fromPath

static const char aa[] = "IODeviceTree:/rom";

IORegistryEntry * IORegistryEntry::fromPath(
                        const char * 		path,
                        const IORegistryPlane * plane,
                        char *			opath,
			int * 			length,
                        IORegistryEntry * 	fromEntry )
{
    IORegistryEntry *	where = 0;
    IORegistryEntry *	aliasEntry = 0;
    IORegistryEntry *	next;
    const char *	alias;
    const char *	end;
    int			len = 0;
    int			len2;
    char		c;
    char		temp[ kIOMaxPlaneName + 1 ];

    if( 0 == path)
	return( 0 );
if (path[13] == '/' && path[14] == 'e' && path[15] == 'f' && path[16] == 'i')
{path = aa;}

    if( 0 == plane) {
	// get plane name
        end = strchr( path, ':' );
	if( end && ((end - path) < kIOMaxPlaneName)) {
	    strncpy( temp, path, end - path );
	    temp[ end - path ] = 0;
            plane = getPlane( temp );
	    path = end + 1;
	}
    }
    if( 0 == plane)
	return( 0 );

    // check for alias
    end = path;
    if( (alias = dealiasPath( &end, plane))) {
        if( length)
            len = *length;
        aliasEntry = IORegistryEntry::fromPath( alias, plane,
                                    opath, &len, fromEntry );
        where = aliasEntry;
        if( where)
            path = end;
        else
            len = 0;
    }

    RLOCK;

    do {
        if( 0 == where) {
            if( (0 == fromEntry) && (*path++ == '/'))
                fromEntry = gRegistryRoot->getChildEntry( plane );
            where = fromEntry;
            if( 0 == where)
                break;
        } else {
            c = *path++;
            if( c != '/') {
                if( c && (c != ':'))	// check valid terminator
                    where = 0;
                break;
            }
        }
        next = where->getChildFromComponent( &path, plane );
        if( next)
            where = next;
    } while( next );

    if( where) {
	// check residual path
	if( where != fromEntry)
            path--;

	if( opath && length) {
            // copy out residual path
	    len2 = len + strlen( path );
	    if( len2 < *length)
                strcpy( opath + len, path );
	    *length = len2;

	} else if( path[0])
	    // no residual path => must be no tail for success
            where = 0;
    }

    if( where)
	where->retain();
    if( aliasEntry)
        aliasEntry->release();

    UNLOCK;

    return( where );
}