# General configuration options # Copyright (c) 2014-2015 Wind River Systems, Inc. # Copyright (c) 2016 Intel Corporation # SPDX-License-Identifier: Apache-2.0 # Include Kconfig.defconfig files first so that they can override defaults and # other symbol/choice properties by adding extra symbol/choice definitions. # After merging all definitions for a symbol/choice, Kconfig picks the first # property (e.g. the first default) with a satisfied condition. # # Shield defaults should have precedence over board defaults, which should have # precedence over SoC defaults, so include them in that order. # # $ARCH and $BOARD_DIR will be glob patterns when building documentation. # This loads custom shields defconfigs (from BOARD_ROOT) osource "$(KCONFIG_BINARY_DIR)/Kconfig.shield.defconfig" # This loads Zephyr base shield defconfigs source "boards/shields/*/Kconfig.defconfig" source "$(BOARD_DIR)/Kconfig.defconfig" # This loads custom SoC root defconfigs osource "$(KCONFIG_BINARY_DIR)/Kconfig.soc.defconfig" # This loads Zephyr base SoC root defconfigs osource "soc/$(ARCH)/*/Kconfig.defconfig" # This loads the toolchain defconfigs osource "$(TOOLCHAIN_KCONFIG_DIR)/Kconfig.defconfig" # This loads the testsuite defconfig source "subsys/testsuite/Kconfig.defconfig" # This should be early since the autogen Kconfig.dts symbols may get # used by modules source "dts/Kconfig" menu "Modules" source "modules/Kconfig" endmenu source "boards/Kconfig" source "soc/Kconfig" source "arch/Kconfig" source "kernel/Kconfig" source "drivers/Kconfig" source "lib/Kconfig" source "subsys/Kconfig" osource "$(TOOLCHAIN_KCONFIG_DIR)/Kconfig" menu "Build and Link Features" menu "Linker Options" choice prompt "Linker Orphan Section Handling" default LINKER_ORPHAN_SECTION_WARN config LINKER_ORPHAN_SECTION_PLACE bool "Place" help Linker puts orphan sections in place without warnings or errors. config LINKER_ORPHAN_SECTION_WARN bool "Warn" help Linker places the orphan sections in output and issues warning about those sections. config LINKER_ORPHAN_SECTION_ERROR bool "Error" help Linker exits with error when an orphan section is found. endchoice config HAS_FLASH_LOAD_OFFSET bool help This option is selected by targets having a FLASH_LOAD_OFFSET and FLASH_LOAD_SIZE. if HAS_FLASH_LOAD_OFFSET config USE_DT_CODE_PARTITION bool "Link application into /chosen/zephyr,code-partition from devicetree" help When enabled, the application will be linked into the flash partition selected by the zephyr,code-partition property in /chosen in devicetree. When this is disabled, the flash load offset and size can be set manually below. # Workaround for not being able to have commas in macro arguments DT_CHOSEN_Z_CODE_PARTITION := zephyr,code-partition config FLASH_LOAD_OFFSET # Only user-configurable when USE_DT_CODE_PARTITION is disabled hex "Kernel load offset" if !USE_DT_CODE_PARTITION default $(dt_chosen_reg_addr_hex,$(DT_CHOSEN_Z_CODE_PARTITION)) if USE_DT_CODE_PARTITION default 0 help This option specifies the byte offset from the beginning of flash that the kernel should be loaded into. Changing this value from zero will affect the Zephyr image's link, and will decrease the total amount of flash available for use by application code. If unsure, leave at the default value 0. config FLASH_LOAD_SIZE # Only user-configurable when USE_DT_CODE_PARTITION is disabled hex "Kernel load size" if !USE_DT_CODE_PARTITION default $(dt_chosen_reg_size_hex,$(DT_CHOSEN_Z_CODE_PARTITION)) if USE_DT_CODE_PARTITION default 0 help If non-zero, this option specifies the size, in bytes, of the flash area that the Zephyr image will be allowed to occupy. If zero, the image will be able to occupy from the FLASH_LOAD_OFFSET to the end of the device. If unsure, leave at the default value 0. endif # HAS_FLASH_LOAD_OFFSET config ROM_START_OFFSET hex prompt "ROM start offset" if !BOOTLOADER_MCUBOOT default 0x200 if BOOTLOADER_MCUBOOT default 0 help If the application is built for chain-loading