7. Build Process

foxBMS uses waf The meta build system for building binaries for the foxBMS MCUs and the documentation.

For detailed information on waf see waf.io. A short introcution to waf is given at waf.io/apidocs/tutorial. The more detailed version of how to use waf is found at waf.io/book.

7.1. General

7.1.1. Where to find the toolchain?

The waf toolchain is located in directory foxbms\tools, and is `waf. This archive is automatically unpacked in a directory named something like waf-{{X}}-{{X}}-{{X}}-{{some-hash-value}} containing the waf library, where {{X}} is the waf version. It is unpacked into foxbms\tools. It is assumed that all commands are run from directory foxbms. Therefore waf has to be always called by python tools\waf some-command where some-command is an argument defined in the wscript.

Additional build tools are located in foxbms\tools\waftools. These are the tooles needed for building the documentation, i.e., doxygen and sphinx.

7.1.2. Where are the build steps described?

The build process is described in files named wscript, that can be found nearly everywhere inside the different directories inside the foxBMS project. Later in this documentation this is explained in detail.

7.1.3. General

waf needs always to be run form the top level of the repository and the path to waf must be given relative to that directory. This path is tools\waf.

Listing 7.1 How to call waf
cd path\to\foxbms
python tools\waf {{some command}}

7.1.4. What commands can be used?

To get an overview of support commands run --help on the waf library:

Listing 7.2 How to call help on waf
python tools\waf --help
Listing 7.3 Waf help in foxBMS
waf [commands] [options]

Main commands (example: ./waf build -j4)
  build            : executes the build
  build_all        : builds all parts of the project (binaries and documentation)
  build_libs       : executes the build of libs
  build_primary    : executes the build of primary
  build_secondary  : executes the build of secondary
  clean            : cleans the project
  clean_all        : cleans all parts of the project
  clean_libs       : cleans the project libs
  clean_primary    : cleans the project primary
  clean_secondary  : cleans the project secondary
  configure        : configures the project
  cpplint          : configures cpplint
  dist             : creates an archive containing the project source code
  distcheck        : creates tar.bz form the source directory and tries to run a build
  distclean        : removes build folders and data
  doxygen          : creates doxygen documentation
  doxygen_libs     : creates the doxygen documentation of libs
  doxygen_primary  : creates the doxygen documentation of primary
  doxygen_secondary: creates the doxygen documentation of secondary
  flake8           : runs flake8 on the foxBMS repository
  list             : lists the targets to execute
  list_libs        : lists the targets to execute for libs
  list_primary     : lists the targets to execute for primary
  list_secondary   : lists the targets to execute for secondary
  sphinx           : creates the sphinx documentation of the project
  step             : executes tasks in a step-by-step fashion, for debugging
  step_libs        : executes tasks in a step-by-step fashion, for debugging of libs
  step_primary     : executes tasks in a step-by-step fashion, for debugging of primary
  step_secondary   : executes tasks in a step-by-step fashion, for debugging of secondary

Options:
  --version             show program's version number and exit
  -c COLORS, --color=COLORS
                        whether to use colors (yes/no/auto) [default: auto]
  -j JOBS, --jobs=JOBS  amount of parallel jobs (8)
  -v, --verbose         verbosity level -v -vv or -vvv [default: 0]
  -h, --help            show this help message and exit
  -t TARGET, --target=TARGET
                        build target: debug (default)/release
  -l LIBS, --libs=LIBS  name of the library to be used

  Configuration options:

  Build and installation options:
    -p, --progress      -p: progress bar; -pp: ide output

  Step options:
    --files=FILES       files to process, by regexp, e.g. "*/main.c,*/test/main.o"

  Installation and uninstallation options:
    --distcheck-args=ARGS
                        arguments to pass to distcheck

Before building any binaries or documentation is possible, the project needs to be configured. A successfull configure command and its ouput is shown below:

Listing 7.4 Configuration of a the project
python tools\waf configure
(...)
'configure' finished successfully (0.340s)

After the project has been configured, a build can be triggered and it is generally exectued by the build command, but as foxBMS requries building variants, one has to use e.g., build_primary in order to build binaries for the primary MCU.

