# # For a description of the syntax of this configuration file, # see misc/tools/kconfig-language.txt. # menuconfig DISABLE_OS_API bool "Disable NuttX interfaces" default y ---help--- The following can be used to disable categories of APIs supported by the OS. If the compiler supports weak functions, then it should not be necessary to disable functions unless you want to restrict usage of those APIs. There are certain dependency relationships in these features. 1) mq_notify logic depends on signals to awaken tasks waiting for queues to become full or empty. 2) pthread_condtimedwait() depends on signals to wake up waiting tasks. if DISABLE_OS_API config DISABLE_POSIX_TIMERS bool "Disable POSIX timers" default y if DEFAULT_SMALL default n if !DEFAULT_SMALL config DISABLE_PTHREAD bool "Disable pthread support" default n config DISABLE_SIGNALS bool "Disable signal support" default n config DISABLE_MQUEUE bool "Disable POSIX message queue support" default n config DISABLE_ENVIRON bool "Disable environment variable support" default y if DEFAULT_SMALL default n if !DEFAULT_SMALL endif # DISABLE_OS_API menu "Clocks and Timers" config ARCH_HAVE_TICKLESS bool config SCHED_TICKLESS bool "Support tick-less OS" default n depends on ARCH_HAVE_TICKLESS && EXPERIMENTAL ---help--- Be default, system time is driven by a periodic timer interrupt. An alternative configurations is a tick-less configuration in which there is no periodic timer interrupt. Instead and interval timer is used to schedule the next OS time event. This option selects that tick-less OS option. If the tick-less OS is selected, then there are additional plaform specific interfaces that must be provided as defined include/nuttx/arch.h config MSEC_PER_TICK int "Milliseconds per system timer tick" default 10 if !SCHED_TICKLESS default 1 if SCHED_TICKLESS ---help--- The default system timer is 100Hz or MSEC_PER_TICK=10. This setting may be defined to inform NuttX that the processor hardware is providing system timer interrupts at some interrupt interval other than 10 msec. If SCHED_TICKLESS is selected, then there are no system timer interrupts. In this case, MSEC_PER_TICK does not control any timer rates. Rather, it only determines the resolution of time reported by clock_systimer() and the resolution of times that can be set for certain delays including watchdog timers and delayed work. In these cases it is better to have the MSEC_PER_TICK as low as possible. if !SCHED_TICKLESS config SYSTEMTICK_EXTCLK bool "Use external clock" default n depends on ARCH_HAVE_EXTCLK ---help--- Use external clock for system tick. When enabled, the platform-specific logic must start its own timer interrupt to make periodic calls to the sched_process_timer() or the functions called within. The purpose is to move the scheduling off the processor clock to allow entering low power states that would disable that clock. endif # !SCHED_TICKLESS config SYSTEM_TIME64 bool "64-bit system clock" default n ---help--- The system timer is incremented at the rate determined by MSEC_PER_TICK, typically at 100Hz. The count at any given time is then the "uptime" in units of system timer ticks. By default, the system time is 32-bits wide. Those defaults provide a range of about 13.6 years which is probably a sufficient range for "uptime". However, if the system timer rate is significantly higher than 100Hz and/or if a very long "uptime" is required, then this option can be selected to support a 64-bit wide timer. config CLOCK_MONOTONIC bool "Support CLOCK_MONOTONIC" default n ---help--- CLOCK_MONOTONIC is an optional standard POSIX clock. Unlike CLOCK_REALTIME which can move forward and backward when the time-of-day changes, CLOCK_MONOTONIC is the elapsed time since some arbitrary point in the post (the system start-up time for NuttX) and, hence, is always monotonically increasing. CLOCK_MONOTONIC is, hence, the more appropriate clock for determining time differences. The value of the CLOCK_MONOTONIC clock cannot be set via clock_settime(). config JULIAN_TIME bool "Enables Julian time conversions" default n ---help--- Enables Julian time conversions if !RTC config START_YEAR int "Start year" default 2014 config START_MONTH int "Start month" default 1 config START_DAY int "Start day" default 1 endif # !RTC config MAX_WDOGPARMS int "Maximum number of watchdog parameters" default 