+++ /dev/null
-Introduction to build-root/Makefile
-===================================
-
-The vpp build system consists of a top-level Makefile, a data-driven
-build-root/Makefile, and a set of makefile fragments. The various parts
-come together as the result of a set of well-thought-out conventions.
-
-This section describes build-root/Makefile in some detail.
-
-Repository Groups and Source Paths
-----------------------------------
-
-Current vpp workspaces comprise a single repository group. The file
-.../build-root/build-config.mk defines a key variable called
-SOURCE\_PATH. The SOURCE\_PATH variable names the set of repository
-groups. At the moment, there is only one repository group.
-
-Single pass build system, dependencies and components
------------------------------------------------------
-
-The vpp build system caters to components built with GNU autoconf /
-automake. Adding such components is a simple process. Dealing with
-components which use BSD-style raw Makefiles is a more difficult.
-Dealing with toolchain components such as gcc, glibc, and binutils can
-be considerably more complicated.
-
-The vpp build system is a **single-pass** build system. A partial order
-must exist for any set of components: the set of (a before b) tuples
-must resolve to an ordered list. If you create a circular dependency of
-the form; (a,b) (b,c) (c,a), gmake will try to build the target list,
-but there’s a 0.0% chance that the results will be pleasant. Cut-n-paste
-mistakes in .../build-data/packages/.mk can produce confusing failures.
-
-In a single-pass build system, it’s best to separate libraries and
-applications which instantiate them. For example, if vpp depends on
-libfoo.a, and myapp depends on both vpp and libfoo.a, it's best to place
-libfoo.a and myapp in separate components. The build system will build
-libfoo.a, vpp, and then (as a separate component) myapp. If you try to
-build libfoo.a and myapp from the same component, it won’t work.
-
-If you absolutely, positively insist on having myapp and libfoo.a in the
-same source tree, you can create a pseudo-component in a separate .mk
-file in the .../build-data/packages/ directory. Define the code
-phoneycomponent\_source = realcomponent, and provide manual
-configure/build/install targets.
-
-Separate components for myapp, libfoo.a, and vpp is the best and easiest
-solution. However, the “mumble\_source = realsource” degree of freedom
-exists to solve intractable circular dependencies, such as: to build
-gcc-bootstrap, followed by glibc, followed by “real” gcc/g++ [which
-depends on glibc too].
-
-.../build-root
---------------
-
-The .../build-root directory contains the repository group specification
-build-config.mk, the main Makefile, and the system-wide set of
-autoconf/automake variable overrides in config.site. We'll describe
-these files in some detail. To be clear about expectations: the main
-Makefile and config.site file are subtle and complex. It's unlikely that
-you'll need or want to modify them. Poorly planned changes in either
-place typically cause bugs that are difficult to solve.
-
-.../build-root/build-config.mk
-------------------------------
-
-As described above, the build-config.mk file is straightforward: it sets
-the make variable SOURCE\_PATH to a list of repository group absolute
-paths.
-
-The SOURCE\_PATH variable If you choose to move a workspace, make sure
-to modify the paths defined by the SOURCE\_PATH variable. Those paths
-need to match changes you make in the workspace paths. For example, if
-you place the vpp directory in the workspace of a user named jsmith, you
-might change the SOURCE\_PATH to:
-
-SOURCE\_PATH = /home/jsmithuser/workspace/vpp
-
-The "out of the box" setting should work 99.5% of the time:
-
-::
-
- SOURCE_PATH = $(CURDIR)/..
-
-.../vpp/build-root/Makefile
----------------------------
-
-The main Makefile is complex in a number of dimensions. If you think you
-need to modify it, it's a good idea to do some research, or ask for
-advice before you change it.
-
-The main Makefile was organized and designed to provide the following
-characteristics: excellent performance, accurate dependency processing,
-cache enablement, timestamp optimizations, git integration,
-extensibility, builds with cross-compilation tool chains, and builds
-with embedded Linux distributions.
