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 These are 32 drivers that have been replaced by something else, and/or are 33 scheduled to be removed in a future kernel release. 34 35 Unless you intend to help test and develop a feature or driver that 36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 TASKSTATS 162 bool "Export task/process statistics through netlink (EXPERIMENTAL)" 163 depends on NET 164 default n 165 help 166 Export selected statistics for tasks/processes through the 167 generic netlink interface. Unlike BSD process accounting, the 168 statistics are available during the lifetime of tasks/processes as 169 responses to commands. Like BSD accounting, they are sent to user 170 space on task exit. 171 172 Say N if unsure. 173 174config TASK_DELAY_ACCT 175 bool "Enable per-task delay accounting (EXPERIMENTAL)" 176 depends on TASKSTATS 177 help 178 Collect information on time spent by a task waiting for system 179 resources like cpu, synchronous block I/O completion and swapping 180 in pages. Such statistics can help in setting a task's priorities 181 relative to other tasks for cpu, io, rss limits etc. 182 183 Say N if unsure. 184 185config AUDIT 186 bool "Auditing support" 187 depends on NET 188 help 189 Enable auditing infrastructure that can be used with another 190 kernel subsystem, such as SELinux (which requires this for 191 logging of avc messages output). Does not do system-call 192 auditing without CONFIG_AUDITSYSCALL. 193 194config AUDITSYSCALL 195 bool "Enable system-call auditing support" 196 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64) 197 default y if SECURITY_SELINUX 198 help 199 Enable low-overhead system-call auditing infrastructure that 200 can be used independently or with another kernel subsystem, 201 such as SELinux. To use audit's filesystem watch feature, please 202 ensure that INOTIFY is configured. 203 204config IKCONFIG 205 bool "Kernel .config support" 206 ---help--- 207 This option enables the complete Linux kernel ".config" file 208 contents to be saved in the kernel. It provides documentation 209 of which kernel options are used in a running kernel or in an 210 on-disk kernel. This information can be extracted from the kernel 211 image file with the script scripts/extract-ikconfig and used as 212 input to rebuild the current kernel or to build another kernel. 213 It can also be extracted from a running kernel by reading 214 /proc/config.gz if enabled (below). 215 216config IKCONFIG_PROC 217 bool "Enable access to .config through /proc/config.gz" 218 depends on IKCONFIG && PROC_FS 219 ---help--- 220 This option enables access to the kernel configuration file 221 through /proc/config.gz. 222 223config CPUSETS 224 bool "Cpuset support" 225 depends on SMP 226 help 227 This option will let you create and manage CPUSETs which 228 allow dynamically partitioning a system into sets of CPUs and 229 Memory Nodes and assigning tasks to run only within those sets. 230 This is primarily useful on large SMP or NUMA systems. 231 232 Say N if unsure. 233 234config RELAY 235 bool "Kernel->user space relay support (formerly relayfs)" 236 help 237 This option enables support for relay interface support in 238 certain file systems (such as debugfs). 239 It is designed to provide an efficient mechanism for tools and 240 facilities to relay large amounts of data from kernel space to 241 user space. 242 243 If unsure, say N. 244 245source "usr/Kconfig" 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 UID16 269 bool "Enable 16-bit UID system calls" if EMBEDDED 270 depends on ARM || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION) 271 default y 272 help 273 This enables the legacy 16-bit UID syscall wrappers. 274 275config SYSCTL 276 bool "Sysctl support" if EMBEDDED 277 default y 278 ---help--- 279 The sysctl interface provides a means of dynamically changing 280 certain kernel parameters and variables on the fly without requiring 281 a recompile of the kernel or reboot of the system. The primary 282 interface consists of a system call, but if you say Y to "/proc 283 file system support", a tree of modifiable sysctl entries will be 284 generated beneath the /proc/sys directory. They are explained in the 285 files in <file:Documentation/sysctl/>. Note that enabling this 286 option will enlarge the kernel by at least 8 KB. 287 288 As it is generally a good thing, you should say Y here unless 289 building a kernel for install/rescue disks or your system is very 290 limited in memory. 