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 These are 33 drivers that have been replaced by something else, and/or are 34 scheduled to be removed in a future kernel release. 35 36 Unless you intend to help test and develop a feature or driver that 37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 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 POSIX_MQUEUE 120 bool "POSIX Message Queues" 121 depends on NET && EXPERIMENTAL 122 ---help--- 123 POSIX variant of message queues is a part of IPC. In POSIX message 124 queues every message has a priority which decides about succession 125 of receiving it by a process. If you want to compile and run 126 programs written e.g. for Solaris with use of its POSIX message 127 queues (functions mq_*) say Y here. To use this feature you will 128 also need mqueue library, available from 129 <http://www.mat.uni.torun.pl/~wrona/posix_ipc/> 130 131 POSIX message queues are visible as a filesystem called 'mqueue' 132 and can be mounted somewhere if you want to do filesystem 133 operations on message queues. 134 135 If unsure, say Y. 136 137config BSD_PROCESS_ACCT 138 bool "BSD Process Accounting" 139 help 140 If you say Y here, a user level program will be able to instruct the 141 kernel (via a special system call) to write process accounting 142 information to a file: whenever a process exits, information about 143 that process will be appended to the file by the kernel. The 144 information includes things such as creation time, owning user, 145 command name, memory usage, controlling terminal etc. (the complete 146 list is in the struct acct in <file:include/linux/acct.h>). It is 147 up to the user level program to do useful things with this 148 information. This is generally a good idea, so say Y. 149 150config BSD_PROCESS_ACCT_V3 151 bool "BSD Process Accounting version 3 file format" 152 depends on BSD_PROCESS_ACCT 153 default n 154 help 155 If you say Y here, the process accounting information is written 156 in a new file format that also logs the process IDs of each 157 process and it's parent. Note that this file format is incompatible 158 with previous v0/v1/v2 file formats, so you will need updated tools 159 for processing it. A preliminary version of these tools is available 160 at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>. 161 162config TASKSTATS 163 bool "Export task/process statistics through netlink (EXPERIMENTAL)" 164 depends on NET 165 default n 166 help 167 Export selected statistics for tasks/processes through the 168 generic netlink interface. Unlike BSD process accounting, the 169 statistics are available during the lifetime of tasks/processes as 170 responses to commands. Like BSD accounting, they are sent to user 171 space on task exit. 172 173 Say N if unsure. 174 175config TASK_DELAY_ACCT 176 bool "Enable per-task delay accounting (EXPERIMENTAL)" 177 depends on TASKSTATS 178 help 179 Collect information on time spent by a task waiting for system 180 resources like cpu, synchronous block I/O completion and swapping 181 in pages. Such statistics can help in setting a task's priorities 182 relative to other tasks for cpu, io, rss limits etc. 183 184 Say N if unsure. 185 186config AUDIT 187 bool "Auditing support" 188 depends on NET 189 help 190 Enable auditing infrastructure that can be used with another 191 kernel subsystem, such as SELinux (which requires this for 192 logging of avc messages output). Does not do system-call 193 auditing without CONFIG_AUDITSYSCALL. 194 195config AUDITSYSCALL 196 bool "Enable system-call auditing support" 197 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64) 198 default y if SECURITY_SELINUX 199 help 200 Enable low-overhead system-call auditing infrastructure that 201 can be used independently or with another kernel subsystem, 202 such as SELinux. To use audit's filesystem watch feature, please 203 ensure that INOTIFY is configured. 204 205config IKCONFIG 206 bool "Kernel .config support" 207 ---help--- 208 This option enables the complete Linux kernel ".config" file 209 contents to be saved in the kernel. It provides documentation 210 of which kernel options are used in a running kernel or in an 211 on-disk kernel. This information can be extracted from the kernel 212 image file with the script scripts/extract-ikconfig and used as 213 input to rebuild the current kernel or to build another kernel. 