1config DEFCONFIG_LIST 2 string 3 option defconfig_list 4 default "/lib/modules/$UNAME_RELEASE/.config" 5 default "/etc/kernel-config" 6 default "/boot/config-$UNAME_RELEASE" 7 default "arch/$ARCH/defconfig" 8 9menu "Code maturity level options" 10 11config EXPERIMENTAL 12 bool "Prompt for development and/or incomplete code/drivers" 13 ---help--- 14 Some of the various things that Linux supports (such as network 15 drivers, file systems, network protocols, etc.) can be in a state 16 of development where the functionality, stability, or the level of 17 testing is not yet high enough for general use. This is usually 18 known as the "alpha-test" phase among developers. If a feature is 19 currently in alpha-test, then the developers usually discourage 20 uninformed widespread use of this feature by the general public to 21 avoid "Why doesn't this work?" type mail messages. However, active 22 testing and use of these systems is welcomed. Just be aware that it 23 may not meet the normal level of reliability or it may fail to work 24 in some special cases. Detailed bug reports from people familiar 25 with the kernel internals are usually welcomed by the developers 26 (before submitting bug reports, please read the documents 27 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>, 28 <file:Documentation/BUG-HUNTING>, and 29 <file:Documentation/oops-tracing.txt> in the kernel source). 30 31 This option will also make obsoleted drivers available. These are 32 drivers that have been replaced by something else, and/or are 33 scheduled to be removed in a future kernel release. 34 35 Unless you intend to help test and develop a feature or driver that 36 falls into this category, or you have a situation that requires 37 using these features, you should probably say N here, which will 38 cause the configurator to present you with fewer choices. If 39 you say Y here, you will be offered the choice of using features or 40 drivers that are currently considered to be in the alpha-test phase. 41 42config BROKEN 43 bool 44 45config BROKEN_ON_SMP 46 bool 47 depends on BROKEN || !SMP 48 default y 49 50config LOCK_KERNEL 51 bool 52 depends on SMP || PREEMPT 53 default y 54 55config INIT_ENV_ARG_LIMIT 56 int 57 default 32 if !UML 58 default 128 if UML 59 help 60 Maximum of each of the number of arguments and environment 61 variables passed to init from the kernel command line. 62 63endmenu 64 65menu "General setup" 66 67config LOCALVERSION 68 string "Local version - append to kernel release" 69 help 70 Append an extra string to the end of your kernel version. 71 This will show up when you type uname, for example. 72 The string you set here will be appended after the contents of 73 any files with a filename matching localversion* in your 74 object and source tree, in that order. Your total string can 75 be a maximum of 64 characters. 76 77config LOCALVERSION_AUTO 78 bool "Automatically append version information to the version string" 79 default y 80 help 81 This will try to automatically determine if the current tree is a 82 release tree by looking for git tags that 83 belong to the current top of tree revision. 84 85 A string of the format -gxxxxxxxx will be added to the localversion 86 if a git based tree is found. The string generated by this will be 87 appended after any matching localversion* files, and after the value 88 set in CONFIG_LOCALVERSION 89 90 Note: This requires Perl, and a git repository, but not necessarily 91 the git or cogito tools to be installed. 92 93config SWAP 94 bool "Support for paging of anonymous memory (swap)" 95 depends on MMU 96 default y 97 help 98 This option allows you to choose whether you want to have support 99 for so called swap devices or swap files in your kernel that are 100 used to provide more virtual memory than the actual RAM present 101 in your computer. If unsure say Y. 102 103config SYSVIPC 104 bool "System V IPC" 105 ---help--- 106 Inter Process Communication is a suite of library functions and 107 system calls which let processes (running programs) synchronize and 108 exchange information. It is generally considered to be a good thing, 109 and some programs won't run unless you say Y here. In particular, if 110 you want to run the DOS emulator dosemu under Linux (read the 111 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>), 112 you'll need to say Y here. 113 114 You can find documentation about IPC with "info ipc" and also in 115 section 6.4 of the Linux Programmer's Guide, available from 116 <http://www.tldp.org/guides.html>. 