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| -rw-r--r-- | docs/build.tex | 55 |
1 files changed, 54 insertions, 1 deletions
diff --git a/docs/build.tex b/docs/build.tex index bfdfc2b..03bd1a9 100644 --- a/docs/build.tex +++ b/docs/build.tex @@ -39,7 +39,7 @@ with the latest compilers, latest kernels and latest applications. So let's take a look at OpenWrt and see how this all works. -\subsubsection{Download openwrt} +\subsubsection{Download OpenWrt} This article refers to the "Kamikaze" branch of OpenWrt, which can be downloaded via subversion using the following command: @@ -373,6 +373,59 @@ After you have created your \texttt{package/\textit{<name>}/Makefile}, the new p will automatically show in the menu the next time you run "make menuconfig" and if selected will be built automatically the next time "\texttt{make}" is run. +\subsection{Creating kernel modules packages} + +The OpenWrt distribution makes the distinction between two kind of kernel modules, those coming along with the mainline kernel, and the others available as a separate project. We will see later that a common template is used for both of them. + +For kernel modules that are part of the mainline kernel source, the makefiles are located in \textit{package/kernel/modules/*.mk} and they appear under the section "Kernel modules" + +For external kernel modules, you can add them to the build system just like if they were software packages by defining a KernelPackage section in the package makefile. + +Here for instance the Makefile for the I2C subsytem kernel modules : + +\begin{Verbatim}[frame=single,numbers=left] +# +# Copyright (C) 2006 OpenWrt.org +# +# This is free software, licensed under the GNU General Public License v2. +# See /LICENSE for more information. +# +# $Id $ + +I2CMENU:=I2C Bus + +define KernelPackage/i2c-core + TITLE:=I2C support + DESCRIPTION:=Kernel modules for i2c support + SUBMENU:=$(I2CMENU) + KCONFIG:=$(CONFIG_I2C_CORE) \ + $(CONFIG_I2C_DEV) + FILES:=$(MODULES_DIR)/kernel/drivers/i2c/*.$(LINUX_KMOD_SUFFIX) + AUTOLOAD:=$(call AutoLoad,50,i2c-core i2c-dev) +endef +$(eval $(call KernelPackage,i2c-core)) +\end{Verbatim} + +To group kernel modules under a common description in menuconfig, you might want to define a \textit{<description>MENU} variable on top of the kernel modules makefile. + +\begin{itemize} + \item \texttt{TITLE} \\ + The name of the module as seen via menuconfig + \item \texttt{DESCRIPTION} \\ + The description as seen via help in menuconfig + \item \texttt{SUBMENU} \\ + The sub menu under which this package will be seen + \item \texttt{KCONFIG} \\ + Kernel configuration option dependency. For external modules, remove it. + \item \texttt{FILES} \\ + Files you want to inlude to this kernel module package, separate with spaces. + \item \texttt{AUTOLOAD} \\ + Modules that will be loaded automatically on boot, the order you write them is the order they would be loaded. +\end{itemize} + +After you have created your \texttt{package/kernel/modules/\textit{<name>}.mk}, the new kernel modules package +will automatically show in the menu under "Kernel modules" next time you run "make menuconfig" and if selected +will be built automatically the next time "\texttt{make}" is run. \subsection{Conventions} |