214 It can also be extracted from a running kernel by reading 215 /proc/config.gz if enabled (below). 216 217config IKCONFIG_PROC 218 bool "Enable access to .config through /proc/config.gz" 219 depends on IKCONFIG && PROC_FS 220 ---help--- 221 This option enables access to the kernel configuration file 222 through /proc/config.gz. 223 224config CPUSETS 225 bool "Cpuset support" 226 depends on SMP 227 help 228 This option will let you create and manage CPUSETs which 229 allow dynamically partitioning a system into sets of CPUs and 230 Memory Nodes and assigning tasks to run only within those sets. 231 This is primarily useful on large SMP or NUMA systems. 232 233 Say N if unsure. 234 235config RELAY 236 bool "Kernel->user space relay support (formerly relayfs)" 237 help 238 This option enables support for relay interface support in 239 certain file systems (such as debugfs). 240 It is designed to provide an efficient mechanism for tools and 241 facilities to relay large amounts of data from kernel space to 242 user space. 243 244 If unsure, say N. 245 246source "usr/Kconfig" 247 248config CC_OPTIMIZE_FOR_SIZE 249 bool "Optimize for size (Look out for broken compilers!)" 250 default y 251 depends on ARM || H8300 || EXPERIMENTAL 252 help 253 Enabling this option will pass "-Os" instead of "-O2" to gcc 254 resulting in a smaller kernel. 255 256 WARNING: some versions of gcc may generate incorrect code with this 257 option. If problems are observed, a gcc upgrade may be needed. 258 259 If unsure, say N. 260 261menuconfig EMBEDDED 262 bool "Configure standard kernel features (for small systems)" 263 help 264 This option allows certain base kernel options and settings 265 to be disabled or tweaked. This is for specialized 266 environments which can tolerate a "non-standard" kernel. 267 Only use this if you really know what you are doing. 268 269config UID16 270 bool "Enable 16-bit UID system calls" if EMBEDDED 271 depends on ARM || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION) 272 default y 273 help 274 This enables the legacy 16-bit UID syscall wrappers. 275 276config SYSCTL 277 bool "Sysctl support" if EMBEDDED 278 default y 279 ---help--- 280 The sysctl interface provides a means of dynamically changing 281 certain kernel parameters and variables on the fly without requiring 282 a recompile of the kernel or reboot of the system. The primary 283 interface consists of a system call, but if you say Y to "/proc 284 file system support", a tree of modifiable sysctl entries will be 285 generated beneath the /proc/sys directory. They are explained in the 286 files in <file:Documentation/sysctl/>. Note that enabling this 287 option will enlarge the kernel by at least 8 KB. 288 289 As it is generally a good thing, you should say Y here unless 290 building a kernel for install/rescue disks or your system is very 291 limited in memory. 292 293config KALLSYMS 294 bool "Load all symbols for debugging/kksymoops" if EMBEDDED 295 default y 296 help 297 Say Y here to let the kernel print out symbolic crash information and 298 symbolic stack backtraces. This increases the size of the kernel 299 somewhat, as all symbols have to be loaded into the kernel image. 300 301config KALLSYMS_ALL 302 bool "Include all symbols in kallsyms" 303 depends on DEBUG_KERNEL && KALLSYMS 304 help 305 Normally kallsyms only contains the symbols of functions, for nicer 306 OOPS messages. Some debuggers can use kallsyms for other 307 symbols too: say Y here to include all symbols, if you need them 308 and you don't care about adding 300k to the size of your kernel. 309 310 Say N. 311 312config KALLSYMS_EXTRA_PASS 313 bool "Do an extra kallsyms pass" 314 depends on KALLSYMS 315 help 316 If kallsyms is not working correctly, the build will fail with 317 inconsistent kallsyms data. If that occurs, log a bug report and 318 turn on KALLSYMS_EXTRA_PASS which should result in a stable build. 