[Buildroot] [PATCHv2 01/10] manual: add section about storing the configuration.
Arnout Vandecappelle (Essensium/Mind)
arnout at mind.be
Wed Oct 24 07:16:58 UTC 2012
From: "Arnout Vandecappelle (Essensium/Mind)" <arnout at mind.be>
Reuse part of board-support.txt, and remove that one because it
was unused.
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout at mind.be>
---
v2: mention LINUX_KERNEL_PATCH also in in-tree documentation
(Samuel Martin)
I would like it if this patch of the series could be committed soon.
It will certainly not make things worse, and if amendments are needed
they can be added in later patches. Committing it soon will make it
simpler to synchronize with other patches e.g. Maxime's barebox config.
Actually, I think documentation-only patches should be committed more
easily in general - especially because we have too few documentation
patches as it is.
---
docs/manual/adding-packages-directory.txt | 1 +
docs/manual/board-support.txt | 35 ----
docs/manual/customize-store.txt | 249 +++++++++++++++++++++++++++++
docs/manual/customize.txt | 2 +
4 files changed, 252 insertions(+), 35 deletions(-)
delete mode 100644 docs/manual/board-support.txt
create mode 100644 docs/manual/customize-store.txt
diff --git a/docs/manual/adding-packages-directory.txt b/docs/manual/adding-packages-directory.txt
index 4a96415..ce9c5ce 100644
--- a/docs/manual/adding-packages-directory.txt
+++ b/docs/manual/adding-packages-directory.txt
@@ -147,6 +147,7 @@ package.
The +.mk+ file
~~~~~~~~~~~~~~
+[[adding-packages-mk]]
Finally, here's the hardest part. Create a file named +libfoo.mk+. It
describes how the package should be downloaded, configured, built,
diff --git a/docs/manual/board-support.txt b/docs/manual/board-support.txt
deleted file mode 100644
index d1d9d63..0000000
--- a/docs/manual/board-support.txt
+++ /dev/null
@@ -1,35 +0,0 @@
-Creating your own board support
-===============================
-
-Creating your own board support in Buildroot allows users of a
-particular hardware platform to easily build a system that is known to
-work.
-
-To do so, you need to create a normal Buildroot configuration that
-builds a basic system for the hardware: toolchain, kernel, bootloader,
-filesystem and a simple Busybox-only userspace. No specific package
-should be selected: the configuration should be as minimal as
-possible, and should only build a working basic Busybox system for the
-target platform. You can of course use more complicated configurations
-for your internal projects, but the Buildroot project will only
-integrate basic board configurations. This is because package
-selections are highly application-specific.
-
-Once you have a known working configuration, run +make
-savedefconfig+. This will generate a minimal +defconfig+ file at the
-root of the Buildroot source tree. Move this file into the +configs/+
-directory, and rename it +MYBOARD_defconfig+.
-
-It is recommended to use as much as possible upstream versions of the
-Linux kernel and bootloaders, and to use as much as possible default
-kernel and bootloader configurations. If they are incorrect for your
-platform, we encourage you to send fixes to the corresponding upstream
-projects.
-
-However, in the mean time, you may want to store kernel or bootloader
-configuration or patches specific to your target platform. To do so,
-create a directory +board/MANUFACTURER+ and a subdirectory
-+board/MANUFACTURER/BOARDNAME+ (after replacing, of course,
-MANUFACTURER and BOARDNAME with the appropriate values, in lower case
-letters). You can then store your patches and configurations in these
-directories, and reference them from the main Buildroot configuration.
diff --git a/docs/manual/customize-store.txt b/docs/manual/customize-store.txt
new file mode 100644
index 0000000..44de356
--- /dev/null
+++ b/docs/manual/customize-store.txt
@@ -0,0 +1,249 @@
+Storing the configuration
+-------------------------
+[[customize-store]]
+
+When you have a buildroot configuration that you are satisfied with
+and you want to move to share it with others, put it under revision
+control or move on to a different buildroot project, you need to store
+the configuration so it can be rebuilt later. The configuration that
+needs to be stored consists of the buildroot configuration, the
+configuration files for packages that you use (kernel, busybox,
+uClibc, ...), and your rootfs modifications.
