1config DEFCONFIG_LIST 2 string 3 depends on !UML 4 option defconfig_list 5 default "/lib/modules/$UNAME_RELEASE/.config" 6 default "/etc/kernel-config" 7 default "/boot/config-$UNAME_RELEASE" 8 default "arch/$ARCH/defconfig" 9 10menu "Code maturity level options" 11 12config EXPERIMENTAL 13 bool "Prompt for development and/or incomplete code/drivers" 14 ---help--- 15 Some of the various things that Linux supports (such as network 16 drivers, file systems, network protocols, etc.) can be in a state 17 of development where the functionality, stability, or the level of 18 testing is not yet high enough for general use. This is usually 19 known as the "alpha-test" phase among developers. If a feature is 20 currently in alpha-test, then the developers usually discourage 21 uninformed widespread use of this feature by the general public to 22 avoid "Why doesn't this work?" type mail messages. However, active 23 testing and use of these systems is welcomed. Just be aware that it 24 may not meet the normal level of reliability or it may fail to work 25 in some special cases. Detailed bug reports from people familiar 26 with the kernel internals are usually welcomed by the developers 27 (before submitting bug reports, please read the documents 28 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>, 29 <file:Documentation/BUG-HUNTING>, and 30 <file:Documentation/oops-tracing.txt> in the kernel source). 31 32 This option will also make obsoleted drivers available. These are 33 drivers that have been replaced by something else, and/or are 34 scheduled to be removed in a future kernel release. 35 36 Unless you intend to help test and develop a feature or driver that 37 falls into this category, or you have a situation that requires 38 using these features, you should probably say N here, which will 39 cause the configurator to present you with fewer choices. If 40 you say Y here, you will be offered the choice of using features or 41 drivers that are currently considered to be in the alpha-test phase. 42 43config BROKEN 44 bool 45 46config BROKEN_ON_SMP 47 bool 48 depends on BROKEN || !SMP 49 default y 50 51config LOCK_KERNEL 52 bool 53 depends on SMP || PREEMPT 54 default y 55 56config INIT_ENV_ARG_LIMIT 57 int 58 default 32 if !UML 59 default 128 if UML 60 help 61 Maximum of each of the number of arguments and environment 62 variables passed to init from the kernel command line. 63 64endmenu 65 66menu "General setup" 67 68config LOCALVERSION 69 string "Local version - append to kernel release" 70 help 71 Append an extra string to the end of your kernel version. 72 This will show up when you type uname, for example. 73 The string you set here will be appended after the contents of 74 any files with a filename matching localversion* in your 75 object and source tree, in that order. Your total string can 76 be a maximum of 64 characters. 77 78config LOCALVERSION_AUTO 79 bool "Automatically append version information to the version string" 80 default y 81 help 82 This will try to automatically determine if the current tree is a 83 release tree by looking for git tags that 84 belong to the current top of tree revision. 85 86 A string of the format -gxxxxxxxx will be added to the localversion 87 if a git based tree is found. The string generated by this will be 88 appended after any matching localversion* files, and after the value 89 set in CONFIG_LOCALVERSION 90 91 Note: This requires Perl, and a git repository, but not necessarily 92 the git or cogito tools to be installed. 93 94config SWAP 95 bool "Support for paging of anonymous memory (swap)" 96 depends on MMU && BLOCK 97 default y 98 help 99 This option allows you to choose whether you want to have support 100 for so called swap devices or swap files in your kernel that are 101 used to provide more virtual memory than the actual RAM present 102 in your computer. If unsure say Y. 103 104config SYSVIPC 105 bool "System V IPC" 106 ---help--- 107 Inter Process Communication is a suite of library functions and 108 system calls which let processes (running programs) synchronize and 109 exchange information. It is generally considered to be a good thing, 110 and some programs won't run unless you say Y here. In particular, if 111 you want to run the DOS emulator dosemu under Linux (read the 112 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>), 113 you'll need to say Y here. 114 115 You can find documentation about IPC with "info ipc" and also in 116 section 6.4 of the Linux Programmer's Guide, available from 117 <http://www.tldp.org/guides.html>. 