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
55 tristate "CRC-CCITT functions"
57 This option is provided for the case where no in-kernel-tree
58 modules require CRC-CCITT functions, but a module built outside
59 the kernel tree does. Such modules that use library CRC-CCITT
60 functions require M here.
63 tristate "CRC16 functions"
65 This option is provided for the case where no in-kernel-tree
66 modules require CRC16 functions, but a module built outside
67 the kernel tree does. Such modules that use library CRC16
68 functions require M here.
71 tristate "CRC calculation for the T10 Data Integrity Field"
73 select CRYPTO_CRCT10DIF
75 This option is only needed if a module that's not in the
76 kernel tree needs to calculate CRC checks for use with the
77 SCSI data integrity subsystem.
80 tristate "CRC ITU-T V.41 functions"
82 This option is provided for the case where no in-kernel-tree
83 modules require CRC ITU-T V.41 functions, but a module built outside
84 the kernel tree does. Such modules that use library CRC ITU-T V.41
85 functions require M here.
88 tristate "CRC32/CRC32c functions"
92 This option is provided for the case where no in-kernel-tree
93 modules require CRC32/CRC32c functions, but a module built outside
94 the kernel tree does. Such modules that use library CRC32/CRC32c
95 functions require M here.
98 bool "CRC32 perform self test on init"
102 This option enables the CRC32 library functions to perform a
103 self test on initialization. The self test computes crc32_le
104 and crc32_be over byte strings with random alignment and length
105 and computes the total elapsed time and number of bytes processed.
108 prompt "CRC32 implementation"
110 default CRC32_SLICEBY8
112 This option allows a kernel builder to override the default choice
113 of CRC32 algorithm. Choose the default ("slice by 8") unless you
114 know that you need one of the others.
116 config CRC32_SLICEBY8
117 bool "Slice by 8 bytes"
119 Calculate checksum 8 bytes at a time with a clever slicing algorithm.
120 This is the fastest algorithm, but comes with a 8KiB lookup table.
121 Most modern processors have enough cache to hold this table without
124 This is the default implementation choice. Choose this one unless
125 you have a good reason not to.
127 config CRC32_SLICEBY4
128 bool "Slice by 4 bytes"
130 Calculate checksum 4 bytes at a time with a clever slicing algorithm.
131 This is a bit slower than slice by 8, but has a smaller 4KiB lookup
134 Only choose this option if you know what you are doing.
137 bool "Sarwate's Algorithm (one byte at a time)"
139 Calculate checksum a byte at a time using Sarwate's algorithm. This
140 is not particularly fast, but has a small 256 byte lookup table.
142 Only choose this option if you know what you are doing.
145 bool "Classic Algorithm (one bit at a time)"
147 Calculate checksum one bit at a time. This is VERY slow, but has
148 no lookup table. This is provided as a debugging option.
150 Only choose this option if you are debugging crc32.
155 tristate "CRC7 functions"
157 This option is provided for the case where no in-kernel-tree
158 modules require CRC7 functions, but a module built outside
159 the kernel tree does. Such modules that use library CRC7
160 functions require M here.
163 tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check"
167 This option is provided for the case where no in-kernel-tree
168 modules require CRC32c functions, but a module built outside the
169 kernel tree does. Such modules that use library CRC32c functions
170 require M here. See Castagnoli93.
171 Module will be libcrc32c.
174 tristate "CRC8 function"
176 This option provides CRC8 function. Drivers may select this
177 when they need to do cyclic redundancy check according CRC8
178 algorithm. Module will be called crc8.
182 depends on AUDIT && !AUDIT_ARCH
185 config RANDOM32_SELFTEST
186 bool "PRNG perform self test on init"
189 This option enables the 32 bit PRNG library functions to perform a
190 self test on initialization.
193 # compression support is select'ed if needed
204 config LZO_DECOMPRESS
210 config LZ4HC_COMPRESS
213 config LZ4_DECOMPRESS
216 source "lib/xz/Kconfig"
219 # These all provide a common interface (hence the apparent duplication with
220 # ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.)
222 config DECOMPRESS_GZIP
226 config DECOMPRESS_BZIP2
229 config DECOMPRESS_LZMA
236 config DECOMPRESS_LZO
237 select LZO_DECOMPRESS
240 config DECOMPRESS_LZ4
241 select LZ4_DECOMPRESS
245 # Generic allocator support is selected if needed
247 config GENERIC_ALLOCATOR
251 # reed solomon support is select'ed if needed
256 config REED_SOLOMON_ENC8
259 config REED_SOLOMON_DEC8
262 config REED_SOLOMON_ENC16
265 config REED_SOLOMON_DEC16
269 # BCH support is selected if needed
274 config BCH_CONST_PARAMS
277 Drivers may select this option to force specific constant
278 values for parameters 'm' (Galois field order) and 't'
279 (error correction capability). Those specific values must
280 be set by declaring default values for symbols BCH_CONST_M
282 Doing so will enable extra compiler optimizations,
283 improving encoding and decoding performance up to 2x for
284 usual (m,t) values (typically such that m*t < 200).
285 When this option is selected, the BCH library supports
286 only a single (m,t) configuration. This is mainly useful
287 for NAND flash board drivers requiring known, fixed BCH
294 Constant value for Galois field order 'm'. If 'k' is the
295 number of data bits to protect, 'm' should be chosen such
296 that (k + m*t) <= 2**m - 1.
297 Drivers should declare a default value for this symbol if
298 they select option BCH_CONST_PARAMS.
303 Constant value for error correction capability in bits 't'.
304 Drivers should declare a default value for this symbol if
305 they select option BCH_CONST_PARAMS.
308 # Textsearch support is select'ed if needed
313 config TEXTSEARCH_KMP
319 config TEXTSEARCH_FSM
325 config ASSOCIATIVE_ARRAY
328 Generic associative array. Can be searched and iterated over whilst
329 it is being modified. It is also reasonably quick to search and
330 modify. The algorithms are non-recursive, and the trees are highly
335 Documentation/assoc_array.txt
337 for more information.
347 depends on HAS_IOMEM && !NO_IOPORT
355 config CHECK_SIGNATURE
358 config CPUMASK_OFFSTACK
359 bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS
361 Use dynamic allocation for cpumask_var_t, instead of putting
362 them on the stack. This is a bit more expensive, but avoids
365 config DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
366 bool "Disable obsolete cpumask functions" if DEBUG_PER_CPU_MAPS
377 # Netlink attribute parsing support is select'ed if needed
383 # Generic 64-bit atomic support is selected if needed
385 config GENERIC_ATOMIC64
388 config ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
389 def_bool y if GENERIC_ATOMIC64
395 bool "Averaging functions"
397 This option is provided for the case where no in-kernel-tree
398 modules require averaging functions, but a module built outside
399 the kernel tree does. Such modules that use library averaging
400 functions require Y here.
408 tristate "CORDIC algorithm"
410 This option provides an implementation of the CORDIC algorithm;
411 calculations are in fixed point. Module will be called cordic.
414 bool "JEDEC DDR data"
416 Data from JEDEC specs for DDR SDRAM memories,
417 particularly the AC timing parameters and addressing
418 information. This data is useful for drivers handling
419 DDR SDRAM controllers.
425 Multiprecision maths library from GnuPG.
426 It is used to implement RSA digital signature verification,
427 which is used by IMA/EVM digital signature extension.
431 depends on KEYS && CRYPTO
435 Digital signature verification. Currently only RSA is supported.
436 Implementation is done using GnuPG MPI library
439 # libfdt files, only selected if needed.
447 Enable fast lookup object identifier registry.
452 source "lib/fonts/Kconfig"