blob: be05b4ae02b635a6f6267ad3f6d8ecd673f2912a [file] [log] [blame]
Chris Metcalf867e3592010-05-28 23:09:12 -04001# For a description of the syntax of this configuration file,
Chris Metcalf5fb682b2011-02-28 15:58:39 -05002# see Documentation/kbuild/kconfig-language.txt.
Chris Metcalf867e3592010-05-28 23:09:12 -04003
Thomas Gleixner8df274062011-01-19 20:44:43 +01004config TILE
5 def_bool y
Zhigang Lu8d61dd72014-01-28 10:03:50 +08006 select HAVE_PERF_EVENTS
7 select USE_PMC if PERF_EVENTS
Chris Metcalf41bb38f2012-06-15 15:23:06 -04008 select HAVE_DMA_ATTRS
9 select HAVE_DMA_API_DEBUG
Thomas Gleixner8df274062011-01-19 20:44:43 +010010 select HAVE_KVM if !TILEGX
11 select GENERIC_FIND_FIRST_BIT
Catalin Marinas7ac57a82012-10-08 16:28:16 -070012 select SYSCTL_EXCEPTION_TRACE
Thomas Gleixner8df274062011-01-19 20:44:43 +010013 select CC_OPTIMIZE_FOR_SIZE
Catalin Marinasb69ec422012-10-08 16:28:11 -070014 select HAVE_DEBUG_KMEMLEAK
Thomas Gleixner8df274062011-01-19 20:44:43 +010015 select GENERIC_IRQ_PROBE
16 select GENERIC_PENDING_IRQ if SMP
Thomas Gleixner61a16742011-03-25 14:21:17 +000017 select GENERIC_IRQ_SHOW
Catalin Marinas9b2a60c2012-10-08 16:28:13 -070018 select HAVE_DEBUG_BUGVERBOSE
Stephen Rothwell4febd952013-03-07 15:48:16 +110019 select VIRT_TO_BUS
Chris Metcalff133ecc2011-05-26 12:40:09 -040020 select SYS_HYPERVISOR
Stephen Boyd446f24d2013-04-30 15:28:42 -070021 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
Dan Williams21266be2015-11-19 18:19:29 -080022 select ARCH_HAS_DEVMEM_IS_ALLOWED
Chris Metcalf8d695142012-03-27 13:47:57 -040023 select ARCH_HAVE_NMI_SAFE_CMPXCHG
Anna-Maria Gleixner4ec008d2012-05-18 16:45:54 +000024 select GENERIC_CLOCKEVENTS
David Howells786d35d2012-09-28 14:31:03 +093025 select MODULES_USE_ELF_RELA
Simon Marchi969f6fe2012-12-22 00:21:12 -050026 select HAVE_ARCH_TRACEHOOK
Simon Marchief567f22013-01-21 19:54:57 -050027 select HAVE_SYSCALL_TRACEPOINTS
Chris Metcalf47ad7b92015-05-08 10:27:35 -040028 select USER_STACKTRACE_SUPPORT
Chris Metcalfadf6d9b2013-02-01 12:37:48 -050029 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
Dave Hansend1a1dc02013-07-01 13:04:42 -070030 select HAVE_DEBUG_STACKOVERFLOW
Chris Metcalf49cf78e2013-08-12 15:00:51 -040031 select ARCH_WANT_FRAME_POINTERS
Chris Metcalf49e4e152015-03-23 14:23:58 -040032 select HAVE_CONTEXT_TRACKING
Borislav Petkovb01aec92015-05-21 19:59:31 +020033 select EDAC_SUPPORT
Chris Metcalf5bf6c072015-04-30 15:12:42 -040034 select GENERIC_STRNCPY_FROM_USER
35 select GENERIC_STRNLEN_USER
Chris Metcalfa0ddef82015-07-22 14:30:14 -040036 select HAVE_ARCH_SECCOMP_FILTER
Thomas Gleixner8df274062011-01-19 20:44:43 +010037
38# FIXME: investigate whether we need/want these options.
