File -Systems Overview

File -Systems OverviewProvides several common file system implementation. -

Purpose

Provides -file system implementations —file server fsy plug-ins — for devices -that are reasonably expected to be used on a Symbian platform device. The -file systems implement a storage and access format most appropriate to the -media. Please see a file system's guide for its specific purpose.

Architecture

The -File Systems collection provides several kinds of file system implementations. -File system binaries are built as FSY plugins -that are loaded (added and mounted) by the file server; either at startup -or as required such as when a device is physically attached to the phone (inserting -a memory card into the card slot).

The file server uses these implementations -to access data on different media.

Description

The -File Systems collection consists of a series of file server plugins, one for -each file system. The various systems are loaded into a file server instance. -Different devices use different file systems based on the characteristics -of the storage medium.

The following table lists several file systems -and the different media that use them.

The ROM file system is implemented -as part of the file server component. The other files systems are implemented -as separate file server plugins, which may be loaded using ESTART or as part -of a mounting operation.

All file system plugins files have .fsy extensions.

File System -Summary

The following file system plug-ins are provided:

Composite -File System (ecomp.fsy): The Composite File System -for NAND flash devices presents a single drive Z: to the File Server that -layers thinly over both the core ROM and the ROFS file systems. It redirects -File Server requests to the core ROM or ROFS as required. See Flash -Translation Layer Technology for more information on why this is required.

This -unifies the file systems for flash devices (ROM, ROFS and FAT file systems) -into a common file system that is used with drive Z:. -The file server will direct requests to the required file system as required.
FAT -File System (efat.fsy or elocal.fsy when -built for an emulator target.) : The FAT File System implements a file system -that supports the VFAT standard. This is used for user data storage on NAND -Flash, internal RAM drives, and removable media.

This is the file -system that was originally used by IBM PCs and is an industry standard for -file systems. It is supported by all operating systems that execute on PCs. -Symbian platform FAT only supports FAT12 and FAT16 types.
FAT32 -File System (efat32.fsy): The FAT32 File System -implements the enhanced version of the FAT file system standard that includes -FAT32 support.

The FAT32 file system is an update of the industry -standard FAT file system. The Symbian platform FAT32 file system supports -the FAT12, FAT16 and FAT32 file systems.
ISO9660 -File System (iso9660.fsy): The ISO9660 File System -implements a ISO9660 file system, that reads CDROM and DVD-ROM. This is only -for the internal X86 port.

The ISO9660 is an internationally agreed -standard for the file system used by CD-ROM and DVD-ROM media.

ISO9660 -is for Symbian internal use only.
LFFS -File System (elffs.fsy): The LFFS File System -provides data storage on NOR type flash memory, and is portable to a wide -range of Flash devices.

LFFS is designed specifically to be used with -NOR flash and has the ability to protect itself against power loss.
NTFS -File System (ntfs.fsy): The NTFS File System provides -read-only support for the NTFS file system standards. This is only for the -internal X86 port.

This is the file system for Windows NT, Windows -2000, Windows-XP, Windows Server 2003, Windows Server 2008 and Windows Vista.

NTFS -is for Symbian internal use only.
ROFS -File System (erofs.fsy): The Read-only File System -(ROFS) supports a ROM-structured local file system that can be located on -NAND flash, or other media, where executables are not executed in place (non-XIP).

ROFS -stands for Read Only File System and is used for accessing code storage on -media that cannot be executed in that media (otherwise known as non-XIP storage), -for example NAND flash.
ROM -File System (No FSY, ROM is the default file system build defined by f32.iby): -The ROM file system is used to access the "core ROM image": this contains -files that are copied from NAND Flash storage into RAM on boot.

This -is the file system that is used when the phone boots up.
USB -Mass Storage File System (msfs.fsy and possibly msfs_db.fsy, -depending on configuration): The USB Mass Storage File System is provided -to support a licensee-provided USB mass storage application, which allows -a desktop host computer access to a FAT-formatted drive on the phone.

The USB Mass Storage Server is -used when a USB memory device is connected directly to the device executing -Symbian platform.

The USB -Mass Storage File System is used when the media on the device is accessed -by an external device i.e. a PC when it is in "USB mass storage" mode.

Using File -System Plug-ins

The file systems are used to allow kernel access -to data on a media storage device such as Flash, MMC cards, SD cards, etc. -A file systems FSY plug-in must be added to the file server and mounted before -the kernel is granted access.

Accessing a file system specific device -requires:

Adding a file system -to the file server using RFs::AddFileSystem()
Mounting the file system -using RFs::MountFileSystem()

The file server handles all requests to access a mounted file system.

