2 # Library configuration
8 menu "Library routines"
19 config GENERIC_STRNCPY_FROM_USER
22 config GENERIC_STRNLEN_USER
25 config GENERIC_NET_UTILS
28 config GENERIC_FIND_FIRST_BIT
31 config NO_GENERIC_PCI_IOPORT_MAP
34 config GENERIC_PCI_IOMAP
39 select GENERIC_PCI_IOMAP
51 config ARCH_USE_CMPXCHG_LOCKREF
54 config ARCH_HAS_FAST_MULTIPLIER
58 tristate "CRC-CCITT functions"
60 This option is provided for the case where no in-kernel-tree
61 modules require CRC-CCITT functions, but a module built outside
62 the kernel tree does. Such modules that use library CRC-CCITT
63 functions require M here.
66 tristate "CRC16 functions"
68 This option is provided for the case where no in-kernel-tree
69 modules require CRC16 functions, but a module built outside
70 the kernel tree does. Such modules that use library CRC16
71 functions require M here.
74 tristate "CRC calculation for the T10 Data Integrity Field"
76 select CRYPTO_CRCT10DIF
78 This option is only needed if a module that's not in the
79 kernel tree needs to calculate CRC checks for use with the
80 SCSI data integrity subsystem.
83 tristate "CRC ITU-T V.41 functions"
85 This option is provided for the case where no in-kernel-tree
86 modules require CRC ITU-T V.41 functions, but a module built outside
87 the kernel tree does. Such modules that use library CRC ITU-T V.41
88 functions require M here.
91 tristate "CRC32/CRC32c functions"
95 This option is provided for the case where no in-kernel-tree
96 modules require CRC32/CRC32c functions, but a module built outside
97 the kernel tree does. Such modules that use library CRC32/CRC32c
98 functions require M here.
100 config CRC32_SELFTEST
101 bool "CRC32 perform self test on init"
105 This option enables the CRC32 library functions to perform a
106 self test on initialization. The self test computes crc32_le
107 and crc32_be over byte strings with random alignment and length
108 and computes the total elapsed time and number of bytes processed.
111 prompt "CRC32 implementation"
113 default CRC32_SLICEBY8
115 This option allows a kernel builder to override the default choice
116 of CRC32 algorithm. Choose the default ("slice by 8") unless you
117 know that you need one of the others.
119 config CRC32_SLICEBY8
120 bool "Slice by 8 bytes"
122 Calculate checksum 8 bytes at a time with a clever slicing algorithm.
123 This is the fastest algorithm, but comes with a 8KiB lookup table.
124 Most modern processors have enough cache to hold this table without
127 This is the default implementation choice. Choose this one unless
128 you have a good reason not to.
130 config CRC32_SLICEBY4
131 bool "Slice by 4 bytes"
133 Calculate checksum 4 bytes at a time with a clever slicing algorithm.
134 This is a bit slower than slice by 8, but has a smaller 4KiB lookup
137 Only choose this option if you know what you are doing.
140 bool "Sarwate's Algorithm (one byte at a time)"
142 Calculate checksum a byte at a time using Sarwate's algorithm. This
143 is not particularly fast, but has a small 256 byte lookup table.
145 Only choose this option if you know what you are doing.
148 bool "Classic Algorithm (one bit at a time)"
150 Calculate checksum one bit at a time. This is VERY slow, but has
151 no lookup table. This is provided as a debugging option.
153 Only choose this option if you are debugging crc32.
158 tristate "CRC7 functions"
160 This option is provided for the case where no in-kernel-tree
161 modules require CRC7 functions, but a module built outside
162 the kernel tree does. Such modules that use library CRC7
163 functions require M here.
166 tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check"
170 This option is provided for the case where no in-kernel-tree
171 modules require CRC32c functions, but a module built outside the
172 kernel tree does. Such modules that use library CRC32c functions
173 require M here. See Castagnoli93.
174 Module will be libcrc32c.
177 tristate "CRC8 function"
179 This option provides CRC8 function. Drivers may select this
180 when they need to do cyclic redundancy check according CRC8
181 algorithm. Module will be called crc8.
185 depends on AUDIT && !AUDIT_ARCH
188 config AUDIT_ARCH_COMPAT_GENERIC
192 config AUDIT_COMPAT_GENERIC
194 depends on AUDIT_GENERIC && AUDIT_ARCH_COMPAT_GENERIC && COMPAT
197 config RANDOM32_SELFTEST
198 bool "PRNG perform self test on init"
201 This option enables the 32 bit PRNG library functions to perform a
202 self test on initialization.
205 # compression support is select'ed if needed
216 config LZO_DECOMPRESS
222 config LZ4HC_COMPRESS
225 config LZ4_DECOMPRESS
228 source "lib/xz/Kconfig"
231 # These all provide a common interface (hence the apparent duplication with
232 # ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.)
