1 # Copyright (C) 2006-2014 OpenWrt.org
3 # This is free software, licensed under the GNU General Public License v2.
4 # See /LICENSE for more information.
7 config KERNEL_BUILD_USER
8 string "Custom Kernel Build User Name"
11 Sets the Kernel build user string, which for example will be returned
12 by 'uname -a' on running systems.
13 If not set, uses system user at build time.
15 config KERNEL_BUILD_DOMAIN
16 string "Custom Kernel Build Domain Name"
19 Sets the Kernel build domain string, which for example will be
20 returned by 'uname -a' on running systems.
21 If not set, uses system hostname at build time.
24 bool "Enable support for printk"
27 config KERNEL_CRASHLOG
29 depends on !(arm || powerpc || sparc || TARGET_uml || i386 || x86_64)
33 bool "Support for paging of anonymous memory (swap)"
34 default y if !SMALL_FLASH
36 config KERNEL_DEBUG_FS
37 bool "Compile the kernel with debug filesystem enabled"
40 debugfs is a virtual file system that kernel developers use to put
41 debugging files into. Enable this option to be able to read and
42 write to these files. Many common debugging facilities, such as
43 ftrace, require the existence of debugfs.
45 config KERNEL_MIPS_FPU_EMULATOR
46 bool "Compile the kernel with MIPS FPU Emulator"
47 default y if TARGET_pistachio
48 depends on (mips || mipsel || mips64 || mips64el)
53 depends on (arm || aarch64)
55 config KERNEL_PERF_EVENTS
56 bool "Compile the kernel with performance events and counters"
58 select KERNEL_ARM_PMU if (arm || aarch64)
60 config KERNEL_PROFILING
61 bool "Compile the kernel with profiling enabled"
63 select KERNEL_PERF_EVENTS
65 Enable the extended profiling support mechanisms used by profilers such
68 config KERNEL_TASKSTATS
69 bool "Compile the kernel with task resource/io statistics and accounting"
72 Enable the collection and publishing of task/io statistics and
73 accounting. Enable this option to enable i/o monitoring in system
78 config KERNEL_TASK_DELAY_ACCT
81 config KERNEL_TASK_IO_ACCOUNTING
84 config KERNEL_TASK_XACCT
89 config KERNEL_KALLSYMS
90 bool "Compile the kernel with symbol table information"
91 default y if !SMALL_FLASH
93 This will give you more information in stack traces from kernel oopses.
96 bool "Compile the kernel with tracing support"
97 depends on !TARGET_uml
100 config KERNEL_FTRACE_SYSCALLS
101 bool "Trace system calls"
102 depends on KERNEL_FTRACE
105 config KERNEL_ENABLE_DEFAULT_TRACERS
106 bool "Trace process context switches and events"
107 depends on KERNEL_FTRACE
110 config KERNEL_FUNCTION_TRACER
111 bool "Function tracer"
112 depends on KERNEL_FTRACE
115 config KERNEL_FUNCTION_GRAPH_TRACER
116 bool "Function graph tracer"
117 depends on KERNEL_FUNCTION_TRACER
120 config KERNEL_DYNAMIC_FTRACE
121 bool "Enable/disable function tracing dynamically"
122 depends on KERNEL_FUNCTION_TRACER
125 config KERNEL_FUNCTION_PROFILER
126 bool "Function profiler"
127 depends on KERNEL_FUNCTION_TRACER
130 config KERNEL_DEBUG_KERNEL
134 config KERNEL_DEBUG_INFO
135 bool "Compile the kernel with debug information"
136 default y if !SMALL_FLASH
137 select KERNEL_DEBUG_KERNEL
139 This will compile your kernel and modules with debug information.
141 config KERNEL_DEBUG_LL_UART_NONE
146 config KERNEL_DEBUG_LL
150 select KERNEL_DEBUG_LL_UART_NONE
152 ARM low level debugging.
154 config KERNEL_DYNAMIC_DEBUG
155 bool "Compile the kernel with dynamic printk"
156 select KERNEL_DEBUG_FS
159 Compiles debug level messages into the kernel, which would not
160 otherwise be available at runtime. These messages can then be
161 enabled/disabled based on various levels of scope - per source file,
162 function, module, format string, and line number. This mechanism
163 implicitly compiles in all pr_debug() and dev_dbg() calls, which
164 enlarges the kernel text size by about 2%.
166 config KERNEL_EARLY_PRINTK
167 bool "Compile the kernel with early printk"
168 default y if TARGET_bcm53xx
171 select KERNEL_DEBUG_KERNEL
172 select KERNEL_DEBUG_LL if arm
174 Compile the kernel with early printk support. This is only useful for
175 debugging purposes to send messages over the serial console in early boot.
