Dev/Embedded/Rootfs/BusyBox - Revision history

Drizzt: /* Example 1 : simple system */

2025-01-15T18:27:41Z

Example 1 : simple system

← Older revision		Revision as of 20:27, 15 January 2025
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	Most of the time when you start with busybox as the heart of your system you do not plan for a multi-user desktop box, but rather aim for a small, single purpose embedded system, so you won't need too many stuff to get it running.<br />		Most of the time when you start with busybox as the heart of your system you do not plan for a multi-user desktop box, but rather aim for a small, single purpose embedded system, so you won't need too many stuff to get it running.<br />

	This example targets such a very simple system : [[Dev/Embedded/Rootfs/BusyBox/Example1\|Example 1 : ~~simple~~ system]]		This example targets such a very simple system : '''[[Dev/Embedded/Rootfs/BusyBox/Example1\|Example 1 : Simple system]]'''

	=== Example 2 : toward a complete system ===		=== Example 2 : toward a complete system ===

Drizzt: /* Create an initramfs image for the rootfs */

2025-01-15T18:20:59Z

Create an initramfs image for the rootfs

← Older revision		Revision as of 20:20, 15 January 2025
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	== Create an initramfs image for the rootfs ==		== Create an initramfs image for the rootfs ==
	~~Creating~~ an initramfs ([[Dev/InitrdVSInitramfs\|~~a real one, not an initrd~~]]) is pretty simple and can be done in two different ways : ~~rrom~~ the command line, on your own, or using the kernel build system.<br />		In order to use your base system on a diskless system you can create either an initial RAM Disk (initrd) or an initial RAM filesystem image (initramfs).<br />
			Do not use an initrd ([[Dev/InitrdVSInitramfs\|read here for the technical explanation]]).

			Creating an initramfs is pretty simple and can be done in two different ways : from the command line, on your own, or using the kernel build system.<br />
	I documented both [[Dev/InitrdVSInitramfs#initramfs\|at the end of the "Initrd VS Initramfs" page]]		I documented both [[Dev/InitrdVSInitramfs#initramfs\|at the end of the "Initrd VS Initramfs" page]]

			Of course, if you have access to some external storage on your target, you can use it to store your rootfs, and pass the appropriate "root=" option to the kernel from your bootloader.

Drizzt: /* Create an initramfs image for the rootfs */

2025-01-15T18:15:49Z

Create an initramfs image for the rootfs

← Older revision		Revision as of 20:15, 15 January 2025
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	== Create an initramfs image for the rootfs ==		== Create an initramfs image for the rootfs ==
	Creating an initramfs ([[Dev/InitrdVSInitramfs\|a real one, not an initrd]]) is pretty simple and can be done in two different ways.		Creating an initramfs ([[Dev/InitrdVSInitramfs\|a real one, not an initrd]]) is pretty simple and can be done in two different ways : rrom the command line, on your own, or using the kernel build system.<br />
	* From the command line, on your own :		I documented both [[Dev/InitrdVSInitramfs#initramfs\|at the end of the "Initrd VS Initramfs" page]]
	~~cd test && find~~ . > ~~../liste_cpio~~
	~~cat ..~~/~~liste_cpio~~ \| ~~cpio -H newc -o > ../initramfs.cpio~~
	~~gzip -9 initramfs.cpio~~
	~~mv initramfs.cpio.gz initramfs.img~~

	* Using the ~~kernel build system.~~
	~~: '''TO BE CONTINUED'''~~

Drizzt: /* Example 2 : toward a complete system */

2025-01-15T17:27:04Z

Example 2 : toward a complete system

← Older revision		Revision as of 19:27, 15 January 2025
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	=== Example 2 : toward a complete system ===		=== Example 2 : toward a complete system ===
	~~''' TO BE COMPLETED '''~~		If you want to use BusyBox as the heart of an almost complete but light system, with multi-user, many services (possibly including SSH for remote access) you will need some more stuff than the pretty small configuration from the previous example.

	[[Dev/Embedded/Rootfs/BusyBox/Example2\|Example 2 : toward a complete system]]		I started collecting some more information to build a more complex Linux based system using BusyBox as a base for the userland part of the system, but it is '''very incomplete''', currently only a collection of the bits which were going too far for the first "simple example".