117 118config POSIX_MQUEUE 119 bool "POSIX Message Queues" 120 depends on NET && EXPERIMENTAL 121 ---help--- 122 POSIX variant of message queues is a part of IPC. In POSIX message 123 queues every message has a priority which decides about succession 124 of receiving it by a process. If you want to compile and run 125 programs written e.g. for Solaris with use of its POSIX message 126 queues (functions mq_*) say Y here. To use this feature you will 127 also need mqueue library, available from 128 <http://www.mat.uni.torun.pl/~wrona/posix_ipc/> 129 130 POSIX message queues are visible as a filesystem called 'mqueue' 131 and can be mounted somewhere if you want to do filesystem 132 operations on message queues. 133 134 If unsure, say Y. 135 136config BSD_PROCESS_ACCT 137 bool "BSD Process Accounting" 138 help 139 If you say Y here, a user level program will be able to instruct the 140 kernel (via a special system call) to write process accounting 141 information to a file: whenever a process exits, information about 142 that process will be appended to the file by the kernel. The 143 information includes things such as creation time, owning user, 144 command name, memory usage, controlling terminal etc. (the complete 145 list is in the struct acct in <file:include/linux/acct.h>). It is 146 up to the user level program to do useful things with this 147 information. This is generally a good idea, so say Y. 148 149config BSD_PROCESS_ACCT_V3 150 bool "BSD Process Accounting version 3 file format" 151 depends on BSD_PROCESS_ACCT 152 default n 153 help 154 If you say Y here, the process accounting information is written 155 in a new file format that also logs the process IDs of each 156 process and it's parent. Note that this file format is incompatible 157 with previous v0/v1/v2 file formats, so you will need updated tools 158 for processing it. A preliminary version of these tools is available 159 at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>. 160 161config SYSCTL 162 bool "Sysctl support" if EMBEDDED 163 default y 164 ---help--- 165 The sysctl interface provides a means of dynamically changing 166 certain kernel parameters and variables on the fly without requiring 167 a recompile of the kernel or reboot of the system. The primary 168 interface consists of a system call, but if you say Y to "/proc 169 file system support", a tree of modifiable sysctl entries will be 170 generated beneath the /proc/sys directory. They are explained in the 171 files in <file:Documentation/sysctl/>. Note that enabling this 172 option will enlarge the kernel by at least 8 KB. 173 174 As it is generally a good thing, you should say Y here unless 175 building a kernel for install/rescue disks or your system is very 176 limited in memory. 177 178config AUDIT 179 bool "Auditing support" 180 depends on NET 181 help 182 Enable auditing infrastructure that can be used with another 183 kernel subsystem, such as SELinux (which requires this for 184 logging of avc messages output). Does not do system-call 185 auditing without CONFIG_AUDITSYSCALL. 186 187config AUDITSYSCALL 188 bool "Enable system-call auditing support" 189 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64) 190 default y if SECURITY_SELINUX 191 help 192 Enable low-overhead system-call auditing infrastructure that 193 can be used independently or with another kernel subsystem, 194 such as SELinux. To use audit's filesystem watch feature, please 195 ensure that INOTIFY is configured. 196 197config IKCONFIG 198 bool "Kernel .config support" 199 ---help--- 200 This option enables the complete Linux kernel ".config" file 201 contents to be saved in the kernel. It provides documentation 202 of which kernel options are used in a running kernel or in an 203 on-disk kernel. This information can be extracted from the kernel 204 image file with the script scripts/extract-ikconfig and used as 205 input to rebuild the current kernel or to build another kernel. 206 It can also be extracted from a running kernel by reading 207 /proc/config.gz if enabled (below). 208 209config IKCONFIG_PROC 210 bool "Enable access to .config through /proc/config.gz" 211 depends on IKCONFIG && PROC_FS 212 ---help--- 213 This option enables access to the kernel configuration file 214 through /proc/config.gz. 215 216config CPUSETS 217 bool "Cpuset support" 218 depends on SMP 219 help 220 This option will let you create and manage CPUSETs which 221 allow dynamically partitioning a system into sets of CPUs and 222 Memory Nodes and assigning tasks to run only within those sets. 223 This is primarily useful on large SMP or NUMA systems. 224 225 Say N if unsure. 