lfs_util.h 7.1 KB

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  1. /*
  2. * lfs utility functions
  3. *
  4. * Copyright (c) 2017, Arm Limited. All rights reserved.
  5. * SPDX-License-Identifier: BSD-3-Clause
  6. */
  7. #ifndef LFS_UTIL_H
  8. #define LFS_UTIL_H
  9. // Users can override lfs_util.h with their own configuration by defining
  10. // LFS_CONFIG as a header file to include (-DLFS_CONFIG=lfs_config.h).
  11. //
  12. // If LFS_CONFIG is used, none of the default utils will be emitted and must be
  13. // provided by the config file. To start, I would suggest copying lfs_util.h
  14. // and modifying as needed.
  15. #ifdef LFS_CONFIG
  16. #define LFS_STRINGIZE(x) LFS_STRINGIZE2(x)
  17. #define LFS_STRINGIZE2(x) #x
  18. #include LFS_STRINGIZE(LFS_CONFIG)
  19. #else
  20. // System includes
  21. #include <stdint.h>
  22. #include <stdbool.h>
  23. #include <string.h>
  24. #include <inttypes.h>
  25. #ifndef LFS_NO_MALLOC
  26. #include <stdlib.h>
  27. #endif
  28. #ifndef LFS_NO_ASSERT
  29. #include <assert.h>
  30. #endif
  31. #if !defined(LFS_NO_DEBUG) || \
  32. !defined(LFS_NO_WARN) || \
  33. !defined(LFS_NO_ERROR) || \
  34. defined(LFS_YES_TRACE)
  35. #include <stdio.h>
  36. #endif
  37. #ifdef __cplusplus
  38. extern "C"
  39. {
  40. #endif
  41. // Macros, may be replaced by system specific wrappers. Arguments to these
  42. // macros must not have side-effects as the macros can be removed for a smaller
  43. // code footprint
  44. // Logging functions
  45. #ifndef LFS_TRACE
  46. #ifdef LFS_YES_TRACE
  47. #define LFS_TRACE_(fmt, ...) \
  48. printf("%s:%d:trace: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
  49. #define LFS_TRACE(...) LFS_TRACE_(__VA_ARGS__, "")
  50. #else
  51. #define LFS_TRACE(...)
  52. #endif
  53. #endif
  54. #ifndef LFS_DEBUG
  55. #ifndef LFS_NO_DEBUG
  56. #define LFS_DEBUG_(fmt, ...) \
  57. printf("%s:%d:debug: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
  58. #define LFS_DEBUG(...) LFS_DEBUG_(__VA_ARGS__, "")
  59. #else
  60. #define LFS_DEBUG(...)
  61. #endif
  62. #endif
  63. #ifndef LFS_WARN
  64. #ifndef LFS_NO_WARN
  65. #define LFS_WARN_(fmt, ...) \
  66. printf("%s:%d:warn: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
  67. #define LFS_WARN(...) LFS_WARN_(__VA_ARGS__, "")
  68. #else
  69. #define LFS_WARN(...)
  70. #endif
  71. #endif
  72. #ifndef LFS_ERROR
  73. #ifndef LFS_NO_ERROR
  74. #define LFS_ERROR_(fmt, ...) \
  75. printf("%s:%d:error: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
  76. #define LFS_ERROR(...) LFS_ERROR_(__VA_ARGS__, "")
  77. #else
  78. #define LFS_ERROR(...)
