1. Configuration

foxBMS 2 is an embedded system and some parts of the code are near to the hardware level. The code relies on a Hardware Abstraction Layer (HAL), which is a set of functions and definitions acting as an interface between the application and the underlying hardware. The HAL must be configured to fit the application and the hardware the software is running on (e.g., configure IO pins for communication with the outside world). This configuration is done through a software called HALCoGen. This is described in HALCoGen.

Another point is that foxBMS 2 is a development platform. As such, many parts of the code must be configured to fit the target application (e.g., which monitoring IC is used to monitor the battery cells). This is explained in BMS application.

1.1. HALCoGen

HALCoGen is a graphic user interface used to configure the HAL sources. It generates sources in form of .h and .c and .asm files. These HAL sources are generated based on the HALCoGen configuration files (*.hcg and *.dil). foxBMS 2 uses the waf tool Waf Tool HALCoGen to automatically run HALCoGen and create the required sources.


In some cases it might be beneficial to not generate the HAL during the build step and instead use a generated version of the HAL. For this use case see How to Use Generated Sources from HALCoGen.

HALCoGen ships with its own version of FreeRTOS and generates the corresponding sources when running the code generator. As foxBMS 2 uses its different own copy of FreeRTOS, the generated FreeRTOS files from HALCoGen are removed after the code generator has run.

HALCoGen creates the source file HL_sys_startup.c which implements (a weak implementation of) the function _c_int00 (the system’s startup routine). foxBMS 2 provides its own non-weak implementation of _c_int00 in fstartup.c. The foxBMS 2 implementation of _c_int00 must be coupled to the the current HALCoGen configuration. Most changes in the HALCoGen project do not alter the startup behavior and no further action needs to be taken into account. However there are settings that alter the startup behavior like e.g., enabling the cache (Setting: TMS570LC4357ZWT_FREERTOS, sub-setting R5-MPU-PMU and then the configuration Cortex-R5, sub-configuration General Configuration: Enable Cache). Such settings need to be ported to fstartup.c as this non-weak implementation of _c_int00 outweighs the generated, new version of _c_int00 in HL_sys_startup.c. Otherwise startup function used by foxBMS 2 would not reflect the HALCoGen configuration. The Waf Tool HALCoGen provides a mechanism to detected such changes. The hash of the current HL_sys_startup.c implementation is stored in src/hal/startup.hash and compared to the actual hash of the generated HL_sys_startup.c file. If these are not the same, the build aborts with the following message:

Listing 1.1 Error message on hash mismatch of HL_sys_startup.c
   C:\Users\vulpes\Documents\foxbms>waf build_bin
   Waf: Entering directory C:\Users\vulpes\Documents\foxbms\build\bin'
   [  2/824] Compiling hcg_compiler: conf\hcg\hcg.hcg conf\hcg\hcg.dil -> build\bin\src\hal\hcg.hcg build\bin\src\hal\hcg.dil build\bin\src\hal\hcg.log build\bin\src\hal\include\config_cpu_clock_hz.h build\bin\src\hal\include\HL_hal_stdtypes.h build\bin\src\hal\include\HL_sys_common.h build\bin\src\hal\include\HL_reg_system.h build\bin\src\hal\include\HL_reg_flash.h build\bin\src\hal\include\HL_reg_l2ramw.h build\bin\src\hal\include\HL_reg_vim.h build\bin\src\hal\include\HL_reg_pbist.h build\bin\src\hal\include\HL_reg_stc.h build\bin\src\hal\include\HL_reg_efc.h build\bin\src\hal\include\HL_reg_pcr.h build\bin\src\hal\include\HL_reg_pmm.h build\bin\src\hal\include\HL_reg_dma.h build\bin\src\hal\include\HL_reg_ccmr5.h build\bin\src\hal\include\HL_sys_core.h build\bin\src\hal\include\HL_system.h build\bin\src\hal\include\HL_sys_mpu.h build\bin\src\hal\include\HL_sys_pmu.h build\bin\src\hal\include\HL_sys_pcr.h build\bin\src\hal\include\HL_sys_pmm.h build\bin\src\hal\include\HL_sys_dma.h build\bin\src\hal\include\HL_reg_epc.h build\bin\src\hal\include\HL_reg_nmpu.h build\bin\src\hal\include\HL_reg_scm.h build\bin\src\hal\include\HL_reg_sdcmmr.h build\bin\src\hal\include\HL_epc.h build\bin\src\hal\include\HL_nmpu.h build\bin\src\hal\include\HL_errata.h build\bin\src\hal\include\HL_errata_SSWF021_45.h build\bin\src\hal\include\HL_errata_SSWF021_45_defs.h build\bin\src\hal\include\HL_sys_vim.h build\bin\src\hal\include\HL_reg_pinmux.h build\bin\src\hal\include\HL_pinmux.h build\bin\src\hal\include\HL_reg_gio.h build\bin\src\hal\include\HL_gio.h build\bin\src\hal\include\HL_reg_esm.h build\bin\src\hal\include\HL_esm.h build\bin\src\hal\include\HL_reg_sci.h build\bin\src\hal\include\HL_sci.h build\bin\src\hal\include\HL_reg_lin.h build\bin\src\hal\include\HL_lin.h build\bin\src\hal\include\HL_reg_mibspi.h build\bin\src\hal\include\HL_mibspi.h build\bin\src\hal\include\HL_reg_spi.h build\bin\src\hal\include\HL_spi.h build\bin\src\hal\include\HL_reg_can.h build\bin\src\hal\include\HL_can.h build\bin\src\hal\include\HL_reg_adc.h build\bin\src\hal\include\HL_adc.h build\bin\src\hal\include\std_nhet.h build\bin\src\hal\include\HL_reg_het.h build\bin\src\hal\include\HL_het.h build\bin\src\hal\include\HL_reg_htu.h build\bin\src\hal\include\HL_htu.h build\bin\src\hal\include\HL_reg_i2c.h build\bin\src\hal\include\HL_i2c.h build\bin\src\hal\include\HL_emac.h build\bin\src\hal\include\HL_hw_emac.h build\bin\src\hal\include\HL_hw_emac_ctrl.h build\bin\src\hal\include\HL_hw_mdio.h build\bin\src\hal\include\HL_hw_reg_access.h build\bin\src\hal\include\HL_mdio.h build\bin\src\hal\include\HL_phy_dp83640.h build\bin\src\hal\include\HL_phy_tlk111.h build\bin\src\hal\include\HL_emac_phyConfig.h build\bin\src\hal\include\HL_reg_dcc.h build\bin\src\hal\include\HL_dcc.h build\bin\src\hal\include\HL_reg_rtp.h build\bin\src\hal\include\HL_rtp.h build\bin\src\hal\include\HL_reg_dmm.h build\bin\src\hal\include\HL_dmm.h build\bin\src\hal\include\HL_reg_emif.h build\bin\src\hal\include\HL_emif.h build\bin\src\hal\include\HL_reg_pom.h build\bin\src\hal\include\HL_pom.h build\bin\src\hal\include\HL_reg_crc.h build\bin\src\hal\include\HL_crc.h build\bin\src\hal\include\HL_reg_etpwm.h build\bin\src\hal\include\HL_etpwm.h build\bin\src\hal\include\HL_reg_ecap.h build\bin\src\hal\include\HL_ecap.h build\bin\src\hal\include\HL_reg_eqep.h build\bin\src\hal\include\HL_eqep.h build\bin\src\hal\include\Device_TMS570LC43.h build\bin\src\hal\include\Device_header.h build\bin\src\hal\include\Device_types.h build\bin\src\hal\include\ti_fee_cfg.h build\bin\src\hal\include\MemMap.h build\bin\src\hal\include\ti_fee_types.h build\bin\src\hal\include\ti_fee.h build\bin\src\hal\include\fee_interface.h build\bin\src\hal\source\HL_sys_pcr.c build\bin\src\hal\source\HL_sys_pmm.c build\bin\src\hal\source\HL_sys_dma.c build\bin\src\hal\source\HL_system.c build\bin\src\hal\source\HL_sys_phantom.c build\bin\src\hal\source\HL_sys_startup.c build\bin\src\hal\source\HL_sys_vim.c build\bin\src\hal\source\HL_notification.c build\bin\src\hal\source\HL_epc.c build\bin\src\hal\source\HL_nmpu.c build\bin\src\hal\source\HL_errata.c build\bin\src\hal\source\HL_errata_SSWF021_45.c build\bin\src\hal\source\HL_sys_core.asm build\bin\src\hal\source\HL_sys_intvecs.asm build\bin\src\hal\source\HL_sys_mpu.asm build\bin\src\hal\source\HL_sys_pmu.asm build\bin\src\hal\source\HL_pinmux.c build\bin\src\hal\source\HL_gio.c build\bin\src\hal\source\HL_esm.c build\bin\src\hal\source\HL_sci.c build\bin\src\hal\source\HL_lin.c build\bin\src\hal\source\HL_spi.c build\bin\src\hal\source\HL_can.c build\bin\src\hal\source\HL_adc.c build\bin\src\hal\source\HL_het.c build\bin\src\hal\source\HL_i2c.c build\bin\src\hal\source\HL_emac.c build\bin\src\hal\source\HL_mdio.c build\bin\src\hal\source\HL_phy_dp83640.c build\bin\src\hal\source\HL_phy_tlk111.c build\bin\src\hal\source\HL_dcc.c build\bin\src\hal\source\HL_emif.c build\bin\src\hal\source\HL_pom.c build\bin\src\hal\source\HL_crc.c build\bin\src\hal\source\HL_etpwm.c build\bin\src\hal\source\HL_ecap.c build\bin\src\hal\source\HL_eqep.c build\bin\src\hal\source\Device_TMS570LC43.c build\bin\src\hal\source\ti_fee_cfg.c build\bin\src\hal\source\ti_fee_Info.c build\bin\src\hal\source\ti_fee_ini.c build\bin\src\hal\source\ti_fee_main.c build\bin\src\hal\source\ti_fee_read.c build\bin\src\hal\source\ti_fee_writeSync.c build\bin\src\hal\source\ti_fee_writeAsync.c build\bin\src\hal\source\ti_fee_util.c build\bin\src\hal\source\ti_fee_cancel.c build\bin\src\hal\source\ti_fee_format.c build\bin\src\hal\source\ti_fee_eraseimmediateblock.c build\bin\src\hal\source\ti_fee_invalidateblock.c build\bin\src\hal\source\ti_fee_shutdown.c build\bin\src\hal\source\Fapi_UserDefinedFunctions.c build\bin\src\hal\source\ti_fee_readSync.c build\bin\src\hal\source\HL_ajsm.asm
   Waf: Leaving directory C:\Users\vulpes\Documents\foxbms\build\bin'
   Build failed
   Traceback (most recent call last):
     File "C:\Users\vulpes\Documents\foxbms\tools\waf3-2.0.22-1241519b19b496207abef1f72bbf61c2\waflib\Task.py", line 180, in process
     File "C:\Users\vulpes\Documents\foxbms\tools\waf-tools\f_hcg.py", line 260, in run
       "The auto-generated file 'HL_sys_startup.c' has changed due to "
     File "C:\Users\vulpes\Documents\foxbms\tools\waf3-2.0.22-1241519b19b496207abef1f72bbf61c2\waflib\Context.py", line 261, in fatal
       raise self.errors.ConfigurationError(msg,ex=ex)
   waflib.Errors.ConfigurationError: The auto-generated file 'HL_sys_startup.c' has changed due to a configuration change in the HALCoGen project.
   The expected hash is b'e2e61496edd65f44d7cc811b504ad1f2' but the generated hash is b'1something-other'.
   Compare 'C:\Users\vulpes\Documents\foxbms\build\bin\src\hal\source\HL_sys_startup.c' with 'fstartup.c' and see if changes need to be applied to to 'fstartup.c'. If everything is changed as needed, updated the hash in 'C:\Users\vulpes\Documents\foxbms\src\hal\startup.hash' and build again.
   For more information see the documentation.