			[[Dev/Embedded/Rootfs/BusyBox/Example2\|Example 2 : toward a complete system]] (''' TO BE COMPLETED ''')

	== Create an initramfs image for the rootfs ==		== Create an initramfs image for the rootfs ==

Drizzt: /* Create an initramfs image for the rootfs */

2025-01-14T13:59:16Z

Create an initramfs image for the rootfs

← Older revision		Revision as of 15:59, 14 January 2025
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	== Create an initramfs image for the rootfs ==		== Create an initramfs image for the rootfs ==
	Creating an initramfs ([[Dev~~/Embedded/Rootfs~~/InitrdVSInitramfs\|a real one, not an initrd]]) is pretty simple and can be done in two different ways.		Creating an initramfs ([[Dev/InitrdVSInitramfs\|a real one, not an initrd]]) is pretty simple and can be done in two different ways.
	* From the command line, on your own :		* From the command line, on your own :
	cd test && find . > ../liste_cpio		cd test && find . > ../liste_cpio

Drizzt: /* Populate the base system */

2025-01-13T20:49:41Z

Populate the base system

Show changes

Drizzt: /* Directories */

2025-01-10T20:03:12Z

Directories

← Older revision		Revision as of 22:03, 10 January 2025
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	But note that in this case you'll still need the selected libc (uClibc) !		But note that in this case you'll still need the selected libc (uClibc) !

	==== Directories ====		==== Directories and links ====
	Here is a very simple set of directories for a configuration without "/usr", according to the minimal configuration given above :		Here is a very simple set of directories for a configuration without "/usr", according to the minimal configuration given above :
	mkdir -p dev etc lib/{modules,firmware} proc root run sys ~~tmp~~ var/{log,spool/cron}		mkdir -p dev etc lib/{modules,firmware} proc root run sys var/{log,spool/cron}
			Then add some links :
			ln -s run/tmp tmp
			ln -s ../run/tmp var/tmp

	==== Libraries ====		==== Libraries ====

Drizzt: /* Minimal configuration */

2025-01-10T20:00:13Z

Minimal configuration

← Older revision		Revision as of 22:00, 10 January 2025
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	==== Minimal configuration ====		==== Minimal configuration ====
	''' ~~FIXME~~''' : ~~Add link to example minimal config~~		You can start with this '''[http://data.nathael.net/Dev/Base/BusyBox/config_mini_example_2025-01-10 example minimal config]'''.<br />
	* No "/usr"		Some information about my choices :
	* ~~''' TO BE COMPLETED '''~~		* This configuration is based upon the "defaultconfig", but with many modifications (not all listed here)
			* No "/usr" support (all binaries under /bin and /sbin)
			* Archival utilities limited to tar with "xz" and "bz2" support
			* Removed console utilities
			* Removed most users handling utilities : users should be known when building the system (or added by direct editting of the files)
			* Removed disk partitionning and formatting utilities save for UBIFS
			* Removed runit support
			* Removed all commands I never used on a full blown system

	==== Compile using uClibc ====		==== Compile using uClibc ====

Drizzt: /* Configuration files */

2025-01-10T19:33:31Z

Configuration files

← Older revision		Revision as of 21:33, 10 January 2025
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	==== Configuration files ====		==== Configuration files ====
	''' TO BE COMPLETED '''		''' TO BE COMPLETED '''
			* /etc/nologin
			* /etc/securetty
			* /etc/shells
			* /etc/{passwd,shadow,groups}

	==== Application binaries ====		==== Application binaries ====
	''' TO BE COMPLETED '''		''' TO BE COMPLETED '''

Drizzt: /* Directories */

2025-01-10T19:29:31Z

Directories

← Older revision		Revision as of 21:29, 10 January 2025
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	==== Directories ====		==== Directories ====
	Here is a very simple set of directories for a configuration without "/usr" :		Here is a very simple set of directories for a configuration without "/usr", according to the minimal configuration given above :
	mkdir -p dev etc lib/{modules,firmware} proc root run sys tmp var/{log,spool/cron}		mkdir -p dev etc lib/{modules,firmware} proc root run sys tmp var/{log,spool/cron}