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Diffstat (limited to 'docs/adding.tex')
| -rw-r--r-- | docs/adding.tex | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/docs/adding.tex b/docs/adding.tex index ec14eaec26..97547ac859 100644 --- a/docs/adding.tex +++ b/docs/adding.tex @@ -478,3 +478,113 @@ module_exit(device_mtd_cleanup); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Me, myself and I <memyselfandi@domain.tld"); \end{verbatim} + +\subsection{Adding your target in OpenWrt} + +Once you spotted the key changes that were made to the Linux kernel +to support your target, you will want to create a target in OpenWrt +for your hardware. This can be useful to benefit from the toolchain +that OpenWrt builds as well as the resulting user-space and kernel +configuration options. + +Provided that your target is already known to OpenWrt, it will be +as simple as creating a \texttt{target/linux/board} directory +where you will be creating the following directories and files. + +Here for example, is a \texttt{target/linux/board/Makefile}: + +\begin{Verbatim}[frame=single,numbers=left] +# +# Copyright (C) 2009 OpenWrt.org +# +# This is free software, licensed under the GNU General Public License v2. +# See /LICENSE for more information. +# +include $(TOPDIR)/rules.mk + +ARCH:=mips +BOARD:=board +BOARDNAME:=Eval board +FEATURES:=squashfs jffs2 pci usb + +LINUX_VERSION:=2.6.27.10 + +include $(INCLUDE_DIR)/target.mk + +DEFAULT_PACKAGES += hostapd-mini + +define Target/Description + Build firmware images for Evaluation board +endef + +$(eval $(call BuildTarget)) +\end{Verbatim} + +\begin{itemize} + \item \texttt{ARCH} \\ + The name of the architecture known by Linux and uClibc + \item \texttt{BOARD} \\ + The name of your board that will be used as a package and build directory identifier + \item \texttt{BOARDNAME} \\ + Expanded name that will appear in menuconfig + \item \texttt{FEATURES} \\ + Set of features to build filesystem images, USB, PCI, VIDEO kernel support + \item \texttt{LINUX\_VERSION} \\ + Linux kernel version to use for this target + \item \texttt{DEFAULT\_PACKAGES} \\ + Set of packages to be built by default +\end{itemize} + +A partial kernel configuration which is either named \texttt{config-default} or which matches the kernel version \texttt{config-2.6.x} should be present in \texttt{target/linux/board/}. +This kernel configuration will only contain the relevant symbols to support your target and can be changed using \texttt{make kernel\_menuconfig}. + +To patch the kernel sources with the patches required to support your hardware, you will have to drop them in \texttt{patches} or in \texttt{patches-2.6.x} if there are specific +changes between kernel versions. Additionnaly, if you want to avoid creating a patch that will create files, you can put those files into \texttt{files} or \texttt{files-2.6.x} +with the same directory structure that the kernel uses (e.g: drivers/mtd/maps, arch/mips ..). + +The build system will require you to create a \texttt{target/linux/board/image/Makefile}: + +\begin{Verbatim}[frame=single,numbers=left] +# +# Copyright (C) 2009 OpenWrt.org +# +# This is free software, licensed under the GNU General Public License v2. +# See /LICENSE for more information. +# +include $(TOPDIR)/rules.mk +include $(INCLUDE_DIR)/image.mk + +define Image/BuildKernel + cp $(KDIR)/vmlinux.elf $(BIN_DIR)/openwrt-$(BOARD)-vmlinux.elf + gzip -9 -c $(KDIR)/vmlinux > $(KDIR)/vmlinux.bin.gz + $(STAGING_DIR_HOST)/bin/lzma e $(KDIR)/vmlinux $(KDIR)/vmlinux.bin.l7 + dd if=$(KDIR)/vmlinux.bin.l7 of=$(BIN_DIR)/openwrt-$(BOARD)-vmlinux.lzma bs=65536 conv=sync + dd if=$(KDIR)/vmlinux.bin.gz of=$(BIN_DIR)/openwrt-$(BOARD)-vmlinux.gz bs=65536 conv=sync +endef + +define Image/Build/squashfs + $(call prepare_generic_squashfs,$(KDIR)/root.squashfs) +endef + +define Image/Build + $(call Image/Build/$(1)) + dd if=$(KDIR)/root.$(1) of=$(BIN_DIR)/openwrt-$(BOARD)-root.$(1) bs=128k conv=sync + + -$(STAGING_DIR_HOST)/bin/mkfwimage \ + -B XS2 -v XS2.ar2316.OpenWrt \ + -k $(BIN_DIR)/openwrt-$(BOARD)-vmlinux.lzma \ + -r $(BIN_DIR)/openwrt-$(BOARD)-root.$(1) \ + -o $(BIN_DIR)/openwrt-$(BOARD)-ubnt2-$(1).bin +endef + +$(eval $(call BuildImage)) + +\end{Verbatim} + +\begin{itemize} + \item \texttt{Image/BuildKernel} \\ + This template defines changes to be made to the ELF kernel file + \item \texttt{Image/Build} \\ + This template defines the final changes to apply to the rootfs and kernel, either combined or separated + firmware creation tools can be called here as well. +\end{itemize} |