core: new infra to ease building kernel modules (branch yem/kernel-modules)

index 2ed7cf7..545694f 100644
@@ -399,3 +399,4 @@ include package/pkg-virtual.mk
 include package/pkg-generic.mk
 include package/pkg-kconfig.mk
 include package/pkg-rebar.mk
+include package/pkg-kernel-module.mk

96 lines not on this page · raw message

new file mode 100644
index 0000000..39575f7
@@ -0,0 +1,142 @@
+// -*- mode:doc; -*-
+// vim: set syntax=asciidoc:
+
+=== Infrastructure for packages building kernel modules
+
+Buildroot offers a helper infrastructure to make it easy to write packages that
+build and install Linux kernel modules. Some packages only contain a kernel
+module, other packages contain programs and libraries in addition to kernel
+modules. Buildroot's helper infrastructure supports either case.
+
+[[kernel-module-tutorial]]
+==== +kernel-module+ tutorial
+
+Let's start with an example on how to prepare a simple package that only
+builds a kernel module, and no other component:
+
+----
+01: ################################################################################
+02: #
+03: # foo
+04: #
+05: ################################################################################
+06: 
+07: FOO_VERSION = 1.2.3
+08: FOO_SOURCE = foo-$(FOO_VERSION).tar.xz
+09: FOO_SITE = http://www.foosoftware.org/download
+10: FOO_LICENSE = GPLv2
+11: FOO_LICENSE_FILES = COPYING
+12: 
+13: $(eval $(kernel-module))
+14: $(eval $(generic-package))
+----
+
+Lines 7-11 define the usual meta-data to specify the version, archive name,
+remote URI where to find the package source, licensing information.
+
+On line 13, we invoke the +kernel-module+ helper infrastructure, that
+generates all the appropriate Makefile rules and variables to build
+that kernel module.
+
+Finally, on line 14, we invoke the
+xref:generic-package-tutorial[+generic-package+ infrastructure].
+
+The dependency on +linux+ is automatically added, so it is not needed to
+specify it in +FOO_DEPENDENCIES+.
+
+What you may have noticed is that, unlike other package infrastructures,
+we explicitly invoke a second infrastructure. This allows a package to
+build a kernel module, but also, if needed, use any one of other package
+infrastructures to build normal userland components (libraries,
+executables...). Using the +kernel-module+ infrastructure on its own is
+not sufficient; another package infrastructure *must* be used.
+
+Let's look at a more complex example:
+
+----
+01: ################################################################################
+02: #
+03: # foo
+04: #
+05: ################################################################################
+06: 
+07: FOO_VERSION = 1.2.3
+08: FOO_SOURCE = foo-$(FOO_VERSION).tar.xz
+09: FOO_SITE = http://www.foosoftware.org/download
+10: FOO_LICENSE = GPLv2
+11: FOO_LICENSE_FILES = COPYING
+12: 
+13: FOO_MODULE_SUBDIRS = driver/base
+14: FOO_MODULE_MAKE_OPTS = KVERSION=$(LINUX_VERSION_PROBED)
+15: 
+16: ifeq ($(BR2_PACKAGE_LIBBAR),y)
+17: FOO_DEPENDENCIES = libbar
+18: FOO_CONF_OPTS = --enable-bar
+19: FOO_MODULE_SUBDIRS += driver/bar
+20: else
+21: FOO_CONF_OPTS = --disable-bar
+22: endif
+23: 
+24: $(eval $(kernel-module))
+26: $(eval $(autotools-package))
+----
+
+Here, we see that we have an autotools-based package, that also builds
+the kernel module located in sub-directory +driver/base+ and, if libbar
+is enabled, the kernel module located in sub-directory +driver/bar+, and
+defines the variable +KVERSION+ to be passed to the Linux buildsystem
+when building the module(s).
+
+
+[[kernel-module-reference]]
+==== +kernel-module+ reference
+
+The main macro for the  kernel module infrastructure is +kernel-module+.
+Unlike other package infrastructures, it is not stand-alone, and requires
+any of the other +*-package+ macros be called after it.
+
+The +kernel-module+ macro defines post-build and post-target-install
+hooks to build the kernel modules. If the package's +.mk+ needs access
+to the built kernel modules, it should do so in a post-build hook,
+*registered after* the call to +kernel-module+. Similarly, if the
+package's +.mk+ needs access to the kernel module after it has been
+installed, it should do so in a post-install hook, *registered after*
+the call to +kernel-module+. Here's an example:
+
+----
+$(eval $(kernel-module))
+
+define FOO_DO_STUFF_WITH_KERNEL_MODULE
+    # Do something with it...
+endef
+FOO_POST_BUILD_HOOKS += FOO_DO_STUFF_WITH_KERNEL_MODULE
+
+$(eval $(generic-package))
+----
+
+Finally, unlike the other package infrastructures, there is no
++host-kernel-module+ variant to build a host kernel module.
+
+The following additional variables can optionally be defined to further
+configure the build of the kernel module:
+
+* +FOO_MODULE_SUBDIRS+ may be set to one or more sub-directories (relative
+  to the package source top-directory) where the kernel module sources are.
+  If empty or not set, the sources for the kernel module(s) are considered
+  to be located at the top of the package source tree.
+
+* +FOO_MODULE_MAKE_OPTS+ may be set to contain extra variable definitions
+  to pass to the Linux buildsystem.
+
+Yo may also reference (but you may *not* set!) those variables:
+
+ * +LINUX_DIR+ contains the path to where the Linux kernel has been
+   extracted and built.
+
+ * +LINUX_VERSION+ contains the version string as configured by the user.
+
+ * +LINUX_VERSION_PROBED+ contains the real version string of the kernel,
+   retrieved with running `make -C $(LINUX_DIR) kernelrelease`
+
+ * +KERNEL_ARCH+ contains the name of the current architecture, like `arm`,
+   `mips`...