176 Enable this to debug early boot problems.
178 config KERNEL_KPROBES
179 bool "Compile the kernel with kprobes support"
182 select KERNEL_PERF_EVENTS
184 Compiles the kernel with KPROBES support, which allows you to trap
185 at almost any kernel address and execute a callback function.
186 register_kprobe() establishes a probepoint and specifies the
187 callback. Kprobes is useful for kernel debugging, non-intrusive
188 instrumentation and testing.
189 If in doubt, say "N".
191 config KERNEL_KPROBE_EVENT
193 default y if KERNEL_KPROBES
196 bool "Compile the kernel with asynchronous IO support"
199 config KERNEL_FHANDLE
200 bool "Compile the kernel with support for fhandle syscalls"
203 config KERNEL_FANOTIFY
204 bool "Compile the kernel with modern file notification support"
207 config KERNEL_BLK_DEV_BSG
208 bool "Compile the kernel with SCSI generic v4 support for any block device"
211 config KERNEL_MAGIC_SYSRQ
212 bool "Compile the kernel with SysRq support"
215 config KERNEL_DEBUG_PINCTRL
216 bool "Compile the kernel with pinctrl debugging"
217 select KERNEL_DEBUG_KERNEL
219 config KERNEL_DEBUG_GPIO
220 bool "Compile the kernel with gpio debugging"
221 select KERNEL_DEBUG_KERNEL
223 config KERNEL_COREDUMP
226 config KERNEL_ELF_CORE
227 bool "Enable process core dump support"
228 select KERNEL_COREDUMP
229 default y if !SMALL_FLASH
231 config KERNEL_PROVE_LOCKING
232 bool "Enable kernel lock checking"
233 select KERNEL_DEBUG_KERNEL
236 config KERNEL_PRINTK_TIME
237 bool "Enable printk timestamps"
240 config KERNEL_SLUB_DEBUG
243 config KERNEL_SLUB_DEBUG_ON
246 config KERNEL_SLABINFO
247 select KERNEL_SLUB_DEBUG
248 select KERNEL_SLUB_DEBUG_ON
249 bool "Enable /proc slab debug info"
251 config KERNEL_PROC_PAGE_MONITOR
252 bool "Enable /proc page monitoring"
258 bool "Enable kexec support"
260 config KERNEL_PROC_VMCORE
263 config KERNEL_CRASH_DUMP
264 depends on i386 || x86_64 || arm || armeb
266 select KERNEL_PROC_VMCORE
267 bool "Enable support for kexec crashdump"
271 bool "Enable rfkill support"
272 default RFKILL_SUPPORT
275 bool "Enable sparse check during kernel build"
278 config KERNEL_DEVTMPFS
279 bool "Compile the kernel with device tmpfs enabled"
282 devtmpfs is a simple, kernel-managed /dev filesystem. The kernel creates
283 devices nodes for all registered devices to simplify boot, but leaves more
284 complex tasks to userspace (e.g. udev).
288 config KERNEL_DEVTMPFS_MOUNT
289 bool "Automatically mount devtmpfs after root filesystem is mounted"
295 bool "Enable kernel access key retention support"
298 config KERNEL_PERSISTENT_KEYRINGS
299 bool "Enable kernel persistent keyrings"
300 depends on KERNEL_KEYS
303 config KERNEL_BIG_KEYS
304 bool "Enable large payload keys on kernel keyrings"
305 depends on KERNEL_KEYS
308 config KERNEL_ENCRYPTED_KEYS
309 tristate "Enable keys with encrypted payloads on kernel keyrings"
310 depends on KERNEL_KEYS
314 # CGROUP support symbols
317 config KERNEL_CGROUPS
318 bool "Enable kernel cgroups"
323 config KERNEL_CGROUP_DEBUG
324 bool "Example debug cgroup subsystem"
327 This option enables a simple cgroup subsystem that
328 exports useful debugging information about the cgroups
331 config KERNEL_FREEZER
333 default y if KERNEL_CGROUP_FREEZER
335 config KERNEL_CGROUP_FREEZER
336 bool "Freezer cgroup subsystem"
339 Provides a way to freeze and unfreeze all tasks in a
342 config KERNEL_CGROUP_DEVICE
343 bool "Device controller for cgroups"
346 Provides a cgroup implementing whitelists for devices which
347 a process in the cgroup can mknod or open.