39# select HAVE_IOREMAP_PROT
Chris Metcalf5fb682b2011-02-28 15:58:39 -050040# select HAVE_OPTPROBES
41# select HAVE_REGS_AND_STACK_ACCESS_API
42# select HAVE_HW_BREAKPOINT
43# select PERF_EVENTS
44# select HAVE_USER_RETURN_NOTIFIER
45# config NO_BOOTMEM
46# config ARCH_SUPPORTS_DEBUG_PAGEALLOC
47# config HUGETLB_PAGE_SIZE_VARIABLE
Thomas Gleixner8df274062011-01-19 20:44:43 +010048
Chris Metcalf867e3592010-05-28 23:09:12 -040049config MMU
50 def_bool y
51
52config GENERIC_CSUM
53 def_bool y
54
Chris Metcalf867e3592010-05-28 23:09:12 -040055config HAVE_ARCH_ALLOC_REMAP
56 def_bool y
57
58config HAVE_SETUP_PER_CPU_AREA
59 def_bool y
60
61config NEED_PER_CPU_PAGE_FIRST_CHUNK
Chris Metcalf5fb682b2011-02-28 15:58:39 -050062 def_bool y
Chris Metcalf867e3592010-05-28 23:09:12 -040063
64config SYS_SUPPORTS_HUGETLBFS
65 def_bool y
66
Chris Metcalf621b1952012-04-01 14:04:21 -040067# Support for additional huge page sizes besides HPAGE_SIZE.
68# The software support is currently only present in the TILE-Gx
69# hypervisor. TILEPro in any case does not support page sizes
70# larger than the default HPAGE_SIZE.
71config HUGETLB_SUPER_PAGES
72 depends on HUGETLB_PAGE && TILEGX
73 def_bool y
74
Chris Metcalf4a556f42013-08-07 15:33:32 -040075config GENERIC_TIME_VSYSCALL
76 def_bool y
77
Zhigang Lu8e3441e2014-01-27 15:11:07 +080078# Enable PMC if PERF_EVENTS, OPROFILE, or WATCHPOINTS are enabled.
79config USE_PMC
80 bool
81
Lucas De Marchi25985ed2011-03-30 22:57:33 -030082# FIXME: tilegx can implement a more efficient rwsem.
Chris Metcalf867e3592010-05-28 23:09:12 -040083config RWSEM_GENERIC_SPINLOCK
84 def_bool y
85
Chris Metcalf867e3592010-05-28 23:09:12 -040086# We only support gcc 4.4 and above, so this should work.
87config ARCH_SUPPORTS_OPTIMIZED_INLINING
88 def_bool y
89
90config ARCH_PHYS_ADDR_T_64BIT
91 def_bool y
92
FUJITA Tomonorid31eb512010-10-27 15:32:58 -070093config ARCH_DMA_ADDR_T_64BIT
94 def_bool y
95
Chris Metcalf3d1e8a82012-03-27 13:53:30 -040096config NEED_DMA_MAP_STATE
97 def_bool y
98
Chris Metcalf41bb38f2012-06-15 15:23:06 -040099config ARCH_HAS_DMA_SET_COHERENT_MASK
100 bool
101
Chris Metcalf867e3592010-05-28 23:09:12 -0400102config LOCKDEP_SUPPORT
103 def_bool y
104
105config STACKTRACE_SUPPORT
106 def_bool y
107 select STACKTRACE
108
109# We use discontigmem for now; at some point we may want to switch
110# to sparsemem (Tilera bug 7996).
111config ARCH_DISCONTIGMEM_ENABLE
112 def_bool y
113
114config ARCH_DISCONTIGMEM_DEFAULT
115 def_bool y
116
117config TRACE_IRQFLAGS_SUPPORT
118 def_bool y
119
Chris Metcalf867e3592010-05-28 23:09:12 -0400120# SMP is required for Tilera Linux.
121config SMP
122 def_bool y
123
Chris Metcalf867e3592010-05-28 23:09:12 -0400124config HVC_TILE
Joe Millenbach4f73bc42013-01-17 22:44:22 -0800125 depends on TTY
Chris Metcalf867e3592010-05-28 23:09:12 -0400126 select HVC_DRIVER
Chris Metcalfbda0f5b2013-08-06 14:11:21 -0400127 select HVC_IRQ if TILEGX
Chris Metcalf867e3592010-05-28 23:09:12 -0400128 def_bool y
129
Chris Metcalf41dd4962015-06-03 10:37:56 -0400130# Building with ARCH=tilegx (or ARCH=tile) implies using the
131# 64-bit TILE-Gx toolchain, so force CONFIG_TILEGX on.
