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
195 config KERNEL_KPROBE_EVENTS
197 default y if KERNEL_KPROBES
200 bool "Compile the kernel with asynchronous IO support"
203 config KERNEL_FHANDLE
204 bool "Compile the kernel with support for fhandle syscalls"
207 config KERNEL_FANOTIFY
208 bool "Compile the kernel with modern file notification support"
211 config KERNEL_BLK_DEV_BSG
212 bool "Compile the kernel with SCSI generic v4 support for any block device"
215 config KERNEL_MAGIC_SYSRQ
216 bool "Compile the kernel with SysRq support"
219 config KERNEL_DEBUG_PINCTRL
220 bool "Compile the kernel with pinctrl debugging"
221 select KERNEL_DEBUG_KERNEL
223 config KERNEL_DEBUG_GPIO
224 bool "Compile the kernel with gpio debugging"
225 select KERNEL_DEBUG_KERNEL
227 config KERNEL_COREDUMP
230 config KERNEL_ELF_CORE
231 bool "Enable process core dump support"
232 select KERNEL_COREDUMP
233 default y if !SMALL_FLASH
235 config KERNEL_PROVE_LOCKING
236 bool "Enable kernel lock checking"
237 select KERNEL_DEBUG_KERNEL
240 config KERNEL_PRINTK_TIME
241 bool "Enable printk timestamps"
244 config KERNEL_SLUB_DEBUG
247 config KERNEL_SLUB_DEBUG_ON
250 config KERNEL_SLABINFO
251 select KERNEL_SLUB_DEBUG
252 select KERNEL_SLUB_DEBUG_ON
253 bool "Enable /proc slab debug info"
255 config KERNEL_PROC_PAGE_MONITOR
256 bool "Enable /proc page monitoring"
262 bool "Enable kexec support"
264 config KERNEL_PROC_VMCORE
267 config KERNEL_CRASH_DUMP
268 depends on i386 || x86_64 || arm || armeb
270 select KERNEL_PROC_VMCORE
271 bool "Enable support for kexec crashdump"
275 bool "Enable rfkill support"
276 default RFKILL_SUPPORT
279 bool "Enable sparse check during kernel build"
282 config KERNEL_DEVTMPFS
283 bool "Compile the kernel with device tmpfs enabled"
286 devtmpfs is a simple, kernel-managed /dev filesystem. The kernel creates
287 devices nodes for all registered devices to simplify boot, but leaves more
288 complex tasks to userspace (e.g. udev).
292 config KERNEL_DEVTMPFS_MOUNT
293 bool "Automatically mount devtmpfs after root filesystem is mounted"
299 bool "Enable kernel access key retention support"
302 config KERNEL_PERSISTENT_KEYRINGS
303 bool "Enable kernel persistent keyrings"
304 depends on KERNEL_KEYS
307 config KERNEL_BIG_KEYS
308 bool "Enable large payload keys on kernel keyrings"
309 depends on KERNEL_KEYS
312 config KERNEL_ENCRYPTED_KEYS
313 tristate "Enable keys with encrypted payloads on kernel keyrings"
314 depends on KERNEL_KEYS
318 # CGROUP support symbols
321 config KERNEL_CGROUPS
322 bool "Enable kernel cgroups"
327 config KERNEL_CGROUP_DEBUG
328 bool "Example debug cgroup subsystem"
331 This option enables a simple cgroup subsystem that
332 exports useful debugging information about the cgroups
335 config KERNEL_FREEZER
337 default y if KERNEL_CGROUP_FREEZER
339 config KERNEL_CGROUP_FREEZER
340 bool "Freezer cgroup subsystem"
343 Provides a way to freeze and unfreeze all tasks in a
346 config KERNEL_CGROUP_DEVICE
347 bool "Device controller for cgroups"
350 Provides a cgroup implementing whitelists for devices which
351 a process in the cgroup can mknod or open.
353 config KERNEL_CGROUP_PIDS
354 bool "PIDs cgroup subsystem"
357 Provides enforcement of process number limits in the scope of a
360 config KERNEL_CPUSETS
361 bool "Cpuset support"
364 This option will let you create and manage CPUSETs which
365 allow dynamically partitioning a system into sets of CPUs and
366 Memory Nodes and assigning tasks to run only within those sets.
367 This is primarily useful on large SMP or NUMA systems.
369 config KERNEL_PROC_PID_CPUSET
370 bool "Include legacy /proc/<pid>/cpuset file"
372 depends on KERNEL_CPUSETS
374 config KERNEL_CGROUP_CPUACCT
375 bool "Simple CPU accounting cgroup subsystem"
378 Provides a simple Resource Controller for monitoring the
379 total CPU consumed by the tasks in a cgroup.