index b8674f8..721fe39 100644
@@ -29,6 +29,8 @@ include::adding-packages-kconfig.txt[]
 
 include::adding-packages-rebar.txt[]
 
+include::adding-packages-kernel-module.txt[]
+
 include::adding-packages-asciidoc.txt[]
 
 include::adding-packages-hooks.txt[]

index 6833ad2..30c581e 100644
@@ -10,14 +10,5 @@ LTTNG_MODULES_SOURCE = lttng-modules-$(LTTNG_MODULES_VERSION).tar.bz2
 LTTNG_MODULES_LICENSE = LGPLv2.1/GPLv2 for kernel modules; MIT for lib/bitfield.h and lib/prio_heap/*
 LTTNG_MODULES_LICENSE_FILES = lgpl-2.1.txt gpl-2.0.txt mit-license.txt LICENSE
 
-LTTNG_MODULES_DEPENDENCIES = linux
-
-define LTTNG_MODULES_BUILD_CMDS
-	$(MAKE) -C $(@D) $(LINUX_MAKE_FLAGS) KERNELDIR=$(LINUX_DIR)
-endef
-
-define LTTNG_MODULES_INSTALL_TARGET_CMDS
-	$(MAKE) -C $(@D) $(LINUX_MAKE_FLAGS) KERNELDIR=$(LINUX_DIR) modules_install
-endef
-
+$(eval $(kernel-module))
 $(eval $(generic-package))

index b5221f8..32c49a3 100644
@@ -10,7 +10,6 @@ IGH_ETHERCAT_SOURCE = ethercat-$(IGH_ETHERCAT_VERSION).tar.bz2
 IGH_ETHERCAT_LICENSE = GPLv2 (IgH EtherCAT master), LGPLv2.1 (libraries)
 IGH_ETHERCAT_LICENSE_FILES = COPYING COPYING.LESSER
 
-IGH_ETHERCAT_DEPENDENCIES = linux
 IGH_ETHERCAT_INSTALL_STAGING = YES
 
 IGH_ETHERCAT_CONF_OPTS = \

@@ -22,16 +21,5 @@ IGH_ETHERCAT_CONF_OPTS += $(if $(BR2_PACKAGE_IGH_ETHERCAT_E1000),--enable-e1000,
 IGH_ETHERCAT_CONF_OPTS += $(if $(BR2_PACKAGE_IGH_ETHERCAT_E1000E),--enable-e1000e,--disable-e1000e)
 IGH_ETHERCAT_CONF_OPTS += $(if $(BR2_PACKAGE_IGH_ETHERCAT_R8169),--enable-r8169,--disable-r8169)
 
-define IGH_ETHERCAT_BUILD_MODULES
-	$(MAKE) -C $(@D) $(LINUX_MAKE_FLAGS) modules
-endef
-
-IGH_ETHERCAT_POST_BUILD_HOOKS += IGH_ETHERCAT_BUILD_MODULES
-
-define IGH_ETHERCAT_INSTALL_MODULES
-	$(MAKE) -C $(@D) $(LINUX_MAKE_FLAGS) modules_install
-endef
-
-IGH_ETHERCAT_POST_INSTALL_TARGET_HOOKS += IGH_ETHERCAT_INSTALL_MODULES
-
+$(eval $(kernel-module))
 $(eval $(autotools-package))

index 4a0e51c..966b51c 100644
@@ -9,8 +9,6 @@ KTAP_SITE = $(call github,ktap,ktap,$(KTAP_VERSION))
 KTAP_LICENSE = GPLv2
 KTAP_LICENSE_FILES = LICENSE-GPL
 