Chris Metcalf867e3592010-05-28 23:09:12 -0400132config TILEGX
Chris Metcalf41dd4962015-06-03 10:37:56 -0400133 def_bool ARCH != "tilepro"
Thomas Gleixnerb26d8512014-05-07 15:44:16 +0000134 select SPARSE_IRQ
135 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
Tony Lua61fd5e2013-08-09 13:26:09 -0400136 select HAVE_FUNCTION_TRACER
Tony Lua61fd5e2013-08-09 13:26:09 -0400137 select HAVE_FUNCTION_GRAPH_TRACER
138 select HAVE_DYNAMIC_FTRACE
139 select HAVE_FTRACE_MCOUNT_RECORD
Tony Lu3fa17c32013-08-09 15:08:57 -0400140 select HAVE_KPROBES
141 select HAVE_KRETPROBES
Chris Metcalf81571072013-08-28 19:53:17 -0400142 select HAVE_ARCH_KGDB
Chris Metcalf3e247652014-08-01 15:26:46 -0400143 select ARCH_SUPPORTS_ATOMIC_RMW
Chris Metcalf867e3592010-05-28 23:09:12 -0400144
Chris Metcalfacd1a192012-04-07 15:58:24 -0400145config TILEPRO
146 def_bool !TILEGX
147
Chris Metcalf867e3592010-05-28 23:09:12 -0400148config 64BIT
Chris Metcalfacd1a192012-04-07 15:58:24 -0400149 def_bool TILEGX
Chris Metcalf867e3592010-05-28 23:09:12 -0400150
151config ARCH_DEFCONFIG
152 string
Chris Metcalf3d1e8a82012-03-27 13:53:30 -0400153 default "arch/tile/configs/tilepro_defconfig" if !TILEGX
Chris Metcalf867e3592010-05-28 23:09:12 -0400154 default "arch/tile/configs/tilegx_defconfig" if TILEGX
155
Kirill A. Shutemov909d45e2015-04-14 15:46:08 -0700156config PGTABLE_LEVELS
157 int
158 default 3 if 64BIT
159 default 2
160
Chris Metcalf867e3592010-05-28 23:09:12 -0400161source "init/Kconfig"
162
Chris Metcalf99a844b2013-01-31 21:21:36 -0500163source "kernel/Kconfig.freezer"
164
Chris Metcalf867e3592010-05-28 23:09:12 -0400165menu "Tilera-specific configuration"
166
167config NR_CPUS
168 int "Maximum number of tiles (2-255)"
169 range 2 255
170 depends on SMP
171 default "64"
172 ---help---
173 Building with 64 is the recommended value, but a slightly
174 smaller kernel memory footprint results from using a smaller
175 value on chips with fewer tiles.
176
Chris Metcalfd5d14ed2012-03-29 13:58:43 -0400177choice
178 prompt "Kernel page size"
179 default PAGE_SIZE_64KB
180 help
181 This lets you select the page size of the kernel. For best
182 performance on memory-intensive applications, a page size of 64KB
183 is recommended. For workloads involving many small files, many
184 connections, etc., it may be better to select 16KB, which uses
185 memory more efficiently at some cost in TLB performance.
186
Chris Metcalfc1b27ab2015-12-22 12:28:51 -0500187 Note that for TILEPro, you must also rebuild the hypervisor
188 with a matching page size.
189
190config PAGE_SIZE_4KB
191 bool "4KB" if TILEPRO
Chris Metcalfd5d14ed2012-03-29 13:58:43 -0400192
193config PAGE_SIZE_16KB
194 bool "16KB"
195
196config PAGE_SIZE_64KB
197 bool "64KB"
198
199endchoice
200
Chris Metcalf867e3592010-05-28 23:09:12 -0400201source "kernel/Kconfig.hz"
202
203config KEXEC
204 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -0700205 select KEXEC_CORE
Chris Metcalf867e3592010-05-28 23:09:12 -0400206 ---help---
207 kexec is a system call that implements the ability to shutdown your
208 current kernel, and to start another kernel. It is like a reboot
209 but it is independent of the system firmware. It is used
210 to implement the "mboot" Tilera booter.
