建立套件包
我們試著讓OpenWrt的軟體移植變得更容易。如果你打開OpenWrt套件包,你會發現這二個目錄
- package/Makefile
- package/patches
patches目錄是可選的,通常包含錯誤修復或最佳化,以減少可執行文件的大小。 套件裡makefile檔案是非常重要的項目,提供實際需要的“步驟”、“下載”並編譯套件包。
Looking at one of the package makefiles, you'd hardly recognize it as a makefile. Through what can only be described as blatant disregard and abuse of the traditional make format, the makefile has been transformed into an object oriented template which simplifies the entire ordeal.
Here for example, is package/bridge/Makefile:
include $(TOPDIR)/rules.mk PKG_NAME:=bridge PKG_VERSION:=1.0.6 PKG_RELEASE:=1 PKG_BUILD_DIR:=$(BUILD_DIR)/bridge-utils-$(PKG_VERSION) PKG_SOURCE:=bridge-utils-$(PKG_VERSION).tar.gz PKG_SOURCE_URL:=@SF/bridge PKG_MD5SUM:=9b7dc52656f5cbec846a7ba3299f73bd PKG_CAT:=zcat include $(INCLUDE_DIR)/package.mk define Package/bridge SECTION:=base CATEGORY:=Network DEFAULT:=y TITLE:=Ethernet bridging configuration utility #DESCRIPTION:=This variable is obsolete. use the Package/name/description define instead! URL:=http://bridge.sourceforge.net/ endef define Package/bridge/description Ethernet bridging configuration utility Manage ethernet bridging; a way to connect networks together to form a larger network. endef define Build/Configure $(call Build/Configure/Default,--with-linux-headers=$(LINUX_DIR)) endef define Package/bridge/install $(INSTALL_DIR) $(1)/usr/sbin $(INSTALL_BIN) $(PKG_BUILD_DIR)/brctl/brctl $(1)/usr/sbin/ endef $(eval $(call BuildPackage,bridge))
BuildPackage variables
As you can see, there's not much work to be done; everything is hidden in other makefiles and abstracted to the point where you only need to specify a few variables.
- PKG_NAME -The name of the package, as seen via menuconfig and ipkg
- PKG_VERSION -The upstream version number that we're downloading
- PKG_RELEASE -The version of this package Makefile
- PKG_BUILD_DIR -Where to compile the package
- PKG_SOURCE -The filename of the original sources
- PKG_SOURCE_URL -Where to download the sources from
- PKG_MD5SUM -A checksum to validate the download
- PKG_CAT -How to decompress the sources (zcat, bzcat, unzip)
- PKG_BUILD_DEPENDS -Packages that need to be built before this package, but are not required at runtime. Uses the same syntax as DEPENDS below.
The PKG_* variables define where to download the package from; @SF is a special keyword for downloading packages from sourceforge. The md5sum is used to verify the package was downloaded correctly and PKG_BUILD_DIR defines where to find the package after the sources are uncompressed into $(BUILD_DIR).
At the bottom of the file is where the real magic happens, “BuildPackage” is a macro setup by the earlier include statements. BuildPackage only takes one argument directly -- the name of the package to be built, in this case “bridge”. All other information is taken from the define blocks. This is a way of providing a level of verbosity, it's inherently clear what the DESCRIPTION variable in Package/bridge is, which wouldn't be the case if we passed this information directly as the Nth argument to BuildPackage.
BuildPackage defines
Package/
matches the argument passed to buildroot, this describes the package the menuconfig and ipkg entries. Within Package/ you can define the following variables:
- SECTION - The type of package (currently unused)
- CATEGORY - Which menu it appears in menuconfig
- TITLE - A short description of the package
- DESCRIPTION - (deprecated) A long description of the package
- URL - Where to find the original software
- MAINTAINER - (optional) Who to contact concerning the package
- DEPENDS - (optional) Which packages must be built/installed before this package. See below for the syntax.