-Using ECom - - -File Server + + + + + +File +Systems OverviewProvides several common file system implementation. +

Purpose

Provides +file system implementations —file server fsy plug-ins — for devices +that are reasonably expected to be used on a Symbian platform device. The +file systems implement a storage and access format most appropriate to the +media. Please see a file system's guide for its specific purpose.

Architecture

The +File Systems collection provides several kinds of file system implementations. +File system binaries are built as FSY plugins +that are loaded (added and mounted) by the file server; either at startup +or as required such as when a device is physically attached to the phone (inserting +a memory card into the card slot).

The file server uses these implementations +to access data on different media.

Description

The +File Systems collection consists of a series of file server plugins, one for +each file system. The various systems are loaded into a file server instance. +Different devices use different file systems based on the characteristics +of the storage medium.

The following table lists several file systems +and the different media that use them.

The ROM file system is implemented +as part of the file server component. The other files systems are implemented +as separate file server plugins, which may be loaded using ESTART or as part +of a mounting operation.

All file system plugins files have .fsy extensions.

File System +Summary

The following file system plug-ins are provided:

Composite +File System (ecomp.fsy): The Composite File System +for NAND flash devices presents a single drive Z: to the File Server that +layers thinly over both the core ROM and the ROFS file systems. It redirects +File Server requests to the core ROM or ROFS as required. See Flash +Translation Layer Technology for more information on why this is required.

This +unifies the file systems for flash devices (ROM, ROFS and FAT file systems) +into a common file system that is used with drive Z:. +The file server will direct requests to the required file system as required.
FAT +File System (efat.fsy or elocal.fsy when +built for an emulator target.) : The FAT File System implements a file system +that supports the VFAT standard. This is used for user data storage on NAND +Flash, internal RAM drives, and removable media.

This is the file +system that was originally used by IBM PCs and is an industry standard for +file systems. It is supported by all operating systems that execute on PCs. +Symbian platform FAT only supports FAT12 and FAT16 types.
FAT32 +File System (efat32.fsy): The FAT32 File System +implements the enhanced version of the FAT file system standard that includes +FAT32 support.

The FAT32 file system is an update of the industry +standard FAT file system. The Symbian platform FAT32 file system supports +the FAT12, FAT16 and FAT32 file systems.
ISO9660 +File System (iso9660.fsy): The ISO9660 File System +implements a ISO9660 file system, that reads CDROM and DVD-ROM. This is only +for the internal X86 port.

The ISO9660 is an internationally agreed +standard for the file system used by CD-ROM and DVD-ROM media.

ISO9660 +is for Symbian internal use only.
LFFS +File System (elffs.fsy): The LFFS File System +provides data storage on NOR type flash memory, and is portable to a wide +range of Flash devices.

LFFS is designed specifically to be used with +NOR flash and has the ability to protect itself against power loss.
NTFS +File System (ntfs.fsy): The NTFS File System provides +read-only support for the NTFS file system standards. This is only for the +internal X86 port.

This is the file system for Windows NT, Windows +2000, Windows-XP, Windows Server 2003, Windows Server 2008 and Windows Vista.

NTFS +is for Symbian internal use only.
ROFS +File System (erofs.fsy): The Read-only File System +(ROFS) supports a ROM-structured local file system that can be located on +NAND flash, or other media, where executables are not executed in place (non-XIP).

ROFS +stands for Read Only File System and is used for accessing code storage on +media that cannot be executed in that media (otherwise known as non-XIP storage), +for example NAND flash.
ROM +File System (No FSY, ROM is the default file system build defined by f32.iby): +The ROM file system is used to access the "core ROM image": this contains +files that are copied from NAND Flash storage into RAM on boot.

This +is the file system that is used when the phone boots up.
USB +Mass Storage File System (msfs.fsy and possibly msfs_db.fsy, +depending on configuration): The USB Mass Storage File System is provided +to support a licensee-provided USB mass storage application, which allows +a desktop host computer access to a FAT-formatted drive on the phone.

The USB Mass Storage Server is +used when a USB memory device is connected directly to the device executing +Symbian platform.

The USB +Mass Storage File System is used when the media on the device is accessed +by an external device i.e. a PC when it is in "USB mass storage" mode.

Using File +System Plug-ins

The file systems are used to allow kernel access +to data on a media storage device such as Flash, MMC cards, SD cards, etc. +A file systems FSY plug-in must be added to the file server and mounted before +the kernel is granted access.

Accessing a file system specific device +requires:

Adding a file system +to the file server using RFs::AddFileSystem()
Mounting the file system +using RFs::MountFileSystem()

The file server handles all requests to access a mounted file system.

+Using ECom + + +File Server

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