118 119config IPC_NS 120 bool "IPC Namespaces" 121 depends on SYSVIPC 122 default n 123 help 124 Support ipc namespaces. This allows containers, i.e. virtual 125 environments, to use ipc namespaces to provide different ipc 126 objects for different servers. If unsure, say N. 127 128config POSIX_MQUEUE 129 bool "POSIX Message Queues" 130 depends on NET && EXPERIMENTAL 131 ---help--- 132 POSIX variant of message queues is a part of IPC. In POSIX message 133 queues every message has a priority which decides about succession 134 of receiving it by a process. If you want to compile and run 135 programs written e.g. for Solaris with use of its POSIX message 136 queues (functions mq_*) say Y here. To use this feature you will 137 also need mqueue library, available from 138 <http://www.mat.uni.torun.pl/~wrona/posix_ipc/> 139 140 POSIX message queues are visible as a filesystem called 'mqueue' 141 and can be mounted somewhere if you want to do filesystem 142 operations on message queues. 143 144 If unsure, say Y. 145 146config BSD_PROCESS_ACCT 147 bool "BSD Process Accounting" 148 help 149 If you say Y here, a user level program will be able to instruct the 150 kernel (via a special system call) to write process accounting 151 information to a file: whenever a process exits, information about 152 that process will be appended to the file by the kernel. The 153 information includes things such as creation time, owning user, 154 command name, memory usage, controlling terminal etc. (the complete 155 list is in the struct acct in <file:include/linux/acct.h>). It is 156 up to the user level program to do useful things with this 157 information. This is generally a good idea, so say Y. 158 159config BSD_PROCESS_ACCT_V3 160 bool "BSD Process Accounting version 3 file format" 161 depends on BSD_PROCESS_ACCT 162 default n 163 help 164 If you say Y here, the process accounting information is written 165 in a new file format that also logs the process IDs of each 166 process and it's parent. Note that this file format is incompatible 167 with previous v0/v1/v2 file formats, so you will need updated tools 168 for processing it. A preliminary version of these tools is available 169 at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>. 170 171config TASKSTATS 172 bool "Export task/process statistics through netlink (EXPERIMENTAL)" 173 depends on NET 174 default n 175 help 176 Export selected statistics for tasks/processes through the 177 generic netlink interface. Unlike BSD process accounting, the 178 statistics are available during the lifetime of tasks/processes as 179 responses to commands. Like BSD accounting, they are sent to user 180 space on task exit. 181 182 Say N if unsure. 183 184config TASK_DELAY_ACCT 185 bool "Enable per-task delay accounting (EXPERIMENTAL)" 186 depends on TASKSTATS 187 help 188 Collect information on time spent by a task waiting for system 189 resources like cpu, synchronous block I/O completion and swapping 190 in pages. Such statistics can help in setting a task's priorities 191 relative to other tasks for cpu, io, rss limits etc. 192 193 Say N if unsure. 194 195config TASK_XACCT 196 bool "Enable extended accounting over taskstats (EXPERIMENTAL)" 197 depends on TASKSTATS 198 help 199 Collect extended task accounting data and send the data 200 to userland for processing over the taskstats interface. 201 202 Say N if unsure. 203 204config TASK_IO_ACCOUNTING 205 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)" 206 depends on TASK_XACCT 207 help 208 Collect information on the number of bytes of storage I/O which this 209 task has caused. 210 211 Say N if unsure. 