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PR 1793/doc * .cvsignore, Makefile.am, README, configure.ac, index.html.in, main.am, project.am, ada_user/.cvsignore, ada_user/ada_user.texi, ada_user/example.texi, bsp_howto/.cvsignore, bsp_howto/bsp_howto.texi, cpu_supplement/.cvsignore, cpu_supplement/cpu_supplement.texi, cpu_supplement/preface.texi, develenv/.cvsignore, develenv/develenv.texi, develenv/intro.texi, filesystem/.cvsignore, filesystem/filesystem.texi, filesystem/preface.texi, networking/.cvsignore, networking/networking.texi, networking/preface.texi, porting/.cvsignore, porting/porting.texi, porting/preface.texi, posix1003.1/.cvsignore, posix1003.1/posix1003_1.texi, posix_users/.cvsignore, posix_users/posix_users.texi, posix_users/preface.texi, shell/.cvsignore, shell/preface.texi, shell/shell.texi, started/.cvsignore, started/started.texi, user/.cvsignore, user/c_user.texi, user/dirstat.texi, user/example.texi, user/glossary.texi, user/preface.texi: Convert from texi2www to texi2html. * texi2html_init.in: New file. * rtems_footer.html.in, rtems_header.html.in: Removed.
82 lines
2.8 KiB
Plaintext
82 lines
2.8 KiB
Plaintext
@c
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@c COPYRIGHT (c) 1989-2011.
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@c On-Line Applications Research Corporation (OAR).
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@c All rights reserved.
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@c
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@c $Id$
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@c
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@node Preface, , Top, Top
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@unnumbered Preface
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This document describes the implementation of the RTEMS filesystem
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infrastructure. This infrastructure supports the following
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capabilities:
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@itemize @bullet
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@item Mountable file systems
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@item Hierarchical file system directory structure
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@item POSIX compliant set of routines for the manipulation of files and directories
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@item Individual file and directory support for the following:
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@enumerate
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@item Permissions for read, write and execute
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@item User ID
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@item Group ID
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@item Access time
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@item Modification time
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@item Creation time
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@end enumerate
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@item Hard links to files and directories
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@item Symbolic links to files and directories
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@end itemize
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This has been implemented to provide the framework for a UNIX-like
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file system support. POSIX file and directory functions have been
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implemented that allow a standard method of accessing file, device and
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directory information within file systems. The file system concept that
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has been implemented allows for expansion and adaptation of the file
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system to a variety of existing and future data storage devices. To this
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end, file system mount and unmount capabilities have been included in this
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RTEMS framework.
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This framework slightly alters the manner in which devices are handled
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under RTEMS from that of public release 4.0.0 and earlier. Devices that
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are defined under a given RTEMS configuration will now be registered as
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files in a mounted file system. Access to these device drivers and their
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associated devices may now be performed through the traditional file system
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open(), read(), write(), lseek(), fstat() and ioctl() functions in addition
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to the interface provided by the IO Manager in the RTEMS Classic API.
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An In-Memory File System (IMFS) is included which provides full POSIX
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filesystem functionality yet is RAM based. The IMFS maintains a
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node structure for each file, device, and directory in each mounted
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instantiation of its file system. The node structure is used to
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manage ownership, access rights, access time, modification time,
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and creation time. A union of structures within the IMFS nodal
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structure provide for manipulation of file data, device selection,
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or directory content as required by the nodal type. Manipulation of
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these properties is accomplished through the POSIX set of file and
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directory functions. In addition to being useful in its own right,
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the IMFS serves as a full featured example filesystem.
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The intended audience for this document is those persons implementing
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their own filesystem. Users of the filesystem may find information
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on the implementation useful. But the user interface to the filesystem
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is through the ISO/ANSI C Library and POSIX 1003.1b file and directory
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APIs.
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