The build aborts as the expected hash is b'e2e61496edd65f44d7cc811b504ad1f2' while the actual hash is b'1something-other'. Next, the function _c_int00 in the two files (fstartup.c) and HL_sys_startup.c needs to be compared by the developer and the developer needs to update the _c_int00 implementation in the file fstartup.c to reflect the HALCoGen startup routine. The concluding step is to update the hash value in src/hal/startup.hash with 1something-other. Now the build toolchain knows, that the changes applied in the HALCoGen are reflected in the dependencies and the build will not abort after the HAL sources are generated.

The process is illustrated in figure Fig. 1.1.

HALCoGen configuration

Fig. 1.1 HALCoGen configuration change detection process

1.2. BMS application

The project provides two basic configuration options:

  • source options in conf/bms/bms.json

  • compiler options in conf/cc/cc-options.yaml (path is an option, see f_ti_arm_cgt.options()) and compiler remarks and remark severity level in conf/cc/remarks.txt

1.2.1. Source Options

Some BMS configurations require compiling different sources. That applies to the Operating System and the measurement IC.


Only very basic configurations can be changed via these options described here. Everything not mentioned here must still be configured by programming the application behavior in the sources. Operating System

The Operating System is configured in conf/bms/bms.json. The value for os must be the name of the source directory in src/os/ that includes the Operating System sources. Currently only FreeRTOS is supported (option: "os": "freertos"). Measurement IC

The measurement IC is configured in conf/bms/bms.json. The joint path from the values of manufacturer and chip must be the name of the source directory in src/app/driver/mic/<manufacturer>/<chip> that includes the driver implementation. A list of supported ICs is found in Section 4.26.