Listing 7.5 Example of a wrong and a correct build command.
python tools\waf build
Waf: Entering directory `.\foxbms\build'
A build variant must be specified, run 'python tools\waf --help'
python tools\waf build_primary
(...)
'build_primary' finished successfully (8.800s)

The possible build commands, the definition of the and corresponding targets and the targets itself is listet below:

  • Primary MCU
    Listing 7.6 Build primary binaries
    python tools\waf build_primary

    The targets are defined at:

    • foxbms\embedded-software\mcu-primary\src\application\wscript
    • foxbms\embedded-software\mcu-common\src\engine\wscript
    • foxbms\embedded-software\mcu-common\src\module\wscript
    • foxbms\embedded-software\mcu-primary\src\engine\wscript
    • foxbms\embedded-software\mcu-primary\src\module\wscript
    • foxbms\embedded-software\mcu-freertos\wscript
    • foxbms\embedded-software\mcu-hal\STM32F4xx_HAL_Driver\wscript
    • foxbms\embedded-software\mcu-primary\src\general\wscript
    Listing 7.7 Primary targets
    foxbms-application
foxbms-common-driver
foxbms-common-engine
foxbms-common-module
foxbms-common-util
foxbms-driver
foxbms-engine
foxbms-module
foxbms-os
foxbms-stmhal
foxbms_primary.elf
'list_primary' finished successfully (0.052s)
  • Secondary MCU
    Listing 7.8 Build secondary binaries
    python tools\waf build_secondary

    The targets are defined at:

    • foxbms\embedded-software\mcu-secondary\src\application\wscript
    • foxbms\embedded-software\mcu-common\src\engine\wscript
    • foxbms\embedded-software\mcu-common\src\module\wscript
    • foxbms\embedded-software\mcu-secondary\src\engine\wscript
    • foxbms\embedded-software\mcu-secondary\src\module\wscript
    • foxbms\embedded-software\mcu-freertos\wscript
    • foxbms\embedded-software\mcu-hal\STM32F4xx_HAL_Driver\wscript
    • foxbms\embedded-software\mcu-secondary\src\general\wscript
    Listing 7.9 Secondary targets
    foxbms-application
foxbms-common-driver
foxbms-common-engine
foxbms-common-module
foxbms-common-util
foxbms-engine
foxbms-os
foxbms-stmhal
foxbms_secondary.elf
'list_secondary' finished successfully (0.100s)
  • General documentation

    The general documenation is build by

    Listing 7.10 Build the general foxBMS documentation
    python tools\waf sphinx
  • API documentation

    The API documentation is build using the doxygen_{{variant}}, therefore

    Listing 7.11 Build the general foxBMS documentation
    python tools\waf doxygen_primary
python tools\waf doxygen_secondary
  • Cleaning

    It is also possible to clean the binaries and Doxygen documentation. This step is performed by the clean command.

    As seen from --help the possible clean commands are

    • clean_primary
    • clean_secondary
    • distclean

    Cleaning the general sphinx documentation alone is currently not supported. However it is possible to make a complete clean by distclean. After distclean the entire build direcory and all lock files etc. are deleted and the project needs to be configured again.

7.2. Targets

As stated above thetargets and subtargets of the build process are shown by list_x where x is the specified target. The main target is the *.elf file. However some targets are build afterwards. After successfully linking the map file is generated.

These logging files are found in build and build\{{target}}. Addiotional to the *.elf file a *.hex of the binary is generated.

The *.hex is needed, as it is used to calculate the checksum of the binary. Afterwards the calculted checksum is written back into the *.elf and *.hex files. Based on this binary the flash and flashheader are generated by gcc’s objcopy. The implementation of this can be found in

  • foxbms\tools\chksum\*: All files in are neeed
  • foxbms\wscript: See implementation of def add_chksum_task(self) and class chksum(Task.Task).

In a post build step the size is run on all binaries and generates a logfile.

7.3. Build Process

Note

For testing the following explanations it is assumed that python tools\waf configure has been run.

This sections gives an overview how the build process is defined. All features are generally defined in the top wscript located at foxbms\wscript.

The minimum of functions that need to be defined to build are in waf

  • configure and
  • build.

As the toolchain needs more targets the following functions need to be implemented: options, size, dist, doxygen, sphinx. Furthermore functions and classes for calculataing the checksum (chksum, add_chksum_task), stripping debug symbols in release mode (strip, add_strip_task), creating a hex file from the elf file (hexgen, add_hexgen_task), generating bin files from elf files (binflashheadergen, binflashgen, add_bingen_task) and compiling assembler files (Sasm, asm_hook).

For implemenation details see the wscript itself.

Some of these functionalities require scripts from foxbms\tools.

Overview of the build process

7.3.1. General Documentation

This build target uses the function def sphinx(bld). Since this definition of a function called sphinx, it is accepted as command to waf.

This general documentation is generated by running

Listing 7.12 Generate general foxBMS documentation
python tools\waf sphinx

The implementation details of the sphinx command can be found in foxbms\tools\waftools\sphinx_build.py.

7.3.2. Primary and Secondary Binaries and Doxygen Documentation

In order to have different build variants, these variants have to be defined. This is done at the top of the main wscript at foxbms\wscript. The variants have to be defined for the binary build and Doxygen documentation.

