Running a shell, or even a shell script, at boot time is fine for simple cases, but really you need something more flexible. Normally, Unix systems run a program called
init that starts up and monitors other programs. Over the years, there have been many
init programs, some of which I will describe in Chapter 9, Starting up - the init Program. For now, I will briefly introduce the
init from BusyBox.
init begins by reading the configuration file,
/etc/inittab. Here is a simple example which is adequate for our needs:
The first line runs a shell script,
init is started. The second line prints the message Please press Enter to activate this console to the console, and starts a ...