+
+Basics for storing the configuration
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+[[customize-store-basics]]
+
+Buildroot configuration
+^^^^^^^^^^^^^^^^^^^^^^^
+
+For storing the buildroot configuration itself, buildroot offers the
+following command: +make savedefconfig+
+
+This strips the buildroot configuration down by removing configuration
+options that are at their default value. The result is stored in a file
+called +defconfig+. Copy this file to +foo_defconfig+ in the +configs+
+directory. The configuration can then be rebuilt by running
++make foo_defconfig+
+
+Alternatively, you can copy the file to any other place and rebuild with
++make BR2_DEFCONFIG=<path-to-defconfig> defconfig+
+
+
+Other package configuration
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The configuration files for busybox, the linux kernel, uClibc and
+crosstool-NG should be stored as well. For each of these, a
+buildroot configuration option exists to point to an input configuration
+file, e.g. +BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE+. To save their
+configuration, set those configuration options to a path outside
+your output directory. Then, copy the configuration files
+to that path.
+
+Make sure that you create a configuration file 'before' changing
+the +BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE+ etc. options. Otherwise,
+buildroot will try to access this config file, which doesn't exist
+yet, and will fail.
+
+Buildroot provides a few helper targets to make the saving of
+configuration files easier.
+
+* +make linux-update-defconfig+ saves the linux configuration to the
+ path specified by +BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE+. It
+ simplifies the config file by removing default values. However,
+ this only works with kernels starting from 2.6.33. For earlier
+ kernels, use +make linux-update-config+.
+* +make busybox-update-config+ saves the busybox configuration to the
+ path specified by +BR2_PACKAGE_BUSYBOX_CONFIG+.
+* +make uclibc-update-config+ saves the uClibc configuration to the
+ path specified by +BR2_UCLIBC_CONFIG+.
+* For crosstool-NG, no helper exists so you have to copy the config
+ file manually to +BR2_TOOLCHAIN_CTNG_CONFIG+.
+
+
+Creating your own board support
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Creating your own board support in Buildroot allows users of a
+particular hardware platform to easily build a system that is known to
+work.
+
+To do so, you need to create a normal Buildroot configuration that
+builds a basic system for the hardware: toolchain, kernel, bootloader,
+filesystem and a simple Busybox-only userspace. No specific package
+should be selected: the configuration should be as minimal as
+possible, and should only build a working basic Busybox system for the
+target platform. You can of course use more complicated configurations
+for your internal projects, but the Buildroot project will only
+integrate basic board configurations. This is because package
+selections are highly application-specific.
+
+Once you have a known working configuration, run +make
+savedefconfig+. This will generate a minimal +defconfig+ file at the
+root of the Buildroot source tree. Move this file into the +configs/+
+directory, and rename it +<boardname>_defconfig+.
+
+It is recommended to use as much as possible upstream versions of the
+Linux kernel and bootloaders, and to use as much as possible default
+kernel and bootloader configurations. If they are incorrect for your
+platform, we encourage you to send fixes to the corresponding upstream
+projects.
+
+However, in the mean time, you may want to store kernel or bootloader
+configuration or patches specific to your target platform. To do so,
+create a directory +board/<manufacturer>+ and a subdirectory
++board/<manufacturer>/<boardname>+. You can then store your patches
+and configurations in these directories, and reference them from the main
+Buildroot configuration.
+
+
+Step-by-step instructions for storing configuration inside the buildroot tree
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+To store the configuration for a specific product, device or
+application, it is advisable to use the same conventions as for the
+board support: put the buildroot defconfig in the +configs+ directory,
+and any other files in a subdirectory of the +boards+ directory. This
+section gives step-by-step instructions about how to do that. Of course,
+you can skip the steps that are not relevant for your use case.