4 ---help--- Maximum number of parameters that can be passed to a watchdog handler config PREALLOC_WDOGS int "Number of pre-allocated watchdog timers" default 32 ---help--- The number of pre-allocated watchdog structures. The system manages a pool of preallocated watchdog structures to minimize dynamic allocations config PREALLOC_TIMERS int "Number of pre-allocated POSIX timers" default 8 ---help--- The number of pre-allocated POSIX timer structures. The system manages a pool of preallocated timer structures to minimize dynamic allocations. Set to zero for all dynamic allocations. endmenu # Clocks and Timers menu "Tasks and Scheduling" config USER_ENTRYPOINT string "Application entry point" default "user_start" ---help--- The name of the entry point for user applications. For the example applications this is of the form 'app_main' where 'app' is the application name. If not defined, USER_ENTRYPOINT defaults to "user_start." config RR_INTERVAL int "Round robin timeslice (MSEC)" default 0 ---help--- The round robin timeslice will be set this number of milliseconds; Round robin scheduling can be disabled by setting this value to zero. config TASK_NAME_SIZE int "Maximum task name size" default 32 ---help--- Spcifies that maximum size of a task name to save in the TCB. Useful if scheduler instrumentation is selected. Set to zero to disable. config MAX_TASK_ARGS int "Maximum number of task arguments" default 4 ---help--- This controls the maximum number of of parameters that a task may receive (i.e., maxmum value of 'argc') config MAX_TASKS int "Max number of tasks" default 32 ---help--- The maximum number of simultaneously active tasks. This value must be a power of two. config SCHED_HAVE_PARENT bool "Support parent/child task relationships" default n ---help--- Remember the ID of the parent task when a new child task is created. This support enables some additional features (such as SIGCHLD) and modifies the behavior of other interfaces. For example, it makes waitpid() more standards complete by restricting the waited-for tasks to the children of the caller. Default: disabled. config SCHED_CHILD_STATUS bool "Retain child exit status" default n depends on SCHED_HAVE_PARENT ---help--- If this option is selected, then the exit status of the child task will be retained after the child task exits. This option should be selected if you require knowledge of a child process' exit status. Without this setting, wait(), waitpid() or waitid() may fail. For example, if you do: 1) Start child task 2) Wait for exit status (using wait(), waitpid(), or waitid()). This can fail because the child task may run to completion before the wait begins. There is a non-standard work-around in this case: The above sequence will work if you disable pre-emption using sched_lock() prior to starting the child task, then re-enable pre- emption with sched_unlock() after the wait completes. This works because the child task is not permitted to run until the wait is in place. The standard solution would be to enable SCHED_CHILD_STATUS. In this case the exit status of the child task is retained after the child exits and the wait will successful obtain the child task's exit status whether it is called before the child task exits or not. Warning: If you enable this feature, then your application must either (1) take responsibility for reaping the child status with wait(), waitpid(), or waitid(), or (2) suppress retention of child status. If you do not reap the child status, then you have a memory leak and your system will eventually fail. Retention of child status can be suppressed on the parent using logic like: struct sigaction sa; sa.sa_handler = SIG_IGN; sa.sa_flags = SA_NOCLDWAIT; int ret = sigaction(SIGCHLD, &sa, NULL); if SCHED_CHILD_STATUS config PREALLOC_CHILDSTATUS int "Number of pre-allocated child status" default 0 ---help--- To prevent runaway child status allocations and to improve allocation performance, child task exit status structures are pre- allocated when the system boots. This setting determines the number of child status structures that will be pre-allocated. If this setting is not defined or if it is defined to be zero then a value of 2*MAX_TASKS is used. Note that there cannot be more than MAX_TASKS tasks in total. However, the number of child status structures may need to be significantly