buildrootschalter/docs/manual/customize-packages.txt
Thomas De Schampheleire 86a415df8a manual: use one-line titles instead of two-line titles (trivial)
Asciidoc supports two syntaxes for section titles: two-line titles (title
plus underline consisting of a particular symbol), and one-line titles
(title prefixed with a specific number of = signs).

The two-line title underlines are:
Level 0 (top level):     ======================
Level 1:                 ----------------------
Level 2:                 ~~~~~~~~~~~~~~~~~~~~~~
Level 3:                 ^^^^^^^^^^^^^^^^^^^^^^
Level 4 (bottom level):  ++++++++++++++++++++++

and the one-line title prefixes:
= Document Title (level 0) =
== Section title (level 1) ==

=== Section title (level 2) ===
==== Section title (level 3) ====
===== Section title (level 4) =====

The buildroot manual is currenly using the two-line titles, but this has
multiple disadvantages:

- asciidoc also uses some of the underline symbols for other purposes (like
  preformatted code, example blocks, ...), which makes it difficult to do
  mass replacements, such as a planned follow-up patch that needs to move
  all sections one level down.

- it is difficult to remember which level a given underline symbol (=-~^+)
  corresponds to, while counting = signs is easy.

This patch changes all two-level titles to one-level titles in the manual.
The bulk of the change was done with the following Python script, except for
the level 1 titles (-----) as these underlines are also used for literal
code blocks.
This patch only changes the titles, no other changes. In
adding-packages-directory.txt, I did add missing newlines between some
titles and their content.

----------------------------------------------------------------------------
#!/usr/bin/env python

import sys
import mmap
import re

for input in sys.argv[1:]:

    f = open(input, 'r+')
    f.flush()
    s = mmap.mmap(f.fileno(), 0)

    # Level 0 (top level):     ======================   =
    # Level 1:                 ----------------------   ==
    # Level 2:                 ~~~~~~~~~~~~~~~~~~~~~~   ===
    # Level 3:                 ^^^^^^^^^^^^^^^^^^^^^^   ====
    # Level 4 (bottom level):  ++++++++++++++++++++++   =====

    def replace_title(s, symbol, replacement):
        pattern = re.compile(r'(.+\n)\%s{2,}\n' % symbol, re.MULTILINE)
        return pattern.sub(r'%s \1' % replacement, s)

    new = s
    new = replace_title(new, '=', '=')
    new = replace_title(new, '+', '=====')
    new = replace_title(new, '^', '====')
    new = replace_title(new, '~', '===')
    #new = replace_title(new, '-', '==')

    s.seek(0)
    s.write(new)
    s.resize(s.tell())
    s.close()
    f.close()

----------------------------------------------------------------------------

Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
2014-05-02 10:27:59 +02:00

97 lines
3.5 KiB
Plaintext

// -*- mode:doc -*- ;
[[packages-custom]]
=== Customizing packages
It is sometimes useful to apply 'extra' patches to packages - over and
above those provided in Buildroot. This might be used to support custom
features in a project, for example, or when working on a new architecture.
The +BR2_GLOBAL_PATCH_DIR+ configuration option can be used to specify
a space separated list of one or more directories containing package
patches. By specifying multiple global patch directories, a user could
implement a layered approach to patches. This could be useful when a
user has multiple boards that share a common processor architecture.
It is often the case that a subset of patches for a package need to be
shared between the different boards a user has. However, each board
may require specific patches for the package that build on top of the
common subset of patches.
For a specific version +<packageversion>+ of a specific package
+<packagename>+, patches are applied from +BR2_GLOBAL_PATCH_DIR+ as
follows:
. For every directory - +<global-patch-dir>+ - that exists in
+BR2_GLOBAL_PATCH_DIR+, a +<package-patch-dir>+ will be determined as
follows:
+
* +<global-patch-dir>/<packagename>/<packageversion>/+ if the
directory exists.
+
* Otherwise, +<global-patch-dir>/<packagename>+ if the directory
exists.
. Patches will then be applied from a +<package-patch-dir>+ as
follows:
+
* If a +series+ file exists in the package directory, then patches are
applied according to the +series+ file;
+
* Otherwise, patch files matching +<packagename>-*.patch+
are applied in alphabetical order.
So, to ensure they are applied in the right order, it is highly
recommended to name the patch files like this:
+<packagename>-<number>-<description>.patch+, where +<number>+
refers to the 'apply order'.
For information about how patches are applied for a package, see
xref:patch-apply-order[]
The +BR2_GLOBAL_PATCH_DIR+ option is the preferred method for
specifying a custom patch directory for packages. It can be used to
specify a patch directory for any package in buildroot. It should also
be used in place of the custom patch directory options that are
available for packages such as U-Boot and Barebox. By doing this, it
will allow a user to manage their patches from one top-level
directory.
The exception to +BR2_GLOBAL_PATCH_DIR+ being the preferred method for
specifying custom patches is +BR2_LINUX_KERNEL_PATCH+.
+BR2_LINUX_KERNEL_PATCH+ should be used to specify kernel patches that
are available at an URL. *Note:* +BR2_LINUX_KERNEL_PATCH+ specifies kernel
patches that are applied after patches available in +BR2_GLOBAL_PATCH_DIR+,
as it is done from a post-patch hook of the Linux package.
An example directory structure for where a user has multiple
directories specified for +BR2_GLOBAL_PATCH_DIR+ may look like this:
-----
board/
+-- common-fooarch
| +-- patches
| +-- linux
| | +-- linux-patch1.patch
| | +-- linux-patch2.patch
| +-- uboot
| +-- foopkg
+-- fooarch-board
+-- patches
+-- linux
| +-- linux-patch3.patch
+-- uboot
+-- foopkg
-----
If the user has the +BR2_GLOBAL_PATCH_DIR+ configuration option set as
follows:
-----
BR2_GLOBAL_PATCH_DIR="board/common-fooarch board/fooarch-board"
-----
Then the patches would applied as follows for the Linux kernel:
. board/common-fooarch/patches/linux/linux-patch1.patch
. board/common-fooarch/patches/linux/linux-patch2.patch
. board/fooarch-board/patches/linux/linux-patch3.patch