381 config KERNEL_RESOURCE_COUNTERS
382 bool "Resource counters"
385 This option enables controller independent resource accounting
386 infrastructure that works with cgroups.
388 config KERNEL_MM_OWNER
390 default y if KERNEL_MEMCG
393 bool "Memory Resource Controller for Control Groups"
395 depends on KERNEL_RESOURCE_COUNTERS || !LINUX_3_18
397 Provides a memory resource controller that manages both anonymous
398 memory and page cache. (See Documentation/cgroups/memory.txt)
400 Note that setting this option increases fixed memory overhead
401 associated with each page of memory in the system. By this,
402 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
403 usage tracking struct at boot. Total amount of this is printed out
406 Only enable when you're ok with these tradeoffs and really
407 sure you need the memory resource controller. Even when you enable
408 this, you can set "cgroup_disable=memory" at your boot option to
409 disable memory resource controller and you can avoid overheads
410 (but lose benefits of memory resource controller).
412 This config option also selects MM_OWNER config option, which
413 could in turn add some fork/exit overhead.
415 config KERNEL_MEMCG_SWAP
416 bool "Memory Resource Controller Swap Extension"
418 depends on KERNEL_MEMCG
420 Add swap management feature to memory resource controller. When you
421 enable this, you can limit mem+swap usage per cgroup. In other words,
422 when you disable this, memory resource controller has no cares to
423 usage of swap...a process can exhaust all of the swap. This extension
424 is useful when you want to avoid exhaustion swap but this itself
425 adds more overheads and consumes memory for remembering information.
426 Especially if you use 32bit system or small memory system, please
427 be careful about enabling this. When memory resource controller
428 is disabled by boot option, this will be automatically disabled and
429 there will be no overhead from this. Even when you set this config=y,
430 if boot option "swapaccount=0" is set, swap will not be accounted.
431 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
432 size is 4096bytes, 512k per 1Gbytes of swap.
434 config KERNEL_MEMCG_SWAP_ENABLED
435 bool "Memory Resource Controller Swap Extension enabled by default"
437 depends on KERNEL_MEMCG_SWAP
439 Memory Resource Controller Swap Extension comes with its price in
440 a bigger memory consumption. General purpose distribution kernels
441 which want to enable the feature but keep it disabled by default
442 and let the user enable it by swapaccount boot command line
443 parameter should have this option unselected.
445 Those who want to have the feature enabled by default should
446 select this option (if, for some reason, they need to disable it,
447 then swapaccount=0 does the trick).
450 config KERNEL_MEMCG_KMEM
451 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
453 depends on KERNEL_MEMCG
455 The Kernel Memory extension for Memory Resource Controller can limit
456 the amount of memory used by kernel objects in the system. Those are
457 fundamentally different from the entities handled by the standard
458 Memory Controller, which are page-based, and can be swapped. Users of
459 the kmem extension can use it to guarantee that no group of processes
460 will ever exhaust kernel resources alone.
462 config KERNEL_CGROUP_PERF
463 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
464 select KERNEL_PERF_EVENTS
467 This option extends the per-cpu mode to restrict monitoring to
468 threads which belong to the cgroup specified and run on the
471 menuconfig KERNEL_CGROUP_SCHED
472 bool "Group CPU scheduler"
475 This feature lets CPU scheduler recognize task groups and control CPU
476 bandwidth allocation to such task groups. It uses cgroups to group
479 if KERNEL_CGROUP_SCHED
481 config KERNEL_FAIR_GROUP_SCHED
482 bool "Group scheduling for SCHED_OTHER"
485 config KERNEL_CFS_BANDWIDTH
486 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
488 depends on KERNEL_FAIR_GROUP_SCHED
490 This option allows users to define CPU bandwidth rates (limits) for
491 tasks running within the fair group scheduler. Groups with no limit
492 set are considered to be unconstrained and will run with no
494 See tip/Documentation/scheduler/sched-bwc.txt for more information.
496 config KERNEL_RT_GROUP_SCHED
497 bool "Group scheduling for SCHED_RR/FIFO"
500 This feature lets you explicitly allocate real CPU bandwidth
501 to task groups. If enabled, it will also make it impossible to
502 schedule realtime tasks for non-root users until you allocate
503 realtime bandwidth for them.
