (time_t) tp.tv_sec;

#elif defined(CYGPKG_KERNEL) 

    // If all else fails, get the current realtime clock value and

    // convert it to seconds ourself.

    static struct Cyg_Clock::converter sec_converter;

    static cyg_bool initialized = false;

    cyg_tick_count ticks;

    if( !initialized )

    {

        Cyg_Clock::real_time_clock->get_clock_to_other_converter( 1000000000, &sec_converter );

        initialized = true;

    }

    ticks = Cyg_Clock::real_time_clock->current_value();

    return (time_t) Cyg_Clock::convert( ticks, &sec_converter );

#else    

    /* No clock support at all. */

    return (time_t) 0;

#endif    

}

//==========================================================================

// Default functions

__externC int cyg_fileio_enosys() { return ENOSYS; }

__externC int cyg_fileio_erofs() { return EROFS; }

__externC int cyg_fileio_enoerr() { return ENOERR; }

__externC int cyg_fileio_enotdir() { return ENOTDIR; }

__externC cyg_bool cyg_fileio_seltrue (struct CYG_FILE_TAG *fp, int which, CYG_ADDRWORD info)

{ return 1; }

// -------------------------------------------------------------------------

// EOF misc.cxx