-
-If you really need to do so, you can build double-cross tools with it,
-with a minimum amount of fuss. For example, you could: compile gdb on
-x86\_64, to run on PowerPC, to debug the Xtensa instruction set.
-
-The PLATFORM variable
----------------------
-
-The PLATFORM make/environment variable controls a number of important
-characteristics, primarily:
-
-- CPU architecture
-- The list of images to build.
-
-With respect to .../build-root/Makefile, the list of images to build is
-specified by the target. For example:
-
-::
-
- make PLATFORM=vpp TAG=vpp_debug install-deb
-
-builds vpp debug Debian packages.
-
-The main Makefile interprets $PLATFORM by attempting to "-include" the
-file /build-data/platforms.mk:
-
-::
-
- $(foreach d,$(FULL_SOURCE_PATH), \
- $(eval -include $(d)/platforms.mk))
-
-By convention, we don't define **platforms** in the
-...//build-data/platforms.mk file.
-
-In the vpp case, we search for platform definition makefile fragments in
-.../vpp/build-data/platforms.mk, as follows:
-
-::
-
- $(foreach d,$(SOURCE_PATH_BUILD_DATA_DIRS), \
- $(eval -include $(d)/platforms/*.mk))
-
-With vpp, which uses the "vpp" platform as discussed above, we end up
-"-include"-ing .../vpp/build-data/platforms/vpp.mk.
-
-The platform-specific .mk fragment
-----------------------------------
-
-Here are the contents of .../build-data/platforms/vpp.mk:
-
-::
-
- MACHINE=$(shell uname -m)
-
- vpp_arch = native
- ifeq ($(TARGET_PLATFORM),thunderx)
- vpp_dpdk_target = arm64-thunderx-linuxapp-gcc
- endif
- vpp_native_tools = vppapigen
-
- vpp_uses_dpdk = yes
-
- # Uncoment to enable building unit tests
- # vpp_enable_tests = yes
-
- vpp_root_packages = vpp vom japi
-
- # DPDK configuration parameters
- # vpp_uses_dpdk_mlx4_pmd = yes
- # vpp_uses_dpdk_mlx5_pmd = yes
- # vpp_uses_external_dpdk = yes
- # vpp_dpdk_inc_dir = /usr/include/dpdk
- # vpp_dpdk_lib_dir = /usr/lib
- # vpp_dpdk_shared_lib = yes
-
- # Use '--without-libnuma' for non-numa aware architecture
- # Use '--enable-dlmalloc' to use dlmalloc instead of mheap
- vpp_configure_args_vpp = --enable-dlmalloc
- sample-plugin_configure_args_vpp = --enable-dlmalloc
-
- # load balancer plugin is not portable on 32 bit platform
- ifeq ($(MACHINE),i686)
- vpp_configure_args_vpp += --disable-lb-plugin
- endif
-
- vpp_debug_TAG_CFLAGS = -g -O0 -DCLIB_DEBUG -DFORTIFY_SOURCE=2 \
- -fstack-protector-all -fPIC -Werror
- vpp_debug_TAG_CXXFLAGS = -g -O0 -DCLIB_DEBUG -DFORTIFY_SOURCE=2 \
- -fstack-protector-all -fPIC -Werror
- vpp_debug_TAG_LDFLAGS = -g -O0 -DCLIB_DEBUG -DFORTIFY_SOURCE=2 \
- -fstack-protector-all -fPIC -Werror
-
- vpp_TAG_CFLAGS = -g -O2 -DFORTIFY_SOURCE=2 -fstack-protector -fPIC -Werror
- vpp_TAG_CXXFLAGS = -g -O2 -DFORTIFY_SOURCE=2 -fstack-protector -fPIC -Werror
- vpp_TAG_LDFLAGS = -g -O2 -DFORTIFY_SOURCE=2 -fstack-protector -fPIC -Werror -pie -Wl,-z,now
-
- vpp_clang_TAG_CFLAGS = -g -O2 -DFORTIFY_SOURCE=2 -fstack-protector -fPIC -Werror
- vpp_clang_TAG_LDFLAGS = -g -O2 -DFORTIFY_SOURCE=2 -fstack-protector -fPIC -Werror
-
- vpp_gcov_TAG_CFLAGS = -g -O0 -DCLIB_DEBUG -fPIC -Werror -fprofile-arcs -ftest-coverage
- vpp_gcov_TAG_LDFLAGS = -g -O0 -DCLIB_DEBUG -fPIC -Werror -coverage
-
- vpp_coverity_TAG_CFLAGS = -g -O2 -fPIC -Werror -D__COVERITY__
- vpp_coverity_TAG_LDFLAGS = -g -O2 -fPIC -Werror -D__COVERITY__
-
-Note the following variable settings:
-
-- The variable \_arch sets the CPU architecture used to build the
- per-platform cross-compilation toolchain. With the exception of the
- "native" architecture - used in our example - the vpp build system
- produces cross-compiled binaries.