Package/conffiles (optional)
A list of config files installed by this package, one file per line.
Package/description
A free text description of the package
Build/Prepare (optional)
A set of commands to unpack and patch the sources. You may safely leave this undefined.
Build/Configure (optional)
You can leave this undefined if the source doesn't use configure or has a normal config script, otherwise you can put your own commands here or use "$(call Build/Configure/Default,)" as above to pass in additional arguments for a standard configure script.
Build/Compile (optional)
How to compile the source; in most cases you should leave this undefined.
Package/install
A set of commands to copy files out of the compiled source and into the ipkg which is represented by the $(1) directory.
Package/preinst
The actual text of the script which is to be executed before installation. Dont forget to include the #!/bin/sh. If you need to abort installation have the script return false.
Package/postinst
The actual text of the script which is to be executed after installation. Dont forget to include the #!/bin/sh.
Package/prerm
The actual text of the script which is to be executed before removal. Dont forget to include the #!/bin/sh. If you need to abort removal have the script return false.
Package/postrm
The actual text of the script which is to be executed after removal. Dont forget to include the #!/bin/sh.
The reason that some of the defines are prefixed by “Package/” and others are simply “Build” is because of the possibility of generating multiple packages from a single source. OpenWrt works under the assumption of one source per package makefile, but you can split that source into as many packages as desired. Since you only need to compile the sources once, there's one global set of “Build” defines, but you can add as many “Package/” defines as you want by adding extra calls to BuildPackage -- see the dropbear package for an example.
Dependency Types
Various types of dependencies can be specified, which require a bit of explanation for their differences.
+<foo> | Package will depend on package <foo> and will select it when selected. |
<foo> | Package will depend on package <foo> and will be invisible until <foo> is selected. |
@FOO | Package depends on the config symbol CONFIG_FOO and will be invisible unless CONFIG_FOO is set. This usually used for depending on certain Linux versions or targets, e.g. @TARGET_foo will make a package only available for target foo. You can also use boolean expressions for complex dependencies, e.g. @(!TARGET_foo&&!TARGET_bar) will make the package unavailable for foo and bar. |
+FOO:<bar> | Package will depend on <bar> if CONFIG_FOO is set, and will select <bar> when it is selected itself. The typical use case would be if there compile time options for this package toggling features that depend on external libraries. Note that the + replaces the @. |
@FOO:<bar> | Package will depend on <bar> if CONFIG_FOO is set, and will be invisible until <bar> is selected when CONFIG_FOO is set. |
Some typical config symbols for (conditional) dependencies are:
TARGET_<foo> | Target <foo> is selected |
TARGET_<foo>_<bar> | If the target <foo> has subtargets, subtarget <foo> is selected. If not, profile <foo> is selected. This is in addition to TARGET_<foo> |
TARGET_<foo>_<bar>_<baz> | Target <foo> with subtarget <bar> and profile <baz> is selected. |
LINUX_3_X | Linux version used is 3.x.* |
LINUX_2_6_X | Linux version used is 2.6.x.* (:1: only used for backfire and earlier) |
LINUX_2_4 | Linux version is 2.4 ( only used in backfire and earlier, and only for target brcm-2.4) |
USE_UCLIBC, USE_GLIBC, USE_EGLIBC | To (not) depend on a certain libc. |
BROKEN | Package doesn't build or work, and should only be visible if “Show broken targets/packages” is selected. Prevents the package from failing builds by accidentally selecting it. |
IPV6 | IPv6 support in packages is selected. |
NOTES
All variables in your pre/post install/removal scripts should have double ($$) instead of a single ($) string characters. This will inform “make” to not interpret the value as a variable, but rather just ignore the string and replace the double $$ by a single $ -- More Info
After you've created your package Makefile, the new package will automatically show in the menu the next time you run “make menuconfig” and if selected will be built automatically the next time “make” is run.