by a bootloader this variable is required to be set to value that leaves sufficient space between the beginning of the image and the start of the first section to store an image header or any other metadata. In the particular case of the MCUboot bootloader this reserves enough space to store the image header, which should also meet vector table alignment requirements on most ARM targets, although some targets may require smaller or larger values. config LD_LINKER_SCRIPT_SUPPORTED bool default y choice LINKER_SCRIPT prompt "Linker script" default LD_LINKER_TEMPLATE if LD_LINKER_SCRIPT_SUPPORTED config LD_LINKER_TEMPLATE bool "LD template" depends on LD_LINKER_SCRIPT_SUPPORTED help Select this option to use the LD linker script templates. The templates are pre-processed by the C pre-processor to create the final LD linker script. config CMAKE_LINKER_GENERATOR bool "CMake generator" depends on ARM help Select this option to use the Zephyr CMake linker script generator. The linker configuration is written in CMake and the final linker script will be generated by the toolchain specific linker generator. For LD based linkers, this will be the ld generator, for ARMClang / armlink based linkers it will be the scatter generator. endchoice config LLVM_USE_LD bool "LLVM use ld linker" depends on "${ZEPHYR_TOOLCHAIN_VARIANT}" = "llvm" default y help Use binutils ld linker instead of LLVM built-in lld linker. config HAVE_CUSTOM_LINKER_SCRIPT bool "Custom linker script provided" help Set this option if you have a custom linker script which needed to be define in CUSTOM_LINKER_SCRIPT. config CUSTOM_LINKER_SCRIPT string "Path to custom linker script" depends on HAVE_CUSTOM_LINKER_SCRIPT help Path to the linker script to be used instead of the one define by the board. The linker script must be based on a version provided by Zephyr since the kernel can expect a certain layout/certain regions. This is useful when an application needs to add sections into the linker script and avoid having to change the script provided by Zephyr. config KERNEL_ENTRY string "Kernel entry symbol" default "__start" help Code entry symbol, to be set at linking phase. config LINKER_SORT_BY_ALIGNMENT bool "Sort input sections by alignment" default y help This turns on the linker flag to sort sections by alignment in decreasing size of symbols. This helps to minimize padding between symbols. config SRAM_VECTOR_TABLE bool "Place the vector table in SRAM instead of flash" help The option specifies that the vector table should be placed at the start of SRAM instead of the start of flash. config HAS_SRAM_OFFSET bool help This option is selected by targets that require SRAM_OFFSET. config SRAM_OFFSET hex "Kernel SRAM offset" if HAS_SRAM_OFFSET default 0 help This option specifies the byte offset from the beginning of SRAM where the kernel begins. Changing this value from zero will affect the Zephyr image's link, and will decrease the total amount of SRAM available for use by application code. If unsure, leave at the default value 0. menu "Linker Sections" config LINKER_USE_BOOT_SECTION bool "Use Boot Linker Section" help If enabled, the symbols which are needed for the boot process will be put into another linker section reserved for these symbols. Requires that boot sections exist in the architecture, SoC, board or custom linker script. config LINKER_USE_PINNED_SECTION bool "Use Pinned Linker Section" help If enabled, the symbols which need to be pinned in memory will be put into another linker section reserved for pinned symbols. During boot, the corresponding memory will be marked as pinned. Requires that pinned sections exist in the architecture, SoC, board or custom linker script. config LINKER_GENERIC_SECTIONS_PRESENT_AT_BOOT bool "Generic sections are present at boot" if DEMAND_PAGING && LINKER_USE_PINNED_SECTION default y help When disabled, the linker sections other than the boot and pinned sections will be marked as not present in the page