Support Guide Hints and tips BusyBox

BusyBox

BusyBox describes itself as "The Swiss Army Knife of Embedded Linux". It is a very small executable that combines much of the functionality of many standard Linux utilities, such as ls, cp, mv, sed, grep, init and many others. Although the BusyBox versions of these utilities are not as full-featured as the standard version, it generally provides sufficient functionality to build a complete root file system, sufficient for use on a target board. The main advantage of BusyBox is that it reduces the size of the root file system. Instead of many 10's of Megabytes for the full-featured versions plus their libraries, the entire BusyBox-based filesystem can fit in only a few Megabytes. This impressive reduction in size can allow the entire file system to fit in Flash or even a RAMdisk, that would not be possible with the full-featured versions. See http://www.busybox.net for further details.

The BusyBox version of init can run quite happily without an /etc/inittab, but again this may not work if the shell is running on /dev/console.

This again is fixed by changing or creating /etc/inittab. Note that the syntax for this file when using the BusyBox version of init is slightly different, for example:

::sysinit:/etc/init.d/rcS
ttyAS1::askfirst:/bin/sh
::ctrlaltdel:/sbin/reboot
::shutdown:/sbin/swapoff -a
::shutdown:/bin/umount -a -r
::restart:/sbin/init

Here the second line is starting a shell on the specified console, in this case
/dev/ttyAS1.