507 config KERNEL_BLK_CGROUP
508 bool "Block IO controller"
511 Generic block IO controller cgroup interface. This is the common
512 cgroup interface which should be used by various IO controlling
515 Currently, CFQ IO scheduler uses it to recognize task groups and
516 control disk bandwidth allocation (proportional time slice allocation)
517 to such task groups. It is also used by bio throttling logic in
518 block layer to implement upper limit in IO rates on a device.
520 This option only enables generic Block IO controller infrastructure.
521 One needs to also enable actual IO controlling logic/policy. For
522 enabling proportional weight division of disk bandwidth in CFQ, set
523 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
524 CONFIG_BLK_DEV_THROTTLING=y.
528 config KERNEL_CFQ_GROUP_IOSCHED
529 bool "Proportional weight of disk bandwidth in CFQ"
531 config KERNEL_BLK_DEV_THROTTLING
532 bool "Enable throttling policy"
533 default y if TARGET_brcm2708
535 config KERNEL_BLK_DEV_THROTTLING_LOW
536 bool "Block throttling .low limit interface support (EXPERIMENTAL)"
537 depends on KERNEL_BLK_DEV_THROTTLING
540 config KERNEL_DEBUG_BLK_CGROUP
541 bool "Enable Block IO controller debugging"
543 depends on KERNEL_BLK_CGROUP
545 Enable some debugging help. Currently it exports additional stat
546 files in a cgroup which can be useful for debugging.
548 config KERNEL_NET_CLS_CGROUP
549 bool "Control Group Classifier"
552 config KERNEL_NETPRIO_CGROUP
553 bool "Network priority cgroup"
559 # Namespace support symbols
562 config KERNEL_NAMESPACES
563 bool "Enable kernel namespaces"
572 In this namespace, tasks see different info provided
573 with the uname() system call.
579 In this namespace, tasks work with IPC ids which correspond to
580 different IPC objects in different namespaces.
582 config KERNEL_USER_NS
583 bool "User namespace (EXPERIMENTAL)"
586 This allows containers, i.e. vservers, to use user namespaces
587 to provide different user info for different servers.
590 bool "PID Namespaces"
593 Support process id namespaces. This allows having multiple
594 processes with the same pid as long as they are in different
595 pid namespaces. This is a building block of containers.
598 bool "Network namespace"
601 Allow user space to create what appear to be multiple instances
602 of the network stack.
607 # LXC related symbols
610 config KERNEL_LXC_MISC
611 bool "Enable miscellaneous LXC related options"
616 config KERNEL_DEVPTS_MULTIPLE_INSTANCES
617 bool "Support multiple instances of devpts"
620 Enable support for multiple instances of devpts filesystem.
621 If you want to have isolated PTY namespaces (eg: in containers),
622 say Y here. Otherwise, say N. If enabled, each mount of devpts
623 filesystem with the '-o newinstance' option will create an
624 independent PTY namespace.
626 config KERNEL_POSIX_MQUEUE
627 bool "POSIX Message Queues"
630 POSIX variant of message queues is a part of IPC. In POSIX message
631 queues every message has a priority which decides about succession
632 of receiving it by a process. If you want to compile and run
633 programs written e.g. for Solaris with use of its POSIX message
634 queues (functions mq_*) say Y here.
636 POSIX message queues are visible as a filesystem called 'mqueue'
637 and can be mounted somewhere if you want to do filesystem
638 operations on message queues.
642 config KERNEL_SECCOMP_FILTER
646 config KERNEL_SECCOMP
647 bool "Enable seccomp support"
648 depends on !(TARGET_uml)
649 select KERNEL_SECCOMP_FILTER
652 Build kernel with support for seccomp.
658 config KERNEL_IP_MROUTE
659 bool "Enable IPv4 multicast routing"
662 Multicast routing requires a multicast routing daemon in
663 addition to kernel support.
674 config KERNEL_IPV6_MULTIPLE_TABLES
677 config KERNEL_IPV6_SUBTREES
680 config KERNEL_IPV6_MROUTE
681 bool "Enable IPv6 multicast routing"
684 Multicast routing requires a multicast routing daemon in
685 addition to kernel support.
687 config KERNEL_IPV6_PIMSM_V2
693 # NFS related symbols
696 bool "Compile the kernel with rootfs on NFS"
698 If you want to make your kernel boot off a NFS server as root
699 filesystem, select Y here.
703 config KERNEL_IP_PNP_DHCP
706 config KERNEL_IP_PNP_BOOTP
709 config KERNEL_IP_PNP_RARP
721 config KERNEL_ROOT_NFS
726 menu "Filesystem ACL and attr support options"
727 config USE_FS_ACL_ATTR
728 bool "Use filesystem ACL and attr support by default"
731 Make using ACLs (e.g. POSIX ACL, NFSv4 ACL) the default
732 for kernel and packages, except tmpfs, flash filesystems,
733 and old NFS. Also enable userspace extended attribute support
734 by default. (OpenWrt already has an expection it will be
735 present in the kernel).