349 config KERNEL_CGROUP_PIDS
350 bool "PIDs cgroup subsystem"
353 Provides enforcement of process number limits in the scope of a
356 config KERNEL_CPUSETS
357 bool "Cpuset support"
360 This option will let you create and manage CPUSETs which
361 allow dynamically partitioning a system into sets of CPUs and
362 Memory Nodes and assigning tasks to run only within those sets.
363 This is primarily useful on large SMP or NUMA systems.
365 config KERNEL_PROC_PID_CPUSET
366 bool "Include legacy /proc/<pid>/cpuset file"
368 depends on KERNEL_CPUSETS
370 config KERNEL_CGROUP_CPUACCT
371 bool "Simple CPU accounting cgroup subsystem"
374 Provides a simple Resource Controller for monitoring the
375 total CPU consumed by the tasks in a cgroup.
377 config KERNEL_RESOURCE_COUNTERS
378 bool "Resource counters"
381 This option enables controller independent resource accounting
382 infrastructure that works with cgroups.
384 config KERNEL_MM_OWNER
386 default y if KERNEL_MEMCG
389 bool "Memory Resource Controller for Control Groups"
391 depends on KERNEL_RESOURCE_COUNTERS || !LINUX_3_18
393 Provides a memory resource controller that manages both anonymous
394 memory and page cache. (See Documentation/cgroups/memory.txt)
396 Note that setting this option increases fixed memory overhead
397 associated with each page of memory in the system. By this,
398 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
399 usage tracking struct at boot. Total amount of this is printed out
402 Only enable when you're ok with these tradeoffs and really
403 sure you need the memory resource controller. Even when you enable
404 this, you can set "cgroup_disable=memory" at your boot option to
405 disable memory resource controller and you can avoid overheads
406 (but lose benefits of memory resource controller).
408 This config option also selects MM_OWNER config option, which
409 could in turn add some fork/exit overhead.
411 config KERNEL_MEMCG_SWAP
412 bool "Memory Resource Controller Swap Extension"
414 depends on KERNEL_MEMCG
416 Add swap management feature to memory resource controller. When you
417 enable this, you can limit mem+swap usage per cgroup. In other words,
418 when you disable this, memory resource controller has no cares to
419 usage of swap...a process can exhaust all of the swap. This extension
420 is useful when you want to avoid exhaustion swap but this itself
421 adds more overheads and consumes memory for remembering information.
422 Especially if you use 32bit system or small memory system, please
423 be careful about enabling this. When memory resource controller
424 is disabled by boot option, this will be automatically disabled and
425 there will be no overhead from this. Even when you set this config=y,
426 if boot option "swapaccount=0" is set, swap will not be accounted.
427 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
428 size is 4096bytes, 512k per 1Gbytes of swap.
430 config KERNEL_MEMCG_SWAP_ENABLED
431 bool "Memory Resource Controller Swap Extension enabled by default"
433 depends on KERNEL_MEMCG_SWAP
435 Memory Resource Controller Swap Extension comes with its price in
436 a bigger memory consumption. General purpose distribution kernels
437 which want to enable the feature but keep it disabled by default
438 and let the user enable it by swapaccount boot command line
439 parameter should have this option unselected.
441 Those who want to have the feature enabled by default should
442 select this option (if, for some reason, they need to disable it,
443 then swapaccount=0 does the trick).
446 config KERNEL_MEMCG_KMEM
447 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
449 depends on KERNEL_MEMCG
451 The Kernel Memory extension for Memory Resource Controller can limit
452 the amount of memory used by kernel objects in the system. Those are
453 fundamentally different from the entities handled by the standard
454 Memory Controller, which are page-based, and can be swapped. Users of
455 the kmem extension can use it to guarantee that no group of processes
456 will ever exhaust kernel resources alone.
458 config KERNEL_CGROUP_PERF
459 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
460 select KERNEL_PERF_EVENTS
463 This option extends the per-cpu mode to restrict monitoring to
464 threads which belong to the cgroup specified and run on the
467 menuconfig KERNEL_CGROUP_SCHED
468 bool "Group CPU scheduler"
471 This feature lets CPU scheduler recognize task groups and control CPU
472 bandwidth allocation to such task groups. It uses cgroups to group
475 if KERNEL_CGROUP_SCHED
477 config KERNEL_FAIR_GROUP_SCHED
478 bool "Group scheduling for SCHED_OTHER"
481 config KERNEL_CFS_BANDWIDTH
482 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
484 depends on KERNEL_FAIR_GROUP_SCHED
486 This option allows users to define CPU bandwidth rates (limits) for
487 tasks running within the fair group scheduler. Groups with no limit
488 set are considered to be unconstrained and will run with no
490 See tip/Documentation/scheduler/sched-bwc.txt for more information.
492 config KERNEL_RT_GROUP_SCHED
493 bool "Group scheduling for SCHED_RR/FIFO"
496 This feature lets you explicitly allocate real CPU bandwidth
497 to task groups. If enabled, it will also make it impossible to
498 schedule realtime tasks for non-root users until you allocate
499 realtime bandwidth for them.
