#
# For a description of the syntax of this configuration file,
# see misc/tools/kconfig-language.txt.
#
config MSEC_PER_TICK
int "Milliseconds per system timer tick"
default 10
---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.
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 SCHED_INSTRUMENTATION
bool "Monitor system performance"
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 _TCB *tcb);
void sched_note_stop(FAR _TCB *tcb);
void sched_note_switch(FAR _TCB *pFromTcb, FAR _TCB *pToTcb);
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 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);
config PREALLOC_CHILDSTATUS
int "Number of pre-allocated child status"
default 0
depends on SCHED_CHILD_STATUS
---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 that CONFIG_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 JULIAN_TIME
bool "Enables Julian time conversions"
default n
---help---
Enables Julian time conversions
config START_YEAR
int "Start year"
default 2013
config START_MONTH
int "Start month"
default 1
config START_DAY
int "Start day"
default 1
config DEV_CONSOLE
bool "Enable /dev/console"
default y
---help---
Set if architecture-specific logic provides /dev/console. Enables
stdout, stderr, stdin.
config MUTEX_TYPES:
bool "Enable mutex types"
default n
---help---
Set to enable support for recursive and errorcheck mutexes. Enables
pthread_mutexattr_settype().
config PRIORITY_INHERITANCE
bool "Enable priority inheritance "
default n
---help---
Set to enable support for priority inheritance on mutexes and semaphores.
config SEM_PREALLOCHOLDERS
int "Number of pre-allocated holders"
default 16
depends on PRIORITY_INHERITANCE
---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
depends on PRIORITY_INHERITANCE
---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.
config FDCLONE_DISABLE
bool "Disable cloning of file descriptors"
default n
---help---
Disable cloning of all file descriptors
by task_create() when a new task 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 SCHED_WORKQUEUE
bool "Enable worker thread"
default n
depends on !DISABLE_SIGNALS
---help---
Create a dedicated "worker" thread to handle delayed processing from interrupt
handlers. This feature is required for some drivers but, if there are no
complaints, can be safely disabled. The worker thread also performs
garbage collection -- completing any delayed memory deallocations from
interrupt handlers. If the worker thread is disabled, then that clean up will
be performed by the IDLE thread instead (which runs at the lowest of priority
and may not be appropriate if memory reclamation is of high priority).
config SCHED_WORKPRIORITY
int "Worker thread priority"
default 192
depends on SCHED_WORKQUEUE
---help---
The execution priority of the worker thread. Default: 192
config SCHED_WORKPERIOD
int "Worker thread period"
default 50000
depends on SCHED_WORKQUEUE
---help---
How often the worker thread checks for work in units of microseconds.
Default: 50*1000 (50 MS).
config SCHED_WORKSTACKSIZE
int "Worker thread stack size"
default 2048
depends on SCHED_WORKQUEUE
---help---
The stack size allocated for the worker thread. Default: 2K.
config SCHED_LPWORK
bool "Enable a lower priority worker thread"
default n
depends on SCHED_WORKQUEUE
---help---
If SCHED_WORKQUEUE is defined, then a single work queue is created by
default. If SCHED_LPWORK is also defined then an additional, lower-
priority work queue will also be created. This lower priority work
queue is better suited for more extended processing (such as file system
clean-up operations)
config SCHED_LPWORKPRIORITY
int "Lower priority worker thread priority"
default 50
depends on SCHED_LPWORK
---help---
The execution priority of the lopwer priority worker thread. Default: 192
config SCHED_LPWORKPERIOD
int "Lower priority worker thread period"
default 50000
depends on SCHED_LPWORK
---help---
How often the lower priority worker thread checks for work in units
of microseconds. Default: 50*1000 (50 MS).
config SCHED_LPWORKSTACKSIZE
int "Lower priority worker thread stack size"
default 2048
depends on SCHED_LPWORK
---help---
The stack size allocated for the lower priority worker thread. Default: 2K.
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.
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.
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 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.
o mq_notify logic depends on signals to awaken tasks
waiting for queues to become full or empty.
o pthread_condtimedwait() depends on signals to wake
up waiting tasks.
config DISABLE_CLOCK
bool "Disable clock interfaces"
depends on DISABLE_OS_API
default n
config DISABLE_POSIX_TIMERS
bool "Disable POSIX timers"
depends on DISABLE_OS_API
default n
config DISABLE_PTHREAD
bool "Disable pthread support"
depends on DISABLE_OS_API
default n
config DISABLE_SIGNALS
bool "Disable signal support"
depends on DISABLE_OS_API
default n
config DISABLE_MQUEUE
bool "Disable POSIX message queue support"
depends on DISABLE_OS_API
default n
config DISABLE_MOUNTPOINT
bool "Disable support for mount points"
depends on DISABLE_OS_API
default n
config DISABLE_ENVIRON
bool "Disable environment variable support"
depends on DISABLE_OS_API
default n
config DISABLE_POLL
bool "Disable driver poll interfaces"
depends on DISABLE_OS_API
default n
if !DISABLE_SIGNALS
comment "Signal Numbers"
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
endif
comment "Sizes of configurable things (0 disables)"
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 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 NPTHREAD_KEYS
int "Maximum number of pthread keys"
default 4
---help---
The number of items of thread-
specific data that can be retained
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.
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.
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.
comment "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