Manual Pages  — NANOBSD

nanobsd.sh – utility used to create a FreeBSD system image suitable for embedded applications

SYNOPSIS DESCRIPTION NanoBSD Media Layout BUILDING NanoBSD CUSTOMIZING NanoBSD FILES EXAMPLES SEE ALSO HISTORY AUTHORS

nanobsd.sh [-bfhiKknqvwX] [-c config-file]

This is probably the most important and most interesting feature of NanoBSD. This is also where you will be spending most of the time when developing with NanoBSD.

Customization is done in two ways:

• Configuration options.
• Custom functions.

With configuration settings, it is possible to configure options passed to both the buildworld and installworld stages of the NanoBSD build process, as well as internal options passed to the main build process of NanoBSD. Through these options it is possible to cut the system down, so it will fit on as little as 64MB. You can use the configuration options to trim down the system even more, until it will consist of just the kernel and two or three files in the userland.

The configuration file consists of configuration options, which override the default values. The most important directives are:

NANO_NAME
	Build name (used to construct the working directory names).
NANO_SRC
	Path to the source tree used to build the image.
NANO_KERNEL
	Name of the kernel configuration file used to build the kernel.
NANO_ARCH
	Machine processor architecture to build. Defaults to output of uname -p.
NANO_BOOT0CFG
	Controls the options passed to boot0cfg(8); these dictate boot0 behaviour.
NANO_BOOTLOADER
	The boot0 loader to use relative to the NANO_WORLDDIR variable. This defaults to boot/boot0sio and should be overridden to boot/boot0 to provide a VGA console.
CONF_BUILD
	Options passed to the buildworld stage of the build.
CONF_INSTALL
	Options passed to the installworld stage of the build.
CONF_WORLD
	Options passed to both the buildworld and installworld stages of the build.
FlashDevice
	Defines the type of media to use. Check the FlashDevice.sub file for more details.

For more configuration options, please check the nanobsd.sh script.

To build NanoBSD image using the nanobsd.conf configuration file, use the following command:

sh nanobsd.sh -c nanobsd.conf

It is possible to fine-tune NanoBSD using shell functions in the configuration file. The following example illustrates the basic model of custom functions:

cust_foo () (
        echo "bar=topless" > \
             ${NANO_WORLDDIR}/etc/foo
)
customize_cmd cust_foo

There are a few pre-defined customization functions ready for use:

cust_comconsole	Disables getty(8) on the virtual syscons(4) or vt(4) terminals ( /dev/ttyv*) and enables the use of the first serial port as the system console.
cust_allow_ssh_root
	Allow root to log in via sshd(8).
cust_install_files	Installs files from the nanobsd/Files directory, which contains some useful scripts for system administration.

src/tools/tools/nanobsd
	Base directory of the NanoBSD build script.

Making persistent changes to /etc/resolv.conf:

vi /etc/resolv.conf
amp;...
mount /cfg
cp /etc/resolv.conf /cfg
umount /cfg

A more useful example of a customization function is the following, which changes the default size of the /etc directory from 5MB to 30MB:

cust_etc_size () (
        cd ${NANO_WORLDDIR}/conf
        echo 30000 > default/etc/md_size
)
customize_cmd cust_etc_size

The nanobsd.sh utility first appeared in FreeBSD 6.0 .

NanoBSD was developed by Poul-Henning Kamp <Mt phk@FreeBSD.org>. This manual page was written by Daniel Gerzo <Mt danger@FreeBSD.org>.