Listing 7.13 Implementation of the variant build
from waflib.Build import BuildContext, CleanContext, InstallContext, \
    UninstallContext, ListContext, StepContext
for x in variants:
    for y in (
        BuildContext,
        CleanContext,
        InstallContext,
        UninstallContext,
        ListContext,
        StepContext
        ):
        name = y.__name__.replace('Context','').lower()
        class tmp(y):
            if name == 'build':
                __doc__ = '''executes the {} of {}'''.format(name, x)
            elif name == 'clean':
                __doc__ = '''cleans the project {}'''.format(x)
            elif name == 'install' or name == 'uninstall':
                __doc__ = '''CURRENTLY NOT SUPPORTED:{}s the project {}'''.format(name, x)
            elif name == 'list':
                __doc__ = '''lists the targets to execute for {}'''.format(x)
            elif name == 'step':
                __doc__ = '''executes tasks in a step-by-step fashion, for \
debugging of {}'''.format(x)
            cmd = name + '_' + x
            variant = x

    dox = 'doxygen'
    class tmp(BuildContext):
        __doc__ = '''creates the {} documentation of {}'''.format(dox, x)
        cmd = dox + '_' + x
        fun = dox
        variant = x

In the function build and doxygen the build variant is checked, the the correct sources are selected. If no build variant is specified, an error message is displayed, telling to specify a variant. This is generally implemented something like this:

Listing 7.14 Implementation to ensure a variant build
def build(bld):
    import sys
    import logging
    from waflib import Logs
    if not bld.variant:
        bld.fatal('A {} variant must be specified, run \'{} {} --help\'\
'.format(bld.cmd, sys.executable, sys.argv[0]))

    bld.env.__sw_dir = os.path.normpath('embedded-software')

    src_dir = os.path.normpath('mcu-{}'.format(bld.variant))
    ldscript = os.path.join(bld.env.__sw_dir, src_dir, 'src', bld.env.ldscript_filename)

For doxygen it is implemented very similar:

Listing 7.15 Implementation to ensure a variant doxgen API documentation
def doxygen(bld):
    import sys
    import logging
    from waflib import Logs

    if not bld.variant:
        bld.fatal('A build variant must be specified, run \'{} {} --help\'\
'.format(sys.executable, sys.argv[0]))

    if not bld.env.DOXYGEN:
        bld.fatal('Doxygen was not configured. Run \'{} {} --help\'\
'.format(sys.executable, sys.argv[0]))

    _docbuilddir = os.path.normpath(bld.bldnode.abspath())
    doxygen_conf_dir = os.path.join('documentation', 'doxygen')
    os.makedirs(_docbuilddir, exist_ok=True)
    conf_file = 'doxygen-{}.conf'.format(bld.variant)
    doxygenconf = os.path.join(doxygen_conf_dir, conf_file)

7.4. wscripts

As mentioned above, the build process is described in wscripts, which are itself valid python scripts. The top is foxbms\wscript which defines the functions needed for the build, e.g., configure, build etc.

From the top wscript the other wscript s are called recursive by bld.recurse(..).

To get a detailed view on the single build steps, see these files.

7.5. Building and Linking with a Library

The toolchain enables to build a library and then links against the library. it is possible to build and link multiple libraries to the binaries.

The wscript in embedded-software\libs lists the libraries to be build. Libraries that should be build have to be listed here. Based on the example library testlib it is shown how to include a library in foxBMS.

Note

Infact the libs directory contains two test libraries (foxbms-user-lib and my-foxbms-library) in order to show how multiple libraries can be used. The first example shows how to build one single library and in the second example it is shown, how to build and use more than one library.

General Setup

The wscript in embedded-software\libs lists in the function bld.recurse(...) the directories containg the sources for the to be build library (see line 11 in Listing 7.16).

Listing 7.16 The wscript in embedded-software\libs
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11
def build(bld):
    header_files_src = bld.path.ant_glob('**/*.h')
    header_filenames = [n.name for n in header_files_src]
    if not len(header_filenames) == len(set(header_filenames)):
        duplicates = list(set([x for x in header_filenames
                          if header_filenames.count(x) > 1]))
        err_msg = 'There are headers with the same file name recursively ' \
                  ' inside directory \'{}\':\n' \
                  '{}'.format(bld.path.abspath(), '\n'.join(duplicates))
        bld.fatal(err_msg)
    bld.recurse('testlib myfoxbmslibrary')

Note

For every additional library that should be build, the directory containing the library must be added to this line, e.g., if the library sources are in a directory called advancedalgorithms this lines needs to look like this:

Listing 7.17 Adding the library source directory advancedalgorithms
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2
def build(bld):
    bld.recurse('testlib myfoxbmslibrary advancedalgorithms')

The actual build of the library is defined in the wscript in embedded-software\libs\testlib. All source and header files have to be in the library directory, for this example these are are testlib.c and testlib.h. The library is then build by the wscript in embedded-software\libs\testlib.

