# Kconfig - general architecture configuration options # # Copyright (c) 2014-2015 Wind River Systems, Inc. # Copyright (c) 2015 Intel Corporation # Copyright (c) 2016 Cadence Design Systems, Inc. # # SPDX-License-Identifier: Apache-2.0 # choice prompt "Architecture" default X86 config ARC bool "ARC architecture" select HAS_DTS config ARM bool "ARM architecture" select ARCH_HAS_THREAD_ABORT config X86 bool "x86 architecture" select ATOMIC_OPERATIONS_BUILTIN config NIOS2 bool "Nios II Gen 2 architecture" select ATOMIC_OPERATIONS_C config RISCV32 bool "RISCV32 architecture" config XTENSA bool "Xtensa architecture" config ARCH_POSIX bool "POSIX (native) architecture" select ATOMIC_OPERATIONS_BUILTIN select ARCH_HAS_CUSTOM_SWAP_TO_MAIN select ARCH_HAS_CUSTOM_BUSY_WAIT select ARCH_HAS_THREAD_ABORT select NATIVE_APPLICATION endchoice menu "General Architecture Options" config HW_STACK_PROTECTION bool "Hardware Stack Protection" depends on ARCH_HAS_STACK_PROTECTION help Select this option to enable hardware-based platform features to catch stack overflows when the system is running in privileged mode. If CONFIG_USERSPACE is not enabled, the system is always running in privileged mode. Note that this does not necessarily prevent corruption and assertions about the overall system state when a fault is triggered cannot be made. config USERSPACE bool "User mode threads (EXPERIMENTAL)" depends on ARCH_HAS_USERSPACE help When enabled, threads may be created or dropped down to user mode, which has significantly restricted permissions and must interact with the kernel via system calls. See Zephyr documentation for more details about this feature. If a user thread overflows its stack, this will be caught and the kernel itself will be shielded from harm. Enabling this option may or may not catch stack overflows when the system is in privileged mode or handling a system call; to ensure these are always caught, enable CONFIG_HW_STACK_PROTECTION. This feature is under heavy development and APIs related to it are subject to change, even if declared non-private. config PRIVILEGED_STACK_SIZE int "Size of privileged stack" default 256 depends on ARCH_HAS_USERSPACE help This option sets the privileged stack region size that will be used in addition to the user mode thread stack. During normal execution, this region will be inaccessible from user mode. During system calls, this region will be utilized by the system call. config STACK_GROWS_UP bool "Stack grows towards higher memory addresses" default n help Select this option if the architecture has upward growing thread stacks. This is not common. config MAX_THREAD_BYTES int "Bytes to use when tracking object thread permissions" default 2 depends on USERSPACE help Every kernel object will have an associated bitfield to store thread permissions for that object. This controls the size of the bitfield (in bytes) and imposes a limit on how many threads can be created in the system. config DYNAMIC_OBJECTS bool "Allow kernel objects to be allocated at runtime" default n depends on USERSPACE help Enabling this option allows for kernel objects to be requested from the calling thread's resource pool, at a slight cost in performance due to the supplemental run-time tables required to validate such objects. Objects allocated in this way can be freed with a supervisor-only API call, or when the number of references to that object drops to zero. config SIMPLE_FATAL_ERROR_HANDLER prompt "Simple system fatal error handler" bool default n default y if !MULTITHREADING help Provides an implementation of _SysFatalErrorHandler() that hard hangs instead of aborting the faulting thread, and does not print anything, for footprint-concerned systems. Only enable this option if you do not want debug capabilities in case of system fatal error. menu "Interrupt Configuration" # # Interrupt related configs # config GEN_ISR_TABLES bool prompt "Use generated IRQ tables" default n help This option controls whether a platform uses the gen_isr_tables script to generate its interrupt tables. This mechanism will create an appropriate hardware vector table and/or software IRQ table. config GEN_IRQ_VECTOR_TABLE bool prompt "Generate an interrupt vector table" default y depends on GEN_ISR_TABLES help This option controls whether a platform using gen_isr_tables needs an interrupt vector table created. Only disable this if the platform does not use a vector table at all, or requires the vector table to be in a format that is not an array of function pointers indexed by IRQ line. In the latter case, the vector table must be supplied by the application or architecture code. config GEN_SW_ISR_TABLE bool prompt "Generate a software ISR table" default y depends on GEN_ISR_TABLES help This option controls whether a platform using gen_isr_tables needs a software ISR table table created. This is an array of struct _isr_table_entry containing the interrupt service routine and supplied parameter. config GEN_IRQ_START_VECTOR int default 0 depends on GEN_ISR_TABLES help On some architectures, part of the vector table may be reserved for system exceptions and is declared separately from the tables created by gen_isr_tables.py. When creating these tables, this value will be subtracted from CONFIG_NUM_IRQS to properly size them. This is a hidden option which needs to be set per architecture and left alone. config IRQ_OFFLOAD bool "Enable IRQ offload" default n help Enable irq_offload() API which allows functions to be synchronously run in interrupt context. Mainly useful for test cases. endmenu # Interrupt configuration endmenu # # Architecture Capabilities # config ARCH_HAS_STACK_PROTECTION bool config ARCH_HAS_USERSPACE bool config ARCH_HAS_EXECUTABLE_PAGE_BIT bool # # Other architecture related options # config ARCH_HAS_THREAD_ABORT bool # # Hidden PM feature configs which are to be selected by # individual SoC. # config SYS_POWER_LOW_POWER_STATE_SUPPORTED # Hidden bool default n help This option signifies that the target supports the SYS_POWER_LOW_POWER_STATE configuration option. config SYS_POWER_DEEP_SLEEP_SUPPORTED # Hidden bool default n help This option signifies that the target supports the SYS_POWER_DEEP_SLEEP configuration option. config BOOTLOADER_CONTEXT_RESTORE_SUPPORTED # Hidden bool default n help This option signifies that the target has options of bootloaders that support context restore upon resume from deep sleep # End hidden CPU family configs # config CPU_HAS_FPU bool default n help This option is enabled when the CPU has hardware floating point unit. config CPU_HAS_MPU bool # Omit prompt to signify "hidden" option default n help This option is enabled when the CPU has a Memory Protection Unit (MPU). config MPU_REQUIRES_POWER_OF_TWO_ALIGNMENT bool # Omit prompt to signify "hidden" option default n help This option is enabled when the MPU requires a power of two alignment and size for MPU regions. menu "Floating Point Options" depends on CPU_HAS_FPU config FLOAT bool prompt "Floating point registers" default n help This option allows threads to use the floating point registers. By default, only a single thread may use the registers. Disabling this option means that any thread that uses a floating point register will get a fatal exception. config FP_SHARING bool prompt "Floating point register sharing" depends on FLOAT default n help This option allows multiple threads to use the floating point registers. endmenu # # End hidden PM feature configs # config ARCH string help System architecture string. config SOC string help SoC name which can be found under arch//soc/. This option holds the directory name used by the build system to locate the correct linker and header files for the SoC. This option will go away once all SoCs are using family/series structure. config SOC_SERIES string help SoC series name which can be found under arch//soc//. This option holds the directory name used by the build system to locate the correct linker and header files. config SOC_FAMILY string help SoC family name which can be found under arch//soc/. This option holds the directory name used by the build system to locate the correct linker and header files. config BOARD string help This option holds the name of the board and is used to locate the files related to the board in the source tree (under boards/). The Board is the first location where we search for a linker.ld file, if not found we look for the linker file in arch//soc// # $ENV_VAR_ARCH might be a glob pattern gsource "arch/$ENV_VAR_ARCH/Kconfig" source "boards/Kconfig"