tables. This allows kernel to pull in data pages on demand as required by current execution context when demand paging is enabled. There is no need to load all code and data into memory at once. If unsure, say Y. config LINKER_LAST_SECTION_ID bool "Last section identifier" default y depends on ARM || ARM64 || RISCV help If enabled, the last section will contain an identifier. This ensures that the '_flash_used' linker symbol will always be correctly calculated, even in cases where the location counter may have been incremented for alignment purposes but no data is placed after alignment. Note: in cases where the flash is fully used, for example application specific data is written at the end of the flash area, then writing a last section identifier may cause rom region overflow. In such cases this setting should be disabled. config LINKER_LAST_SECTION_ID_PATTERN hex "Last section identifier pattern" default "0xE015E015" depends on LINKER_LAST_SECTION_ID help Pattern to fill into last section as identifier. Default pattern is 0xE015 (end of last section), but any pattern can be used. The size of the pattern must not exceed 4 bytes. endmenu # "Linker Sections" endmenu menu "Compiler Options" config CODING_GUIDELINE_CHECK bool "Enforce coding guideline rules" help Use available compiler flags to check coding guideline rules during the build. config NATIVE_APPLICATION bool "Build as a native host application" help Build as a native application that can run on the host and using resources and libraries provided by the host. choice COMPILER_OPTIMIZATIONS prompt "Optimization level" default NO_OPTIMIZATIONS if COVERAGE default DEBUG_OPTIMIZATIONS if DEBUG default SIZE_OPTIMIZATIONS help Note that these flags shall only control the compiler optimization level, and that no extra debug code shall be conditionally compiled based on them. config SIZE_OPTIMIZATIONS bool "Optimize for size" help Compiler optimizations will be set to -Os independently of other options. config SPEED_OPTIMIZATIONS bool "Optimize for speed" help Compiler optimizations will be set to -O2 independently of other options. config DEBUG_OPTIMIZATIONS bool "Optimize debugging experience" help Compiler optimizations will be set to -Og independently of other options. config NO_OPTIMIZATIONS bool "Optimize nothing" help Compiler optimizations will be set to -O0 independently of other options. endchoice config COMPILER_COLOR_DIAGNOSTICS bool "Colored diagnostics" default y help Compiler diagnostic messages are colorized. config COMPILER_OPT string "Custom compiler options" help This option is a free-form string that is passed to the compiler when building all parts of a project (i.e. kernel). The compiler options specified by this string supplement the predefined set of compiler supplied by the build system, and can be used to change compiler optimization, warning and error messages, and so on. config MISRA_SANE bool "MISRA standards compliance features" help Causes the source code to build in "MISRA" mode, which disallows some otherwise-permitted features of the C standard for safety reasons. Specifically variable length arrays are not permitted (and gcc will enforce this). endmenu choice prompt "Error checking behavior for CHECK macro" default RUNTIME_ERROR_CHECKS config ASSERT_ON_ERRORS bool "Assert on all errors" help Assert on errors covered with the CHECK macro. config NO_RUNTIME_CHECKS bool "No runtime error checks" help Do not do any runtime checks or asserts when using the CHECK macro. config RUNTIME_ERROR_CHECKS bool "Runtime error checks" help Always perform runtime checks covered with the CHECK macro. This option is the default and the only option used during testing. endchoice menu "Build Options" config KERNEL_BIN_NAME string "The kernel binary name" default "zephyr" help This option sets the name of the generated kernel binary. config OUTPUT_STAT bool "Create a statistics file" default y help Create a stat file using readelf -e config