larger because this number includes the maximum number of tasks that are running PLUS the number of tasks that have exit'ed without having their exit status reaped (via wait(), waitid(), or waitpid()). Obviously, if tasks spawn children indefinitely and never have the exit status reaped, then you may have a memory leak! If you enable the SCHED_CHILD_STATUS feature, then your application must take responsibility for either (1) reaping the child status with wait(), waitpid(), or waitid() or it must (2) suppress retention of child status. Otherwise, your system will eventually fail. Retention of child status can be suppressed on the parent using logic like: struct sigaction sa; sa.sa_handler = SIG_IGN; sa.sa_flags = SA_NOCLDWAIT; int ret = sigaction(SIGCHLD, &sa, NULL); config DEBUG_CHILDSTATUS bool "Enable Child Status Debug Output" default n depends on SCHED_CHILD_STATUS && DEBUG ---help--- Very detailed... I am sure that you do not want this. endif # SCHED_CHILD_STATUS config SCHED_WAITPID bool "Enable waitpid() API" default n ---help--- Enables the waitpid() interface in a default, non-standard mode (non-standard in the sense that the waited for PID need not be child of the caller). If SCHED_HAVE_PARENT is also defined, then this setting will modify the behavior or waitpid() (making more spec compliant) and will enable the waitid() and wait() interfaces as well. endmenu # Tasks and Scheduling menu "Pthread Options" depends on !DISABLE_PTHREAD config MUTEX_TYPES: bool "Enable mutex types" default n ---help--- Set to enable support for recursive and errorcheck mutexes. Enables pthread_mutexattr_settype(). config NPTHREAD_KEYS int "Maximum number of pthread keys" default 4 ---help--- The number of items of thread- specific data that can be retained endmenu # Pthread Options menu "Performance Monitoring" config SCHED_CPULOAD bool "Enable CPU load monitoring" default n select SCHED_CPULOAD_EXTCLK if SCHED_TICKLESS ---help--- If this option is selected, the timer interrupt handler will monitor if the system is IDLE or busy at the time of that the timer interrupt occurs. This is a very coarse measurement, but over a period of time, it can very accurately determined the percentage of the time that the CPU is IDLE. The statistics collected in this could be used, for example in the PROCFS file system to provide CPU load measurements when read. if SCHED_CPULOAD config SCHED_CPULOAD_EXTCLK bool "Use external clock" default n ---help--- The CPU load measurements are determined by sampling the active tasks periodically at the occurrence to a timer expiration. By default, the system clock is used to do that sampling. There is a serious issue for the accuracy of measurements if the system clock is used, however. NuttX threads are often started at the time of the system timer expiration. Others may be stopped at the time of the system timer expiration (if round-robin time-slicing is enabled). Such thread behavior occurs synchronously with the system timer and, hence, is not randomly sampled. As a consequence, the CPU load attributed to these threads that run synchronously with they system timer may be grossly in error. The solution is to use some other clock that runs at a different rate and has timer expirations that are asynchronous with the system timer. Then truly accurate load measurements can be achieved. This option enables use of such an "external" clock. The implementation of the clock must be provided by platform-specific logic; that platform-specific logic must call the system function sched_process_cpuload() at each timer expiration with interrupts disabled. config SCHED_CPULOAD_TICKSPERSEC int "External clock rate" default 100 depends on SCHED_CPULOAD_EXTCLK ---help--- If an external clock is used to drive the sampling for the CPU load calculations, then this value must be provided. This value provides the rate of the external clock in units of ticks per second. The default value of 100 corresponds to 100Hz clock. NOTE: that 100Hz is the default frequency of the system time and, hence, the worst possible choice in most cases. config SCHED_CPULOAD_TIMECONSTANT int "CPU load time constant" default 2 ---help--- The accumulated CPU count is divided by two when the accumulated tick count exceeds this time constant. This time constant is in units of seconds. endif # SCHED_CPULOAD config