ubi rootfs

### UBI Root File System Configuration and Usage In embedded Linux systems, configuring a root file system (rootfs) on an UBI volume involves several steps to ensure proper initialization and operation. For creating a UBIFS filesystem image from an existing directory tree, one can use specific tools designed for this purpose[^1]. This process typically includes preparing the necessary files and directories that will constitute the rootfs. For generating the root file system specifically within environments like those mentioned where commands are executed directly through shell scripts or manually via command line interfaces such as `vim` used in editing bash script files for automation purposes[^2], preparation might involve setting up essential binaries, libraries, configurations, etc., ensuring all dependencies required by applications running inside the target environment are met before packaging into a format suitable for deployment onto flash storage managed under UBI framework. When dealing with boot loaders and their configuration files—such as extlinux.conf—it's crucial to correctly specify paths pointing towards kernel images along with device trees alongside other critical parameters needed during startup processes including specifying correct partition identifiers which serve as mount points for accessing data stored within these volumes after power-on sequences complete successfully[^3]. Regarding features supported by UBIFS, notably absent is automatic access timestamping (`atime`) functionality due largely because frequent metadata changes associated with tracking accesses could lead to unnecessary wear leveling concerns particularly relevant when considering longevity aspects related to solid-state memory devices commonly found in resource-constrained platforms; however, networked filesystem protocols like NFS may still be utilized depending upon implementation specifics even though direct support isn't natively provided out-of-the-box according to some sources[^5]. #### Example Script for Creating UBIFS Image To illustrate how one might go about crafting a UBIFS image programmatically using available utilities: ```bash #!/bin/bash # Define variables ROOTFS_DIR="/path/to/rootfs" OUTPUT_IMAGE="ubifs.img" # Create temporary working area TEMP=$(mktemp -d) # Prepare ubinize.cfg cat <<EOF > $TEMP/ubinize.cfg [ubifs] mode=ubi image=$OUTPUT_IMAGE vol_id=0 vol_type=dynamic vol_name=rootfs vol_flags=autoresize EOF # Build UBIFS image mkfs.ubifs -r "$ROOTFS_DIR" -m 2048 -e 126976 -c 4096 -o "${TEMP}/rootfs.ubifs" # Combine everything together ubinize -o "$OUTPUT_IMAGE" -p 128KiB -m 2048 ${TEMP}/ubinize.cfg # Cleanup rm -rf "$TEMP" ``` This example demonstrates scripting techniques aimed at automating creation tasks while adhering closely to best practices recommended for handling UBI-based filesystems intended primarily but not exclusively for use cases involving deeply integrated hardware/software solutions built around ARM architectures among others prevalent today across various industries leveraging IoT technologies extensively.