emFile is a file system library that enables an embedded application or system to store data securely and reliably on any kind of storage device.
The library is the result of more than 28 years of continuous and ongoing development. It is deployed on several million devices worldwide, making it a proven in-field file system for the embedded industry. emFile is hardware-agnostic and can run on any 16/32/64-bit target for which a C/C++ compiler is available. Most 8-bit targets are supported.
Ready-to-use device drivers are available for NAND, and NOR flash, SD/SDHC/SDXC/MMC cards, e.MMC storage devices, CompactFlash cards, and USB flash drives. emFile comes with support for the common FAT12/16/32 file systems and for SEGGER's proprietary file system EFS (Embedded File System) that has been specifically designed to meet the requirements of state-of-the-art embedded applications.
Encryption
emFile offers an additional component that can be used to secure the data on the file system with minimal changes of the application. It can be used with FAT and EFS file systems and supports all device types such as NAND, NOR, SD/MMC cards.
NOR flash driver
The NOR driver allows the file system layer to efficiently write and read blocks of data (logical sectors) to and from a NOR flash device.
emFile comes with two different NOR drivers:
- Block map NOR driver
- Sector map NOR driver
NAND flash driver
The emFile NAND drivers allow the file system layer to efficiently write and read blocks of data (logical sectors) to and from a NAND flash device.
emFile comes with two different NAND drivers:
- SLC driver
- Universal driver
Fail-safe file system
emFile is designed with security in mind. All access operations are atomic, which means even an interrupt by failure does not leave storage nor data in an undefined state. In addition, RAID modes 1 and 5 can be supported to increase security at the storage layer and journaling at the file system layer.
Journaling
emFile Journaling is an additional component which sits on top of the file system and makes the file system layer fail-safe. Journaling means that a file system logs all changes to a journal before committing them to the main file system and thus ensuring the consistency of the file system.
RAID 1
emFile offers maximum data integrity and reliability with RAID 1. It provides protection from storage device defects and failures and works on the storage layer with FAT and EFS file systems.
RAID 5
emFile offers maximum data integrity and reliability with RAID 5 with increased usable capacity. RAID 5 requires at least three strorage partitions to distribute date over several partitions. Additionally, it uses less data storage to achieve the same data security as RAID 1.