+
+1. +make menuconfig+ to configure toolchain, packages and kernel.
+1. +make linux-menuconfig+ to update the kernel config, similar for
+ other configuration.
+1. +mkdir -p board/<manufacturer>/<boardname>+
+1. Set the following options to +board/<manufacturer>/<boardname>/<package>.config+
+ (as far as they are relevant):
+ * +BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE+
+ * +BR2_PACKAGE_BUSYBOX_CONFIG+
+ * +BR2_TOOLCHAIN_CTNG_CONFIG+
+ * +BR2_UCLIBC_CONFIG+
+ * +BR2_TARGET_AT91BOOTSTRAP3_CUSTOM_CONFIG_FILE+
+1. Write the configuration files:
+ * +make linux-update-defconfig+
+ * +make busybox-update-config+
+ * +cp <output>/build/build-toolchain/.config board/<manufacturer>/<boardname>/ctng.config+
+ * +make uclibc-update-config+
+ * +cp <output>/build/at91bootstrap3-*/.config board/<manufacturer>/<boardname>/at91bootstrap3.config+
+1. Create +board/<manufacturer>/<boardname>/fs-overlay+ and fill it
+ with additional files you need on your rootfs, e.g.
+ +board/<manufacturer>/<boardname>/etc/inittab+.
+1. Create a post-build script
+ +board/<manufacturer>/<boardname>/post-build.sh+. It should contain
+ the following command:
++
+------------
+rsync -a --exclude .empty --exclude '*~' ${0%/*}/fs-overlay $1
+------------
++
+1. Set +BR2_ROOTFS_POST_BUILD_SCRIPT+ to +board/<manufacturer>/<boardname>/post-build.sh+
+1. If additional setuid permissions have to be set or device nodes have
+ to be created, create +board/<manufacturer>/<boardname>/device_table.txt+
+ and add that path to +BR2_ROOTFS_DEVICE_TABLE+.
+1. +make savedefconfig+ to save the buildroot configuration.
+1. +cp defconfig configs/<boardname>_defconfig+
+1. To add patches to the linux build, set +BR2_LINUX_KERNEL_PATCH+ to
+ +board/<manufacturer>/<boardname>/patches/linux+ and add your
+ patches in that directory. Each patch should be called
+ +linux-<num>-<description>.patch+. Similar for U-Boot, barebox,
+ at91bootstrap and at91bootstrap3.
+1. If you need modifications to other packages, or if you need to add
+ packages, do that directly in the +packages/+ directory.
+
+
+Step-by-step instructions for storing configuration outside the buildroot tree
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+When you use buildroot in different projects, you may want to keep
+each project separate from buildroot itself. This requires an extra
+script or Makefile, but is otherwise easy to do with buildroot.
+Take the following steps (very similar to storing configuration inside
+the buildroot tree).
+
+1. +make menuconfig+ to configure toolchain, packages and kernel.
+1. +make linux-menuconfig+ to update the kernel config, similar for
+ other configuration.
+1. +mkdir -p <path-to-board-directory>+
+1. Set the following options to +$(BOARDDIR)/<package>.config+
+ (as far as they are relevant):
+ * +BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE+
+ * +BR2_PACKAGE_BUSYBOX_CONFIG+
+ * +BR2_TOOLCHAIN_CTNG_CONFIG+
+ * +BR2_UCLIBC_CONFIG+
+ * +BR2_TARGET_AT91BOOTSTRAP3_CUSTOM_CONFIG_FILE+
+1. Write the configuration files:
+ * +make linux-update-defconfig+
+ * +make busybox-update-config+
+ * +cp <output>/build/build-toolchain/.config <path-to-board-directory>/ctng.config+
+ * +make uclibc-update-config+
+ * +cp <output>/build/at91bootstrap3-*/.config <path-to-board-directory>/at91bootstrap3.config+
+1. Create +<path-to-board-directory>/fs-overlay+ and fill it
+ with additional files you need on your rootfs, e.g.