OUTPUT_SYMBOLS bool "Create a symbol file" help Create a symbol file using nm config OUTPUT_DISASSEMBLY bool "Create a disassembly file" default y help Create an .lst file with the assembly listing of the firmware. config OUTPUT_DISASSEMBLE_ALL bool "Disassemble all sections with source. Fill zeros." default n depends on OUTPUT_DISASSEMBLY help The .lst file will contain complete disassembly of the firmware not just those expected to contain instructions including zeros config OUTPUT_PRINT_MEMORY_USAGE bool "Print memory usage to stdout" default y help If the toolchain supports it, this option will pass --print-memory-region to the linker when it is doing it's first linker pass. Note that the memory regions are symbolic concepts defined by the linker scripts and do not necessarily map directly to the real physical address space. Take also note that some platforms do two passes of the linker so the results do not match exactly to the final elf file. See also rom_report, ram_report and https://sourceware.org/binutils/docs/ld/MEMORY.html config CLEANUP_INTERMEDIATE_FILES bool "Remove all intermediate files" help Delete intermediate files to save space and cleanup clutter resulting from the build process. config BUILD_NO_GAP_FILL bool "Don't fill gaps in generated hex/bin/s19 files." config BUILD_OUTPUT_HEX bool "Build a binary in HEX format" help Build an Intel HEX binary zephyr/zephyr.hex in the build directory. The name of this file can be customized with CONFIG_KERNEL_BIN_NAME. config BUILD_OUTPUT_BIN bool "Build a binary in BIN format" default y help Build a "raw" binary zephyr/zephyr.bin in the build directory. The name of this file can be customized with CONFIG_KERNEL_BIN_NAME. config BUILD_OUTPUT_EFI bool "Build as an EFI application" default n depends on X86_64 help Build as an EFI application. This works by creating a "zephyr.efi" EFI binary containing a zephyr image extracted from a built zephyr.elf file. EFI applications are relocatable, and cannot be placed at specific locations in memory. Instead, the stub code will copy the embedded zephyr sections to the appropriate locations at startup, clear any zero-filled (BSS, etc...) areas, then jump into the 64 bit entry point. config BUILD_OUTPUT_EXE bool "Build a binary in ELF format with .exe extension" help Build an ELF binary that can run in the host system at zephyr/zephyr.exe in the build directory. The name of this file can be customized with CONFIG_KERNEL_BIN_NAME. config BUILD_OUTPUT_S19 bool "Build a binary in S19 format" help Build an S19 binary zephyr/zephyr.s19 in the build directory. The name of this file can be customized with CONFIG_KERNEL_BIN_NAME. config BUILD_OUTPUT_UF2 bool "Build a binary in UF2 format" depends on BUILD_OUTPUT_BIN help Build a UF2 binary zephyr/zephyr.uf2 in the build directory. The name of this file can be customized with CONFIG_KERNEL_BIN_NAME. if BUILD_OUTPUT_UF2 config BUILD_OUTPUT_UF2_FAMILY_ID string "UF2 device family ID" default "0x1c5f21b0" if SOC_ESP32 default "0x621e937a" if SOC_NRF52833_QIAA default "0xada52840" if SOC_NRF52840_QIAA default "0x4fb2d5bd" if SOC_SERIES_IMX_RT default "0x2abc77ec" if SOC_SERIES_LPC55XXX default "0xe48bff56" if SOC_SERIES_RP2XXX default "0x68ed2b88" if SOC_SERIES_SAMD21 default "0x55114460" if SOC_SERIES_SAMD51 default "0x647824b6" if SOC_SERIES_STM32F0X default "0x5d1a0a2e" if SOC_SERIES_STM32F2X default "0x6b846188" if SOC_SERIES_STM32F3X default "0x53b80f00" if SOC_SERIES_STM32F7X default "0x300f5633" if SOC_SERIES_STM32G0X default "0x4c71240a" if SOC_SERIES_STM32G4X default "0x6db66082" if SOC_SERIES_STM32H7X default "0x202e3a91" if SOC_SERIES_STM32L0X default "0x1e1f432d" if SOC_SERIES_STM32L1X default "0x00ff6919" if SOC_SERIES_STM32L4X default "0x04240bdf" if SOC_SERIES_STM32L5X default "0x70d16653" if SOC_SERIES_STM32WBX default "0x5ee21072" if SOC_STM32F103XE default "0x57755a57" if SOC_STM32F401XC || SOC_STM32F401XE default "0x6d0922fa" if SOC_STM32F407XE default "0x8fb060fe" if SOC_STM32F407XG help UF2 bootloaders only accept UF2 files with a matching family ID. This can be either a hex, e.g. 0x68ed2b88, or well-known family name string. If the SoC in use is known by UF2, the Family ID will be pre-filled with the known value. config BUILD_OUTPUT_UF2_USE_FLASH_BASE bool default n config BUILD_OUTPUT_UF2_USE_FLASH_OFFSET bool default n endif # BUILD_OUTPUT_UF2 config BUILD_OUTPUT_STRIPPED bool "Build a stripped binary" help Build a stripped binary zephyr/zephyr.strip in the build directory. The name of this file can be customized with CONFIG_KERNEL_BIN_NAME. config BUILD_OUTPUT_ADJUST_LMA string help This will adjust the LMA address in the final ELF and hex files with the value provided. This will not affect the internal address symbols inside the image but can be useful when adjusting the LMA address for flash tools or multi stage loaders where a pre-loader may copy image to a second location before booting a second core. The value will be evaluated as a math expression, this means that following are valid expression - 1024 - 0x1000 - -0x1000 - 0x20000000 - 0x10000000 Note: negative numbers are valid. To adjust according to a chosen flash partition one can specify a default as: DT_CHOSEN_IMAGE_ := ,-partition DT_CHOSEN_Z_FLASH := zephyr,flash config BUILD_OUTPUT_ADJUST_LMA default "$(dt_chosen_reg_addr_hex,$(DT_CHOSEN_IMAGE_M4))-\ $(dt_chosen_reg_addr_hex,$(DT_CHOSEN_Z_FLASH))" config BUILD_OUTPUT_INFO_HEADER bool "Create a image information header" help Create an image information header which will contain image information from the Zephyr binary. Example of information contained in the header file: - Number of segments in the image - LMA address of each segment - VMA address of each segment - Size of each segment config APPLICATION_DEFINED_SYSCALL bool "Scan application folder for any syscall definition" help Scan additional folders inside application source folder for application defined syscalls. config MAKEFILE_EXPORTS bool "Generate build metadata files named Makefile.exports" help Generates a file with build information that can be read by third party Makefile-based build systems. config BUILD_OUTPUT_META bool "Create a build meta file" help Create a build meta file in the build directory containing lists of: - Zephyr: path and revision (if git repo) - Zephyr modules: name, path, and revision (if git repo) - West: - manifest: path and revision - projects: path and revision - Workspace: - dirty: one or more repositories are marked dirty - extra: extra Zephyr modules are manually included in the build - off: the SHA of one or more west projects are not what the manifest defined when `west update` was run the last time (`manifest-rev`). The off state is only present if a west workspace is found. File extension is .meta config BUILD_OUTPUT_META_STATE_PROPAGATE bool "Propagate module and project state" depends on BUILD_OUTPUT_META help Propagate to state of each module to the Zephyr revision field. If west is used the state of each west project is also propagated to the Zephyr revision field. West manifest repo revision field will also be marked with the same state as the Zephyr revision. The final revision will become: ---... If no states are appended to the SHA it means the build is of a clean tree. - dirty: one or more repositories are marked dirty - extra: extra Zephyr modules are manually included in the build - off: the SHA of one or more west projects are not what the manifest defined when `west update` was run the last time (`manifest-rev`). The off state is only present if a west workspace is found. endmenu config DEPRECATED bool help Symbol that must be selected by a feature or module if it is considered to be deprecated. config WARN_DEPRECATED bool default y prompt "Warn on deprecated usage" help Print a warning when the Kconfig tree is parsed if any deprecated features are enabled. config EXPERIMENTAL bool help Symbol that must be selected by a