212 213config UTS_NS 214 bool "UTS Namespaces" 215 default n 216 help 217 Support uts namespaces. This allows containers, i.e. 218 vservers, to use uts namespaces to provide different 219 uts info for different servers. If unsure, say N. 220 221config AUDIT 222 bool "Auditing support" 223 depends on NET 224 help 225 Enable auditing infrastructure that can be used with another 226 kernel subsystem, such as SELinux (which requires this for 227 logging of avc messages output). Does not do system-call 228 auditing without CONFIG_AUDITSYSCALL. 229 230config AUDITSYSCALL 231 bool "Enable system-call auditing support" 232 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64) 233 default y if SECURITY_SELINUX 234 help 235 Enable low-overhead system-call auditing infrastructure that 236 can be used independently or with another kernel subsystem, 237 such as SELinux. To use audit's filesystem watch feature, please 238 ensure that INOTIFY is configured. 239 240config IKCONFIG 241 tristate "Kernel .config support" 242 ---help--- 243 This option enables the complete Linux kernel ".config" file 244 contents to be saved in the kernel. It provides documentation 245 of which kernel options are used in a running kernel or in an 246 on-disk kernel. This information can be extracted from the kernel 247 image file with the script scripts/extract-ikconfig and used as 248 input to rebuild the current kernel or to build another kernel. 249 It can also be extracted from a running kernel by reading 250 /proc/config.gz if enabled (below). 251 252config IKCONFIG_PROC 253 bool "Enable access to .config through /proc/config.gz" 254 depends on IKCONFIG && PROC_FS 255 ---help--- 256 This option enables access to the kernel configuration file 257 through /proc/config.gz. 258 259config CPUSETS 260 bool "Cpuset support" 261 depends on SMP 262 help 263 This option will let you create and manage CPUSETs which 264 allow dynamically partitioning a system into sets of CPUs and 265 Memory Nodes and assigning tasks to run only within those sets. 266 This is primarily useful on large SMP or NUMA systems. 267 268 Say N if unsure. 269 270config SYSFS_DEPRECATED 271 bool "Create deprecated sysfs files" 272 default y 273 help 274 This option creates deprecated symlinks such as the 275 "device"-link, the <subsystem>:<name>-link, and the 276 "bus"-link. It may also add deprecated key in the 277 uevent environment. 278 None of these features or values should be used today, as 279 they export driver core implementation details to userspace 280 or export properties which can't be kept stable across kernel 281 releases. 282 283 If enabled, this option will also move any device structures 284 that belong to a class, back into the /sys/class heirachy, in 285 order to support older versions of udev. 286 287 If you are using a distro that was released in 2006 or later, 288 it should be safe to say N here. 289 290config RELAY 291 bool "Kernel->user space relay support (formerly relayfs)" 292 help 293 This option enables support for relay interface support in 294 certain file systems (such as debugfs). 295 It is designed to provide an efficient mechanism for tools and 296 facilities to relay large amounts of data from kernel space to 297 user space. 298 299 If unsure, say N. 300 301if BLK_DEV_INITRD 302 303source "usr/Kconfig" 304 305endif 306 307config CC_OPTIMIZE_FOR_SIZE 308 bool "Optimize for size (Look out for broken compilers!)" 309 default y 310 depends on ARM || H8300 || EXPERIMENTAL 311 help 312 Enabling this option will pass "-Os" instead of "-O2" to gcc 313 resulting in a smaller kernel. 314 315 WARNING: some versions of gcc may generate incorrect code with this 316 option. If problems are observed, a gcc upgrade may be needed. 317 318 If unsure, say N. 319 320config SYSCTL 321 bool 322 323menuconfig EMBEDDED 324 bool "Configure standard kernel features (for small systems)" 325 help 326 This option allows certain base kernel options and settings 327 to be disabled or tweaked. This is for specialized 328 environments which can tolerate a "non-standard" kernel. 329 Only use this if you really know what you are doing. 330 331config UID16 332 bool "Enable 16-bit UID system calls" if EMBEDDED 333 depends on ARM || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION) 334 default y 335 help 336 This enables the legacy 16-bit UID syscall wrappers. 