This page gives an overview of the XILFFS library.

Introduction

This page provides details related to the xilffs library.

The LibXil fat file system (FFS) library consists of a file system and a glue layer. This FAT file system can be used with an interface supported in the glue layer.
The file system code is open source and is used as it is. Glue layer implementation supports SD/eMMC, UFS and RAMFS interface presently.
Application should make use of APIs provided in ff.h. These file system APIs access the driver functions through the glue layer.

Library Sources

The source code for the driver is included with the Vitis Unified Software Platform installation, as well as being available in the Xilinx Github repository.

Library Name	Path in Vitis	Path in Github
Xilffs	<Vitis Install Directory>/data/embedded/lib/sw_services/xilffs	https://github.com/Xilinx/embeddedsw/tree/master/lib/sw_services/xilffs

The driver source code is organized into different folders. The table below shows the xilffs library source organization.

Directory	Description
Doc	Provides the API and data structure details
data	Driver .tcl, .yaml and .mld file
examples	Example applications that show how to use the driver features
src	Library source files, make and cmakelists file

Note: AMD Xilinx embeddedsw build flow has been changed from 2023.2 release to adapt to the new system device tree based flow. For further information, refer to the wiki link Porting embeddedsw components to system device tree (SDT) based flow

The .yaml(in data folder) and CMakeLists.txt(in src folder) files are needed for the System Device Tree based flow. The Driver .tcl and .mdd files are for the older build flow which will be deprecated in future.

Library Implementation

Features

Parameters supported by this library are listed in xilffs.mld(legacy flow) and xilffs_config.h.in(Vitis NG flow). Some of the parameters listed below for reference.

read_only: Enables the file system in Read Only mode, if true. Default is false. Zynq® UltraScale+™ MPSoC fsbl sets this option as true.
use_lfn: Enables the long file name (LFN) support, if true. Default is false.
enable_multi_partition: Enables the multi partition support, if true. Default is false.
num_logical_vol: Number of volumes (logical drives, from 1 to 10) to be used. Default is 2.
use_mkfs: Enables the mkfs support, if true. Default is true. Zynq UltraScale+ MPSoC fsbl set this option as false.

File System

The file system supports FAT16 and FAT32. The APIs are standard file system APIs. A detailed description can be found at http://elm-chan.org/fsw/ff/00index_e.html
Revision R0.15 is used in the library

Documentation corresponding to 0.15 version (or any specific library version) is available in the doc folder if we download the 0.15 version (or corresponding version) from this link http://elm-chan.org/fsw/ff/archives.html

f_mkfs() in 0.15 version is NOT backward compatible with earlier FATFS supported version R0.13B.

AR link:

https://support.xilinx.com/s/article/000034757?language=en_US

Known Issues and Limitations

None

Example Applications

Refer to the xillfs library examples directory for various example applications that exercise the different features of the xillfs.

Each application is linked in the table below. The following sections describe the usage and expected output of the various applications.

These example applications can be imported into the Vitis IDE from the Board Support Package settings tab.

Links to Examples

Examples Path: https://github.com/Xilinx/embeddedsw/tree/master/lib/sw_services/xilffs/examples

Test Name	Example Source	Description
SD xilffs example	xilffs_polled_example.c	This examples does basic file system read and write test from SD/eMMC device in Polled mode.
UFS xilffs example	xilffs_polled_ufs_example.c	This example uses file system with UFS to write to and read from an UFS device in polled mode.

Example Application Usage

SD Xilffs examples

Read and write test from SD/eMMC device in Polled mode.

Expected Output

SD Polled File System Example Test

Successfully ran SD Polled File System Example Test

UFS Xilffs examples

Write to and read from an UFS device in polled mode.

Expected Output

UFS Polled File System Example Test
Successfully ran UFS Polled File System Example Test

changelog

2025.1

https://github.com/Xilinx/embeddedsw/blob/xlnx_rel_v2025.1/doc/ChangeLog#L110

2024.2

https://github.com/Xilinx/embeddedsw/blob/xlnx_rel_v2024.2/doc/ChangeLog#L167

2024.1

https://github.com/Xilinx/embeddedsw/blob/xlnx_rel_v2024.1/doc/ChangeLog#L962

2023.2

https://github.com/Xilinx/embeddedsw/blob/xlnx_rel_v2023.2/doc/ChangeLog#L622

2023.1

https://github.com/Xilinx/embeddedsw/blob/xlnx_rel_v2023.1/doc/ChangeLog#L166

2022.2

https://github.com/Xilinx/embeddedsw/blob/xlnx_rel_v2022.2/doc/ChangeLog#L159

2022.1

https://github.com/Xilinx/embeddedsw/blob/xlnx_rel_v2022.1/doc/ChangeLog#L133

2021.2

https://github.com/Xilinx/embeddedsw/blob/xilinx_v2021.2/doc/ChangeLog#L307

2021.1

https://github.com/Xilinx/embeddedsw/blob/xilinx_v2021.1/doc/ChangeLog#L497

2020.2

https://github.com/Xilinx/embeddedsw/blob/xilinx-v2020.2/doc/ChangeLog#L721

2020.1

https://github.com/Xilinx/embeddedsw/blob/xilinx-v2020.1/doc/ChangeLog#L162

Table of Contents