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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 | # Kconfig - kernel 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. # choice prompt "Kernel Type" default MICROKERNEL config NANOKERNEL bool "Nano Kernel" config MICROKERNEL bool "Micro Kernel" endchoice menu "General Kernel Options" config SYS_CLOCK_TICKS_PER_SEC int prompt "System tick frequency (in ticks/second)" default 100 help This option specifies the frequency of the system clock in Hz. config SYS_CLOCK_HW_CYCLES_PER_SEC int "System clock's h/w timer frequency" help This option specifies the frequency of the hardware timer used for the system clock (in Hz). This option is set by the platform's Kconfig file and the user should generally avoid modifying it via the menu configuration. config SYS_CLOCK_EXISTS bool # omit prompt to signify a "hidden" option default y default n if (SYS_CLOCK_TICKS_PER_SEC = 0) help This option specifies that the kernel lacks timer support. config INIT_STACKS bool prompt "Initialize stack areas" default n help This option instructs the kernel to initialize stack areas with a known value (0xaa) before they are first used, so that the high water mark can be easily determined. This applies to the stack areas for both tasks and fibers, as well as for the microkernel server's command stack. config XIP bool prompt "Execute in place" help This option allows the kernel to operate with its text and read-only sections residing in ROM (or similar read-only memory). Not all platforms support this option so it must be used with care; you must also supply a linker command file when building your image. Enabling this option increases both the code and data footprint of the image. config RING_BUFFER bool prompt "Enable ring buffers" default n help Enable usage of ring buffers. Similar to nanokernel FIFOs but manage their own buffer memory and can store arbitrary data. For optimal performance, use buffer sizes that are a power of 2. config KERNEL_EVENT_LOGGER bool prompt "Enable kernel event logger features" default n help This feature enables the usage of the profiling logger. Provides the logging of sleep events (either entering or leaving low power conditions), context switch events, interrupt events, boot events and a method to collect these event messages. config KERNEL_EVENT_LOGGER_BUFFER_SIZE int prompt "Kernel event logger buffer size" default 128 depends on KERNEL_EVENT_LOGGER help Buffer size in 32-bit words. config THREAD_MONITOR bool prompt "Task and fiber monitoring [EXPERIMENTAL]" default n help This option instructs the kernel to maintain a list of all tasks and fibers (excluding those that have not yet started or have already terminated). config KERNEL_INIT_PRIORITY_DEFAULT int prompt "Default init priority" help Defaut minimal init priority for each init level. config KERNEL_INIT_PRIORITY_DEVICE int prompt "Default init priority for device drivers" help Device driver, that depends on common components, such as interrupt controller, but does not depend on other devices, uses this init priority. menu "Kernel event logging points" depends on KERNEL_EVENT_LOGGER config KERNEL_EVENT_LOGGER_CONTEXT_SWITCH bool prompt "Context switch event logging point" default n depends on KERNEL_EVENT_LOGGER help Enable the context switch event messages. config KERNEL_EVENT_LOGGER_INTERRUPT bool prompt "Interrupt event logging point" default n depends on KERNEL_EVENT_LOGGER help Enable interrupt event messages. These messages provide the following information: The time when interrupts occur. config KERNEL_EVENT_LOGGER_SLEEP bool prompt "Sleep event logging point" default n depends on KERNEL_EVENT_LOGGER && ((MICROKERNEL && SYS_POWER_MANAGEMENT) || NANOKERNEL) help Enable low power condition event messages. These messages provide the following information: - When the CPU went to sleep mode. - When the CPU woke up. - The ID of the interrupt that woke the CPU up. endmenu menu "Security Options" config STACK_CANARIES bool prompt "Compiler stack canaries" default n help This option enables compiler stack canaries support kernel functions. If stack canaries are supported by the compiler, it will emit extra code that inserts a canary value into the stack frame when a function is entered and validates this value upon exit. Stack corruption (such as that caused by buffer overflow) results in a fatal error condition for the running entity. Enabling this option can result in a significant increase in footprint and an associated decrease in performance. If stack canaries are not supported by the compiler, enabling this option has no effect. endmenu endmenu source "kernel/nanokernel/Kconfig" if MICROKERNEL source "kernel/microkernel/Kconfig" endif menu "Power Management" config SYS_POWER_MANAGEMENT bool prompt "Power management" default n help This option enables the platform to implement extra power management policies whenever the kernel becomes idle. The kernel informs the power management subsystem of the number of ticks until the next kernel timer is due to expire. menu "Power Management Features" depends on SYS_POWER_MANAGEMENT config SYS_POWER_LOW_POWER_STATE bool prompt "Low power state" default n depends on MICROKERNEL && SYS_POWER_MANAGEMENT && SYS_POWER_LOW_POWER_STATE_SUPPORTED help This option enables the kernel to interface with a power manager application. This permits the system to enter a custom CPU low power state when the kernel becomes idle. The low power state could be any of the CPU low power states supported by the processor. Generally the one saving most power. config SYS_POWER_DEEP_SLEEP bool prompt "Deep sleep state" default n depends on MICROKERNEL && SYS_POWER_MANAGEMENT && SYS_POWER_DEEP_SLEEP_SUPPORTED help This option enables the kernel to interface with a power manager application. This permits the system to enter a Deep sleep state supported by the SOC where the system clock is turned off while RAM is retained. This state would be entered when the kernel becomes idle for extended periods and would have a high wake latency. Resume would be from the reset vector same as cold boot. The interface allows restoration of states that were saved at the time of suspend. config DEVICE_POWER_MANAGEMENT bool prompt "Device power management" default n depends on MICROKERNEL && SYS_POWER_MANAGEMENT help This option enables the device power management interface. The interface consists of hook functions implemented by device drivers that get called by the power manager application when the system is going to suspend state or resuming from suspend state. This allows device drivers to do any necessary power management operations like turning off device clocks and peripherals. The device drivers may also save and restore states in these hook functions. config TICKLESS_IDLE bool prompt "Tickless idle" default y depends on MICROKERNEL || NANOKERNEL_TICKLESS_IDLE_SUPPORTED help This option suppresses periodic system clock interrupts whenever the kernel becomes idle. This permits the system to remain in a power saving state for extended periods without having to wake up to service each tick as it occurs. As a policy, an architecture should always provide support for tickless in the microkernel. If an architecture also provides support for nanokernel systems, it must select the NANOKERNEL_TICKLESS_IDLE_SUPPORTED kconfig option. config TICKLESS_IDLE_THRESH int prompt "Tickless idle threshold" default 3 depends on TICKLESS_IDLE help This option enables clock interrupt suppression when the kernel idles for only a short period of time. It specifies the minimum number of ticks that must occur before the next kernel timer expires in order for suppression to happen. endmenu endmenu |