[bitbake-devel] Documentation: A few tweaks to Chapter 2, BitBake User Manual
@@ -7,7 +7,8 @@
The primary purpose for running BitBake is to produce some kind
of output such as a single installable package, a kernel, a software
- development kit, or even a full, board-specific bootable Linux image.
+ development kit, or even a full, board-specific bootable Linux image,
+ complete with bootloader, kernel and root filesystem.
Of course, you can execute the <filename>bitbake</filename>
command with options that cause it to execute single tasks,
compile single recipe files, capture or clear data, or simply
@@ -45,6 +46,11 @@
build host with hyper-threading will most likely show eight processors,
which is the value you would then assign to that variable.
+ A possibly simpler solution is that some Linux distributions
+ (Debian, Ubuntu) provide the <filename>ncpus</filename> command.
@@ -84,7 +90,7 @@
<filename>BBPATH</filename> is used to search for
configuration and class files under the
- <filename>conf</filename> and <filename>classes</filename>
+ <filename>conf/</filename> and <filename>classes/</filename>
<filename>BBFILES</filename> is used to locate both recipe
and recipe append files
@@ -464,6 +470,29 @@
PREFERRED_VERSION_a = "1.1"
+ It's common for a recipe to provide two versions -- a stable,
+ numbered (and preferred) version, and a version that is
+ automatically checked out from a source code repository that
+ is considered more "bleeding edge" but can be selected only
+ For example, in the OpenEmbedded codebase, there is a standard,
+ versioned recipe file for BusyBox,
+ but there is also a Git-based version,
+ <filename>busybox_git.bb</filename>, which explicitly contains the line
+ <literallayout class='monospaced'>
+ DEFAULT_PREFERENCE = "-1"
+ to ensure that the numbered, stable version is always preferred
+ unless the developer selects otherwise.