-
-- The variable \_native\_tools lists the required set of self-compiled
- build tools.
-
-- The variable \_root\_packages lists the set of images to build when
- specifying the target: make PLATFORM= TAG= [install-deb \|
- install-rpm].
-
-The TAG variable
-----------------
-
-The TAG variable indirectly sets CFLAGS and LDFLAGS, as well as the
-build and install directory names in the .../vpp/build-root directory.
-See definitions above.
-
-Important targets build-root/Makefile
--------------------------------------
-
-The main Makefile and the various makefile fragments implement the
-following user-visible targets:
-
-+------------------+----------------------+--------------------------------------------------------------------------------------+
-| Target | ENV Variable Settings| Notes |
-| | | |
-+==================+======================+======================================================================================+
-| foo | bar | mumble |
-+------------------+----------------------+--------------------------------------------------------------------------------------+
-| bootstrap-tools | none | Builds the set of native tools needed by the vpp build system to |
-| | | build images. Example: vppapigen. In a full cross compilation case might include |
-| | | include "make", "git", "find", and "tar |
-+------------------+----------------------+--------------------------------------------------------------------------------------+
-| install-tools | PLATFORM | Builds the tool chain for the indicated <platform>. Not used in vpp builds |
-+------------------+----------------------+--------------------------------------------------------------------------------------+
-| distclean | none | Roto-rooters everything in sight: toolchains, images, and so forth. |
-+------------------+----------------------+--------------------------------------------------------------------------------------+
-| install-deb | PLATFORM and TAG | Build Debian packages comprising components listed in <platform>_root_packages, |
-| | | using compile / link options defined by TAG. |
-+------------------+----------------------+--------------------------------------------------------------------------------------+
-| install-rpm | PLATFORM and TAG | Build RPMs comprising components listed in <platform>_root_packages, |
-| | | using compile / link options defined by TAG. |
-+------------------+----------------------+--------------------------------------------------------------------------------------+
-
-Additional build-root/Makefile environment variable settings
-------------------------------------------------------------
-
-These variable settings may be of use:
-
-+----------------------+------------------------------------------------------------------------------------------------------------+
-| ENV Variable | Notes |
-+======================+======================+=====================================================================================+
-| BUILD_DEBUG=vx | Directs Makefile et al. to make a good-faith effort to show what's going on in excruciating detail. |
-| | Use it as follows: "make ... BUILD_DEBUG=vx". Fairly effective in Makefile debug situations. |
-+----------------------+------------------------------------------------------------------------------------------------------------+
-| V=1 | print detailed cc / ld command lines. Useful for discovering if -DFOO=11 is in the command line or not |
-+----------------------+------------------------------------------------------------------------------------------------------------+
-| CC=mygcc | Override the configured C-compiler |
-+----------------------+------------------------------------------------------------------------------------------------------------+
-
-.../build-root/config.site
---------------------------
-
-The contents of .../build-root/config.site override individual autoconf /
-automake default variable settings. Here are a few sample settings related to
-building a full toolchain:
-
-::
-
- # glibc needs these setting for cross compiling
- libc_cv_forced_unwind=yes
- libc_cv_c_cleanup=yes
- libc_cv_ssp=no
-
-Determining the set of variables which need to be overridden, and the
-override values is a matter of trial and error. It should be
-unnecessary to modify this file for use with fd.io vpp.