319 Always say N here unless you find a bug in kallsyms, which must be 320 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while 321 you wait for kallsyms to be fixed. 322 323 324config HOTPLUG 325 bool "Support for hot-pluggable devices" if EMBEDDED 326 default y 327 help 328 This option is provided for the case where no hotplug or uevent 329 capabilities is wanted by the kernel. You should only consider 330 disabling this option for embedded systems that do not use modules, a 331 dynamic /dev tree, or dynamic device discovery. Just say Y. 332 333config PRINTK 334 default y 335 bool "Enable support for printk" if EMBEDDED 336 help 337 This option enables normal printk support. Removing it 338 eliminates most of the message strings from the kernel image 339 and makes the kernel more or less silent. As this makes it 340 very difficult to diagnose system problems, saying N here is 341 strongly discouraged. 342 343config BUG 344 bool "BUG() support" if EMBEDDED 345 default y 346 help 347 Disabling this option eliminates support for BUG and WARN, reducing 348 the size of your kernel image and potentially quietly ignoring 349 numerous fatal conditions. You should only consider disabling this 350 option for embedded systems with no facilities for reporting errors. 351 Just say Y. 352 353config ELF_CORE 354 default y 355 bool "Enable ELF core dumps" if EMBEDDED 356 help 357 Enable support for generating core dumps. Disabling saves about 4k. 358 359config BASE_FULL 360 default y 361 bool "Enable full-sized data structures for core" if EMBEDDED 362 help 363 Disabling this option reduces the size of miscellaneous core 364 kernel data structures. This saves memory on small machines, 365 but may reduce performance. 366 367config FUTEX 368 bool "Enable futex support" if EMBEDDED 369 default y 370 select RT_MUTEXES 371 help 372 Disabling this option will cause the kernel to be built without 373 support for "fast userspace mutexes". The resulting kernel may not 374 run glibc-based applications correctly. 375 376config EPOLL 377 bool "Enable eventpoll support" if EMBEDDED 378 default y 379 help 380 Disabling this option will cause the kernel to be built without 381 support for epoll family of system calls. 382 383config SHMEM 384 bool "Use full shmem filesystem" if EMBEDDED 385 default y 386 depends on MMU 387 help 388 The shmem is an internal filesystem used to manage shared memory. 389 It is backed by swap and manages resource limits. It is also exported 390 to userspace as tmpfs if TMPFS is enabled. Disabling this 391 option replaces shmem and tmpfs with the much simpler ramfs code, 392 which may be appropriate on small systems without swap. 393 394config SLAB 395 default y 396 bool "Use full SLAB allocator" if EMBEDDED 397 help 398 Disabling this replaces the advanced SLAB allocator and 399 kmalloc support with the drastically simpler SLOB allocator. 400 SLOB is more space efficient but does not scale well and is 401 more susceptible to fragmentation. 402 403config VM_EVENT_COUNTERS 404 default y 405 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED 406 help 407 VM event counters are only needed to for event counts to be 408 shown. They have no function for the kernel itself. This 409 option allows the disabling of the VM event counters. 410 /proc/vmstat will only show page counts. 411 412endmenu # General setup 413 414config RT_MUTEXES 415 boolean 416 select PLIST 417 418config TINY_SHMEM 419 default !SHMEM 420 bool 421 422config BASE_SMALL 423 int 424 default 0 if BASE_FULL 425 default 1 if !BASE_FULL 426 427config SLOB 428 default !SLAB 429 bool 430 431menu "Loadable module support" 432 433config MODULES 434 bool "Enable loadable module support" 435 help 436 Kernel modules are small pieces of compiled code which can 437 be inserted in the running kernel, rather than being 438 permanently built into the kernel. You use the "modprobe" 439 tool to add (and sometimes remove) them. If you say Y here, 440 many parts of the kernel can be built as modules (by 441 answering M instead of Y where indicated): this is most 442 useful for infrequently used options which are not required 443 for booting. For more information, see the man pages for 444 modprobe, lsmod, modinfo, insmod and rmmod. 