configs and overlays

Important Build System Variables

• CONF_FILE: Indicates the name of one or more Kconfig configuration fragment files. Multiple filenames can be separated with either spaces or semicolons. Each file includes Kconfig configuration values that override the default configuration values.
• EXTRA_CONF_FILE: Additional Kconfig configuration fragment files. Multiple filenames can be separated with either spaces or semicolons. This can be useful in order to leave CONF_FILE at its default value, but “mix in” some additional configuration options.
  • EXTRA_CONF_FILE replaces OVERLAY_CONFIG
  • Example: -DEXTRA_CONF_FILE=overlay-bt_ll_sw_split.conf

• DTC_OVERLAY_FILE One or more devicetree overlay files to use. Multiple files can be separated with semicolons. See Set devicetree overlays for examples and Introduction to devicetree for information about devicetree and Zephyr.
• EXTRA_DTC_OVERLAY_FILE: Additional devicetree overlay files to use. Multiple files can be separated with semicolons. This can be useful to leave DTC_OVERLAY_FILE at its default value, but “mix in” some additional overlay files.

• OVERLAY_CONFIG
• EXTRA_ZEPHYR_MODULES replaces ZEPHYR_EXTRA_MODULES