1. first stage boot loader (BIOS)
  2. second stage boot loader. Depending on the selection of the user, any of the boot loaders such as LILO or syslinx can be used.
  3. The kernel, loaded in the preceding phase, after initialization is complete, loads the custom version of init (by means of the execution of the Tcl interpreter).
  4. init handles:
    • reading the file /etc/init.d/options which contains general options
    • running fsck on the root file system
    • remounting the root filesystem in read/write mode
    • mounting the /proc filesystem (if requested in the options)
    • activating swap (if asked for)
    • mounting all remaining filesystems (as called for)
    • loading desired kernel modules
    • executing in order the boot scripts in /etc/init.d/scripts. The name of the script must be preceded by a prefix that takes the form Snn, where nn is a number between 00 to 99, inclusive, indicating the order of execution.
    • execute an interactive configuration of networking parameters
    • launching user space applications residing in /etc/applications