linux-yocto/lib/Kconfig

Library configuration

config BINARY_PRINTF def_bool n

menu "Library routines"

config RAID6_PQ tristate

config BITREVERSE tristate

config HAVE_ARCH_BITREVERSE bool default n depends on BITREVERSE help This option enables the use of hardware bit-reversal instructions on architectures which support such operations.

config RATIONAL bool

config GENERIC_STRNCPY_FROM_USER bool

config GENERIC_STRNLEN_USER bool

config GENERIC_NET_UTILS bool

config GENERIC_FIND_FIRST_BIT bool

config NO_GENERIC_PCI_IOPORT_MAP bool

config GENERIC_PCI_IOMAP bool

config GENERIC_IOMAP bool select GENERIC_PCI_IOMAP

config GENERIC_IO bool default n

config STMP_DEVICE bool

config ARCH_USE_CMPXCHG_LOCKREF bool

config ARCH_HAS_FAST_MULTIPLIER bool

config CRC_CCITT tristate "CRC-CCITT functions" help This option is provided for the case where no in-kernel-tree modules require CRC-CCITT functions, but a module built outside the kernel tree does. Such modules that use library CRC-CCITT functions require M here.

config CRC16 tristate "CRC16 functions" help This option is provided for the case where no in-kernel-tree modules require CRC16 functions, but a module built outside the kernel tree does. Such modules that use library CRC16 functions require M here.

config CRC_T10DIF tristate "CRC calculation for the T10 Data Integrity Field" select CRYPTO select CRYPTO_CRCT10DIF help This option is only needed if a module that's not in the kernel tree needs to calculate CRC checks for use with the SCSI data integrity subsystem.

config CRC_ITU_T tristate "CRC ITU-T V.41 functions" help This option is provided for the case where no in-kernel-tree modules require CRC ITU-T V.41 functions, but a module built outside the kernel tree does. Such modules that use library CRC ITU-T V.41 functions require M here.

config CRC32 tristate "CRC32/CRC32c functions" default y select BITREVERSE help This option is provided for the case where no in-kernel-tree modules require CRC32/CRC32c functions, but a module built outside the kernel tree does. Such modules that use library CRC32/CRC32c functions require M here.

config CRC32_SELFTEST bool "CRC32 perform self test on init" default n depends on CRC32 help This option enables the CRC32 library functions to perform a self test on initialization. The self test computes crc32_le and crc32_be over byte strings with random alignment and length and computes the total elapsed time and number of bytes processed.

choice prompt "CRC32 implementation" depends on CRC32 default CRC32_SLICEBY8 help This option allows a kernel builder to override the default choice of CRC32 algorithm. Choose the default ("slice by 8") unless you know that you need one of the others.

config CRC32_SLICEBY8 bool "Slice by 8 bytes" help Calculate checksum 8 bytes at a time with a clever slicing algorithm. This is the fastest algorithm, but comes with a 8KiB lookup table. Most modern processors have enough cache to hold this table without thrashing the cache.

  This is the default implementation choice.  Choose this one unless
  you have a good reason not to.

config CRC32_SLICEBY4 bool "Slice by 4 bytes" help Calculate checksum 4 bytes at a time with a clever slicing algorithm. This is a bit slower than slice by 8, but has a smaller 4KiB lookup table.

  Only choose this option if you know what you are doing.

config CRC32_SARWATE bool "Sarwate's Algorithm (one byte at a time)" help Calculate checksum a byte at a time using Sarwate's algorithm. This is not particularly fast, but has a small 256 byte lookup table.

  Only choose this option if you know what you are doing.

config CRC32_BIT bool "Classic Algorithm (one bit at a time)" help Calculate checksum one bit at a time. This is VERY slow, but has no lookup table. This is provided as a debugging option.

  Only choose this option if you are debugging crc32.

endchoice

config CRC7 tristate "CRC7 functions" help This option is provided for the case where no in-kernel-tree modules require CRC7 functions, but a module built outside the kernel tree does. Such modules that use library CRC7 functions require M here.

config LIBCRC32C tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check" select CRYPTO select CRYPTO_CRC32C help This option is provided for the case where no in-kernel-tree modules require CRC32c functions, but a module built outside the kernel tree does. Such modules that use library CRC32c functions require M here. See Castagnoli93. Module will be libcrc32c.

config CRC8 tristate "CRC8 function" help This option provides CRC8 function. Drivers may select this when they need to do cyclic redundancy check according CRC8 algorithm. Module will be called crc8.

config AUDIT_GENERIC bool depends on AUDIT && !AUDIT_ARCH default y

config AUDIT_ARCH_COMPAT_GENERIC bool default n

config AUDIT_COMPAT_GENERIC bool depends on AUDIT_GENERIC && AUDIT_ARCH_COMPAT_GENERIC && COMPAT default y

config RANDOM32_SELFTEST bool "PRNG perform self test on init" default n help This option enables the 32 bit PRNG library functions to perform a self test on initialization.

compression support is select'ed if needed

config 842_COMPRESS select CRC32 tristate

config 842_DECOMPRESS select CRC32 tristate

config ZLIB_INFLATE tristate

config ZLIB_DEFLATE tristate select BITREVERSE

config LZO_COMPRESS tristate

config LZO_DECOMPRESS tristate

config LZ4_COMPRESS tristate

config LZ4HC_COMPRESS tristate

config LZ4_DECOMPRESS tristate

source "lib/xz/Kconfig"

These all provide a common interface (hence the apparent duplication with

ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.)

