Creating a Root File System

• Extract the root file system while logged in as user root on the build machine. This is important, because some of the files extracted are device files, and Linux will refuse to make them unless the extraction is done with root permissions. The command to extract the file systems is:
  tar zxvf root.tgz
   
• Make any changes that you want to the root file system.
   
• Create a new filesystem using the following command:
  mkfs.jffs2 –r root -o root.jffs2 –e 0x40000 –p