737 config KERNEL_FS_POSIX_ACL
738 bool "Enable POSIX ACL support"
739 default y if USE_FS_ACL_ATTR
741 config KERNEL_BTRFS_FS_POSIX_ACL
742 bool "Enable POSIX ACL for BtrFS Filesystems"
743 select KERNEL_FS_POSIX_ACL
744 default y if USE_FS_ACL_ATTR
746 config KERNEL_EXT4_FS_POSIX_ACL
747 bool "Enable POSIX ACL for Ext4 Filesystems"
748 select KERNEL_FS_POSIX_ACL
749 default y if USE_FS_ACL_ATTR
751 config KERNEL_F2FS_FS_POSIX_ACL
752 bool "Enable POSIX ACL for F2FS Filesystems"
753 select KERNEL_FS_POSIX_ACL
756 config KERNEL_JFFS2_FS_POSIX_ACL
757 bool "Enable POSIX ACL for JFFS2 Filesystems"
758 select KERNEL_FS_POSIX_ACL
761 config KERNEL_TMPFS_POSIX_ACL
762 bool "Enable POSIX ACL for TMPFS Filesystems"
763 select KERNEL_FS_POSIX_ACL
766 config KERNEL_CIFS_ACL
767 bool "Enable CIFS ACLs"
768 select KERNEL_FS_POSIX_ACL
769 default y if USE_FS_ACL_ATTR
771 config KERNEL_HFS_FS_POSIX_ACL
772 bool "Enable POSIX ACL for HFS Filesystems"
773 select KERNEL_FS_POSIX_ACL
774 default y if USE_FS_ACL_ATTR
776 config KERNEL_HFSPLUG_FS_POSIX_ACL
777 bool "Enable POSIX ACL for HFS+ Filesystems"
778 select KERNEL_FS_POSIX_ACL
779 default y if USE_FS_ACL_ATTR
781 config KERNEL_NFS_ACL_SUPPORT
782 bool "Enable ACLs for NFS"
783 default y if USE_FS_ACL_ATTR
785 config KERNEL_NFS_V3_ACL_SUPPORT
786 bool "Enable ACLs for NFSv3"
789 config KERNEL_NFSD_V2_ACL_SUPPORT
790 bool "Enable ACLs for NFSDv2"
793 config KERNEL_NFSD_V3_ACL_SUPPORT
794 bool "Enable ACLs for NFSDv3"
797 config KERNEL_REISER_FS_POSIX_ACL
798 bool "Enable POSIX ACLs for ReiserFS"
799 select KERNEL_FS_POSIX_ACL
800 default y if USE_FS_ACL_ATTR
802 config KERNEL_XFS_POSIX_ACL
803 bool "Enable POSIX ACLs for XFS"
804 select KERNEL_FS_POSIX_ACL
805 default y if USE_FS_ACL_ATTR
807 config KERNEL_JFS_POSIX_ACL
808 bool "Enable POSIX ACLs for JFS"
809 select KERNEL_FS_POSIX_ACL
810 default y if USE_FS_ACL_ATTR
815 bool "/dev/mem virtual device support"
817 Say Y here if you want to support the /dev/mem device.
818 The /dev/mem device is used to access areas of physical
821 config KERNEL_DEVKMEM
822 bool "/dev/kmem virtual device support"
824 Say Y here if you want to support the /dev/kmem device. The
825 /dev/kmem device is rarely used, but can be used for certain
826 kind of kernel debugging operations.
828 config KERNEL_SQUASHFS_FRAGMENT_CACHE_SIZE
829 int "Number of squashfs fragments cached"
830 default 2 if (SMALL_FLASH && !LOW_MEMORY_FOOTPRINT)
834 # compile optimiziation setting
837 prompt "Compiler optimization level"
838 default KERNEL_CC_OPTIMIZE_FOR_SIZE if SMALL_FLASH
840 config KERNEL_CC_OPTIMIZE_FOR_PERFORMANCE
841 bool "Optimize for performance"
843 This is the default optimization level for the kernel, building
844 with the "-O2" compiler flag for best performance and most
845 helpful compile-time warnings.
847 config KERNEL_CC_OPTIMIZE_FOR_SIZE
848 bool "Optimize for size"
850 Enabling this option will pass "-Os" instead of "-O2" to
851 your compiler resulting in a smaller kernel.