</section>
<section id='using-bbappend-files'>
- <title>Using .bbappend Files</title>
+ <title>Using .bbappend Files in Your Layer</title>
<para>
- Recipes used to append Metadata to other recipes are called
- BitBake append files.
- BitBake append files use the <filename>.bbappend</filename> file
- type suffix, while the corresponding recipes to which Metadata
- is being appended use the <filename>.bb</filename> file type
- suffix.
+ A recipe that appends Metadata to another recipe is called a
+ BitBake append file.
+ A BitBake append file uses the <filename>.bbappend</filename>
+ file type suffix, while the corresponding recipe to which
+ Metadata is being appended uses the <filename>.bb</filename>
+ file type suffix.
</para>
<para>
- A <filename>.bbappend</filename> file allows your layer to make
- additions or changes to the content of another layer's recipe
- without having to copy the other recipe into your layer.
+ You can use a <filename>.bbappend</filename> file in your
+ layer to make additions or changes to the content of another
+ layer's recipe without having to copy the other layer's
+ recipe into your layer.
Your <filename>.bbappend</filename> file resides in your layer,
while the main <filename>.bb</filename> recipe file to
which you are appending Metadata resides in a different layer.
</para>
<para>
- Append files must have the same root names as their corresponding
- recipes.
+ Being able to append information to an existing recipe not only
+ avoids duplication, but also automatically applies recipe
+ changes from a different layer into your layer.
+ If you were copying recipes, you would have to manually merge
+ changes as they occur.
+ </para>
+
+ <para>
+ When you create an append file, you must use the same root
+ name as the corresponding recipe file.
For example, the append file
<filename>someapp_&DISTRO;.bbappend</filename> must apply to
<filename>someapp_&DISTRO;.bb</filename>.
- This means the original recipe and append file names are version
- number-specific.
+ This means the original recipe and append file names are
+ version number-specific.
If the corresponding recipe is renamed to update to a newer
- version, the corresponding <filename>.bbappend</filename> file must
- be renamed (and possibly updated) as well.
+ version, you must also rename and possibly update
+ the corresponding <filename>.bbappend</filename> as well.
During the build process, BitBake displays an error on starting
if it detects a <filename>.bbappend</filename> file that does
not have a corresponding recipe with a matching name.
variable for information on how to handle this error.
</para>
- <para>
- Being able to append information to an existing recipe not only
- avoids duplication, but also automatically applies recipe
- changes in a different layer to your layer.
- If you were copying recipes, you would have to manually merge
- changes as they occur.
- </para>
-
<para>
As an example, consider the main formfactor recipe and a
corresponding formfactor append file both from the
SUMMARY = "Device formfactor information"
SECTION = "base"
LICENSE = "MIT"
- LIC_FILES_CHKSUM = "file://${COREBASE}/LICENSE;md5=4d92cd373abda3937c2bc47fbc49d690 \
- file://${COREBASE}/meta/COPYING.MIT;md5=3da9cfbcb788c80a0384361b4de20420"
+ LIC_FILES_CHKSUM = "file://${COREBASE}/meta/COPYING.MIT;md5=3da9cfbcb788c80a0384361b4de20420"
PR = "r45"
SRC_URI = "file://config file://machconfig"
if [ -s "${S}/machconfig" ]; then
install -m 0644 ${S}/machconfig ${D}${sysconfdir}/formfactor/
fi
- }
- </literallayout>
+ } </literallayout>
In the main recipe, note the
<ulink url='&YOCTO_DOCS_REF_URL;#var-SRC_URI'><filename>SRC_URI</filename></ulink>
variable, which tells the OpenEmbedded build system where to
<filename>formfactor_0.0.bbappend</filename> and is from the
Raspberry Pi BSP Layer named
<filename>meta-raspberrypi</filename>.
- The file is in <filename>recipes-bsp/formfactor</filename>:
+ The file is in the layer at
+ <filename>recipes-bsp/formfactor</filename>:
<literallayout class='monospaced'>
FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
</literallayout>
</para>
<para>
- The statement in this example extends the directories to include
+ The statement in this example extends the directories to
+ include
<filename>${</filename><ulink url='&YOCTO_DOCS_REF_URL;#var-THISDIR'><filename>THISDIR</filename></ulink><filename>}/${</filename><ulink url='&YOCTO_DOCS_REF_URL;#var-PN'><filename>PN</filename></ulink><filename>}</filename>,
which resolves to a directory named
<filename>formfactor</filename> in the same directory
in which the append file resides (i.e.
- <filename>meta-raspberrypi/recipes-bsp/formfactor/formfactor</filename>.
+ <filename>meta-raspberrypi/recipes-bsp/formfactor</filename>.
This implies that you must have the supporting directory
structure set up that will contain any files or patches you
will be including from the layer.
<para>
Using the immediate expansion assignment operator
- <filename>:=</filename> is important because of the reference to
- <filename>THISDIR</filename>.
+ <filename>:=</filename> is important because of the reference
+ to <filename>THISDIR</filename>.
The trailing colon character is important as it ensures that
items in the list remain colon-separated.
<note>
and <ulink url='&YOCTO_DOCS_REF_URL;#var-SRC_URI'><filename>SRC_URI</filename></ulink>
statements enable the OpenEmbedded build system to find the patch file.
For more information on using append files, see the
- "<link linkend='using-bbappend-files'>Using .bbappend Files</link>"
+ "<link linkend='using-bbappend-files'>Using .bbappend Files in Your Layer</link>"
section.
</para></listitem>
<listitem><para><emphasis>Put the patch file in your layer</emphasis>:
<listitem><para>Add a <filename>psplash</filename>
append file for a branded splash screen.
For information on append files, see the
- "<link linkend='using-bbappend-files'>Using .bbappend Files</link>"
+ "<link linkend='using-bbappend-files'>Using .bbappend Files in Your Layer</link>"
section.</para></listitem>
<listitem><para>Add any other append files to make
custom changes that are specific to individual
projects / thirdparty / openembedded / openembedded-core-contrib.git / commitdiff