337 338config SYSCTL_SYSCALL 339 bool "Sysctl syscall support" if EMBEDDED 340 default y 341 select SYSCTL 342 ---help--- 343 sys_sysctl uses binary paths that have been found challenging 344 to properly maintain and use. The interface in /proc/sys 345 using paths with ascii names is now the primary path to this 346 information. 347 348 Almost nothing using the binary sysctl interface so if you are 349 trying to save some space it is probably safe to disable this, 350 making your kernel marginally smaller. 351 352 If unsure say Y here. 353 354config KALLSYMS 355 bool "Load all symbols for debugging/ksymoops" if EMBEDDED 356 default y 357 help 358 Say Y here to let the kernel print out symbolic crash information and 359 symbolic stack backtraces. This increases the size of the kernel 360 somewhat, as all symbols have to be loaded into the kernel image. 361 362config KALLSYMS_ALL 363 bool "Include all symbols in kallsyms" 364 depends on DEBUG_KERNEL && KALLSYMS 365 help 366 Normally kallsyms only contains the symbols of functions, for nicer 367 OOPS messages. Some debuggers can use kallsyms for other 368 symbols too: say Y here to include all symbols, if you need them 369 and you don't care about adding 300k to the size of your kernel. 370 371 Say N. 372 373config KALLSYMS_EXTRA_PASS 374 bool "Do an extra kallsyms pass" 375 depends on KALLSYMS 376 help 377 If kallsyms is not working correctly, the build will fail with 378 inconsistent kallsyms data. If that occurs, log a bug report and 379 turn on KALLSYMS_EXTRA_PASS which should result in a stable build. 380 Always say N here unless you find a bug in kallsyms, which must be 381 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while 382 you wait for kallsyms to be fixed. 383 384 385config HOTPLUG 386 bool "Support for hot-pluggable devices" if EMBEDDED 387 default y 388 help 389 This option is provided for the case where no hotplug or uevent 390 capabilities is wanted by the kernel. You should only consider 391 disabling this option for embedded systems that do not use modules, a 392 dynamic /dev tree, or dynamic device discovery. Just say Y. 393 394config PRINTK 395 default y 396 bool "Enable support for printk" if EMBEDDED 397 help 398 This option enables normal printk support. Removing it 399 eliminates most of the message strings from the kernel image 400 and makes the kernel more or less silent. As this makes it 401 very difficult to diagnose system problems, saying N here is 402 strongly discouraged. 403 404config BUG 405 bool "BUG() support" if EMBEDDED 406 default y 407 help 408 Disabling this option eliminates support for BUG and WARN, reducing 409 the size of your kernel image and potentially quietly ignoring 410 numerous fatal conditions. You should only consider disabling this 411 option for embedded systems with no facilities for reporting errors. 412 Just say Y. 413 414config ELF_CORE 415 default y 416 bool "Enable ELF core dumps" if EMBEDDED 417 help 418 Enable support for generating core dumps. Disabling saves about 4k. 419 420config BASE_FULL 421 default y 422 bool "Enable full-sized data structures for core" if EMBEDDED 423 help 424 Disabling this option reduces the size of miscellaneous core 425 kernel data structures. This saves memory on small machines, 426 but may reduce performance. 427 428config FUTEX 429 bool "Enable futex support" if EMBEDDED 430 default y 431 select RT_MUTEXES 432 help 433 Disabling this option will cause the kernel to be built without 434 support for "fast userspace mutexes". The resulting kernel may not 435 run glibc-based applications correctly. 436 437config EPOLL 438 bool "Enable eventpoll support" if EMBEDDED 439 default y 440 help 441 Disabling this option will cause the kernel to be built without 442 support for epoll family of system calls. 443 444config SHMEM 445 bool "Use full shmem filesystem" if EMBEDDED 446 default y 447 depends on MMU 448 help 449 The shmem is an internal filesystem used to manage shared memory. 450 It is backed by swap and manages resource limits. It is also exported 451 to userspace as tmpfs if TMPFS is enabled. Disabling this 452 option replaces shmem and tmpfs with the much simpler ramfs code, 453 which may be appropriate on small systems without swap. 454 455config SLAB 456 default y 457 bool "Use full SLAB allocator" if (EMBEDDED && !SMP && !SPARSEMEM) 458 help 459 Disabling this replaces the advanced SLAB allocator and 460 kmalloc support with the drastically simpler SLOB allocator. 