From aba0d000cb57edf54e5a8b16702ae803433512f1 Mon Sep 17 00:00:00 2001 From: Thomas De Schampheleire Date: Thu, 18 Sep 2014 21:39:29 +0200 Subject: [PATCH] manual/user guide/customization: add section on device/permission tables This patch adds basic documentation on device and permission tables, a topic which was currently not yet covered in the manual. Signed-off-by: Thomas De Schampheleire Signed-off-by: Thomas Petazzoni --- .../customize-device-permission-tables.txt | 30 +++++++++++++++++++ docs/manual/customize-rootfs.txt | 2 ++ docs/manual/customize.txt | 4 +++ 3 files changed, 36 insertions(+) create mode 100644 docs/manual/customize-device-permission-tables.txt diff --git a/docs/manual/customize-device-permission-tables.txt b/docs/manual/customize-device-permission-tables.txt new file mode 100644 index 0000000000..99cf5bdd49 --- /dev/null +++ b/docs/manual/customize-device-permission-tables.txt @@ -0,0 +1,30 @@ +// -*- mode:doc; -*- +// vim: set syntax=asciidoc: + +[[customize-device-permission]] +==== Setting file permissions and ownership and adding custom devices nodes + +Sometimes it is needed to set specific permissions or ownership on files +or device nodes. For example, certain files may need to be owned by +root. Since the post-build scripts are not run as root, you cannot do +such changes from there unless you use an explicit fakeroot from the +post-build script. + +Instead, Buildroot provides support for so-called _permission tables_. +To use this feature, set config option +BR2_ROOTFS_DEVICE_TABLE+ to a +space-separated list of permission tables, regular text files following +the xref:makedev-syntax[makedev syntax]. + +If you are using a static device table (i.e. not using +devtmpfs+, ++mdev+, or +(e)udev+) then you can add device nodes using the same +syntax, in so-called _device tables_. To use this feature, set config +option +BR2_ROOTFS_STATIC_DEVICE_TABLE+ to a space-separated list of +device tables. + +As shown in xref:customize-dir-structure[], the recommended location for +such files is +board///+. + +It should be noted that if the specific permissions or device nodes are +related to a specific application, you should set variables ++FOO_PERMISSIONS+ and +FOO_DEVICES+ in the package's +.mk+ file instead +(see xref:generic-package-reference[]). diff --git a/docs/manual/customize-rootfs.txt b/docs/manual/customize-rootfs.txt index 056f8e2ffe..23a38b0da0 100644 --- a/docs/manual/customize-rootfs.txt +++ b/docs/manual/customize-rootfs.txt @@ -97,3 +97,5 @@ To enable this feature, enable config option This method is not recommended because it duplicates the entire skeleton, which prevents taking advantage of the fixes or improvements brought to the default skeleton in later Buildroot releases. + +include::customize-device-permission-tables.txt[] diff --git a/docs/manual/customize.txt b/docs/manual/customize.txt index 85c1fc8203..ad335b9ab5 100644 --- a/docs/manual/customize.txt +++ b/docs/manual/customize.txt @@ -16,6 +16,10 @@ Typical actions you may need to perform for a given project are: +BR2_ROOTFS_POST_BUILD_SCRIPT+) ** running arbitrary commands prior to generating the filesystem image (using +BR2_ROOTFS_POST_BUILD_SCRIPT+) + ** setting file permissions and ownership (using + +BR2_ROOTFS_DEVICE_TABLE+) + ** adding custom devices nodes (using + +BR2_ROOTFS_STATIC_DEVICE_TABLE+) * running arbitrary commands after generating the filesystem image (using +BR2_ROOTFS_POST_IMAGE_SCRIPT+) * adding project-specific patches to some packages (using