DESCRIPTION is obsolete, use Package/PKG_NAME/description.
Adding configuration options
If you would like configure your package installation/compilation in the menuconfig you can do the following: Add MENU:=1 to your package definition like this:
define Package/mjpg-streamer SECTION:=multimedia CATEGORY:=Multimedia TITLE:=MJPG-streamer DEPENDS:=@!LINUX_2_4 +libpthread-stubs +jpeg URL:=http://mjpg-streamer.wiki.sourceforge.net/ MENU:=1 endef
Create a config key in the Makefile:
define Package/mjpg-streamer/config source "$(SOURCE)/Config.in" endef
Create a Config.in file directory where the Makefile is located with the content like this:
# Mjpg-streamer configuration menu "Configuration" depends on PACKAGE_mjpg-streamer
config MJPEG_STREAMER_AUTOSTART bool "Autostart enabled" default n
menu "Input plugins" depends on PACKAGE_mjpg-streamer config MJPEG_STREAMER_INPUT_FILE bool "File input plugin" help You can stream pictures from jpg files on the filesystem default n config MJPEG_STREAMER_INPUT_UVC bool "UVC input plugin" help You can stream pictures from an Universal Video Class compatible webcamera default y config MJPEG_STREAMER_FPS depends MJPEG_STREAMER_INPUT_UVC int "Maximum FPS" default 15
config MJPEG_STREAMER_PICT_HEIGHT depends MJPEG_STREAMER_INPUT_UVC int "Picture height" default 640
config MJPEG_STREAMER_PICT_WIDTH depends MJPEG_STREAMER_INPUT_UVC int "Picture width" default 480
config MJPEG_STREAMER_DEVICE depends MJPEG_STREAMER_INPUT_UVC string "Device" default /dev/video0 config MJPEG_STREAMER_INPUT_GSPCA bool "GSPCA input plugin" help You can stream pictures from a gspca supported webcamera Note this module is deprecated, use the UVVC plugin instead default n endmenu # ...... endmenu
Above you can see examples for various type config parameters.
And finally you can check your configuration parameters in your Makefile in the following way: (Note that you can reference to the parameters value with it name prefixed with CONFIG_)
ifeq ($(CONFIG_MJPEG_STREAMER_INPUT_UVC),y) $(CP) $(PKG_BUILD_DIR)/input_uvc.so $(1)/usr/lib endif
Creating packages for kernel modules
A kernel module is an installable program which extends the behavior of the linux kernel. A kernel module gets loaded after the kernel itself, (e.g. using insmod).
Many kernel programs are included in the linux source distribution; typically the kernel build may be configured to, for each program,
- compile it into the kernel as a built-in,
- compile it as a loadable kernel module, or
- ignore it.
See FIX:Customizingthekerneloptions customizing the kernel options for including it in the kernel.