226 227config RELAY 228 bool "Kernel->user space relay support (formerly relayfs)" 229 help 230 This option enables support for relay interface support in 231 certain file systems (such as debugfs). 232 It is designed to provide an efficient mechanism for tools and 233 facilities to relay large amounts of data from kernel space to 234 user space. 235 236 If unsure, say N. 237 238source "usr/Kconfig" 239 240config UID16 241 bool "Enable 16-bit UID system calls" if EMBEDDED 242 depends on ARM || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION) 243 default y 244 help 245 This enables the legacy 16-bit UID syscall wrappers. 246 247config CC_OPTIMIZE_FOR_SIZE 248 bool "Optimize for size (Look out for broken compilers!)" 249 default y 250 depends on ARM || H8300 || EXPERIMENTAL 251 help 252 Enabling this option will pass "-Os" instead of "-O2" to gcc 253 resulting in a smaller kernel. 254 255 WARNING: some versions of gcc may generate incorrect code with this 256 option. If problems are observed, a gcc upgrade may be needed. 257 258 If unsure, say N. 259 260menuconfig EMBEDDED 261 bool "Configure standard kernel features (for small systems)" 262 help 263 This option allows certain base kernel options and settings 264 to be disabled or tweaked. This is for specialized 265 environments which can tolerate a "non-standard" kernel. 266 Only use this if you really know what you are doing. 267 268config KALLSYMS 269 bool "Load all symbols for debugging/kksymoops" if EMBEDDED 270 default y 271 help 272 Say Y here to let the kernel print out symbolic crash information and 273 symbolic stack backtraces. This increases the size of the kernel 274 somewhat, as all symbols have to be loaded into the kernel image. 275 276config KALLSYMS_ALL 277 bool "Include all symbols in kallsyms" 278 depends on DEBUG_KERNEL && KALLSYMS 279 help 280 Normally kallsyms only contains the symbols of functions, for nicer 281 OOPS messages. Some debuggers can use kallsyms for other 282 symbols too: say Y here to include all symbols, if you need them 283 and you don't care about adding 300k to the size of your kernel. 284 285 Say N. 286 287config KALLSYMS_EXTRA_PASS 288 bool "Do an extra kallsyms pass" 289 depends on KALLSYMS 290 help 291 If kallsyms is not working correctly, the build will fail with 292 inconsistent kallsyms data. If that occurs, log a bug report and 293 turn on KALLSYMS_EXTRA_PASS which should result in a stable build. 294 Always say N here unless you find a bug in kallsyms, which must be 295 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while 296 you wait for kallsyms to be fixed. 297 298 299config HOTPLUG 300 bool "Support for hot-pluggable devices" if EMBEDDED 301 default y 302 help 303 This option is provided for the case where no hotplug or uevent 304 capabilities is wanted by the kernel. You should only consider 305 disabling this option for embedded systems that do not use modules, a 306 dynamic /dev tree, or dynamic device discovery. Just say Y. 307 308config PRINTK 309 default y 310 bool "Enable support for printk" if EMBEDDED 311 help 312 This option enables normal printk support. Removing it 313 eliminates most of the message strings from the kernel image 314 and makes the kernel more or less silent. As this makes it 315 very difficult to diagnose system problems, saying N here is 316 strongly discouraged. 317 318config BUG 319 bool "BUG() support" if EMBEDDED 320 default y 321 help 322 Disabling this option eliminates support for BUG and WARN, reducing 323 the size of your kernel image and potentially quietly ignoring 324 numerous fatal conditions. You should only consider disabling this 325 option for embedded systems with no facilities for reporting errors. 326 Just say Y. 327 328config ELF_CORE 329 default y 330 bool "Enable ELF core dumps" if EMBEDDED 331 help 332 Enable support for generating core dumps. Disabling saves about 4k. 333 334config BASE_FULL 335 default y 336 bool "Enable full-sized data structures for core" if EMBEDDED 337 help 338 Disabling this option reduces the size of miscellaneous core 339 kernel data structures. This saves memory on small machines, 340 but may reduce performance. 341 342config RT_MUTEXES 343 boolean 344 select PLIST 345 346config FUTEX 347 bool "Enable futex support" if EMBEDDED 348 default y 349 select RT_MUTEXES 350 help 351 Disabling this option will cause the kernel to be built without 352 support for "fast userspace mutexes". The resulting kernel may not 353 run glibc-based applications correctly. 354 355config EPOLL 356 bool "Enable eventpoll support" if EMBEDDED 357 default y 358 help 359 Disabling this option will cause the kernel to be built without 360 support for epoll family of system calls. 