feature if it is considered to be at an experimental implementation stage. config WARN_EXPERIMENTAL bool prompt "Warn on experimental usage" help Print a warning when the Kconfig tree is parsed if any experimental features are enabled. config TAINT bool help Symbol that must be selected by a feature or module if the Zephyr build is considered tainted. config ENFORCE_ZEPHYR_STDINT bool prompt "Enforce Zephyr convention for stdint" depends on !ARCH_POSIX default y help This enforces the Zephyr stdint convention where int32_t = int, int64_t = long long, and intptr_t = long so that short string format length modifiers can be used universally across ILP32 and LP64 architectures. Sometimes this is not possible e.g. when linking against a binary-only C++ library whose type mangling is incompatible with the Zephyr convention, or if the build environment doesn't allow such enforcement, in which case this should be turned off with the caveat that argument type validation on Zephyr code will be skipped. endmenu menu "Boot Options" config IS_BOOTLOADER bool "Act as a bootloader" depends on XIP depends on ARM help This option indicates that Zephyr will act as a bootloader to execute a separate Zephyr image payload. config BOOTLOADER_SRAM_SIZE int "SRAM reserved for bootloader" default 16 depends on !XIP || IS_BOOTLOADER depends on ARM || XTENSA help This option specifies the amount of SRAM (measure in kB) reserved for a bootloader image, when either: - the Zephyr image itself is to act as the bootloader, or - Zephyr is a !XIP image, which implicitly assumes existence of a bootloader that loads the Zephyr !XIP image onto SRAM. config MCUBOOT bool help Hidden option used to indicate that the current image is MCUBoot config BOOTLOADER_MCUBOOT bool "MCUboot bootloader support" select USE_DT_CODE_PARTITION imply INIT_ARCH_HW_AT_BOOT if ARCH_SUPPORTS_ARCH_HW_INIT depends on !MCUBOOT help This option signifies that the target uses MCUboot as a bootloader, or in other words that the image is to be chain-loaded by MCUboot. This sets several required build system and Device Tree options in order for the image generated to be bootable using the MCUboot open source bootloader. Currently this includes: * Setting ROM_START_OFFSET to a default value that allows space for the MCUboot image header * Activating SW_VECTOR_RELAY_CLIENT on Cortex-M0 (or Armv8-M baseline) targets with no built-in vector relocation mechanisms By default, this option instructs Zephyr to initialize the core architecture HW registers during boot, when this is supported by the application. This removes the need by MCUboot to reset the core registers' state itself. if BOOTLOADER_MCUBOOT config MCUBOOT_SIGNATURE_KEY_FILE string "Path to the mcuboot signing key file" default "" depends on !MCUBOOT_GENERATE_UNSIGNED_IMAGE help The file contains a key pair whose public half is verified by your target's MCUboot image. The file is in PEM format. If set to a non-empty value, the build system tries to sign the final binaries using a 'west sign -t imgtool' command. The signed binaries are placed in the build directory at zephyr/zephyr.signed.bin and zephyr/zephyr.signed.hex. The file names can be customized with CONFIG_KERNEL_BIN_NAME. The existence of bin and hex files depends on CONFIG_BUILD_OUTPUT_BIN and CONFIG_BUILD_OUTPUT_HEX. This option should contain a path to the same file as the BOOT_SIGNATURE_KEY_FILE option in your MCUboot .config. The path may be absolute or relative to the west workspace topdir. (The MCUboot config option is used for the MCUboot bootloader image; this option is for your application which is to be loaded by MCUboot. The MCUboot config option can be a relative path from the MCUboot repository root.) If left empty, you must sign the Zephyr binaries manually. config MCUBOOT_ENCRYPTION_KEY_FILE string "Path to the mcuboot encryption key file" default "" depends on MCUBOOT_SIGNATURE_KEY_FILE != "" help The file contains the public key that is used