-KTAP_DEPENDENCIES = linux
-
 ifeq ($(BR2_PACKAGE_ELFUTILS),y)
 KTAP_DEPENDENCIES += elfutils
 else

@@ -19,12 +17,13 @@ endif
 
 define KTAP_BUILD_CMDS
 	$(MAKE) -C $(@D) $(TARGET_CONFIGURE_OPTS) $(KTAP_FLAGS) ktap
-	$(MAKE) -C $(@D) $(LINUX_MAKE_FLAGS) KERNEL_SRC=$(LINUX_DIR) KVERSION=$(LINUX_VERSION_PROBED) mod
 endef
 
 define KTAP_INSTALL_TARGET_CMDS
 	$(INSTALL) -D -m755 $(@D)/ktap  $(TARGET_DIR)/usr/bin/ktap
-	$(MAKE) -C $(@D) $(LINUX_MAKE_FLAGS) KERNEL_SRC=$(LINUX_DIR) KVERSION=$(LINUX_VERSION_PROBED) modules_install
 endef
 
+KTAP_MODULE_MAKE_OPTS = KVERSION=$(LINUX_VERSION_PROBED)
+
+$(eval $(kernel-module))
 $(eval $(generic-package))

index 6f41930..6001c71 100644
@@ -6,23 +6,19 @@
 
 CRYPTODEV_LINUX_VERSION = 1.7
 CRYPTODEV_LINUX_SITE = http://download.gna.org/cryptodev-linux
-CRYPTODEV_LINUX_DEPENDENCIES = linux
 CRYPTODEV_LINUX_INSTALL_STAGING = YES
 CRYPTODEV_LINUX_LICENSE = GPLv2+
 CRYPTODEV_LINUX_LICENSE_FILES = COPYING
 
-define CRYPTODEV_LINUX_BUILD_CMDS
-	$(MAKE) -C $(@D) $(LINUX_MAKE_FLAGS) KERNEL_DIR=$(LINUX_DIR)
-endef
-
-define CRYPTODEV_LINUX_INSTALL_TARGET_CMDS
-	$(MAKE) -C $(@D) $(LINUX_MAKE_FLAGS) KERNEL_DIR=$(LINUX_DIR) \
-		PREFIX=$(TARGET_DIR) modules_install
+define CRYPTODEV_LINUX_MODULE_GEN_VERSION_H
+	$(MAKE) -C $(@D) version.h
 endef
+CRYPTODEV_LINUX_PRE_BUILD_HOOKS += CRYPTODEV_LINUX_MODULE_GEN_VERSION_H
 
 define CRYPTODEV_LINUX_INSTALL_STAGING_CMDS
 	$(INSTALL) -D -m 644 $(@D)/crypto/cryptodev.h \
 		$(STAGING_DIR)/usr/include/crypto/cryptodev.h
 endef
 
+$(eval $(kernel-module))
 $(eval $(generic-package))