config DECOMPRESS_GZIP select ZLIB_INFLATE tristate

config DECOMPRESS_BZIP2 tristate

config DECOMPRESS_LZMA tristate

config DECOMPRESS_XZ select XZ_DEC tristate

config DECOMPRESS_LZO select LZO_DECOMPRESS tristate

config DECOMPRESS_LZ4 select LZ4_DECOMPRESS tristate

Generic allocator support is selected if needed

config GENERIC_ALLOCATOR bool

reed solomon support is select'ed if needed

config REED_SOLOMON tristate

config REED_SOLOMON_ENC8 bool

config REED_SOLOMON_DEC8 bool

config REED_SOLOMON_ENC16 bool

config REED_SOLOMON_DEC16 bool

BCH support is selected if needed

config BCH tristate

config BCH_CONST_PARAMS bool help Drivers may select this option to force specific constant values for parameters 'm' (Galois field order) and 't' (error correction capability). Those specific values must be set by declaring default values for symbols BCH_CONST_M and BCH_CONST_T. Doing so will enable extra compiler optimizations, improving encoding and decoding performance up to 2x for usual (m,t) values (typically such that m*t < 200). When this option is selected, the BCH library supports only a single (m,t) configuration. This is mainly useful for NAND flash board drivers requiring known, fixed BCH parameters.

config BCH_CONST_M int range 5 15 help Constant value for Galois field order 'm'. If 'k' is the number of data bits to protect, 'm' should be chosen such that (k + m*t) <= 2**m - 1. Drivers should declare a default value for this symbol if they select option BCH_CONST_PARAMS.

config BCH_CONST_T int help Constant value for error correction capability in bits 't'. Drivers should declare a default value for this symbol if they select option BCH_CONST_PARAMS.

Textsearch support is select'ed if needed

config TEXTSEARCH bool

config TEXTSEARCH_KMP tristate

config TEXTSEARCH_BM tristate

config TEXTSEARCH_FSM tristate

config BTREE bool

config INTERVAL_TREE bool help Simple, embeddable, interval-tree. Can find the start of an overlapping range in log(n) time and then iterate over all overlapping nodes. The algorithm is implemented as an augmented rbtree.

  See:

	Documentation/rbtree.txt

  for more information.

config RADIX_TREE_MULTIORDER bool

config ASSOCIATIVE_ARRAY bool help Generic associative array. Can be searched and iterated over whilst it is being modified. It is also reasonably quick to search and modify. The algorithms are non-recursive, and the trees are highly capacious.

  See:

	Documentation/assoc_array.txt

  for more information.

config HAS_IOMEM bool depends on !NO_IOMEM select GENERIC_IO default y

config HAS_IOPORT_MAP bool depends on HAS_IOMEM && !NO_IOPORT_MAP default y

config HAS_DMA bool depends on !NO_DMA default y

config CHECK_SIGNATURE bool

config CPUMASK_OFFSTACK bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS help Use dynamic allocation for cpumask_var_t, instead of putting them on the stack. This is a bit more expensive, but avoids stack overflow.

config CPU_RMAP bool depends on SMP

config DQL bool

config GLOB bool

This actually supports modular compilation, but the module overhead

is ridiculous for the amount of code involved. Until an out-of-tree

driver asks for it, we'll just link it directly it into the kernel

when required. Since we're ignoring out-of-tree users, there's also

no need bother prompting for a manual decision:

prompt "glob_match() function"

help
  This option provides a glob_match function for performing
  simple text pattern matching.  It originated in the ATA code
  to blacklist particular drive models, but other device drivers
  may need similar functionality.

  All drivers in the Linux kernel tree that require this function
  should automatically select this option.  Say N unless you
  are compiling an out-of tree driver which tells you that it
  depends on this.

config GLOB_SELFTEST bool "glob self-test on init" default n depends on GLOB help This option enables a simple self-test of the glob_match function on startup. It is primarily useful for people working on the code to ensure they haven't introduced any regressions.

  It only adds a little bit of code and slows kernel boot (or
  module load) by a small amount, so you're welcome to play with
  it, but you probably don't need it.

Netlink attribute parsing support is select'ed if needed

config NLATTR bool

Generic 64-bit atomic support is selected if needed

config GENERIC_ATOMIC64 bool

config LRU_CACHE tristate

config CLZ_TAB bool

config CORDIC tristate "CORDIC algorithm" help This option provides an implementation of the CORDIC algorithm; calculations are in fixed point. Module will be called cordic.

config DDR bool "JEDEC DDR data" help Data from JEDEC specs for DDR SDRAM memories, particularly the AC timing parameters and addressing information. This data is useful for drivers handling DDR SDRAM controllers.

config IRQ_POLL bool "IRQ polling library" help Helper library to poll interrupt mitigation using polling.

config MPILIB tristate select CLZ_TAB help Multiprecision maths library from GnuPG. It is used to implement RSA digital signature verification, which is used by IMA/EVM digital signature extension.

config SIGNATURE tristate depends on KEYS select CRYPTO select CRYPTO_SHA1 select MPILIB help Digital signature verification. Currently only RSA is supported. Implementation is done using GnuPG MPI library

libfdt files, only selected if needed.

config LIBFDT bool

config OID_REGISTRY tristate help Enable fast lookup object identifier registry.

config UCS2_STRING tristate

source "lib/fonts/Kconfig"

config SG_SPLIT def_bool n help Provides a helper to split scatterlists into chunks, each chunk being a scatterlist. This should be selected by a driver or an API which whishes to split a scatterlist amongst multiple DMA channels.

config SG_POOL def_bool n help Provides a helper to allocate chained scatterlists. This should be selected by a driver or an API which whishes to allocate chained scatterlist.

sg chaining option

config ARCH_HAS_SG_CHAIN def_bool n

config ARCH_HAS_PMEM_API bool

config ARCH_HAS_MMIO_FLUSH bool

config STACKDEPOT bool select STACKTRACE

config SBITMAP bool

endmenu