# Kconfig - miscellany configuration options # # Copyright (c) 2014-2015 Wind River Systems, Inc. # # SPDX-License-Identifier: Apache-2.0 # menu "Build and Link Features" menu "Linker Options" config HAS_FLASH_LOAD_OFFSET bool help This option is selected by targets having a FLASH_LOAD_OFFSET and FLASH_LOAD_SIZE. if !HAS_DTS config FLASH_LOAD_OFFSET hex "Kernel load offset" default 0 depends on HAS_FLASH_LOAD_OFFSET 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 hex "Kernel load size" default 0 depends on HAS_FLASH_LOAD_OFFSET 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 config TEXT_SECTION_OFFSET hex "TEXT section offset" default 0 default 0x200 if BOOTLOADER_MCUBOOT 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 .text 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 HAVE_CUSTOM_LINKER_SCRIPT prompt "Custom linker scripts provided" def_bool n 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" default "" 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 CUSTOM_RODATA_LD bool "Include custom-rodata.ld" default n help Include a customized linker script fragment for inserting additional data and linker directives into the rodata section. config CUSTOM_RWDATA_LD bool "Include custom-rwdata.ld" default n help Include a customized linker script fragment for inserting additional data and linker directives into the data section. config CUSTOM_SECTIONS_LD bool "Include custom-sections.ld" default n help Include a customized linker script fragment for inserting additional arbitrary sections. config LINK_WHOLE_ARCHIVE bool "Allow linking with --whole-archive" default n help This options allows linking external libraries with the --whole-archive option to keep all symbols. config KERNEL_ENTRY string "Kernel entry symbol" default "__start" help Code entry symbol, to be set at linking phase. config CHECK_LINK_MAP bool "Check linker map" default y help Run a linker address generation validity checker at the end of the build. endmenu menu "Compiler Options" config CROSS_COMPILE string "Cross-compiler tool prefix" help Same as running 'make CROSS_COMPILE=prefix-' but stored for default make runs in this kernel build directory. You don't need to set this unless you want the configured kernel build directory to select the cross-compiler automatically. config NATIVE_APPLICATION bool "Build as a native host application" default n help Build as a native application that can run on the host and using resources and libraries provided by the host. choice 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 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_OPT string prompt "Custom compiler options" default "" 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 TOOLCHAIN_VARIANT string "Cross-compiler variant name" help For optimized compilers with reduced features, specify the name of the variant. endmenu 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_DISASSEMBLY bool "Create a disassembly file" default y help Create an .lst file with the assembly listing of the firmware. 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 BUILD_OUTPUT_HEX bool "Build a binary in HEX format" default n help Build a binary in HEX format. This will build a zephyr.hex file need by some platforms. config BUILD_OUTPUT_BIN bool "Build a binary in BIN format" default y help Build a binary in BIN format. This will build a zephyr.bin file need by some platforms. config BUILD_OUTPUT_EXE bool "Build a binary in ELF format with .exe extension" default n help Build a binary in ELF format that can run in the host system. This will build a zephyr.exe file. config BUILD_OUTPUT_S19 bool "Build a binary in S19 format" default n help Build a binary in S19 format. This will build a zephyr.s19 file need by some platforms. config BUILD_OUTPUT_STRIPPED bool "Build a stripped binary" default n help Build a stripped binary. This will build a zephyr.stripped file need by some platforms. endmenu endmenu menu "System Monitoring Options" config PERFORMANCE_METRICS bool prompt "Enable performance metrics [EXPERIMENTAL]" default n help Enable Performance Metrics. config BOOT_TIME_MEASUREMENT bool prompt "Boot time measurements [EXPERIMENTAL]" default n depends on PERFORMANCE_METRICS help This option enables the recording of timestamps during system start up. The global variable __start_time_stamp records the time kernel begins executing, while __main_time_stamp records when main() begins executing, and __idle_time_stamp records when the CPU becomes idle. All values are recorded in terms of CPU clock cycles since system reset. config CPU_CLOCK_FREQ_MHZ int prompt "CPU Clock Frequency in MHz" default 20 depends on BOOT_TIME_MEASUREMENT help This option specifies the CPU Clock Frequency in MHz in order to convert Intel RDTSC timestamp to microseconds. endmenu menu "Boot Options" config IS_BOOTLOADER bool "Act as a bootloader" default n 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 when Zephyr acts as a bootloader" default 16 depends on !XIP || IS_BOOTLOADER depends on ARM help This option specifies the amount of SRAM (measure in kB) reserved for when Zephyr is to act as a bootloader. config BOOTLOADER_MCUBOOT bool prompt "MCUboot bootloader support" default n 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 TEXT_LOAD_OFFSET to a default value that allows space for the MCUboot image header * Activating SW_VECTOR_RELAY on Cortex-M0 (or Armv8-M baseline) targets with no built-in vector relocation mechanisms * Including dts/common/mcuboot.overlay when building the Device Tree in order to place and link the image at the slot0 offset config BOOTLOADER_KEXEC bool prompt "Boot using Linux kexec() system call" depends on X86 default n help This option signifies that Linux boots the kernel using kexec system call and utility. This method is used to boot the kernel over the network. config BOOTLOADER_UNKNOWN bool prompt "Generic boot loader support" default n depends on X86 help This option signifies that the target has a generic bootloader or that it supports multiple ways of booting and it isn't clear at build time which method is to be used. When this option is enabled the board may have to do extra work to ensure a proper startup. config BOOTLOADER_CONTEXT_RESTORE bool prompt "Boot loader has context restore support" default y depends on SYS_POWER_DEEP_SLEEP && BOOTLOADER_CONTEXT_RESTORE_SUPPORTED help This option signifies that the target has a bootloader that restores CPU context upon resuming from deep sleep power state. config REBOOT bool "Reboot functionality" default n select SYSTEM_CLOCK_DISABLE help Enable the sys_reboot() API. Enabling this can drag in other subsystems needed to perform a "safe" reboot (e.g. SYSTEM_CLOCK_DISABLE, to stop the system clock before issuing a reset). endmenu