To include one of these programs as a loadable module, select the corresponding kernel option in the OpenWrt configuration (see Build Configuration). If your favorite kernel module does not appear in the OpenWrt configuration menus, you must add a stanza to one of the files in the package/kernel/modules directory. Here is an example extracted from package/kernel/modules/block.mk:
define KernelPackage/loop SUBMENU:=$(BLOCK_MENU) TITLE:=Loopback device support KCONFIG:= \ CONFIG_BLK_DEV_LOOP \ CONFIG_BLK_DEV_CRYPTOLOOP=n FILES:=$(LINUX_DIR)/drivers/block/loop.ko AUTOLOAD:=$(call AutoLoad,30,loop) endef define KernelPackage/loop/description Kernel module for loopback device support endef $(eval $(call KernelPackage,loop))
You can also add kernel modules which are not part of the linux source distribution. In this case, a kernel module appears in the package/ directory, just as any other package does. The package/Makefile uses
KernelPackage/xxx
definitions in place of
Package/xxx
. For example, here is package/madwifi/Makefile:
# # Copyright (C) 2006 OpenWrt.org # # This is free software, licensed under the GNU General Public License v2. # See /LICENSE for more information. # # $Id$ include $(TOPDIR)/rules.mk include $(INCLUDE_DIR)/kernel.mk PKG_NAME:=madwifi PKG_VERSION:=0.9.2 PKG_RELEASE:=1 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.bz2 PKG_SOURCE_URL:=@SF/$(PKG_NAME) PKG_MD5SUM:=a75baacbe07085ddc5cb28e1fb43edbb PKG_CAT:=bzcat PKG_BUILD_DIR:=$(KERNEL_BUILD_DIR)/$(PKG_NAME)-$(PKG_VERSION) include $(INCLUDE_DIR)/package.mk RATE_CONTROL:=sample ifeq ($(ARCH),mips) HAL_TARGET:=mips-be-elf endif ifeq ($(ARCH),mipsel) HAL_TARGET:=mips-le-elf endif ifeq ($(ARCH),i386) HAL_TARGET:=i386-elf endif ifeq ($(ARCH),armeb) HAL_TARGET:=xscale-be-elf endif ifeq ($(ARCH),powerpc) HAL_TARGET:=powerpc-be-elf endif BUS:=PCI ifneq ($(CONFIG_LINUX_2_4_AR531X),) BUS:=AHB endif ifneq ($(CONFIG_LINUX_2_6_ARUBA),) BUS:=PCI AHB # no suitable HAL for AHB yet. endif BUS_MODULES:= ifeq ($(findstring AHB,$(BUS)),AHB) BUS_MODULES+=$(PKG_BUILD_DIR)/ath/ath_ahb.$(LINUX_KMOD_SUFFIX) endif ifeq ($(findstring PCI,$(BUS)),PCI) BUS_MODULES+=$(PKG_BUILD_DIR)/ath/ath_pci.$(LINUX_KMOD_SUFFIX) endif MADWIFI_AUTOLOAD:= \ wlan \ wlan_scan_ap \ wlan_scan_sta \ ath_hal \ ath_rate_$(RATE_CONTROL) \ wlan_acl \ wlan_ccmp \ wlan_tkip \ wlan_wep \ wlan_xauth ifeq ($(findstring AHB,$(BUS)),AHB) MADWIFI_AUTOLOAD += ath_ahb endif ifeq ($(findstring PCI,$(BUS)),PCI) MADWIFI_AUTOLOAD += ath_pci endif define KernelPackage/madwifi SUBMENU:=Wireless Drivers DEFAULT:=y if LINUX_2_6_BRCM | LINUX_2_6_ARUBA | LINUX_2_4_AR531X | LINUX_2_6_XSCALE, m if ALL TITLE:=Driver for Atheros wireless chipsets DESCRIPTION:=\ This package contains a driver for Atheros 802.11a/b/g chipsets. URL:=http://madwifi.org/ VERSION:=$(LINUX_VERSION)+$(PKG_VERSION)-$(BOARD)-$(PKG_RELEASE) FILES:= \ $(PKG_BUILD_DIR)/ath/ath_hal.$(LINUX_KMOD_SUFFIX) \ $(BUS_MODULES) \ $(PKG_BUILD_DIR)/ath_rate/$(RATE_CONTROL)/ath_rate_$(RATE_CONTROL).$(LINUX_KMOD_SUFFIX) \ $(PKG_BUILD_DIR)/net80211/wlan*.