SCHED_INSTRUMENTATION bool "System performance monitor hooks" default n ---help--- Enables instrumentation in scheduler to monitor system performance. If enabled, then the board-specific logic must provide the following functions (see include/sched.h): void sched_note_start(FAR struct tcb_s *tcb); void sched_note_stop(FAR struct tcb_s *tcb); void sched_note_switch(FAR struct tcb_s *pFromTcb, FAR struct tcb_s *pToTcb); endmenu # Performance Monitoring menu "Files and I/O" config DEV_CONSOLE bool "Enable /dev/console" default y ---help--- Set if architecture-specific logic provides /dev/console at boot-up time. Enables stdout, stderr, stdin in the start-up application. You need this setting if your console device is ready at boot time. For example, if you are using a serial console, then /dev/console (aka, /dev/ttyS0) will be available when the application first starts. You must not select DEV_CONSOLE if you console device comes up later and is not ready until after the application starts. At this time, the only console device that behaves this way is a USB serial console. When the application first starts, the USB is (probably) not yet connected and /dev/console will not be created until later when the host connects to the USB console. config FDCLONE_DISABLE bool "Disable cloning of file descriptors" default n ---help--- Disable cloning of all file descriptors by task_create() when a new ask is started. If set, all files/drivers will appear to be closed in the new task. config FDCLONE_STDIO bool "Disable clone file descriptors without stdio" default n ---help--- Disable cloning of all but the first three file descriptors (stdin, stdout, stderr) by task_create() when a new task is started. If set, all files/drivers will appear to be closed in the new task except for stdin, stdout, and stderr. config SDCLONE_DISABLE bool "Disable cloning of socket descriptors" default n ---help--- Disable cloning of all socket desciptors by task_create() when a new task is started. If set, all sockets will appear to be closed in the new task. config NFILE_DESCRIPTORS int "Maximum number of file descriptors per task" default 16 ---help--- The maximum number of file descriptors per task (one for each open) config NFILE_STREAMS int "Maximum number of FILE streams" default 16 ---help--- The maximum number of streams that can be fopen'ed config NAME_MAX int "Maximum size of a file name" default 32 ---help--- The maximum size of a file name. endmenu # Files and I/O menuconfig PRIORITY_INHERITANCE bool "Enable priority inheritance " default n ---help--- Set to enable support for priority inheritance on mutexes and semaphores. if PRIORITY_INHERITANCE config SEM_PREALLOCHOLDERS int "Number of pre-allocated holders" default 16 ---help--- This setting is only used if priority inheritance is enabled. It defines the maximum number of different threads (minus one) that can take counts on a semaphore with priority inheritance support. This may be set to zero if priority inheritance is disabled OR if you are only using semaphores as mutexes (only one holder) OR if no more than two threads participate using a counting semaphore. config SEM_NNESTPRIO int "Maximum number of higher priority threads" default 16 ---help--- If priority inheritance is enabled, then this setting is the maximum number of higher priority threads (minus 1) than can be waiting for another thread to release a count on a semaphore. This value may be set to zero if no more than one thread is expected to wait for a semaphore. endif # PRIORITY_INHERITANCE menu "RTOS hooks" config BOARD_INITIALIZE bool "Custom board/driver initialization" default n ---help--- By default, there are three points in time where you can insert custom initialization logic: 1) _boardinitialize(): This function is used only for initialization of very low-level things like configuration of GPIO pins, power setting. The OS has not been initialized at this point, so you cannot allocate memory or initialize device drivers at this phase. 2) The next level of initialization is performed by a call to up_initialize() (in arch//src/common/up_initialize.c). The OS has been initialized at this point and it is okay to initialize drivers in this phase. 