Zephyr Kernel Configuration Options¶

Kconfig files describe build-time configuration options (called symbols in Kconfig-speak), how they’re grouped into menus and sub-menus, and dependencies between them that determine what configurations are valid.

Kconfig files appear throughout the directory tree. For example, subsys/power/Kconfig defines power-related options.

This documentation is generated automatically from the Kconfig files by the gen_kconfig_rest.py script. Click on symbols for more information.

Configuration Options¶

Symbol name	Prompt
`CONFIG_APPLICATION_INIT_PRIORITY`	Default init priority for application level drivers
`CONFIG_ARCH_HAS_CUSTOM_BUSY_WAIT`
`CONFIG_ARCH_HAS_CUSTOM_SWAP_TO_MAIN`
`CONFIG_ARCH_MEM_DOMAIN_DATA`
`CONFIG_ARCH_MEM_DOMAIN_SYNCHRONOUS_API`
`CONFIG_ATOMIC_OPERATIONS_ARCH`
`CONFIG_ATOMIC_OPERATIONS_BUILTIN`
`CONFIG_ATOMIC_OPERATIONS_C`
`CONFIG_BOOT_BANNER`	Boot banner
`CONFIG_BOOT_DELAY`	Boot delay in milliseconds
`CONFIG_BOUNDS_CHECK_BYPASS_MITIGATION`	Enable bounds check bypass mitigations for speculative execution
`CONFIG_COOP_ENABLED`
`CONFIG_DEVICE_HANDLE_PADDING`	Number of additional device handles to use for padding
`CONFIG_ERRNO`	Enable errno support
`CONFIG_ERRNO_IN_TLS`	Store errno in thread local storage (TLS)
`CONFIG_EXECUTE_XOR_WRITE`	Enable W^X for memory partitions
`CONFIG_HEAP_MEM_POOL_SIZE`	Heap memory pool size (in bytes)
`CONFIG_IDLE_STACK_SIZE`	Size of stack for idle thread
`CONFIG_INIT_STACKS`	Initialize stack areas
`CONFIG_INSTRUMENT_THREAD_SWITCHING`
`CONFIG_ISR_STACK_SIZE`	ISR and initialization stack size (in bytes)
`CONFIG_KERNEL_COHERENCE`	Place all shared data into coherent memory
`CONFIG_KERNEL_INIT_PRIORITY_DEFAULT`	Default init priority
`CONFIG_KERNEL_INIT_PRIORITY_DEVICE`	Default init priority for device drivers
`CONFIG_KERNEL_INIT_PRIORITY_OBJECTS`	Kernel objects initialization priority
`CONFIG_KERNEL_MEM_POOL`	Use Kernel Memory Pool
`CONFIG_MAIN_STACK_SIZE`	Size of stack for initialization and main thread
`CONFIG_MAIN_THREAD_PRIORITY`	Priority of initialization/main thread
`CONFIG_MAX_DOMAIN_PARTITIONS`	Maximum number of partitions per memory domain
`CONFIG_MEM_SLAB_TRACE_MAX_UTILIZATION`	Enable getting maximum slab utilization
`CONFIG_MP_NUM_CPUS`	Number of CPUs/cores
`CONFIG_MULTITHREADING`	Multi-threading
`CONFIG_NUM_COOP_PRIORITIES`	Number of coop priorities
`CONFIG_NUM_MBOX_ASYNC_MSGS`	Maximum number of in-flight asynchronous mailbox messages
`CONFIG_NUM_METAIRQ_PRIORITIES`	Number of very-high priority ‘preemptor’ threads
`CONFIG_NUM_PIPE_ASYNC_MSGS`	Maximum number of in-flight asynchronous pipe messages
`CONFIG_NUM_PREEMPT_PRIORITIES`	Number of preemptible priorities
`CONFIG_POLL`	Async I/O Framework
`CONFIG_PREEMPT_ENABLED`
`CONFIG_PRIORITY_CEILING`	Priority inheritance ceiling
`CONFIG_SCHED_CPU_MASK`	Enable CPU mask affinity/pinning API
`CONFIG_SCHED_DEADLINE`	Enable earliest-deadline-first scheduling
`CONFIG_SCHED_DUMB`	Simple linked-list ready queue
`CONFIG_SCHED_IPI_SUPPORTED`
`CONFIG_SCHED_MULTIQ`	Traditional multi-queue ready queue
`CONFIG_SCHED_SCALABLE`	Red/black tree ready queue
`CONFIG_SMP`	Enable symmetric multithreading support
`CONFIG_SMP_BOOT_DELAY`	Delay booting secondary cores
`CONFIG_STACK_CANARIES`	Compiler stack canaries
`CONFIG_STACK_POINTER_RANDOM`	Initial stack pointer randomization bounds
`CONFIG_SWAP_NONATOMIC`
`CONFIG_SYSTEM_WORKQUEUE_NO_YIELD`	Select whether system work queue yields
`CONFIG_SYSTEM_WORKQUEUE_PRIORITY`	System workqueue priority
`CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE`	System workqueue stack size
`CONFIG_SYS_CLOCK_EXISTS`	System clock exists and is enabled
`CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC`	Hardware clock cycles per second, 2000000 for ISS
`CONFIG_SYS_CLOCK_TICKS_PER_SEC`	System tick frequency (in ticks/second)
`CONFIG_THREAD_CUSTOM_DATA`	Thread custom data
`CONFIG_THREAD_LOCAL_STORAGE`	Thread Local Storage (TLS)
`CONFIG_THREAD_MAX_NAME_LEN`	Max length of a thread name
`CONFIG_THREAD_MONITOR`	Thread monitoring
`CONFIG_THREAD_NAME`	Thread name
`CONFIG_THREAD_RUNTIME_STATS`	Thread runtime statistics
`CONFIG_THREAD_RUNTIME_STATS_USE_TIMING_FUNCTIONS`	Use timing functions to gather statistics
`CONFIG_THREAD_STACK_INFO`	Thread stack info
`CONFIG_THREAD_USERSPACE_LOCAL_DATA`
`CONFIG_TICKLESS_KERNEL`	Tickless kernel
`CONFIG_TIMEOUT_64BIT`	Store kernel timeouts in 64 bit precision
`CONFIG_TIMESLICE_PRIORITY`	Time slicing thread priority ceiling
`CONFIG_TIMESLICE_SIZE`	Time slice size (in ms)
`CONFIG_TIMESLICING`	Thread time slicing
`CONFIG_TOOLCHAIN_SUPPORTS_THREAD_LOCAL_STORAGE`
`CONFIG_TRACE_SCHED_IPI`	Enable Test IPI
`CONFIG_USE_SWITCH`	Use new-style _arch_switch instead of arch_swap
`CONFIG_USE_SWITCH_SUPPORTED`
`CONFIG_WAITQ_DUMB`	Simple linked-list wait_q
`CONFIG_WAITQ_SCALABLE`	Use scalable wait_q implementation
`CONFIG_XIP`	Execute in place