503 config KERNEL_BLK_CGROUP
504 bool "Block IO controller"
507 Generic block IO controller cgroup interface. This is the common
508 cgroup interface which should be used by various IO controlling
511 Currently, CFQ IO scheduler uses it to recognize task groups and
512 control disk bandwidth allocation (proportional time slice allocation)
513 to such task groups. It is also used by bio throttling logic in
514 block layer to implement upper limit in IO rates on a device.
516 This option only enables generic Block IO controller infrastructure.
517 One needs to also enable actual IO controlling logic/policy. For
518 enabling proportional weight division of disk bandwidth in CFQ, set
519 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
520 CONFIG_BLK_DEV_THROTTLING=y.
522 config KERNEL_DEBUG_BLK_CGROUP
523 bool "Enable Block IO controller debugging"
525 depends on KERNEL_BLK_CGROUP
527 Enable some debugging help. Currently it exports additional stat
528 files in a cgroup which can be useful for debugging.
530 config KERNEL_NET_CLS_CGROUP
531 bool "Control Group Classifier"
534 config KERNEL_NETPRIO_CGROUP
535 bool "Network priority cgroup"
541 # Namespace support symbols
544 config KERNEL_NAMESPACES
545 bool "Enable kernel namespaces"
554 In this namespace, tasks see different info provided
555 with the uname() system call.
561 In this namespace, tasks work with IPC ids which correspond to
562 different IPC objects in different namespaces.
564 config KERNEL_USER_NS
565 bool "User namespace (EXPERIMENTAL)"
568 This allows containers, i.e. vservers, to use user namespaces
569 to provide different user info for different servers.
572 bool "PID Namespaces"
575 Support process id namespaces. This allows having multiple
576 processes with the same pid as long as they are in different
577 pid namespaces. This is a building block of containers.
580 bool "Network namespace"
583 Allow user space to create what appear to be multiple instances
584 of the network stack.
589 # LXC related symbols
592 config KERNEL_LXC_MISC
593 bool "Enable miscellaneous LXC related options"
598 config KERNEL_DEVPTS_MULTIPLE_INSTANCES
599 bool "Support multiple instances of devpts"
602 Enable support for multiple instances of devpts filesystem.
603 If you want to have isolated PTY namespaces (eg: in containers),
604 say Y here. Otherwise, say N. If enabled, each mount of devpts
605 filesystem with the '-o newinstance' option will create an
606 independent PTY namespace.
608 config KERNEL_POSIX_MQUEUE
609 bool "POSIX Message Queues"
612 POSIX variant of message queues is a part of IPC. In POSIX message
613 queues every message has a priority which decides about succession
614 of receiving it by a process. If you want to compile and run
615 programs written e.g. for Solaris with use of its POSIX message
616 queues (functions mq_*) say Y here.
618 POSIX message queues are visible as a filesystem called 'mqueue'
619 and can be mounted somewhere if you want to do filesystem
620 operations on message queues.
624 config KERNEL_SECCOMP_FILTER
628 config KERNEL_SECCOMP
629 bool "Enable seccomp support"
630 depends on !(TARGET_uml)
631 select KERNEL_SECCOMP_FILTER
634 Build kernel with support for seccomp.
640 config KERNEL_IP_MROUTE
641 bool "Enable IPv4 multicast routing"
644 Multicast routing requires a multicast routing daemon in
645 addition to kernel support.
656 config KERNEL_IPV6_MULTIPLE_TABLES
659 config KERNEL_IPV6_SUBTREES
662 config KERNEL_IPV6_MROUTE
663 bool "Enable IPv6 multicast routing"
666 Multicast routing requires a multicast routing daemon in
667 addition to kernel support.
669 config KERNEL_IPV6_PIMSM_V2
675 # NFS related symbols
678 bool "Compile the kernel with rootfs on NFS"
680 If you want to make your kernel boot off a NFS server as root
681 filesystem, select Y here.
685 config KERNEL_IP_PNP_DHCP
688 config KERNEL_IP_PNP_BOOTP
691 config KERNEL_IP_PNP_RARP
703 config KERNEL_ROOT_NFS
708 menu "Filesystem ACL and attr support options"
709 config USE_FS_ACL_ATTR
710 bool "Use filesystem ACL and attr support by default"
713 Make using ACLs (e.g. POSIX ACL, NFSv4 ACL) the default
714 for kernel and packages, except tmpfs, flash filesystems,
715 and old NFS. Also enable userspace extended attribute support
716 by default. (OpenWrt already has an expection it will be
717 present in the kernel).