3) And, finally, when the user application code starts. If BOARD_INITIALIZE is selected, then an additional initialization call will be performed in the boot-up sequence to a function called board_initialize(). board_initialize() will be call between phases 2) and 3) above, immediately after up_initialize() is called. This additional initialization phase may be used, for example, to initialize board-specific device drivers. config SCHED_STARTHOOK bool "Enable startup hook" default n ---help--- Enable a non-standard, internal OS API call task_starthook(). task_starthook() registers a function that will be called on task startup before that actual task entry point is called. The starthook is useful, for example, for setting up automatic configuration of C++ constructors. config SCHED_ATEXIT bool "Enable atexit() API" default n ---help--- Enables the atexit() API config SCHED_ATEXIT_MAX int "Max number of atexit() functions" default 1 depends on SCHED_ATEXIT && !SCHED_ONEXIT ---help--- By default if SCHED_ATEXIT is selected, only a single atexit() function is supported. That number can be increased by defined this setting to the number that you require. If both SCHED_ONEXIT and SCHED_ATEXIT are selected, then atexit() is built on top of the on_exit() implementation. In that case, SCHED_ONEXIT_MAX determines the size of the combined number of atexit(0) and on_exit calls and SCHED_ATEXIT_MAX is not used. config SCHED_ONEXIT bool "Enable on_exit() API" default n ---help--- Enables the on_exit() API config SCHED_ONEXIT_MAX int "Max number of on_exit() functions" default 1 depends on SCHED_ONEXIT ---help--- By default if SCHED_ONEXIT is selected, only a single on_exit() function is supported. That number can be increased by defined this setting to the number that you require. If both SCHED_ONEXIT and SCHED_ATEXIT are selected, then atexit() is built on top of the on_exit() implementation. In that case, SCHED_ONEXIT_MAX determines the size of the combined number of atexit(0) and on_exit calls. endmenu # RTOS hooks menu "Signal Numbers" depends on !DISABLE_SIGNALS config SIG_SIGUSR1 int "SIGUSR1" default 1 ---help--- Value of standard user signal 1 (SIGUSR1). Default: 1 config SIG_SIGUSR2 int "SIGUSR2" default 2 ---help--- Value of standard user signal 2 (SIGUSR2). Default: 2 config SIG_SIGALARM int "SIGALRM" default 3 ---help--- Default the signal number used with POSIX timers (SIGALRM). Default: 3 config SIG_SIGCHLD int "SIGCHLD" default 4 depends on SCHED_HAVE_PARENT ---help--- The SIGCHLD signal is sent to the parent of a child process when it exits, is interrupted (stopped), or resumes after being interrupted. Default: 4 config SIG_SIGCONDTIMEDOUT int "SIGCONDTIMEDOUT" default 16 depends on !DISABLE_PTHREAD ---help--- This non-standard signal number is used the implementation of pthread_cond_timedwait(). Default 16. config SIG_SIGWORK int "SIGWORK" default 17 depends on SCHED_WORKQUEUE ---help--- SIGWORK is a non-standard signal used to wake up the internal NuttX worker thread. This setting specifies the signal number that will be used for SIGWORK. Default: 17 endmenu # Signal Numbers menu "POSIX Message Queue Options" depends on !DISABLE_MQUEUE config PREALLOC_MQ_MSGS int "Number of pre-allocated messages" default 32 ---help--- The number of pre-allocated message structures. The system manages a pool of preallocated message structures to minimize dynamic allocations config MQ_MAXMSGSIZE int "Maximum message size" default 32 ---help--- Message structures are allocated with a fixed payload size given by this setting (does not include other message structure overhead. endmenu # POSIX Message Queue Options menu "Stack and heap information" config IDLETHREAD_STACKSIZE int "Idle thread stack size" default 1024 ---help--- The size of the initial stack used by the IDLE thread. The IDLE thread is the thread that (1) performs the inital boot of the system up to the point where user_start() is spawned, and (2) there after is the IDLE thread that executes only when there is no other thread ready to run. config USERMAIN_STACKSIZE int "Main thread stack size" default 2048 ---help--- The size of the stack to allocate for the main user thread that begins at the user_start() entry point. config PTHREAD_STACK_MIN int "Minimum pthread stack size" default 256 ---help--- Minimum pthread stack size config PTHREAD_STACK_DEFAULT int "Default pthread stack size" default 2048 ---help--- Default pthread stack size endmenu # Stack and heap information