234 config DECOMPRESS_GZIP
238 config DECOMPRESS_BZIP2
241 config DECOMPRESS_LZMA
248 config DECOMPRESS_LZO
249 select LZO_DECOMPRESS
252 config DECOMPRESS_LZ4
253 select LZ4_DECOMPRESS
257 # Generic allocator support is selected if needed
259 config GENERIC_ALLOCATOR
263 # reed solomon support is select'ed if needed
268 config REED_SOLOMON_ENC8
271 config REED_SOLOMON_DEC8
274 config REED_SOLOMON_ENC16
277 config REED_SOLOMON_DEC16
281 # BCH support is selected if needed
286 config BCH_CONST_PARAMS
289 Drivers may select this option to force specific constant
290 values for parameters 'm' (Galois field order) and 't'
291 (error correction capability). Those specific values must
292 be set by declaring default values for symbols BCH_CONST_M
294 Doing so will enable extra compiler optimizations,
295 improving encoding and decoding performance up to 2x for
296 usual (m,t) values (typically such that m*t < 200).
297 When this option is selected, the BCH library supports
298 only a single (m,t) configuration. This is mainly useful
299 for NAND flash board drivers requiring known, fixed BCH
306 Constant value for Galois field order 'm'. If 'k' is the
307 number of data bits to protect, 'm' should be chosen such
308 that (k + m*t) <= 2**m - 1.
309 Drivers should declare a default value for this symbol if
310 they select option BCH_CONST_PARAMS.
315 Constant value for error correction capability in bits 't'.
316 Drivers should declare a default value for this symbol if
317 they select option BCH_CONST_PARAMS.
320 # Textsearch support is select'ed if needed
325 config TEXTSEARCH_KMP
331 config TEXTSEARCH_FSM
340 Simple, embeddable, interval-tree. Can find the start of an
341 overlapping range in log(n) time and then iterate over all
342 overlapping nodes. The algorithm is implemented as an
347 Documentation/rbtree.txt
349 for more information.
351 config ASSOCIATIVE_ARRAY
354 Generic associative array. Can be searched and iterated over whilst
355 it is being modified. It is also reasonably quick to search and
356 modify. The algorithms are non-recursive, and the trees are highly
361 Documentation/assoc_array.txt
363 for more information.
371 config HAS_IOPORT_MAP
373 depends on HAS_IOMEM && !NO_IOPORT_MAP
381 config CHECK_SIGNATURE
384 config CPUMASK_OFFSTACK
385 bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS
387 Use dynamic allocation for cpumask_var_t, instead of putting
388 them on the stack. This is a bit more expensive, but avoids
391 config DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
392 bool "Disable obsolete cpumask functions" if DEBUG_PER_CPU_MAPS
404 # This actually supports modular compilation, but the module overhead
405 # is ridiculous for the amount of code involved. Until an out-of-tree
406 # driver asks for it, we'll just link it directly it into the kernel
407 # when required. Since we're ignoring out-of-tree users, there's also
408 # no need bother prompting for a manual decision:
409 # prompt "glob_match() function"
411 This option provides a glob_match function for performing
412 simple text pattern matching. It originated in the ATA code
413 to blacklist particular drive models, but other device drivers
414 may need similar functionality.
416 All drivers in the Linux kernel tree that require this function
417 should automatically select this option. Say N unless you
418 are compiling an out-of tree driver which tells you that it
422 bool "glob self-test on init"
426 This option enables a simple self-test of the glob_match
427 function on startup. It is primarily useful for people
428 working on the code to ensure they haven't introduced any
431 It only adds a little bit of code and slows kernel boot (or
432 module load) by a small amount, so you're welcome to play with
433 it, but you probably don't need it.
436 # Netlink attribute parsing support is select'ed if needed
442 # Generic 64-bit atomic support is selected if needed
444 config GENERIC_ATOMIC64
447 config ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
448 def_bool y if GENERIC_ATOMIC64
454 bool "Averaging functions"
456 This option is provided for the case where no in-kernel-tree
457 modules require averaging functions, but a module built outside
458 the kernel tree does. Such modules that use library averaging
459 functions require Y here.
467 tristate "CORDIC algorithm"
469 This option provides an implementation of the CORDIC algorithm;
470 calculations are in fixed point. Module will be called cordic.
473 bool "JEDEC DDR data"
475 Data from JEDEC specs for DDR SDRAM memories,
476 particularly the AC timing parameters and addressing
477 information. This data is useful for drivers handling
478 DDR SDRAM controllers.
484 Multiprecision maths library from GnuPG.
485 It is used to implement RSA digital signature verification,
486 which is used by IMA/EVM digital signature extension.
495 Digital signature verification. Currently only RSA is supported.
496 Implementation is done using GnuPG MPI library
499 # libfdt files, only selected if needed.
507 Enable fast lookup object identifier registry.
512 source "lib/fonts/Kconfig"
518 config ARCH_HAS_SG_CHAIN