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|
#
# 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
---help---
By 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 platform specific interfaces that must be provided as
defined include/nuttx/arch.h
if SCHED_TICKLESS
config SCHED_TICKLESS_ALARM
bool "Tickless alarm"
default n
---help---
The tickless option can be supported either via a simple interval
timer (plus elapsed time) or via an alarm. The interval timer allows
programming events to occur after an interval. With the alarm,
you can set a time in the future and get an event when that alarm
goes off. This option selects the use of an alarm.
The advantage of an alarm is that it avoids some small timing
errors; the advantage of the use of the interval timer is that
the hardware requirement may be less.
endif
config USEC_PER_TICK
int "System timer tick period (microseconds)"
default 10000 if !SCHED_TICKLESS
default 100 if SCHED_TICKLESS
---help---
In the "normal" configuration where system time is provided by a
periodic timer interrupt, the default system timer is expected to
run at 100Hz or USEC_PER_TICK=10000. This setting must be defined
to inform of NuttX the interval that the the processor hardware is
providing system timer interrupts to the OS.
If SCHED_TICKLESS is selected, then there are no system timer
interrupts. In this case, USEC_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 this
case there is a trade-off: It is better to have the USEC_PER_TICK as
low as possible for higher timing resolution. However, the the time
is currently held in 'unsigned int' on some systems, this may be
16-bits but on most contemporary systems it will be 32-bits. In
either case, smaller values of USEC_PER_TICK will reduce the range
of values that delays that can be represented. So the trade-off is
between range and resolution (you could also modify the code to use
a 64-bit value if you really want both).
The default, 100 microseconds, will provide for a range of delays
up to 120 hours.
This value should never be less than the underlying resolution of
the timer. Error may ensue.
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
USEC_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. Dynamic allocations will still be made if this pool is
exhausted. You will, however, get better performance and memory
usage if this value is tuned to minimize such allocations.
config WDOG_INTRESERVE
int "Watchdog structures reserved for interrupt handlers"
default 4
---help---
Watchdog structures may be allocated from normal task and also from
interrupt handlers. Interrupt handlers, however, can only use pre-
allocated watchdog timer. So, in order to keep normal task
allocations from exhausting all watchdog structures, a small number
of pre-allocated watchdog timers must be reserved for exclusive use
by interrupt handler. This setting determines that number of
reserved watchdogs.
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"
choice
prompt "Initialization Task"
default INIT_ENTRYPOINT if !BUILD_KERNEL
default INIT_FILEPATH if BUILD_KERNEL && !BINFMT_DISABLE
default INIT_NONE if BUILD_KERNEL && BINFMT_DISABLE
config INIT_NONE
bool "None"
config INIT_ENTRYPOINT
bool "Via application entry point"
depends on !BUILD_KERNEL
config INIT_FILEPATH
bool "Via executable file"
depends on !BINFMT_DISABLE
endchoice # Initialization task
if INIT_ENTRYPOINT
config USER_ENTRYPOINT
string "Application entry point"
default "main"
---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 "main".
endif # INIT_ENTRYPOINT
if INIT_FILEPATH
config USER_INITPATH
string "Application initialization path"
default "/bin/init"
---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 "main".
config INIT_SYMTAB
string "Symbol table"
default "NULL"
depends on !BUILD_PROTECTED && !BUILD_KERNEL
---help---
The name of othe global array that holds the exported symbol table.
The special string "NULL" may be provided if there is no symbol
table. Quotation marks will be stripped when config.h is generated.
NOTE: This setting cannot be used in protected or kernel builds.
Any kernel mode symbols tables would not be usable for resolving
symbols in user mode executables.
config INIT_NEXPORTS
string "Symbol table size"
default "0"
depends on !BUILD_PROTECTED && !BUILD_KERNEL
---help---
The size of the symbol table. NOTE that is is logically a numeric
value but is represent by a string. That allows you to put
sizeof(something) or a macro or a global variable name for the
symbol table size. Quotation marks will be stripped when config.h
is generated.
NOTE: This setting cannot be used in protected or kernel builds.
Any kernel mode symbols tables would not be usable for resolving
symbols in user mode executables.
endif # INIT_FILEPATH
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) <arch>_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/<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.
if BOARD_INITIALIZE
config BOARD_INITTHREAD
bool "Board initialization thread"
default n
---help---
Some initialization operations cannot be performed on the start-up,
initialization thread. That is because the initialization thread
cannot wait for event. If waiting is required as part of the board
initialization then this option must be selected. Waiting may be
required, for example, to mount a file system or or initialize a
device such as an SD card.
if BOARD_INITTHREAD
config BOARD_INITTHREAD_STACKSIZE
int "Board initialization thread stack size"
default 2048
---help---
The size of the stack to allocate when starting the board
initialization thread.
config BOARD_INITTHREAD_PRIORITY
int "Board initialization thread priority"
default 240
---help---
The priority of the board initialization thread. This priority is
not a critical setting. No other application threads will be
started until the board initialization is completed. Hence, there
is very little competition for the CPU.
endif # BOARD_INITTHREAD
endif # BOARD_INITIALIZE
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_POLL
int "SIGPOLL"
default 5
depends on LIBC_AIO
---help---
The SIGPOLL signal is sent to a process when an asynchronous I/O
event occurs (meaning it has been polled). Default: 5
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 initial boot of the system up to the
point where start-up appliation 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 user initialization thread
that is started as soon as the OS completes its initialization.
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
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