445 446 If you say Y here, you will need to run "make 447 modules_install" to put the modules under /lib/modules/ 448 where modprobe can find them (you may need to be root to do 449 this). 450 451 If unsure, say Y. 452 453config MODULE_UNLOAD 454 bool "Module unloading" 455 depends on MODULES 456 help 457 Without this option you will not be able to unload any 458 modules (note that some modules may not be unloadable 459 anyway), which makes your kernel slightly smaller and 460 simpler. If unsure, say Y. 461 462config MODULE_FORCE_UNLOAD 463 bool "Forced module unloading" 464 depends on MODULE_UNLOAD && EXPERIMENTAL 465 help 466 This option allows you to force a module to unload, even if the 467 kernel believes it is unsafe: the kernel will remove the module 468 without waiting for anyone to stop using it (using the -f option to 469 rmmod). This is mainly for kernel developers and desperate users. 470 If unsure, say N. 471 472config MODVERSIONS 473 bool "Module versioning support" 474 depends on MODULES 475 help 476 Usually, you have to use modules compiled with your kernel. 477 Saying Y here makes it sometimes possible to use modules 478 compiled for different kernels, by adding enough information 479 to the modules to (hopefully) spot any changes which would 480 make them incompatible with the kernel you are running. If 481 unsure, say N. 482 483config MODULE_SRCVERSION_ALL 484 bool "Source checksum for all modules" 485 depends on MODULES 486 help 487 Modules which contain a MODULE_VERSION get an extra "srcversion" 488 field inserted into their modinfo section, which contains a 489 sum of the source files which made it. This helps maintainers 490 see exactly which source was used to build a module (since 491 others sometimes change the module source without updating 492 the version). With this option, such a "srcversion" field 493 will be created for all modules. If unsure, say N. 494 495config MODULE_SIG 496 bool "Module signature verification (EXPERIMENTAL)" 497 depends on MODULES && EXPERIMENTAL 498 select CRYPTO 499 select CRYPTO_SHA1 500 select CRYPTO_SIGNATURE 501 help 502 Check modules for valid signatures upon load. 503 504config MODULE_SIG_FORCE 505 bool "Required modules to be validly signed (EXPERIMENTAL)" 506 depends on MODULE_SIG 507 help 508 Reject unsigned modules or signed modules for which we don't have a 509 key. 510 511config KMOD 512 bool "Automatic kernel module loading" 513 depends on MODULES 514 help 515 Normally when you have selected some parts of the kernel to 516 be created as kernel modules, you must load them (using the 517 "modprobe" command) before you can use them. If you say Y 518 here, some parts of the kernel will be able to load modules 519 automatically: when a part of the kernel needs a module, it 520 runs modprobe with the appropriate arguments, thereby 521 loading the module if it is available. If unsure, say Y. 522 523config STOP_MACHINE 524 bool 525 default y 526 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU 527 help 528 Need stop_machine() primitive. 529endmenu 530 531menu "Process debugging support" 532 533config UTRACE 534 bool "Infrastructure for tracing and debugging user processes" 535 default y 536 help 537 Enable the utrace process tracing interface. 538 This is an internal kernel interface to track events in user 539 threads, extract and change user thread state. This interface 540 is exported to kernel modules, and is also used to implement ptrace. 541 If you disable this, no facilities for debugging user processes 542 will be available, nor the facilities used by UML and other 543 applications. Unless you are making a specially stripped-down 544 kernel and are very sure you don't need these facilitiies, 545 say Y. 546 547config PTRACE 548 bool "Legacy ptrace system call interface" 549 default y 550 depends on UTRACE 551 help 552 Enable the ptrace system call. 553 This is traditionally used by debuggers like GDB, 554 and is used by UML and some other applications. 555 Unless you are very sure you won't run anything that needs it, 556 say Y. 557 558endmenu 559 560menu "Block layer" 561source "block/Kconfig" 562endmenu 563