291 292config KALLSYMS 293 bool "Load all symbols for debugging/kksymoops" if EMBEDDED 294 default y 295 help 296 Say Y here to let the kernel print out symbolic crash information and 297 symbolic stack backtraces. This increases the size of the kernel 298 somewhat, as all symbols have to be loaded into the kernel image. 299 300config KALLSYMS_ALL 301 bool "Include all symbols in kallsyms" 302 depends on DEBUG_KERNEL && KALLSYMS 303 help 304 Normally kallsyms only contains the symbols of functions, for nicer 305 OOPS messages. Some debuggers can use kallsyms for other 306 symbols too: say Y here to include all symbols, if you need them 307 and you don't care about adding 300k to the size of your kernel. 308 309 Say N. 310 311config KALLSYMS_EXTRA_PASS 312 bool "Do an extra kallsyms pass" 313 depends on KALLSYMS 314 help 315 If kallsyms is not working correctly, the build will fail with 316 inconsistent kallsyms data. If that occurs, log a bug report and 317 turn on KALLSYMS_EXTRA_PASS which should result in a stable build. 318 Always say N here unless you find a bug in kallsyms, which must be 319 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while 320 you wait for kallsyms to be fixed. 321 322 323config HOTPLUG 324 bool "Support for hot-pluggable devices" if EMBEDDED 325 default y 326 help 327 This option is provided for the case where no hotplug or uevent 328 capabilities is wanted by the kernel. You should only consider 329 disabling this option for embedded systems that do not use modules, a 330 dynamic /dev tree, or dynamic device discovery. Just say Y. 331 332config PRINTK 333 default y 334 bool "Enable support for printk" if EMBEDDED 335 help 336 This option enables normal printk support. Removing it 337 eliminates most of the message strings from the kernel image 338 and makes the kernel more or less silent. As this makes it 339 very difficult to diagnose system problems, saying N here is 340 strongly discouraged. 341 342config BUG 343 bool "BUG() support" if EMBEDDED 344 default y 345 help 346 Disabling this option eliminates support for BUG and WARN, reducing 347 the size of your kernel image and potentially quietly ignoring 348 numerous fatal conditions. You should only consider disabling this 349 option for embedded systems with no facilities for reporting errors. 350 Just say Y. 351 352config ELF_CORE 353 default y 354 bool "Enable ELF core dumps" if EMBEDDED 355 help 356 Enable support for generating core dumps. Disabling saves about 4k. 357 358config BASE_FULL 359 default y 360 bool "Enable full-sized data structures for core" if EMBEDDED 361 help 362 Disabling this option reduces the size of miscellaneous core 363 kernel data structures. This saves memory on small machines, 364 but may reduce performance. 365 366config FUTEX 367 bool "Enable futex support" if EMBEDDED 368 default y 369 select RT_MUTEXES 370 help 371 Disabling this option will cause the kernel to be built without 372 support for "fast userspace mutexes". The resulting kernel may not 373 run glibc-based applications correctly. 374 375config EPOLL 376 bool "Enable eventpoll support" if EMBEDDED 377 default y 378 help 379 Disabling this option will cause the kernel to be built without 380 support for epoll family of system calls. 381 382config SHMEM 383 bool "Use full shmem filesystem" if EMBEDDED 384 default y 385 depends on MMU 386 help 387 The shmem is an internal filesystem used to manage shared memory. 388 It is backed by swap and manages resource limits. It is also exported 389 to userspace as tmpfs if TMPFS is enabled. Disabling this 390 option replaces shmem and tmpfs with the much simpler ramfs code, 391 which may be appropriate on small systems without swap. 392 393config SLAB 394 default y 395 bool "Use full SLAB allocator" if EMBEDDED 396 help 397 Disabling this replaces the advanced SLAB allocator and 398 kmalloc support with the drastically simpler SLOB allocator. 