deleted file mode 100644
index f80ef06..0000000
@@ -1,42 +0,0 @@
-Remove the OCF linux kernel extension instead opting to build ocf-linux
-modules out of tree.
-This is easier for users since no kernel config tweaking is required.
-On the downside the OCF drivers can't be used, but then all of the
-kernel crypto drivers are available to users via cryptosoft which is
-preferred.
-
-Signed-off-by: Gustavo Zacarias <[email protected]>
-
-diff -Nura ocf-linux-20120127.orig/ocf/Makefile ocf-linux-20120127/ocf/Makefile
---- ocf-linux-20120127.orig/ocf/Makefile	2013-04-27 09:27:04.413911866 -0300
-+++ ocf-linux-20120127/ocf/Makefile	2013-04-27 09:27:31.131775576 -0300
-@@ -2,6 +2,7 @@
- -include $(ROOTDIR)/modules/.config
-
- OCF_OBJS = crypto.o criov.o
-+KDIR ?= /lib/modules/$(shell uname -r)/build
-
- ifdef CONFIG_OCF_RANDOMHARVEST
- 	OCF_OBJS += random.o
-@@ -78,20 +79,13 @@
- #
-
- ocf_make:
--	make -C /lib/modules/$(shell uname -r)/build M=`pwd` $(OCF_TARGET) CONFIG_OCF_OCF=m
--	make -C /lib/modules/$(shell uname -r)/build M=`pwd` $(OCF_TARGET) CONFIG_OCF_OCF=m CONFIG_OCF_CRYPTOSOFT=m
--	-make -C /lib/modules/$(shell uname -r)/build M=`pwd` $(OCF_TARGET) CONFIG_OCF_OCF=m CONFIG_OCF_BENCH=m
--	-make -C /lib/modules/$(shell uname -r)/build M=`pwd` $(OCF_TARGET) CONFIG_OCF_OCF=m CONFIG_OCF_OCFNULL=m
--	-make -C /lib/modules/$(shell uname -r)/build M=`pwd` $(OCF_TARGET) CONFIG_OCF_OCF=m CONFIG_OCF_HIFN=m
-+	make -C $(KDIR) M=`pwd` $(OCF_TARGET) CONFIG_OCF_OCF=m CONFIG_OCF_CRYPTOSOFT=m CONFIG_OCF_BENCH=m CONFIG_OCF_OCFNULL=m
-
- ocf_modules:
- 	$(MAKE) ocf_make OCF_TARGET=modules
-
- ocf_install:
- 	$(MAKE) ocf_make OCF_TARGET="modules modules_install"
--	depmod
--	mkdir -p /usr/include/crypto
--	cp cryptodev.h /usr/include/crypto/.
-
- #
- # generate full kernel patches for 2.4 and 2.6 kernels to make patching

index 8ca5578..35968d5 100644
@@ -6,22 +6,19 @@
 
 OCF_LINUX_VERSION = 20120127
 OCF_LINUX_SITE = http://downloads.sourceforge.net/project/ocf-linux/ocf-linux/$(OCF_LINUX_VERSION)
-OCF_LINUX_DEPENDENCIES = linux
 OCF_LINUX_INSTALL_STAGING = YES
 
-define OCF_LINUX_BUILD_CMDS
-	$(MAKE) -C $(@D)/ocf $(LINUX_MAKE_FLAGS) KDIR=$(LINUX_DIR) \
-		ocf_modules
-endef
-
-define OCF_LINUX_INSTALL_TARGET_CMDS
-	$(MAKE) -C $(@D)/ocf $(LINUX_MAKE_FLAGS) KDIR=$(LINUX_DIR) \
-		ocf_install
-endef
+OCF_LINUX_MODULE_SUBDIRS = ocf
+OCF_LINUX_MODULE_MAKE_OPTS = \
+	CONFIG_OCF_OCF=m \
+	CONFIG_OCF_CRYPTOSOFT=m \
+	CONFIG_OCF_BENCH=m \
+	CONFIG_OCF_OCFNULL=m
 
 define OCF_LINUX_INSTALL_STAGING_CMDS
 	$(INSTALL) -D -m 644 $(@D)/ocf/cryptodev.h \
 		$(STAGING_DIR)/usr/include/crypto/cryptodev.h
 endef
 
+$(eval $(kernel-module))
 $(eval $(generic-package))

index 209bcb5..b40ed86 100644
@@ -7,17 +7,8 @@
 ON2_8170_MODULES_VERSION = 73b08061d30789178e692bc332b73d1d9922bf39
 ON2_8170_MODULES_SITE = $(call github,alexandrebelloni,on2-8170-modules,$(ON2_8170_MODULES_VERSION))
 
-ON2_8170_MODULES_DEPENDENCIES = linux
-
 ON2_8170_MODULES_LICENSE = GPLv2+
 #There is no license file
 
-define ON2_8170_MODULES_BUILD_CMDS
-	$(MAKE) -C $(LINUX_DIR) $(LINUX_MAKE_FLAGS) M=$(@D)
-endef
-
-define ON2_8170_MODULES_INSTALL_TARGET_CMDS
-	$(MAKE) -C $(LINUX_DIR) $(LINUX_MAKE_FLAGS) M=$(@D) modules_install
-endef
-
+$(eval $(kernel-module))
 $(eval $(generic-package))

deleted file mode 100644
index 14b4631..0000000
@@ -1,16 +0,0 @@
-Fix the owl-linux Makefile so that it protects spaces in the CROSS_COMPILE
-variable. For example, this variable will contain spaces if ccache is used.
-
-Signed-off-by: Simon Dawson <[email protected]>
-diff -Nurp a/Makefile b/Makefile
---- a/Makefile	2012-06-14 10:51:45.000000000 +0100
-+++ b/Makefile	2012-07-20 10:46:41.636752148 +0100
-@@ -35,7 +35,7 @@ else
- 	PWD := $(shell pwd)
- 
- default:
--	$(MAKE) -C $(KERNELDIR) ARCH=$(ARCH) CROSS_COMPILE=$(CROSS_COMPILE) M=$(PWD) MODE=$(MODE) modules
-+	$(MAKE) -C $(KERNELDIR) ARCH=$(ARCH) CROSS_COMPILE="$(CROSS_COMPILE)" M=$(PWD) MODE=$(MODE) modules
- 
- clean: 
- 	-rm -f *.o *.mod.c *.ko modules.order Module.symvers

