# Kconfig - microkernel configuration options # # Copyright (c) 2014-2015 Wind River Systems, Inc. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # menu "Microkernel Options" config MICROKERNEL_SERVER_STACK_SIZE int prompt "Microkernel server fiber (_k_server) stack size" default 1024 depends on MICROKERNEL help This option specifies the size of the stack used by the microkernel server fiber, whose entry point is _k_server(). This must be able to handle the deepest call stack for internal handling of microkernel config MICROKERNEL_SERVER_PRIORITY int prompt "Priority of the kernel service fiber" default 0 depends on MICROKERNEL help Priority of the microkernel server fiber that performs kernel requests and task scheduling assignments. config PRIORITY_CEILING int prompt "Maximum priority for priority inheritance algorithm" default 0 depends on MICROKERNEL help The highest task priority for the mutex priority inheritance algorithm. A task of low priority holding a mutex will see its priority bumped to the priority of a task trying to acquire the mutex. This option puts an upper boundary to the priority a task may get bumped to. config COMMAND_STACK_SIZE int prompt "Microkernel server command stack size (in packets)" default 64 depends on MICROKERNEL help This option specifies the maximum number of command packets that can be queued up for processing by the kernel's _k_server fiber. config NUM_COMMAND_PACKETS int prompt "Number of command packets" default 16 depends on MICROKERNEL help This option specifies the number of packets in the command packet pool. This pool needs to be large enough to accommodate all in-flight asynchronous command requests as well as those internally issued by the microkernel server fiber (_k_server). config NUM_TIMER_PACKETS int prompt "Number of timer packets" if SYS_CLOCK_EXISTS default 0 if !SYS_CLOCK_EXISTS default 10 if SYS_CLOCK_EXISTS depends on MICROKERNEL help This option specifies the number of timer packets to create. Each explicit and implicit timer usage consumes one timer packet. config NUM_TASK_PRIORITIES int prompt "Number of task priorities" default 16 range 1 256 depends on MICROKERNEL help This option specifies the number of task priorities supported by the task scheduler. Specifying "N" provides support for task priorities ranging from 0 (highest) through N-2; task priority N-1 (lowest) is reserved for the kernel's idle task. config WORKLOAD_MONITOR bool prompt "Workload monitoring [EXPERIMENTAL]" default n depends on MICROKERNEL help This option instructs the kernel to record the percentage of time the system is doing useful work (i.e. is not idle). config MAX_NUM_TASK_IRQS int prompt "Number of task IRQ objects" default 0 depends on MICROKERNEL help This option specifies the maximum number of IRQs that may be utilized by task level device drivers. A value of zero disables this feature. menu "Timer API Options" config TIMESLICING bool prompt "Task time slicing" default y depends on MICROKERNEL && SYS_CLOCK_EXISTS help This option enables time slicing between tasks of equal priority. config TIMESLICE_SIZE int prompt "Time slice size (in ticks)" default 0 depends on TIMESLICING help This option specifies the maximum amount of time a task can execute before other tasks of equal priority are given an opportunity to run. A time slice size of zero means "no limit" (i.e. an infinitely large time slice). config TIMESLICE_PRIORITY int prompt "Time slicing task priority threshold" default 0 depends on TIMESLICING help This option specifies the task priority level at which time slicing takes effect; tasks having a higher priority than this threshold are not subject to time slicing. A threshold level of zero means that all tasks are potentially subject to time slicing. endmenu config TASK_MONITOR bool prompt "Task monitoring [EXPERIMENTAL]" default n depends on MICROKERNEL && KERNEL_EVENT_LOGGER help This option instructs the kernel to record significant task activities. These can include: task switches, task state changes, kernel service requests, and the signalling of events. config TASK_MONITOR_MASK int prompt "Trace buffer mask" default 15 depends on TASK_MONITOR help This option specifies which task execution activities are captured in the task monitor's trace buffer. The following values can be OR-ed together to form the mask: 1 (MON_TSWAP): task switch 2 (MON_STATE): task state change 4 (MON_KSERV): task execution of kernel APIs 8 (MON_EVENT): task event signalled config OBJECT_MONITOR bool prompt "Kernel object monitoring [EXPERIMENTAL]" default n depends on MICROKERNEL help This option instructs the kernel to record statistics about microkernel object usage. endmenu