How to build a linux root file system?

Building a Linux root filesystem (Root Filesystem) usually involves the following steps:

1. Select the basic distribution : choose a suitable Linux distribution as the basis according to your needs. Common choices include Ubuntu, Debian, CentOS, etc.
2. Install the base system : Install the Linux distribution of choice in a clean environment. This usually involves installing using installation media such as an ISO file or network installation.

3. Customize the root file system : After installing the basic system, you can customize it according to your needs to build a root file system suitable for specific application scenarios. Customization can include the following:

   • Package Management : Install and configure required packages as needed. Use your distribution's package manager (such as apt, yum, etc.) to install the package.
   • Configure network : Configure network-related configurations such as network interfaces, DNS settings, and hostnames. This can be done by editing network configuration files such as  /etc/network/interfacesor  /etc/sysconfig/network-scripts/ifcfg-eth0.
   • Configure users and permissions : Set up users, groups, and file permissions. This can be done through command-line tools (like useradd, groupadd, chmod, etc.) or by editing related files (like  /etc/passwdand  /etc/group).
   • Configure services and startup items : Enable, configure and manage services and startup items that need to be run according to requirements. This can be achieved by editing the relevant configuration files (eg  /etc/init.d. , /etc/systemdetc.).
   • Configure Storage : Configure disks, file systems, and storage options based on your needs. This can include partitioning, formatting disks, mounting filesystems, etc.
4. Clean and optimize : After customization is complete, clean and optimize to reduce the size of the root file system. This can include removing unnecessary files, cleaning up temporary directories, compressing log files, etc.
5. Pack the root file system : Pack the customized root file system into a suitable format, such as tarball ( .tar.gz) or compressed image file (such as  .img). This can be done with tools (eg  tar, mkfsetc.) and scripts.

Note that the exact procedure for building a Linux root filesystem may vary depending on the chosen distribution, requirements, and environment. This is a basic mentoring process that you can adapt and expand to suit your needs and circumstances. It is recommended to refer to the official documentation and other authoritative sources for your chosen distribution for more detailed steps and guidance.