211
212 The name comes from the similarity to the exec system call.
213
214config COMPAT
215 bool "Support 32-bit TILE-Gx binaries in addition to 64-bit"
216 depends on TILEGX
217 select COMPAT_BINFMT_ELF
218 default y
219 ---help---
220 If enabled, the kernel will support running TILE-Gx binaries
221 that were built with the -m32 option.
222
Chris Metcalfa0ddef82015-07-22 14:30:14 -0400223config SECCOMP
224 bool "Enable seccomp to safely compute untrusted bytecode"
225 depends on PROC_FS
226 help
227 This kernel feature is useful for number crunching applications
228 that may need to compute untrusted bytecode during their
229 execution. By using pipes or other transports made available to
230 the process as file descriptors supporting the read/write
231 syscalls, it's possible to isolate those applications in
232 their own address space using seccomp. Once seccomp is
233 enabled via prctl, it cannot be disabled and the task is only
234 allowed to execute a few safe syscalls defined by each seccomp
235 mode.
236
237 If unsure, say N.
238
Chris Metcalf867e3592010-05-28 23:09:12 -0400239config SYSVIPC_COMPAT
240 def_bool y
241 depends on COMPAT && SYSVIPC
242
Chris Metcalfd7c96612013-08-15 16:23:24 -0400243# We do not currently support disabling HIGHMEM on tilepro.
Chris Metcalf867e3592010-05-28 23:09:12 -0400244config HIGHMEM
245 bool # "Support for more than 512 MB of RAM"
246 default !TILEGX
247 ---help---
248 Linux can use the full amount of RAM in the system by
249 default. However, the address space of TILE processors is
250 only 4 Gigabytes large. That means that, if you have a large
251 amount of physical memory, not all of it can be "permanently
252 mapped" by the kernel. The physical memory that's not
253 permanently mapped is called "high memory".
254
255 If you are compiling a kernel which will never run on a
256 machine with more than 512 MB total physical RAM, answer
257 "false" here. This will result in the kernel mapping all of
258 physical memory into the top 1 GB of virtual memory space.
259
260 If unsure, say "true".
261
Chris Metcalfeef015c2012-05-09 12:26:30 -0400262config ZONE_DMA
263 def_bool y
264
Chris Metcalf41bb38f2012-06-15 15:23:06 -0400265config IOMMU_HELPER
266 bool
267
268config NEED_SG_DMA_LENGTH
269 bool
270
271config SWIOTLB
272 bool
273 default TILEGX
274 select IOMMU_HELPER
275 select NEED_SG_DMA_LENGTH
276 select ARCH_HAS_DMA_SET_COHERENT_MASK
277
Chris Metcalf867e3592010-05-28 23:09:12 -0400278# We do not currently support disabling NUMA.
279config NUMA
280 bool # "NUMA Memory Allocation and Scheduler Support"
281 depends on SMP && DISCONTIGMEM
282 default y
283 ---help---
284 NUMA memory allocation is required for TILE processors
285 unless booting with memory striping enabled in the
286 hypervisor, or with only a single memory controller.
287 It is recommended that this option always be enabled.
288
289config NODES_SHIFT
290 int "Log base 2 of the max number of memory controllers"
291 default 2
292 depends on NEED_MULTIPLE_NODES
293 ---help---
294 By default, 2, i.e. 2^2 == 4 DDR2 controllers.
295 In a system with more controllers, this value should be raised.
296
Chris Metcalf867e3592010-05-28 23:09:12 -0400297choice
298 depends on !TILEGX
David Rientjes6a108a12011-01-20 14:44:16 -0800299 prompt "Memory split" if EXPERT
Chris Metcalf867e3592010-05-28 23:09:12 -0400300 default VMSPLIT_3G
301 ---help---
302 Select the desired split between kernel and user memory.
303
304 If the address range available to the kernel is less than the
305 physical memory installed, the remaining memory will be available
306 as "high memory". Accessing high memory is a little more costly
307 than low memory, as it needs to be mapped into the kernel first.
308 Note that increasing the kernel address space limits the range
309 available to user programs, making the address space there
310 tighter. Selecting anything other than the default 3G/1G split
311 will also likely make your kernel incompatible with binary-only
312 kernel modules.