361 362config SHMEM 363 bool "Use full shmem filesystem" if EMBEDDED 364 default y 365 depends on MMU 366 help 367 The shmem is an internal filesystem used to manage shared memory. 368 It is backed by swap and manages resource limits. It is also exported 369 to userspace as tmpfs if TMPFS is enabled. Disabling this 370 option replaces shmem and tmpfs with the much simpler ramfs code, 371 which may be appropriate on small systems without swap. 372 373config SLAB 374 default y 375 bool "Use full SLAB allocator" if EMBEDDED 376 help 377 Disabling this replaces the advanced SLAB allocator and 378 kmalloc support with the drastically simpler SLOB allocator. 379 SLOB is more space efficient but does not scale well and is 380 more susceptible to fragmentation. 381 382config VM_EVENT_COUNTERS 383 default y 384 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED 385 help 386 VM event counters are only needed to for event counts to be 387 shown. They have no function for the kernel itself. This 388 option allows the disabling of the VM event counters. 389 /proc/vmstat will only show page counts. 390 391endmenu # General setup 392 393config TINY_SHMEM 394 default !SHMEM 395 bool 396 397config BASE_SMALL 398 int 399 default 0 if BASE_FULL 400 default 1 if !BASE_FULL 401 402config SLOB 403 default !SLAB 404 bool 405 406menu "Loadable module support" 407 408config MODULES 409 bool "Enable loadable module support" 410 help 411 Kernel modules are small pieces of compiled code which can 412 be inserted in the running kernel, rather than being 413 permanently built into the kernel. You use the "modprobe" 414 tool to add (and sometimes remove) them. If you say Y here, 415 many parts of the kernel can be built as modules (by 416 answering M instead of Y where indicated): this is most 417 useful for infrequently used options which are not required 418 for booting. For more information, see the man pages for 419 modprobe, lsmod, modinfo, insmod and rmmod. 420 421 If you say Y here, you will need to run "make 422 modules_install" to put the modules under /lib/modules/ 423 where modprobe can find them (you may need to be root to do 424 this). 425 426 If unsure, say Y. 427 428config MODULE_UNLOAD 429 bool "Module unloading" 430 depends on MODULES 431 help 432 Without this option you will not be able to unload any 433 modules (note that some modules may not be unloadable 434 anyway), which makes your kernel slightly smaller and 435 simpler. If unsure, say Y. 436 437config MODULE_FORCE_UNLOAD 438 bool "Forced module unloading" 439 depends on MODULE_UNLOAD && EXPERIMENTAL 440 help 441 This option allows you to force a module to unload, even if the 442 kernel believes it is unsafe: the kernel will remove the module 443 without waiting for anyone to stop using it (using the -f option to 444 rmmod). This is mainly for kernel developers and desperate users. 445 If unsure, say N. 446 447config MODVERSIONS 448 bool "Module versioning support" 449 depends on MODULES 450 help 451 Usually, you have to use modules compiled with your kernel. 452 Saying Y here makes it sometimes possible to use modules 453 compiled for different kernels, by adding enough information 454 to the modules to (hopefully) spot any changes which would 455 make them incompatible with the kernel you are running. If 456 unsure, say N. 457 458config MODULE_SRCVERSION_ALL 459 bool "Source checksum for all modules" 460 depends on MODULES 461 help 462 Modules which contain a MODULE_VERSION get an extra "srcversion" 463 field inserted into their modinfo section, which contains a 464 sum of the source files which made it. This helps maintainers 465 see exactly which source was used to build a module (since 466 others sometimes change the module source without updating 467 the version). With this option, such a "srcversion" field 468 will be created for all modules. If unsure, say N. 469 470config KMOD 471 bool "Automatic kernel module loading" 472 depends on MODULES 473 help 474 Normally when you have selected some parts of the kernel to 475 be created as kernel modules, you must load them (using the 476 "modprobe" command) before you can use them. If you say Y 477 here, some parts of the kernel will be able to load modules 478 automatically: when a part of the kernel needs a module, it 479 runs modprobe with the appropriate arguments, thereby 480 loading the module if it is available. If unsure, say Y. 481 482config STOP_MACHINE 483 bool 484 default y 485 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU 486 help 487 Need stop_machine() primitive. 488endmenu 489 490menu "Block layer" 491source "block/Kconfig" 492endmenu 493