719 config KERNEL_FS_POSIX_ACL
720 bool "Enable POSIX ACL support"
721 default y if USE_FS_ACL_ATTR
723 config KERNEL_BTRFS_FS_POSIX_ACL
724 bool "Enable POSIX ACL for BtrFS Filesystems"
725 select KERNEL_FS_POSIX_ACL
726 default y if USE_FS_ACL_ATTR
728 config KERNEL_EXT4_FS_POSIX_ACL
729 bool "Enable POSIX ACL for Ext4 Filesystems"
730 select KERNEL_FS_POSIX_ACL
731 default y if USE_FS_ACL_ATTR
733 config KERNEL_F2FS_FS_POSIX_ACL
734 bool "Enable POSIX ACL for F2FS Filesystems"
735 select KERNEL_FS_POSIX_ACL
738 config KERNEL_JFFS2_FS_POSIX_ACL
739 bool "Enable POSIX ACL for JFFS2 Filesystems"
740 select KERNEL_FS_POSIX_ACL
743 config KERNEL_TMPFS_POSIX_ACL
744 bool "Enable POSIX ACL for TMPFS Filesystems"
745 select KERNEL_FS_POSIX_ACL
748 config KERNEL_CIFS_ACL
749 bool "Enable CIFS ACLs"
750 select KERNEL_FS_POSIX_ACL
751 default y if USE_FS_ACL_ATTR
753 config KERNEL_HFS_FS_POSIX_ACL
754 bool "Enable POSIX ACL for HFS Filesystems"
755 select KERNEL_FS_POSIX_ACL
756 default y if USE_FS_ACL_ATTR
758 config KERNEL_HFSPLUG_FS_POSIX_ACL
759 bool "Enable POSIX ACL for HFS+ Filesystems"
760 select KERNEL_FS_POSIX_ACL
761 default y if USE_FS_ACL_ATTR
763 config KERNEL_NFS_ACL_SUPPORT
764 bool "Enable ACLs for NFS"
765 default y if USE_FS_ACL_ATTR
767 config KERNEL_NFS_V3_ACL_SUPPORT
768 bool "Enable ACLs for NFSv3"
771 config KERNEL_NFSD_V2_ACL_SUPPORT
772 bool "Enable ACLs for NFSDv2"
775 config KERNEL_NFSD_V3_ACL_SUPPORT
776 bool "Enable ACLs for NFSDv3"
779 config KERNEL_REISER_FS_POSIX_ACL
780 bool "Enable POSIX ACLs for ReiserFS"
781 select KERNEL_FS_POSIX_ACL
782 default y if USE_FS_ACL_ATTR
784 config KERNEL_XFS_POSIX_ACL
785 bool "Enable POSIX ACLs for XFS"
786 select KERNEL_FS_POSIX_ACL
787 default y if USE_FS_ACL_ATTR
789 config KERNEL_JFS_POSIX_ACL
790 bool "Enable POSIX ACLs for JFS"
791 select KERNEL_FS_POSIX_ACL
792 default y if USE_FS_ACL_ATTR
797 bool "/dev/mem virtual device support"
799 Say Y here if you want to support the /dev/mem device.
800 The /dev/mem device is used to access areas of physical
803 config KERNEL_DEVKMEM
804 bool "/dev/kmem virtual device support"
806 Say Y here if you want to support the /dev/kmem device. The
807 /dev/kmem device is rarely used, but can be used for certain
808 kind of kernel debugging operations.
810 config KERNEL_SQUASHFS_FRAGMENT_CACHE_SIZE
811 int "Number of squashfs fragments cached"
812 default 2 if (SMALL_FLASH && !LOW_MEMORY_FOOTPRINT)
816 # compile optimiziation setting
819 prompt "Compiler optimization level"
820 default KERNEL_CC_OPTIMIZE_FOR_SIZE if SMALL_FLASH
822 config KERNEL_CC_OPTIMIZE_FOR_PERFORMANCE
823 bool "Optimize for performance"
825 This is the default optimization level for the kernel, building
826 with the "-O2" compiler flag for best performance and most
827 helpful compile-time warnings.
829 config KERNEL_CC_OPTIMIZE_FOR_SIZE
830 bool "Optimize for size"
832 Enabling this option will pass "-Os" instead of "-O2" to
833 your compiler resulting in a smaller kernel.