313
314 If you are not absolutely sure what you are doing, leave this
315 option alone!
316
Chris Metcalf55928402010-09-13 08:50:09 -0400317 config VMSPLIT_3_75G
Chris Metcalf867e3592010-05-28 23:09:12 -0400318 bool "3.75G/0.25G user/kernel split (no kernel networking)"
Chris Metcalf55928402010-09-13 08:50:09 -0400319 config VMSPLIT_3_5G
Chris Metcalf867e3592010-05-28 23:09:12 -0400320 bool "3.5G/0.5G user/kernel split"
321 config VMSPLIT_3G
322 bool "3G/1G user/kernel split"
Chris Metcalf09c17ea2011-02-28 16:01:09 -0500323 config VMSPLIT_2_75G
324 bool "2.75G/1.25G user/kernel split (for full 1G low memory)"
325 config VMSPLIT_2_5G
326 bool "2.5G/1.5G user/kernel split"
327 config VMSPLIT_2_25G
328 bool "2.25G/1.75G user/kernel split"
Chris Metcalf867e3592010-05-28 23:09:12 -0400329 config VMSPLIT_2G
330 bool "2G/2G user/kernel split"
331 config VMSPLIT_1G
332 bool "1G/3G user/kernel split"
333endchoice
334
335config PAGE_OFFSET
336 hex
Chris Metcalf884197f2012-03-27 13:56:04 -0400337 depends on !64BIT
Chris Metcalf55928402010-09-13 08:50:09 -0400338 default 0xF0000000 if VMSPLIT_3_75G
339 default 0xE0000000 if VMSPLIT_3_5G
Chris Metcalf09c17ea2011-02-28 16:01:09 -0500340 default 0xB0000000 if VMSPLIT_2_75G
341 default 0xA0000000 if VMSPLIT_2_5G
342 default 0x90000000 if VMSPLIT_2_25G
Chris Metcalf867e3592010-05-28 23:09:12 -0400343 default 0x80000000 if VMSPLIT_2G
344 default 0x40000000 if VMSPLIT_1G
345 default 0xC0000000
346
347source "mm/Kconfig"
348
Chris Metcalfbc1a2982013-08-07 11:36:54 -0400349source "kernel/Kconfig.preempt"
350
Chris Metcalf867e3592010-05-28 23:09:12 -0400351config CMDLINE_BOOL
352 bool "Built-in kernel command line"
353 default n
354 ---help---
355 Allow for specifying boot arguments to the kernel at
356 build time. On some systems (e.g. embedded ones), it is
357 necessary or convenient to provide some or all of the
358 kernel boot arguments with the kernel itself (that is,
359 to not rely on the boot loader to provide them.)
360
361 To compile command line arguments into the kernel,
362 set this option to 'Y', then fill in the
363 the boot arguments in CONFIG_CMDLINE.
364
365 Systems with fully functional boot loaders (e.g. mboot, or
366 if booting over PCI) should leave this option set to 'N'.
367
368config CMDLINE
369 string "Built-in kernel command string"
370 depends on CMDLINE_BOOL
371 default ""
372 ---help---
373 Enter arguments here that should be compiled into the kernel
374 image and used at boot time. If the boot loader provides a
375 command line at boot time, it is appended to this string to
376 form the full kernel command line, when the system boots.
377
378 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
379 change this behavior.
380
381 In most cases, the command line (whether built-in or provided
382 by the boot loader) should specify the device for the root
383 file system.
384
385config CMDLINE_OVERRIDE
386 bool "Built-in command line overrides boot loader arguments"
387 default n
388 depends on CMDLINE_BOOL
389 ---help---
390 Set this option to 'Y' to have the kernel ignore the boot loader
391 command line, and use ONLY the built-in command line.
392
393 This is used to work around broken boot loaders. This should
394 be set to 'N' under normal conditions.
