ref: b6fafb2a2ce5207d032594a80ce3cdd33bcc34b6
dir: /readme.mediawiki/
==About== The main goal of the lwext4 project is to provide ext2/3/4 filesystem for microcontrollers. It may be an interesting alternative for traditional MCU filesystem libraries (mostly based on FAT32). Lwext4 may be used with SD/MMC card, USB flash drive or other block based memory device. However it is not good for flash memory–based storage devices. Code is also available on github: https://github.com/gkostka/lwext4 Feel free to contact me: kostka.grzegorz@gmail.com ==Credits== The most of the source code of lwext4 was taken from HelenOS: * http://helenos.org/ Some features are based on FreeBSD and Linux implementations. KaHo Ng (https://github.com/ngkaho1234): * advanced extents implementation * xattr support * metadata checksum suport * many bugfixes & improvements fuse-lwext4 project: * https://github.com/ngkaho1234/fuse-lwext4 ==Features== * filetypes: regular, directories, softlinks * support for hardlinks * multiple blocksize supported: 1KB, 2KB, 4KB ... 64KB * little/big endian architectures supported * multiple configurations (ext2/ext3/ext4) * only C standard library dependency * various CPU architectures supported (x86/64, cortex-mX, msp430 ...) * small memory footprint ;Memory footprint (for cortex-m4): * .text: 20KB - 40KB * .data: 8KB (minimum 8 x 1KB block cache) * .stack: 2KB ==Supported ext2/3/4 features== ;Features incompatible: * compression: no * filetype: yes * recover: no * journal_dev: no * meta_bg: yes * extents: yes * 64bit: yes * mmp: no * flex_bg: yes * ea_inode: no * dirdata: no * bg_meta_csum: no * largedir: no * inline_data: no ;Features compatible: * dir_prealloc: no * imagic_inodes: no * has_journal: no * ext_attr: yes * resize_inode: no * dir_index: yes ;Features read-only: * sparse_super: yes * large_file: yes * btree_dir: yes * huge_file: yes * gdt_csum: yes * dir_nlink: yes * extra_isize: yes * quota: no * bigalloc: no * metadata_csum: yes ==Project tree== * blockdev - block devices set, supported blockdev * demos - demo directory sources * fs_test - test suite * lwext4 - internals of the lwext4 library * toolchain - specific toolchain cmake files * CMakeLists.txt - CMake config file * ext_images.7z - compressed ext2/3/4 100MB images * fs_test.mk - automatic tests definitions * Makefile - helper makefile to generate cmake and run test suite * readme.mediawiki - readme file ==Compile== Windows: * CMake: http://www.cmake.org/cmake/resources/software.html * MinGw: http://www.mingw.org/ * GnuWin: http://gnuwin32.sourceforge.net/ Linux: * CMake, make, gcc ;Generate makefiles: make ;Compile cd build_generic make ==Generic demo application== Simple lwext4 library presentation: * load ext2/3/4 images * load linux block device with ext2/3/4 part * load windows volume with ext2/3/4 filesystem * directory speed test * file write/read speed test How to use for images/blockdevices: cd build_generic generic -i ext_images/ext2 generic -i ext_images/ext3 generic -i ext_images/ext4 ==Build and run automatic tests== Build and run automatic tests Build automatic test tools: make cd build_generic make Uncompress ext/2/3/4 images: make unpack_images Run server for one of the image file: make server_ext2 make server_ext3 make server_ext4 Execute tests: make test ==Cross compile standalone library== Toolchains needed: * arm-none-eabi-gcc for cortex-mX * avr-gcc for avr * bfin-elf-gcc for bfin * msp430-gcc for msp430 Build bf518 library: make bf518 cd build_bf518 make lwext4 Build avrxmega7 library: make avrxmega7 cd build_avrxmega7 make lwext4 Build cortex-m0 library: make cortex-m0 cd build_cortex-m0 make lwext4 Build cortex-m3 library: make cortex-m3 cd build_cortex-m3 make lwext4 Build cortex-m4 library: make cortex-m4 cd build_cortex-m4 make lwext4