The build process behind this configuration is documented at Building the Measurement IC Library. Balancing Strategy

foxBMS 2 supports three different balancing strategies:

  • Voltage-based balancing: Cell balancing based on voltage differences (key-value: voltage). Details are found in Voltage-based Balancing

  • History-based balancing: Cell balancing based on voltage history (key-value: history). Details are found in History-based Balancing

  • No balancing: No balancing of any cell (key-value: none). Details are found in No Balancing

1.2.2. Compiler and Linker Options and Remarks

All options from conf/cc/cc-options.yaml are passed verbatim into the build process. Compiler options are set during configuration time, that means changing values in conf/cc/cc-options.yaml needs to be followed by waf configure.

See the TI compiler manual before changing the flags in conf/cc/cc-options.yaml.

The following subsections describe the options in conf/cc/cc-options.yaml. INCLUDE_PATHS

Additional INCLUDE_PATHS that are not standard compiler includes. Standard compiler includes are derived in the configure step of the compiler. LIBRARY_PATHS

Additional LIBRARY_PATHS that are not standard compiler library search paths. Standard compiler library search paths are derived in the configure step of the compiler. LIBRARIES

Libraries that are used when linking. CFLAGS

CFLAGS are configured differently or the BMS application, the Operating System and the Hardware Abstraction Layer.

  • common: options are applied to all sources (BMS, OS, HAL).

  • common_compile_only: options are applied to all sources (BMS, OS, HAL), but only for the compile step, not for the preprocessor build steps. The build tool automatically adds that the options --gen_cross_reference_listing, --gen_func_info_listing, --gen_preprocessor_listing. These options control the generation of the *.aux, *.crl and *.rl files.

  • foxbms: CFLAGS that should only be applied to the BMS application sources (src/app/*).

  • hal: CFLAGS that should only be applied to the generated hardware abstraction layer sources (src/hal/*).

  • operating_system: CFLAGS that should only be applied to the operating system sources (src/os/*). LINKFLAGS

Flags that are passed to the compiler when linking (Note: The compiler is used as linker when run with the argument --run_linker). Flags here do typically not needed to be changed except for --heap_size=0x800, --stack_size=0x800 or the optimization flag -oN where N is the level of optimization. HEXGENFLAGS

Flags passed to hex file generation tool armhex (Note: hex files are only generated when passing a node by keyword linker_script_hex in bld.tiprogram(..., linker_script_hex=some_node, ...)). NMFLAGS

Flags passed to hex file generation tool armnm. Flags here do typically not needed to be changed. Remarks

Compiler remarks help to find potential problems at an early stage of development. The file conf/cc/remarks.txt allows to list remarks and how they should be handled. Global remarks are set in conf/cc/remarks.txt. Remarks are re-loaded before compiling. Remarks can be added to a single build step as shown in Listing 1.2

Listing 1.2 Adding command-file that includes remarks to a single build step
def build(bld):


If remarks should be disabled, the option --issue_remarks needs to be removed in conf/cc/cc-options.yaml. Furthermore all command files that specify remarks need to be checked and all diagnosis related commands need to be removed or the severity level needs to be set to --diag_remark=... to avoid compile errors.

The default remark settings are relatively strict to avoid common mistakes. Changing them is generally not recommended.


It is possible to add all kinds of compiler flags in command files, this is not only related to remarks. Linker Output Processing


Linker output validation only works if --scan_libraries is specified.

The linker output is processed in order to validate that the correct symbols are linked into the binary.

If a symbol is defined in multiple places the linker decided which symbol to use. This is described in TI ARM assembly tools manual in section Exhaustively Read and Search Libraries.

Consider the following linker output in Listing 1.3.

Listing 1.3 Linker output
   Linking build\bin\src\app\main\foxbms.elf
   remark #10252-D: Symbol "_c_int00" (pulled from "src\app\main\fstartup.c.1.obj") defined in 3 places:

If the symbol _c_int00 should be pulled from src/app/main/fstartup.c.1.obj, the linking step should be treated as successful. If the symbol is pulled from somewhere else an error must be generated. To tell this to the linker output parser a json file that indicates which symbol should be pulled from where needs to be defined (see Listing 1.4). In this file use Unix-separator and specify the linked source as seen from the build directory.

Listing 1.4 Linker pulls file linker_pulls.json
    "_c_int00": "src/app/main/fstartup.c.1.obj"

This file needs to be specified when a program is built (see Listing 1.5). If the symbol _c_int00 would not be pulled from src/app/main/fstartup.c.1.obj an error would be generated.

Listing 1.5 Checking the linker output to use the correct symbols

def build(bld):
    """Build the binary"""
    source = [
        # list sources here
    includes = [
        # list include directories here
    linker_script = bld.path.find_node("linker_script.cmd")
    linker_pulls = bld.path.find_node("linker_pulls.json")

For implementation details see f_ti_arm_cgt.cprogram.parse_output().