395
396config VMALLOC_RESERVE
397 hex
Chris Metcalfad2a4bb2013-09-16 13:02:57 -0400398 default 0x2000000
Chris Metcalf867e3592010-05-28 23:09:12 -0400399
Chris Metcalf9f9c0382010-06-25 17:00:56 -0400400config HARDWALL
401 bool "Hardwall support to allow access to user dynamic network"
402 default y
403
Chris Metcalfa78c9422010-10-14 16:23:03 -0400404config KERNEL_PL
405 int "Processor protection level for kernel"
406 range 1 2
Chris Metcalfc5399142013-05-02 15:29:04 -0400407 default 2 if TILEGX
408 default 1 if !TILEGX
Chris Metcalfa78c9422010-10-14 16:23:03 -0400409 ---help---
Chris Metcalfc5399142013-05-02 15:29:04 -0400410 Since MDE 4.2, the Tilera hypervisor runs the kernel
411 at PL2 by default. If running under an older hypervisor,
412 or as a KVM guest, you must run at PL1. (The current
413 hypervisor may also be recompiled with "make HV_PL=2" to
414 allow it to run a kernel at PL1, but clients running at PL1
415 are not expected to be supported indefinitely.)
416
417 If you're not sure, don't change the default.
Chris Metcalfa78c9422010-10-14 16:23:03 -0400418
Chris Metcalf37b82b52012-04-04 16:39:58 -0400419source "arch/tile/gxio/Kconfig"
420
Chris Metcalf867e3592010-05-28 23:09:12 -0400421endmenu # Tilera-specific configuration
422
423menu "Bus options"
424
Chris Metcalff02cbbe2010-11-02 12:05:10 -0400425config PCI
426 bool "PCI support"
427 default y
428 select PCI_DOMAINS
Michael S. Tsirkin84550122011-11-29 20:42:56 +0200429 select GENERIC_PCI_IOMAP
Chris Metcalf12962262012-04-07 17:10:17 -0400430 select TILE_GXIO_TRIO if TILEGX
Chris Metcalf12962262012-04-07 17:10:17 -0400431 select PCI_MSI if TILEGX
Chris Metcalff02cbbe2010-11-02 12:05:10 -0400432 ---help---
433 Enable PCI root complex support, so PCIe endpoint devices can
434 be attached to the Tile chip. Many, but not all, PCI devices
435 are supported under Tilera's root complex driver.
436
437config PCI_DOMAINS
438 bool
439
Chris Metcalf867e3592010-05-28 23:09:12 -0400440config NO_IOMEM
441 def_bool !PCI
442
Uwe Kleine-Königce816fa2014-04-07 15:39:19 -0700443config NO_IOPORT_MAP
Chris Metcalf867e3592010-05-28 23:09:12 -0400444 def_bool !PCI
445
Chris Metcalfcf89c422013-08-02 16:45:22 -0400446config TILE_PCI_IO
447 bool "PCI I/O space support"
448 default n
449 depends on PCI
450 depends on TILEGX
451 ---help---
452 Enable PCI I/O space support on TILEGx. Since the PCI I/O space
453 is used by few modern PCIe endpoint devices, its support is disabled
454 by default to save the TRIO PIO Region resource for other purposes.
455
Chris Metcalf867e3592010-05-28 23:09:12 -0400456source "drivers/pci/Kconfig"
457
Chris Metcalff62f73f2013-08-05 13:20:44 -0400458source "drivers/pci/pcie/Kconfig"
459
Chris Metcalf47fc28b2012-05-09 13:58:14 -0400460config TILE_USB
461 tristate "Tilera USB host adapter support"
462 default y
463 depends on USB
464 depends on TILEGX
465 select TILE_GXIO_USB_HOST
466 ---help---
467 Provides USB host adapter support for the built-in EHCI and OHCI
468 interfaces on TILE-Gx chips.
469
Chris Metcalf867e3592010-05-28 23:09:12 -0400470source "drivers/pci/hotplug/Kconfig"
471
472endmenu
473
474menu "Executable file formats"
475
Chris Metcalf867e3592010-05-28 23:09:12 -0400476source "fs/Kconfig.binfmt"
477
478endmenu
479
480source "net/Kconfig"
481
482source "drivers/Kconfig"
483
484source "fs/Kconfig"
485
486source "arch/tile/Kconfig.debug"
487
488source "security/Kconfig"
489
490source "crypto/Kconfig"
491
492source "lib/Kconfig"
Chris Metcalfa78c9422010-10-14 16:23:03 -0400493
494source "arch/tile/kvm/Kconfig"