+ +<path-to-board-directory>/etc/inittab+.
+1. Create a post-build script
+ +<path-to-board-directory>/post-build.sh+. It should contain
+ the following command:
++
+------------
+rsync -a --exclude .empty --exclude '*~' ${0%/*}/fs-overlay $1
+------------
++
+1. Set +BR2_ROOTFS_POST_BUILD_SCRIPT+ to +$(BOARDDIR)/post-build.sh+
+1. If additional setuid permissions have to be set or device nodes have
+ to be created, create +<path-to-board-directory>/device_table.txt+
+ and add that path to +BR2_ROOTFS_DEVICE_TABLE+.
+1. +make savedefconfig+ to save the buildroot configuration.
+1. +cp defconfig <path-to-board-directory>/buildroot.config+
+1. Create a script or Makefile in the board directory that calls
+ buildroot:
++
+------------
+make -C <path-to-buildroot> O=<path-to-board-directory>/output BR2_DEFCONFIG=<path-to-board-directory>/buildroot.config defconfig
+make -C <path-to-buildroot> O=<path-to-board-directory>/output BOARDDIR=<path-to-board-directory>
+------------
++
+1. If you have additional proprietary binaries that are compiled
+ outside of buildroot, you can copy them into the rootfs as
+ part of +post-build.sh+
+1. If you need additional packages that are not available in buildroot
+ and that you don't want to make available (e.g. proprietary
+ applications), set +BR2_PACKAGE_OVERRIDE_FILE+ to
+ +$(BOARDDIR)/local.mk+. Add the following to +local.mk+ to
+ add package 'foo': +include foo/foo.mk+. Add the following in
+ +foo.mk+ (see xref:adding-packages-mk[Adding packages to buildroot]):
++
+------------
+BR2_PACKAGE_FOO = y
+FOO_OVERRIDE_SRCDIR = $(BOARDDIR)/foo
+
+define FOO_BUILD_CMDS
+ $(TARGET_MAKE_ENV) $(MAKE) -C $(@D)
+endef
+
+define FOO_INSTALL_TARGET_CMDS
+ $(INSTALL) -D -m 0755 $(@D)/foo $(TARGET_DIR)/usr/bin/foo
+endef
+
+$(eval $(generic-package))
+------------
++
+The +BR2_PACKAGE_FOO=y+ makes sure the package is always selected,
+so there is no need for a +Config.in+ file. The +FOO_OVERRIDE_SRCDIR+
+tells buildroot to fetch the sources from the +foo+ directory, and
+also makes sure that they are re-synchronized when you call +make
+foo-rebuild+
++
+1. To add patches to the linux build, set +BR2_LINUX_KERNEL_PATCH+ to
+ +$(BOARDDIR)/patches/linux+ and add your patches in that directory.
+ Each patch should be called +linux-<num>-<description>.patch+.
+ Similar for U-Boot, barebox, at91bootstrap and at91bootstrap3.
+1. To add patches for some other package 'foo', put them in the
+ +patches/foo+ directory and add the following to +local.mk+:
++
+------------
+define FOO_LOCAL_PATCHES
+support/scripts/apply-patches.sh $(@D) $(BOARDDIR)/patches/foo foo-\*.patch
+endef
+
+FOO_POST_PATCH_HOOKS += FOO_LOCAL_PATCHES
+------------
diff --git a/docs/manual/customize.txt b/docs/manual/customize.txt
index e8235de..6bd5811 100644
--- a/docs/manual/customize.txt
+++ b/docs/manual/customize.txt
@@ -10,3 +10,5 @@ include::customize-uclibc-config.txt[]
include::customize-kernel-config.txt[]
include::customize-toolchain.txt[]
+
+include::customize-store.txt[]
--
1.7.10.4
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