RTOS/rtems
1
0
Fork 0
forked from Imagelibrary/rtems
Code Pull Requests Activity
Files
3869b5332fd1dec75139afeae29a3e94d6127bc0
rtems/make/README
Joel Sherrill 65a60cd427 Removed all references to HOST_ARCH including the file gcc.cfg.in. All 
host programs are now compiled with automake generated rules.  This was
done after discussions with Ralf Corsepius and Eric Norum.
1999-10-26 14:22:55 +00:00

490 lines
18 KiB
Plaintext
Raw Blame History

#
# $Id$
#
make/README
This file describes the layout and conventions of the make tree used in
the RTEMS software project and others.
All of these "make" trees are substantially similar; however this
file documents the current state of the rtems Makefile tree.
This make tree was developed originally to simplify porting projects
between various os's. The primary goals are:
. simple *and* customizable individual makefiles
. use widely available GNU make. There is no pre-processing or
automatic generation of Makefiles.
. Same makefiles work on *many* host os's due to portability
of GNU make and the host os config files.
. Support for different compilers and operating systems
on a per-user basis. Using the same sources (including
Makefiles) one developer can develop and test under SVR4,
another under 4.x, another under HPUX.
. Builtin support for compiling "variants" such as debug,
profile, and tcov versions. These variants can be built
recursively.
. Control of system dependencies. "hidden" dependencies on
environment variables (such as PATH)
have been removed whenever possible. No matter what your
PATH variable is set to, you should get the same thing
when you 'make' as everyone else on the project.
This description attempts to cover all aspects of the Makefile tree. Most
of what is described here is maintained automatically by the configuration
files.
The example makefiles in make/Templates should be used as a starting
point for new directories.
There are 2 main types of Makefile:
directory and leaf.
Directory Makefiles
-------------------
A Makefile in a source directory with sub-directories is called a
"directory" Makefile.
Directory Makefile's are simply responsible for acting as "middle-men"
and recursing into their sub-directories and propagating the make.
For example, directory src/bin will contain only a Makefile and
sub-directories. No actual source code will reside in the directory.
The following commands:
$ cd src/bin
$ make all
would descend into all the subdirectories of 'src/bin' and recursively
perform a 'make all'.
A 'make debug' will recurse thru sub-directories as a debug build.
A template directory Makefile which should work in almost all
cases is in make/Templates/Makefile.dir
Leaf Makefiles
--------------
Source directories that contain source code for libraries or
programs use a "leaf" Makefile.
These makefiles contain the rules necessary to build programs
(or libraries).
A template leaf Makefile is in Templates/Makefile.leaf . A template
leaf Makefile for building libraries is in Templates/Makefile.lib .
NOTE: To simplify nested makefile's and source maintenance, we disallow
combining source and directories (that make(1) would be expected to
recurse into) in one source directory. Ie., a directory in the source
tree may contain EITHER source files OR recursive sub directories, but NOT
both.
Variants (where objects go)
---------------------------
All binary targets are placed in a sub-directory whose name is (for
example):
o-pc386/ -- binaries (no debug, no profile)
o-pc386-debug/ -- debug binaries
o-pc386-profile/ -- profiling binaries
Using the template Makefiles, this will all happen automatically.
Within a Makefile, the ${ARCH} variable is set to o-pc386,
o-pc386-debug, etc., as appropriate.
Typing 'make' will place objects in o-pc386.
'make debug' will place objects in o-pc386-debug.
'make profile' will place objects in o-pc386-profile.
NOTE: For RTEMS work, the word 'pc386' is the specified
RTEMS_BSP (specified in the modules file)
The debug and profile targets are equivalent to 'all' except that
CFLAGS and/or LDFLAGS are modified as per the compiler config file for
debug and profile support.
The targets debug, profile, etc., can be
invoked recursively at the directory make level. So from the top of a
tree, one could install a debug version of everything under that point
by:
$ cd src/lib
$ gmake debug
$ gmake install
When building a command that is linked with a generated library, the
appropriate version of the library will be linked in.
For example, the following fragments link the normal, debug, or
profile version of "libmine.a" as appropriate:
LDLIBS += $(LIBMINE)
LIBMINE = ../libmine/${ARCH}/libmine.a
${ARCH}/pgm: $(LIBMINE) ${OBJS}
$(LINK.c) -o $@ ${OBJS} $(LDLIBS)
If we do 'gmake debug', then the library in
../libmine/sparc-debug/libmine.a will be linked in. If $(LIBMINE)
might not exist (or might be out of date) at this point, we could add
${LIBMINE}: FORCEIT
cd ../libmine; ${MAKE} ${VARIANT_VA}
The above would generate the following command to build libmine.a:
cd ../libmine; gmake debug
The macro reference ${VARIANT_VA} converts ${ARCH} to the word 'debug'
(in this example) and thus ensures the proper version of the library
is built.
