config FS_EROFS bool "Enable EROFS filesystem support" help This provides support for reading images from EROFS filesystem. EROFS (Enhanced Read-Only File System) is a lightweight read-only file system for scenarios which need high-performance read-only requirements. It also provides fixed-sized output compression support, which improves storage density, keeps relatively higher compression ratios, which is more useful to achieve high performance for embedded devices with limited memory. config FS_EROFS_ZIP bool "EROFS Data Compression Support" depends on FS_EROFS select LZ4 default y help Enable fixed-sized output compression for EROFS. If you don't want to enable compression feature, say N. config FS_EROFS_ZIP_DEFLATE bool "EROFS DEFLATE compressed data support" depends on FS_EROFS_ZIP select ZLIB help Saying Y here includes support for reading EROFS file systems containing DEFLATE compressed data. It gives better compression ratios than the default LZ4 format, while it costs more CPU overhead. DEFLATE support is an experimental feature for now and so most file systems will be readable without selecting this option. If unsure, say N.