similarity index 100%
rename from package/owl-linux/0002-fix-for-linux-3.3.x.patch
rename to package/owl-linux/0001-fix-for-linux-3.3.x.patch

index 371cc02..1262425 100644
@@ -10,14 +10,5 @@ OWL_LINUX_LICENSE = PROPRIETARY
 OWL_LINUX_LICENSE_FILES = LICENSE
 OWL_LINUX_REDISTRIBUTE = NO
 
-OWL_LINUX_DEPENDENCIES = linux
-
-define OWL_LINUX_BUILD_CMDS
-	$(MAKE) -C $(@D) $(LINUX_MAKE_FLAGS) KERNELDIR=$(LINUX_DIR)
-endef
-
-define OWL_LINUX_INSTALL_TARGET_CMDS
-	$(MAKE) -C $(LINUX_DIR) $(LINUX_MAKE_FLAGS) M="$(@D)" modules_install
-endef
-
+$(eval $(kernel-module))
 $(eval $(generic-package))

index 51987c5..91ed413 100644
@@ -8,14 +8,6 @@ SIMICSFS_VERSION = 1.18
 SIMICSFS_SITE = http://download.simics.net/pub
 SIMICSFS_LICENSE = GPLv2+
 SIMICSFS_LICENSE_FILES = hostfs.h
-SIMICSFS_DEPENDENCIES = linux
-
-define SIMICSFS_BUILD_CMDS
-	$(MAKE) $(LINUX_MAKE_FLAGS) -C $(LINUX_DIR) M=$(@D) modules
-endef
-
-define SIMICSFS_INSTALL_TARGET_CMDS
-	$(MAKE) $(LINUX_MAKE_FLAGS) -C $(LINUX_DIR) M=$(@D) INSTALL_MOD_PATH=$(TARGET_DIR) modules_install
-endef
 
+$(eval $(kernel-module))
 $(eval $(generic-package))

index d07d467..85d16a4 100644
@@ -10,13 +10,27 @@ SYSDIG_LICENSE = GPLv2
 SYSDIG_LICENSE_FILES = COPYING
 SYSDIG_CONF_OPTS = -DUSE_BUNDLED_LUAJIT=OFF -DUSE_BUNDLED_ZLIB=OFF \
 	-DUSE_BUNDLED_JSONCPP=OFF -DENABLE_DKMS=OFF
-SYSDIG_DEPENDENCIES = zlib luajit jsoncpp linux
+SYSDIG_DEPENDENCIES = zlib luajit jsoncpp
 SYSDIG_SUPPORTS_IN_SOURCE_BUILD = NO
 
-define SYSDIG_INSTALL_DRIVER
-	$(MAKE) -C $(SYSDIG_BUILDDIR) $(LINUX_MAKE_FLAGS) KERNELDIR="$(LINUX_DIR)" install_driver
+# sysdig creates the module Makefile from a template, which contains a
+# single place-holder, KBUILD_FLAGS, wich is only replaced with two
+# things:
+#   - debug flags, which we don't care about here,
+#   - 'sysdig-feature' flags, which are never set, so always empty
+# So, just replace the place-holder with the only meaningful value: nothing.
+define SYSDIG_MODULE_GEN_MAKEFILE
+	$(INSTALL) -m 0644 $(@D)/driver/Makefile.in $(@D)/driver/Makefile
+	$(SED) 's/@KBUILD_FLAGS@//;' $(@D)/driver/Makefile
 endef
+SYSDIG_POST_PATCH_HOOKS += SYSDIG_MODULE_GEN_MAKEFILE
 
-SYSDIG_POST_INSTALL_TARGET_HOOKS += SYSDIG_INSTALL_DRIVER
+# Don't build the driver as part of the 'standard' procedure, we'll
+# build it on our own with the kernel-module infra.
+SYSDIG_CONF_OPTS += -DBUILD_DRIVER=OFF
 
+SYSDIG_MODULE_SUBDIRS = driver
+SYSDIG_MODULE_MAKE_OPTS = KERNELDIR=$(LINUX_DIR)
+
+$(eval $(kernel-module))
 $(eval $(cmake-package))