Targets
-------
All Makefile's support the following targets:
all -- make "everything"
install -- install "everything"
The following targets are provided automatically by
the included config files:
clean -- delete all targets
clobber -- 'clean' plus delete sccs'd files
lint -- run lint or lint-like tool
get -- "sccs get" all sources
depend -- build a make dependency file
"variant targets" -- special variants, see below
All directory Makefiles automatically propagate all these targets. If
you don't wish to support 'all' or 'install' in your source directory,
you must leave the rules section empty, as the parent directory Makefile
will attempt it on recursive make's.
Configuration
-------------
All the real work described here happens in file(s) included
from your Makefile.
All Makefiles include a customization file which is used to select
compiler and host operating system. The environment variable
RTEMS_CUSTOM must point to this file; eg:
/.../make/custom/pc386.cfg
All leaf Makefile's also include either 'make/leaf.cfg' (or
'make/lib.cfg' for building libraries). These config files provide
default rules and set up the command macros as appropriate.
All directory Makefiles include 'make/directory.cfg'. directory.cfg
provides all the rules for recursing through sub directories.
The Makefile templates already perform these include's.
'make/leaf.cfg' (or directory.cfg) in turn includes:
a file specifying general purpose rules appropriate for
both leaf and directory makefiles.
( make/main.cfg )
personality modules specified by the customization file for:
compiler ( make/compilers/??.cfg )
private customization files
---------------------------
[ $(RTEMS_CUSTOM) ]
Your own private configuration file. Specifies which of the above
files you want to include.
generic rules file
------------------
[ make/main.cfg ]
included by leaf.cfg or directory.cfg.
This file contains some standard rules and variable assignments
that all Makefiles need.
It also includes the FORCEIT: pseudo target.
OS config file for host machine
-------------------------------
[ make/os/OS-NAME.cfg ]
included by main.cfg
Figures out the target architecture and specifies command names
for the OS tools including RCS/CVS (but NOT for the compiler tools).
Compiler configuration for the target
-------------------------------------
[ compilers/COMPILER-NAME.cfg ]
included by leaf.cfg
Specifies the names of tools for compiling programs.
Names in here should be fully qualified, and NOT depend on $PATH.
Also specifies compiler flags to be used to generate optimized,
debugging and profile versions, as well as rules to compile
assembly language and make makefile dependencies.
Configuration Variables
-----------------------
Variables you have to set in the environment or in your Makefile.
Note: the rtems module files set RTEMS_ROOT and RTEMS_CUSTOM
for you.
Environment Variables
---------------------
RTEMS_BSP -- name of your 'bsp' eg: pc386
RTEMS_ROOT -- The root of your source tree.
All other file names are derived from this.
[ eg: % setenv RTEMS_ROOT $HOME/work/rtems ]
RTEMS_CUSTOM -- name of your config files in make/custom
Example:
$(RTEMS_ROOT)/make/custom/$(RTEMS_BSP).cfg
RTEMS_GNUTOOLS -- root of the gcc tools for the target
The value RTEMS_ROOT is used in the custom
files to generate the make(1) variables:
PROJECT_ROOT
PROJECT_RELEASE
PROJECT_TOOLS
etc., which are used within the make config files themselves.
(The files in make/*.cfg try to avoid use of word RTEMS so
they can be more easily shared by other projects)
Preset variables
----------------
Aside from command names set by the os and compiler config files,
a number of MAKE variables are automatically set and maintained by
the config files.
PROJECT_RELEASE
-- release/install directory
[ $(PROJECT_ROOT) ]
PROJECT_BIN
-- directory for installed binaries
[ $(PROJECT_ROOT)/bin ]
PROJECT_TOOLS
-- directory for build environment commands
[ eg: $(PROJECT_ROOT)/build-tools ]
TARCH -- ${TARGET_ARCH}
[ eg: o-forc386 ]
obsolete and should not be referenced
ARCH -- target sub-directory for object code
[ eg: o-pc386 or o-pc386-debug ]
VARIANTS -- full list of all possible values for $(ARCH);
used mainly for 'make clean'
[ eg: "o-pc386 o-pc386-debug o-pc386-profile" ]
VARIANT_VA -- Variant name.