-
-.../build-data/platforms.mk
----------------------------
-
-Each repo group includes the platforms.mk file, which is included by
-the main Makefile. The vpp/build-data/platforms.mk file is not terribly
-complex. As of this writing, .../build-data/platforms.mk file accomplishes two
-tasks.
-
-First, it includes vpp/build-data/platforms/\*.mk:
-
-::
-
- # Pick up per-platform makefile fragments
- $(foreach d,$(SOURCE_PATH_BUILD_DATA_DIRS), \
- $(eval -include $(d)/platforms/*.mk))
-
-This collects the set of platform definition makefile fragments, as discussed above.
-
-Second, platforms.mk implements the user-visible "install-deb" target.
-
-.../build-data/packages/\*.mk
------------------------------
-
-Each component needs a makefile fragment in order for the build system
-to recognize it. The per-component makefile fragments vary
-considerably in complexity. For a component built with GNU autoconf /
-automake which does not depend on other components, the make fragment
-can be empty. See .../build-data/packages/vpp.mk for an uncomplicated
-but fully realistic example.
-
-Here are some of the important variable settings in per-component makefile fragments:
-
-+----------------------+------------------------------------------------------------------------------------------------------------+
-| Variable | Notes |
-+======================+======================+=====================================================================================+
-| xxx_configure_depend | Lists the set of component build dependencies for the xxx component. In plain English: don't try to |
-| | configure this component until you've successfully built the indicated targets. Almost always, |
-| | xxx_configure_depend will list a set of "yyy-install" targets. Note the pattern: |
-| | "variable names contain underscores, make target names contain hyphens" |
-+----------------------+------------------------------------------------------------------------------------------------------------+
-| xxx_configure_args | (optional) Lists any additional arguments to pass to the xxx component "configure" script. |
-| | The main Makefile %-configure rule adds the required settings for --libdir, --prefix, and |
-| | --host (when cross-compiling) |
-+----------------------+------------------------------------------------------------------------------------------------------------+
-| xxx_CPPFLAGS | Adds -I stanzas to CPPFLAGS for components upon which xxx depends. |
-| | Almost invariably "xxx_CPPFLAGS = $(call installed_includes_fn, dep1 dep2 dep3)", where dep1, dep2, and |
-| | dep3 are listed in xxx_configure_depend. It is bad practice to set "-g -O3" here. Those settings |
-| | belong in a TAG. |
-+----------------------+------------------------------------------------------------------------------------------------------------+
-| xxx_LDFLAGS | Adds -Wl,-rpath -Wl,depN stanzas to LDFLAGS for components upon which xxx depends. |
-| | Almost invariably "xxx_LDFLAGS = $(call installed_lib_fn, dep1 dep2 dep3)", where dep1, dep2, and |
-| | dep3 are listed in xxx_configure_depend. It is bad manners to set "-liberty-or-death" here. |
-| | Those settings belong in Makefile.am. |
-+----------------------+------------------------------------------------------------------------------------------------------------+
-
-When dealing with "irritating" components built with raw Makefiles
-which only work when building in the source tree, we use a specific
-strategy in the xxx.mk file.
-
-The strategy is simple for those components: We copy the source tree
-into .../vpp/build-root/build-xxx. This works, but completely defeats
-dependency processing. This strategy is acceptable only for 3rd party
-software which won't need extensive (or preferably any) modifications.
-
-Take a look at .../vpp/build-data/packages/dpdk.mk. When invoked, the
-dpdk_configure variable copies source code into $(PACKAGE_BUILD_DIR),
-and performs the BSD equivalent of "autoreconf -i -f" to configure the
-build area. The rest of the file is similar: a bunch of hand-rolled
-glue code which manages to make the dpdk act like a good vpp build
-citizen even though it is not.
Code Review / vpp.git / blobdiff