399 SLOB is more space efficient but does not scale well and is 400 more susceptible to fragmentation. 401 402config VM_EVENT_COUNTERS 403 default y 404 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED 405 help 406 VM event counters are only needed to for event counts to be 407 shown. They have no function for the kernel itself. This 408 option allows the disabling of the VM event counters. 409 /proc/vmstat will only show page counts. 410 411endmenu # General setup 412 413config RT_MUTEXES 414 boolean 415 select PLIST 416 417config TINY_SHMEM 418 default !SHMEM 419 bool 420 421config BASE_SMALL 422 int 423 default 0 if BASE_FULL 424 default 1 if !BASE_FULL 425 426config SLOB 427 default !SLAB 428 bool 429 430menu "Loadable module support" 431 432config MODULES 433 bool "Enable loadable module support" 434 help 435 Kernel modules are small pieces of compiled code which can 436 be inserted in the running kernel, rather than being 437 permanently built into the kernel. You use the "modprobe" 438 tool to add (and sometimes remove) them. If you say Y here, 439 many parts of the kernel can be built as modules (by 440 answering M instead of Y where indicated): this is most 441 useful for infrequently used options which are not required 442 for booting. For more information, see the man pages for 443 modprobe, lsmod, modinfo, insmod and rmmod. 444 445 If you say Y here, you will need to run "make 446 modules_install" to put the modules under /lib/modules/ 447 where modprobe can find them (you may need to be root to do 448 this). 449 450 If unsure, say Y. 451 452config MODULE_UNLOAD 453 bool "Module unloading" 454 depends on MODULES 455 help 456 Without this option you will not be able to unload any 457 modules (note that some modules may not be unloadable 458 anyway), which makes your kernel slightly smaller and 459 simpler. If unsure, say Y. 460 461config MODULE_FORCE_UNLOAD 462 bool "Forced module unloading" 463 depends on MODULE_UNLOAD && EXPERIMENTAL 464 help 465 This option allows you to force a module to unload, even if the 466 kernel believes it is unsafe: the kernel will remove the module 467 without waiting for anyone to stop using it (using the -f option to 468 rmmod). This is mainly for kernel developers and desperate users. 469 If unsure, say N. 470 471config MODVERSIONS 472 bool "Module versioning support" 473 depends on MODULES 474 help 475 Usually, you have to use modules compiled with your kernel. 476 Saying Y here makes it sometimes possible to use modules 477 compiled for different kernels, by adding enough information 478 to the modules to (hopefully) spot any changes which would 479 make them incompatible with the kernel you are running. If 480 unsure, say N. 481 482config MODULE_SRCVERSION_ALL 483 bool "Source checksum for all modules" 484 depends on MODULES 485 help 486 Modules which contain a MODULE_VERSION get an extra "srcversion" 487 field inserted into their modinfo section, which contains a 488 sum of the source files which made it. This helps maintainers 489 see exactly which source was used to build a module (since 490 others sometimes change the module source without updating 491 the version). With this option, such a "srcversion" field 492 will be created for all modules. If unsure, say N. 493 494config KMOD 495 bool "Automatic kernel module loading" 496 depends on MODULES 497 help 498 Normally when you have selected some parts of the kernel to 499 be created as kernel modules, you must load them (using the 500 "modprobe" command) before you can use them. If you say Y 501 here, some parts of the kernel will be able to load modules 502 automatically: when a part of the kernel needs a module, it 503 runs modprobe with the appropriate arguments, thereby 504 loading the module if it is available. If unsure, say Y. 505 506config STOP_MACHINE 507 bool 508 default y 509 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU 510 help 511 Need stop_machine() primitive. 512endmenu 513 514menu "Block layer" 515source "block/Kconfig" 516endmenu 517