461 SLOB is more space efficient but does not scale well and is 462 more susceptible to fragmentation. 463 464config VM_EVENT_COUNTERS 465 default y 466 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED 467 help 468 VM event counters are needed for event counts to be shown. 469 This option allows the disabling of the VM event counters 470 on EMBEDDED systems. /proc/vmstat will only show page counts 471 if VM event counters are disabled. 472 473endmenu # General setup 474 475config RT_MUTEXES 476 boolean 477 select PLIST 478 479config TINY_SHMEM 480 default !SHMEM 481 bool 482 483config BASE_SMALL 484 int 485 default 0 if BASE_FULL 486 default 1 if !BASE_FULL 487 488config SLOB 489 default !SLAB 490 bool 491 492menu "Loadable module support" 493 494config MODULES 495 bool "Enable loadable module support" 496 help 497 Kernel modules are small pieces of compiled code which can 498 be inserted in the running kernel, rather than being 499 permanently built into the kernel. You use the "modprobe" 500 tool to add (and sometimes remove) them. If you say Y here, 501 many parts of the kernel can be built as modules (by 502 answering M instead of Y where indicated): this is most 503 useful for infrequently used options which are not required 504 for booting. For more information, see the man pages for 505 modprobe, lsmod, modinfo, insmod and rmmod. 506 507 If you say Y here, you will need to run "make 508 modules_install" to put the modules under /lib/modules/ 509 where modprobe can find them (you may need to be root to do 510 this). 511 512 If unsure, say Y. 513 514config MODULE_UNLOAD 515 bool "Module unloading" 516 depends on MODULES 517 help 518 Without this option you will not be able to unload any 519 modules (note that some modules may not be unloadable 520 anyway), which makes your kernel slightly smaller and 521 simpler. If unsure, say Y. 522 523config MODULE_FORCE_UNLOAD 524 bool "Forced module unloading" 525 depends on MODULE_UNLOAD && EXPERIMENTAL 526 help 527 This option allows you to force a module to unload, even if the 528 kernel believes it is unsafe: the kernel will remove the module 529 without waiting for anyone to stop using it (using the -f option to 530 rmmod). This is mainly for kernel developers and desperate users. 531 If unsure, say N. 532 533config MODVERSIONS 534 bool "Module versioning support" 535 depends on MODULES 536 help 537 Usually, you have to use modules compiled with your kernel. 538 Saying Y here makes it sometimes possible to use modules 539 compiled for different kernels, by adding enough information 540 to the modules to (hopefully) spot any changes which would 541 make them incompatible with the kernel you are running. If 542 unsure, say N. 543 544config MODULE_SRCVERSION_ALL 545 bool "Source checksum for all modules" 546 depends on MODULES 547 help 548 Modules which contain a MODULE_VERSION get an extra "srcversion" 549 field inserted into their modinfo section, which contains a 550 sum of the source files which made it. This helps maintainers 551 see exactly which source was used to build a module (since 552 others sometimes change the module source without updating 553 the version). With this option, such a "srcversion" field 554 will be created for all modules. If unsure, say N. 555 556config KMOD 557 bool "Automatic kernel module loading" 558 depends on MODULES 559 help 560 Normally when you have selected some parts of the kernel to 561 be created as kernel modules, you must load them (using the 562 "modprobe" command) before you can use them. If you say Y 563 here, some parts of the kernel will be able to load modules 564 automatically: when a part of the kernel needs a module, it 565 runs modprobe with the appropriate arguments, thereby 566 loading the module if it is available. If unsure, say Y. 567 568config STOP_MACHINE 569 bool 570 default y 571 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU 572 help 573 Need stop_machine() primitive. 574endmenu 575 576menu "Block layer" 577source "block/Kconfig" 578endmenu 579