[aa083e49] | 1 | @c |
---|
| 2 | @c COPYRIGHT (c) 1988-1998. |
---|
| 3 | @c On-Line Applications Research Corporation (OAR). |
---|
| 4 | @c All rights reserved. |
---|
| 5 | @c |
---|
| 6 | @c $Id$ |
---|
| 7 | @c |
---|
| 8 | |
---|
| 9 | @ifinfo |
---|
[df4edf29] | 10 | @node Preface, Base File System, Top, Top |
---|
[aa083e49] | 11 | @end ifinfo |
---|
| 12 | @unnumbered Preface |
---|
| 13 | |
---|
| 14 | The following file system capabilities have been added to the existing |
---|
| 15 | RTEMS system: |
---|
| 16 | |
---|
| 17 | @itemize @bullet |
---|
| 18 | |
---|
| 19 | @item Mountable file systems |
---|
| 20 | |
---|
| 21 | @item Hierarchical file system directory structure |
---|
| 22 | |
---|
| 23 | @item POSIX compliant set of routines for the manipulation of files and directories |
---|
| 24 | |
---|
| 25 | @item Individual file and directory support for the following: |
---|
| 26 | |
---|
| 27 | @enumerate |
---|
| 28 | |
---|
| 29 | @item Permissions for read, write and execute |
---|
| 30 | |
---|
| 31 | @item User ID |
---|
| 32 | |
---|
| 33 | @item Group ID |
---|
| 34 | |
---|
| 35 | @item Access time |
---|
| 36 | |
---|
| 37 | @item Modification time |
---|
| 38 | |
---|
| 39 | @item Creation time |
---|
| 40 | |
---|
| 41 | @end enumerate |
---|
| 42 | |
---|
| 43 | @item Hard links to files and directories are supported |
---|
| 44 | |
---|
| 45 | @item Symbolic links to files and directories are supported |
---|
| 46 | |
---|
| 47 | @end itemize |
---|
| 48 | |
---|
| 49 | These enhancements have been made to provide the framework for `UNIX like' |
---|
| 50 | file system support. The POSIX file and directory functions have been |
---|
| 51 | implemented to allow a standard method of accessing file, device and |
---|
| 52 | directory information within the file system. The file system concept that |
---|
| 53 | has been implemented allows for expansion and adaptation of the file |
---|
| 54 | system to a variety of existing and future data storage devices. To this |
---|
| 55 | end, file system mount and unmount capabilities have been included in this |
---|
| 56 | RTEMS framework. |
---|
| 57 | |
---|
| 58 | This framework slightly alters the manner in which devices are handled |
---|
| 59 | under RTEMS. Devices that are defined under a given RTEMS configuration |
---|
| 60 | will now be registered as files in a mounted file system. Access to these |
---|
| 61 | devices and their associated device handlers will be obtained through the |
---|
| 62 | traditional file system open(), read(), write(), lseek(), fstat() and |
---|
| 63 | ioctl() functions. |
---|
| 64 | |
---|
| 65 | A node structure is maintained for each file, device, and directory in the |
---|
| 66 | file system. The node structure is used to manage ownership, access |
---|
| 67 | rights, access time, modification time, and creation time. A union of |
---|
| 68 | structures within the nodal structure provide for manipulation of file |
---|
| 69 | data, device selection, or directory content as required by the nodal |
---|
| 70 | type. Manipulation of these properties is accomplished through the POSIX |
---|
| 71 | set of file and directory functions. |
---|
| 72 | |
---|