Listing 7.18 explained in detail:

  • All source files that should be build have to be listed in the srcs list (see line 5-6.).

  • The name of the library is set to foxbms-user-lib (see line 11).

    Note

    For later on further expanding the advanced-algorithms example, the library name my-advanced-algorithm is assumed.

  • All header files get copied to the output directory (see line 14-17).

Listing 7.18 wscript
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def build(bld):
    header_files_src = bld.path.ant_glob('*.h')
    header_files_tar = [os.path.join(bld.env.INCLUDE_DIR_LIBS,
                        x.path_from(bld.path)) for x in header_files_src]
    srcs = ' '.join([
        os.path.join('testlib.c')])

    includes = os.path.join(bld.bldnode.abspath()) + ' '
    includes += ' '.join(['.'])

    bld.stlib(target=os.path.join(bld.env.BUILD_DIR_LIBS, 'foxbms-user-lib'),
              source=srcs,
              includes=includes)
    bld(features='subst',
        source=header_files_src,
        target=header_files_tar,
        is_copy=True)
  • The object files (*.o) are found in build\libs\embedded-software\*.
  • The library outputs (the *.a-files) are stored in build\lib\*.a. When building the default dummy libraries these are build\lib\libfoxbms-user-lib.a and build\lib\libmy-foxbms-library.a. The lib-prefix is generated automatically.
  • The headers are copied to build\include.

Warning

The header names for all library headers are checked for uniqueness. Header files with the same name recursively inside the libs directory will lead to a build error. This check needs to be performed, as all headers get copied to include directory at build\include.

The library

The library declaration of super_function(uint8_t a, uint8_t b) is in testlib.h:

Listing 7.19 testlib.h
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#ifndef TESTLIB_H_
#define TESTLIB_H_

/*================== Includes =============================================*/
#include <stdint.h>

/*================== Macros and Definitions ===============================*/

/*================== Constant and Variable Definitions ====================*/
extern uint8_t super_variable;

/*================== Function Prototypes ==================================*/
extern uint16_t super_function(uint8_t a, uint8_t b);

/*================== Function Implementations =============================*/

#endif /* TESTLIB_H_ */

The library defines a function super_function(uint8_t a, uint8_t b) in testlib.c:

Listing 7.20 testlib.c
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uint16_t super_function(uint8_t a, uint8_t b) {
    return a + b;
}

Building

  1. Configure the foxBMS project to work with a library, in the frist example it is the foxbms-user-lib library.

    Listing 7.21 Configuration with library useage
    python tools\waf configure --libs=foxbms-user-lib

Note

For including the hypothetical my-advanced-algorithm library the command would be:

python tools\waf configure --libs=my-advanced-algorithm

  1. Build the library (or libraries):

    Listing 7.22 Build the libraries
    python tools\waf build_libs

  2. Include the headers needed for the functions in the sources and use the functions as needed.

    Listing 7.23 Include header and use a function from the library
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    /*================== Includes =============================================*/
/* some other includes  */
#include "testlib.h"

/*================== Function Prototypes ==================================*/

/*================== Function Implementations =============================*/
int main(void) {
    uint16_t a = 0;
    /* Use the function super_function from the library */
    a = super_function(2,2);
    /* other code */
}

  3. Build the foxBMS binary as usual.

    Listing 7.24 Build the foxBMS binary
    python tools\waf build_primary

Building with Multiple Libraries

A project may want to use multiple libraries. For this example the two provided dummy libraries are assumed (foxbms-user-lib and my-foxbms-library).

  1. The project is configured to work with both libraries. The library names are given as command line argument separated by comma (no addtional whitespace).

    Listing 7.25 Configuration with multiple library useage
    python tools\waf configure --libs=foxbms-user-lib,my-foxbms-library

  2. Build the library (or libraries):

    Listing 7.26 Build the libraries
    python tools\waf build_libs

  3. Include the headers needed for the functions in the sources and use the functions as needed.

    Listing 7.27 Include header and use a function from the library
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    /*================== Includes =============================================*/
/* some other includes  */
#include "testlib.h"
#include "myfoxbmsalgorithms.h"

/*================== Function Prototypes ==================================*/

/*================== Function Implementations =============================*/
int main(void) {
    uint16_t a = 0;
    /* Use the function super_function from the library foxbms-user-lib */
    a = super_function(2,2);
    uint16_t b = 0;
    /* Use the function another_super_function from the library my-foxbms-library */
    a = another_super_function(2,2);
    /* other code */
}

  4. Build the foxBMS binary as usual.

    Listing 7.28 Build the foxBMS binary
    python tools\waf build_primary