$(LINUX_KMOD_SUFFIX) AUTOLOAD:=$(call AutoLoad,50,$(MADWIFI_AUTOLOAD)) endef MADWIFI_MAKEOPTS= -C $(PKG_BUILD_DIR) \ PATH="$(TARGET_PATH)" \ ARCH="$(LINUX_KARCH)" \ CROSS_COMPILE="$(TARGET_CROSS)" \ TARGET="$(HAL_TARGET)" \ TOOLPREFIX="$(KERNEL_CROSS)" \ TOOLPATH="$(KERNEL_CROSS)" \ KERNELPATH="$(LINUX_DIR)" \ LDOPTS=" " \ ATH_RATE="ath_rate/$(RATE_CONTROL)" \ DOMULTI=1 ifeq ($(findstring AHB,$(BUS)),AHB) define Build/Compile/ahb $(MAKE) $(MADWIFI_MAKEOPTS) BUS="AHB" all endef endif ifeq ($(findstring PCI,$(BUS)),PCI) define Build/Compile/pci $(MAKE) $(MADWIFI_MAKEOPTS) BUS="PCI" all endef endif define Build/Compile $(call Build/Compile/ahb) $(call Build/Compile/pci) endef define Build/InstallDev $(INSTALL_DIR) $(STAGING_DIR)/usr/include/madwifi $(CP) $(PKG_BUILD_DIR)/include $(STAGING_DIR)/usr/include/madwifi/ $(INSTALL_DIR) $(STAGING_DIR)/usr/include/madwifi/net80211 $(CP) $(PKG_BUILD_DIR)/net80211/*.h $(STAGING_DIR)/usr/include/madwifi/net80211/ endef define KernelPackage/madwifi/install $(INSTALL_DIR) $(1)/etc/init.d $(INSTALL_DIR) $(1)/lib/modules/$(LINUX_VERSION) $(INSTALL_DIR) $(1)/usr/sbin $(INSTALL_BIN) ./files/madwifi.init $(1)/etc/init.d/madwifi $(CP) $(PKG_BUILD_DIR)/tools/{madwifi_multi,80211debug,80211stats,athchans,athctrl,athdebug,athkey,athstats,wlanconfig} $(1)/usr/sbin/ endef $(eval $(call KernelPackage,madwifi))
NOTES
INSTALL_DIR, INSTALL_BIN, INSTALL_DATA are used for creating a directory, copying an executable, or a data file. +x is set on the target file for INSTALL_BIN, independent of it's mode on the host.
From the big document:
Package/<name>/install:
A set of commands to copy files out of the compiled source and into the ipkg which is represented by the $(1) directory. Note that there are currently 4 defined install macros:
INSTALL_DIR install -d -m0755 INSTALL_BIN install -m0755 INSTALL_DATA install -m0644 INSTALL_CONF install -m0600
Packaging a service
If you want to install a service, (something that should start/stop at boot time, that has a /etc/init.d/blah script), you should make sure that the init.d script can be run on the host. At image build time, all init.d scripts found are run on the host, looking for the START=20/STOP=99 lines.
This is what installs the symlinks in /etc/rc.d, so they are only created when you rebuild the entire image. If you want the symlinks to be created when a package is installed, such as via opkg, you should add a postinstall script which runs
/etc/init.d/foo enable
if $IPKG_INSTROOT is empty. when $IPKG_INSTROOT is defined, you run within the buildroot, if it is empty you run on the target.
Example makefile snippet to install/remove symlinks.
define Package/mrelay/postinst #!/bin/sh # check if we are on real system if [ -z "$${IPKG_INSTROOT}" ]; then echo "Enabling rc.d symlink for mrelay" /etc/init.d/mrelay enable fi exit 0 endef define Package/mrelay/prerm #!/bin/sh # check if we are on real system if [ -z "$${IPKG_INSTROOT}" ]; then echo "Removing rc.d symlink for mrelay" /etc/init.d/mrelay disable fi exit 0 endef
Very basic example of a suitable init.d script
#!/bin/sh /etc/rc.common START=80 APP=mrelay PID_FILE=/var/run/$APP.pid start() { start-stop-daemon -S -x $APP -p $PID_FILE -m -b } stop() { start-stop-daemon -K -n $APP -p $PID_FILE -s TERM rm -rf $PID_FILE }