to encrypt the ephemeral key that encrypts the image. The corresponding private key is hard coded in the MCUboot source code and is used to decrypt the ephemeral key that is embedded in the image. The file is in PEM format. If set to a non-empty value, the build system tries to sign and encrypt the final binaries using a 'west sign -t imgtool' command. The binaries are placed in the build directory at zephyr/zephyr.signed.encrypted.bin and zephyr/zephyr.signed.encrypted.hex. The file names can be customized with CONFIG_KERNEL_BIN_NAME. The existence of bin and hex files depends on CONFIG_BUILD_OUTPUT_BIN and CONFIG_BUILD_OUTPUT_HEX. This option should either be an absolute path or a path relative to the west workspace topdir. Example: './bootloader/mcuboot/enc-rsa2048-pub.pem' If left empty, you must encrypt the Zephyr binaries manually. config MCUBOOT_EXTRA_IMGTOOL_ARGS string "Extra arguments to pass to imgtool" default "" help If CONFIG_MCUBOOT_SIGNATURE_KEY_FILE is a non-empty string, you can use this option to pass extra options to imgtool. For example, you could set this to "--version 1.2". config MCUBOOT_GENERATE_UNSIGNED_IMAGE bool "Generate unsigned binary image bootable with MCUboot" help Enabling this configuration allows automatic unsigned binary image generation when MCUboot signing key is not provided, i.e., MCUBOOT_SIGNATURE_KEY_FILE is left empty. config MCUBOOT_GENERATE_CONFIRMED_IMAGE bool "Also generate a padded, confirmed image" help The signed, padded, and confirmed binaries are placed in the build directory at zephyr/zephyr.signed.confirmed.bin and zephyr/zephyr.signed.confirmed.hex. The file names can be customized with CONFIG_KERNEL_BIN_NAME. The existence of bin and hex files depends on CONFIG_BUILD_OUTPUT_BIN and CONFIG_BUILD_OUTPUT_HEX. endif # BOOTLOADER_MCUBOOT config BOOTLOADER_ESP_IDF bool "ESP-IDF bootloader support" depends on (SOC_ESP32 || SOC_ESP32S2 || SOC_ESP32C3) && !BOOTLOADER_MCUBOOT default y help This option will trigger the compilation of the ESP-IDF bootloader inside the build folder. At flash time, the bootloader will be flashed with the zephyr image config BOOTLOADER_BOSSA bool "BOSSA bootloader support" select USE_DT_CODE_PARTITION help Signifies that the target uses a BOSSA compatible bootloader. If CDC ACM USB support is also enabled then the board will reboot into the bootloader automatically when bossac is run. config BOOTLOADER_BOSSA_DEVICE_NAME string "BOSSA CDC ACM device name" depends on BOOTLOADER_BOSSA && CDC_ACM_DTE_RATE_CALLBACK_SUPPORT default "CDC_ACM_0" help Sets the CDC ACM port to watch for reboot commands. choice prompt "BOSSA bootloader variant" depends on BOOTLOADER_BOSSA config BOOTLOADER_BOSSA_LEGACY bool "Legacy" help Select the Legacy variant of the BOSSA bootloader. This is defined for compatibility mode only. The recommendation is use newer versions like Arduino or Adafruit UF2. config BOOTLOADER_BOSSA_ARDUINO bool "Arduino" help Select the Arduino variant of the BOSSA bootloader. Uses 0x07738135 as the magic value to enter the bootloader. config BOOTLOADER_BOSSA_ADAFRUIT_UF2 bool "Adafruit UF2" help Select the Adafruit UF2 variant of the BOSSA bootloader. Uses 0xf01669ef as the magic value to enter the bootloader. endchoice endmenu menu "Compatibility" config COMPAT_INCLUDES bool "Suppress warnings when using header shims" default y help Suppress any warnings from the pre-processor when including deprecated header files. endmenu config LEGACY_INCLUDE_PATH bool "Allow for the legacy include paths (without the zephyr/ prefix) (DEPRECATED)" select DEPRECATED help DEPRECATED: Allow applications and libraries to use the Zephyr legacy include path which does not use the zephyr/ prefix. For example, the preferred way to include a Zephyr header is to use , but enabling CONFIG_LEGACY_INCLUDE_PATH will allow developers to use instead. This (without the zephyr/ prefix) is deprecated and should be avoided. Eventually, it will not be supported.