The Header File Config System

The header file configurations system is used to fine-tune component options.

The following diagram shows how the system works.

Source files shall include config_tfm.h when necessary to fetch Component option settings. It is expected that all Component options are included in config_tfm.h to explicitly set values for each option.

The config_tfm.h includes base configuration config_base.h. Refer to Base Configuration for details of the base configurations.

The config_tfm.h includes a customized project config file provided via compile definition PROJECT_CONFIG_HEADER_FILE. Customized Component options in the project config file overrides those configured in config_base.h. The project config header file can be

Generated by the TF-M Kconfig system <kconfig_system>
One of the header files of Profiles <tf-m_profiles>, set via the TFM_PROFILE build option.
Manually customized profile based on pre-set profiles.

Users set CMake variable PROJECT_CONFIG_HEADER_FILE with the full path of the configuration header file.

A platform can adjust or place restriction on config options by providing a config_tfm_target.h under the root folder of their platforms. If the build system finds the file, it sets the TARGET_CONFIG_HEADER_FILE compile definition. Platform specific option settings in TARGET_CONFIG_HEADER_FILE overrides those configured in config_base.h.

#ifdef TARGET_CONFIG_HEADER_FILE
#include TARGET_CONFIG_HEADER_FILE
#endif

#ifdef PROJECT_CONFIG_HEADER_FILE
#include PROJECT_CONFIG_HEADER_FILE
#endif

#include "config_base.h"

Each component can implement a config_<comp_name>_check.h to validate component specific config dependencies. config_<comp_name>_check.h shall include config_tfm.h