2 # Library configuration
8 menu "Library routines"
19 config GENERIC_STRNCPY_FROM_USER
22 config GENERIC_STRNLEN_USER
25 config GENERIC_FIND_FIRST_BIT
28 config NO_GENERIC_PCI_IOPORT_MAP
31 config GENERIC_PCI_IOMAP
36 select GENERIC_PCI_IOMAP
49 tristate "CRC-CCITT functions"
51 This option is provided for the case where no in-kernel-tree
52 modules require CRC-CCITT functions, but a module built outside
53 the kernel tree does. Such modules that use library CRC-CCITT
54 functions require M here.
57 tristate "CRC16 functions"
59 This option is provided for the case where no in-kernel-tree
60 modules require CRC16 functions, but a module built outside
61 the kernel tree does. Such modules that use library CRC16
62 functions require M here.
65 tristate "CRC calculation for the T10 Data Integrity Field"
67 This option is only needed if a module that's not in the
68 kernel tree needs to calculate CRC checks for use with the
69 SCSI data integrity subsystem.
72 tristate "CRC ITU-T V.41 functions"
74 This option is provided for the case where no in-kernel-tree
75 modules require CRC ITU-T V.41 functions, but a module built outside
76 the kernel tree does. Such modules that use library CRC ITU-T V.41
77 functions require M here.
80 tristate "CRC32/CRC32c functions"
84 This option is provided for the case where no in-kernel-tree
85 modules require CRC32/CRC32c functions, but a module built outside
86 the kernel tree does. Such modules that use library CRC32/CRC32c
87 functions require M here.
90 bool "CRC32 perform self test on init"
94 This option enables the CRC32 library functions to perform a
95 self test on initialization. The self test computes crc32_le
96 and crc32_be over byte strings with random alignment and length
97 and computes the total elapsed time and number of bytes processed.
100 prompt "CRC32 implementation"
102 default CRC32_SLICEBY8
104 This option allows a kernel builder to override the default choice
105 of CRC32 algorithm. Choose the default ("slice by 8") unless you
106 know that you need one of the others.
108 config CRC32_SLICEBY8
109 bool "Slice by 8 bytes"
111 Calculate checksum 8 bytes at a time with a clever slicing algorithm.
112 This is the fastest algorithm, but comes with a 8KiB lookup table.
113 Most modern processors have enough cache to hold this table without
116 This is the default implementation choice. Choose this one unless
117 you have a good reason not to.
119 config CRC32_SLICEBY4
120 bool "Slice by 4 bytes"
122 Calculate checksum 4 bytes at a time with a clever slicing algorithm.
123 This is a bit slower than slice by 8, but has a smaller 4KiB lookup
126 Only choose this option if you know what you are doing.
129 bool "Sarwate's Algorithm (one byte at a time)"
131 Calculate checksum a byte at a time using Sarwate's algorithm. This
132 is not particularly fast, but has a small 256 byte lookup table.
134 Only choose this option if you know what you are doing.
137 bool "Classic Algorithm (one bit at a time)"
139 Calculate checksum one bit at a time. This is VERY slow, but has
140 no lookup table. This is provided as a debugging option.
142 Only choose this option if you are debugging crc32.
147 tristate "CRC7 functions"
149 This option is provided for the case where no in-kernel-tree
150 modules require CRC7 functions, but a module built outside
151 the kernel tree does. Such modules that use library CRC7
152 functions require M here.
155 tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check"
159 This option is provided for the case where no in-kernel-tree
160 modules require CRC32c functions, but a module built outside the
161 kernel tree does. Such modules that use library CRC32c functions
162 require M here. See Castagnoli93.
163 Module will be libcrc32c.
166 tristate "CRC8 function"
168 This option provides CRC8 function. Drivers may select this
169 when they need to do cyclic redundancy check according CRC8
170 algorithm. Module will be called crc8.
174 depends on AUDIT && !AUDIT_ARCH
178 # compression support is select'ed if needed
189 config LZO_DECOMPRESS
193 bool "LZ4K compression"
196 source "lib/xz/Kconfig"
199 # These all provide a common interface (hence the apparent duplication with
200 # ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.)
202 config DECOMPRESS_GZIP
206 config DECOMPRESS_BZIP2
209 config DECOMPRESS_LZMA
216 config DECOMPRESS_LZO
217 select LZO_DECOMPRESS
221 # Generic allocator support is selected if needed
223 config GENERIC_ALLOCATOR
227 # reed solomon support is select'ed if needed
232 config REED_SOLOMON_ENC8
235 config REED_SOLOMON_DEC8
238 config REED_SOLOMON_ENC16
241 config REED_SOLOMON_DEC16
245 # BCH support is selected if needed
250 config BCH_CONST_PARAMS
253 Drivers may select this option to force specific constant
254 values for parameters 'm' (Galois field order) and 't'
255 (error correction capability). Those specific values must
256 be set by declaring default values for symbols BCH_CONST_M
258 Doing so will enable extra compiler optimizations,
259 improving encoding and decoding performance up to 2x for
260 usual (m,t) values (typically such that m*t < 200).
261 When this option is selected, the BCH library supports
262 only a single (m,t) configuration. This is mainly useful
263 for NAND flash board drivers requiring known, fixed BCH
270 Constant value for Galois field order 'm'. If 'k' is the
271 number of data bits to protect, 'm' should be chosen such
272 that (k + m*t) <= 2**m - 1.
273 Drivers should declare a default value for this symbol if
274 they select option BCH_CONST_PARAMS.
279 Constant value for error correction capability in bits 't'.
280 Drivers should declare a default value for this symbol if
281 they select option BCH_CONST_PARAMS.
284 # Textsearch support is select'ed if needed
289 config TEXTSEARCH_KMP
295 config TEXTSEARCH_FSM
309 depends on HAS_IOMEM && !NO_IOPORT
317 config CHECK_SIGNATURE
320 config CPUMASK_OFFSTACK
321 bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS
323 Use dynamic allocation for cpumask_var_t, instead of putting
324 them on the stack. This is a bit more expensive, but avoids
327 config DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
328 bool "Disable obsolete cpumask functions" if DEBUG_PER_CPU_MAPS
339 # Netlink attribute parsing support is select'ed if needed
345 # Generic 64-bit atomic support is selected if needed
347 config GENERIC_ATOMIC64
350 config ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
351 def_bool y if GENERIC_ATOMIC64
357 bool "Averaging functions"
359 This option is provided for the case where no in-kernel-tree
360 modules require averaging functions, but a module built outside
361 the kernel tree does. Such modules that use library averaging
362 functions require Y here.
370 tristate "CORDIC algorithm"
372 This option provides an implementation of the CORDIC algorithm;
373 calculations are in fixed point. Module will be called cordic.
376 bool "JEDEC DDR data"
378 Data from JEDEC specs for DDR SDRAM memories,
379 particularly the AC timing parameters and addressing
380 information. This data is useful for drivers handling
381 DDR SDRAM controllers.
387 Multiprecision maths library from GnuPG.
388 It is used to implement RSA digital signature verification,
389 which is used by IMA/EVM digital signature extension.
393 depends on KEYS && CRYPTO
397 Digital signature verification. Currently only RSA is supported.
398 Implementation is done using GnuPG MPI library
401 # libfdt files, only selected if needed.
409 Enable fast lookup object identifier registry.