Normally "", but for 'make debug' it is "debug",
for 'make profile', "profile, etc.
see make/leaf.cfg for more info.
Preset compilation variables
----------------------------
This is a list of some of the compilation variables.
Refer to the compiler config files for the complete list.
CFLAGS_OPTIMIZE_V -- value of optimize flag for compiler
[ eg: -O ]
CFLAGS_DEBUG_V -- value of debug flag for compiler
[ eg: -g ]
CFLAGS_PROFILE_V -- compiler profile flags
[ eg: -pg ]
CFLAGS_DEBUG_OPTIMIZE_V
-- optimize flag if compiling for debug
[ eg: "" ]
CFLAGS_DEBUG
CFLAGS_PROFILE
CFLAGS_OPTIMIZE -- current values for each depending
on make variant.
LDFLAGS_STATIC_LIBRARIES_V
-- ld option for static libraries
-Bstatic or -dy (svr4)
LDFLAGS_SHARED_LIBRARIES_V
-- ld option for dynamic libraries
-Bdynamic or -dn (svr4)
LIB_SOCKET
-- ld(1) -l option(s) to provide
socket support.
LIB_MATH -- ld(1) -l option(s) to provide
math library.
Makefile Variables
------------------
The following variables may be set in a typical Makefile.
C_PIECES -- File names of your .c files without '.c' suffix.
[ eg: C_PIECES=main funcs stuff ]
CC_PIECES -- ditto, except for .cc files
S_PIECES -- ditto, except for .S files.
LIB -- target library name in leaf library makefiles.
[ eg: LIB=${ARCH}/libmine.a ]
H_FILES -- your .h files in this directory.
[ eg: H_FILES=stuff.h extra.h ]
DEFINES -- cc -D items. Included in CPPFLAGS.
leaf Makefiles.
[ eg: DEFINES += -DUNIX ]
CPPFLAGS -- -I include directories.
leaf Makefiles.
[ eg: CPPFLAGS += -I../include ]
YFLAGS -- Yacc flags.
leaf Makefiles.
[ eg: YFLAGS += -v ]
LD_PATHS -- arguments to -L for ld.
Will be prefixed with '-L' or '-L ' as appropriate
and included in LDFLAGS.
LDFLAGS -- -L arguments to ld; more may be ADDed.
LD_LIBS -- libraries to be linked in.
[ eg: LDLIBS += ../libfoo/${ARCH}/libfoo.a ]
XCFLAGS -- "extra" CFLAGS for special needs. Pre-pended
to CFLAGS.
Not set or used by Makefiles.
Can be set on command line to pass extra flags
to the compiler.
XCPPFLAGS -- ditto for CPPFLAGS
Can be set on command line to pass extra flags
to the preprocessor.
XCCPPFLAGS -- same as XCPPFLAGS for C++.
XCCFLAGS -- same as XCFLAGS for C++.
SUB_DIRS -- list of sub directories for make recursion.
directory Makefiles only.
[ eg: SUB_DIRS=cpu bsp ]
CLEAN_ADDITIONS
-- list of files or directories that should
be deleted by 'make clean'
[ eg: CLEAN_ADDITIONS += y.tab.c ]
See 'leaf.cfg' for the 'clean:' rule and its
default deletions.
CLOBBER_ADDITIONS
-- list of files or directories that should
be deleted by 'make clobber'
Since 'make clobber' includes 'make clean',
you don't need to duplicate items in both.
TARGET_ARCH -- target architecture (eg: o-pc386)
leaf makefiles only.
Should be specified before 'include leaf.cfg'.
Only needs to be specified if your target is
different from output of `arch`.
Command names
-------------
The following commands should only be called
as make variables:
MAKE,INSTALL,SHELL
ECHO,CAT,RM,CP,MV,LN,MKDIR,CHMOD
ED,SED
CC,CPP,AS,AR,LD,NM,SIZE,RANLIB,MKLIB,
YACC,LEX,LINT,CTAGS,ETAGS
Special Directory Makefile Targets
----------------------------------
all_WRAPUP
clean_WRAPUP
install_WRAPUP
clean_WRAPUP
clobber_WRAPUP
depend_WRAPUP
-- Specify additional commands for recursive
(directory level) targets.
This is handy in certain cases where you need
to do bit of work *after* a recursive make.
make/Templates
--------------
This directory contains Makefile and source file templates that
should help in creating or converting makefiles.
Makefile.leaf
Template leaf Makefiles.
Makefile.lib
Template leaf library Makefiles.
Makefile.dir
Template "directory" makefile.
View Git Blame Copy Permalink