3b1df65609
Signed-off-by: Jerzy Grzegorek <jerzy.grzegorek@trzebnica.net> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
124 lines
4.7 KiB
Plaintext
124 lines
4.7 KiB
Plaintext
// -*- mode:doc; -*-
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// vim: set syntax=asciidoc:
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== Buildroot quick start
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*Important*: you can and should *build everything as a normal user*. There
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is no need to be root to configure and use Buildroot. By running all
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commands as a regular user, you protect your system against packages
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behaving badly during compilation and installation.
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The first step when using Buildroot is to create a configuration.
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Buildroot has a nice configuration tool similar to the one you can
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find in the http://www.kernel.org/[Linux kernel] or in
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http://www.busybox.net/[BusyBox].
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From the buildroot directory, run
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--------------------
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$ make menuconfig
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--------------------
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for the original curses-based configurator, or
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--------------------
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$ make nconfig
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--------------------
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for the new curses-based configurator, or
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--------------------
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$ make xconfig
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--------------------
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for the Qt-based configurator, or
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--------------------
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$ make gconfig
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--------------------
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for the GTK-based configurator.
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All of these "make" commands will need to build a configuration
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utility (including the interface), so you may need to install
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"development" packages for relevant libraries used by the
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configuration utilities. Refer to xref:requirement[] for more details,
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specifically the xref:requirement-optional[optional requirements]
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to get the dependencies of your favorite interface.
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For each menu entry in the configuration tool, you can find associated
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help that describes the purpose of the entry. Refer to xref:configure[]
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for details on some specific configuration aspects.
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Once everything is configured, the configuration tool generates a
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+.config+ file that contains the entire configuration. This file will be
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read by the top-level Makefile.
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To start the build process, simply run:
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--------------------
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$ make
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--------------------
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You *should never* use +make -jN+ with Buildroot: top-level parallel
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make is currently not supported. Instead, use the +BR2_JLEVEL+ option
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to tell Buildroot to run the compilation of each individual package
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with +make -jN+.
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The `make` command will generally perform the following steps:
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* download source files (as required);
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* configure, build and install the cross-compilation toolchain, or
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simply import an external toolchain;
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* configure, build and install selected target packages;
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* build a kernel image, if selected;
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* build a bootloader image, if selected;
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* create a root filesystem in selected formats.
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Buildroot output is stored in a single directory, +output/+.
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This directory contains several subdirectories:
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* +images/+ where all the images (kernel image, bootloader and root
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filesystem images) are stored. These are the files you need to put
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on your target system.
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* +build/+ where all the components are built (this includes tools
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needed by Buildroot on the host and packages compiled for the
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target). This directory contains one subdirectory for each of these
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components.
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* +staging/+ which contains a hierarchy similar to a root filesystem
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hierarchy. This directory contains the headers and libraries of the
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cross-compilation toolchain and all the userspace packages selected
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for the target. However, this directory is 'not' intended to be
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the root filesystem for the target: it contains a lot of development
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files, unstripped binaries and libraries that make it far too big
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for an embedded system. These development files are used to compile
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libraries and applications for the target that depend on other
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libraries.
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* +target/+ which contains 'almost' the complete root filesystem for
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the target: everything needed is present except the device files in
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+/dev/+ (Buildroot can't create them because Buildroot doesn't run
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as root and doesn't want to run as root). Also, it doesn't have the correct
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permissions (e.g. setuid for the busybox binary). Therefore, this directory
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*should not be used on your target*. Instead, you should use one of
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the images built in the +images/+ directory. If you need an
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extracted image of the root filesystem for booting over NFS, then
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use the tarball image generated in +images/+ and extract it as
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root. Compared to +staging/+, +target/+ contains only the files and
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libraries needed to run the selected target applications: the
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development files (headers, etc.) are not present, the binaries are
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stripped.
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* +host/+ contains the installation of tools compiled for the host
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that are needed for the proper execution of Buildroot, including the
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cross-compilation toolchain.
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These commands, +make menuconfig|nconfig|gconfig|xconfig+ and +make+, are the
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basic ones that allow to easily and quickly generate images fitting
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your needs, with all the features and applications you enabled.
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More details about the "make" command usage are given in
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xref:make-tips[].
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