  79. #endif
  80. #endif
  81. // Runtime assertions
  82. #ifndef LFS_ASSERT
  83. #ifndef LFS_NO_ASSERT
  84. #define LFS_ASSERT(test) assert(test)
  85. #else
  86. #define LFS_ASSERT(test)
  87. #endif
  88. #endif
  89. // Builtin functions, these may be replaced by more efficient
  90. // toolchain-specific implementations. LFS_NO_INTRINSICS falls back to a more
  91. // expensive basic C implementation for debugging purposes
  92. // Min/max functions for unsigned 32-bit numbers
  93. static inline uint32_t lfs_max(uint32_t a, uint32_t b) {
  94. return (a > b) ? a : b;
  95. }
  96. static inline uint32_t lfs_min(uint32_t a, uint32_t b) {
  97. return (a < b) ? a : b;
  98. }
  99. // Align to nearest multiple of a size
  100. static inline uint32_t lfs_aligndown(uint32_t a, uint32_t alignment) {
  101. return a - (a % alignment);
  102. }
  103. static inline uint32_t lfs_alignup(uint32_t a, uint32_t alignment) {
  104. return lfs_aligndown(a + alignment-1, alignment);
  105. }
  106. // Find the smallest power of 2 greater than or equal to a
  107. static inline uint32_t lfs_npw2(uint32_t a) {
  108. #if !defined(LFS_NO_INTRINSICS) && (defined(__GNUC__) || defined(__CC_ARM))
  109. return 32 - __builtin_clz(a-1);
  110. #else
  111. uint32_t r = 0;
  112. uint32_t s;
  113. a -= 1;
  114. s = (a > 0xffff) << 4; a >>= s; r |= s;
  115. s = (a > 0xff ) << 3; a >>= s; r |= s;
  116. s = (a > 0xf ) << 2; a >>= s; r |= s;
  117. s = (a > 0x3 ) << 1; a >>= s; r |= s;
  118. return (r | (a >> 1)) + 1;
  119. #endif
  120. }
  121. // Count the number of trailing binary zeros in a
  122. // lfs_ctz(0) may be undefined
  123. static inline uint32_t lfs_ctz(uint32_t a) {
  124. #if !defined(LFS_NO_INTRINSICS) && defined(__GNUC__)
  125. return __builtin_ctz(a);
  126. #else
  127. return lfs_npw2((a & -a) + 1) - 1;
  128. #endif
  129. }
  130. // Count the number of binary ones in a
  131. static inline uint32_t lfs_popc(uint32_t a) {
  132. #if !defined(LFS_NO_INTRINSICS) && (defined(__GNUC__) || defined(__CC_ARM))
  133. return __builtin_popcount(a);
  134. #else
  135. a = a - ((a >> 1) & 0x55555555);
  136. a = (a & 0x33333333) + ((a >> 2) & 0x33333333);
  137. return (((a + (a >> 4)) & 0xf0f0f0f) * 0x1010101) >> 24;
  138. #endif
  139. }
  140. // Find the sequence comparison of a and b, this is the distance
  141. // between a and b ignoring overflow
  142. static inline int lfs_scmp(uint32_t a, uint32_t b) {
  143. return (int)(unsigned)(a - b);
  144. }
  145. // Convert between 32-bit little-endian and native order
  146. static inline uint32_t lfs_fromle32(uint32_t a) {
  147. #if !defined(LFS_NO_INTRINSICS) && ( \
  148. (defined( BYTE_ORDER ) && defined( ORDER_LITTLE_ENDIAN ) && BYTE_ORDER == ORDER_LITTLE_ENDIAN ) || \
  149. (defined(__BYTE_ORDER ) && defined(__ORDER_LITTLE_ENDIAN ) && __BYTE_ORDER == __ORDER_LITTLE_ENDIAN ) || \
  150. (defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__))
  151. return a;
  152. #elif !defined(LFS_NO_INTRINSICS) && ( \
  153. (defined( BYTE_ORDER ) && defined( ORDER_BIG_ENDIAN ) && BYTE_ORDER == ORDER_BIG_ENDIAN ) || \
  154. (defined(__BYTE_ORDER ) && defined(__ORDER_BIG_ENDIAN ) && __BYTE_ORDER == __ORDER_BIG_ENDIAN ) || \
  155. (defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))
  156. return __builtin_bswap32(a);
  157. #else
  158. return (((uint8_t*)&a)[0] << 0) |
  159. (((uint8_t*)&a)[1] << 8) |
  160. (((uint8_t*)&a)[2] << 16) |
  161. (((uint8_t*)&a)[3] << 24);
  162. #endif
  163. }
  164. static inline uint32_t lfs_tole32(uint32_t a) {
  165. return lfs_fromle32(a);
  166. }
  167. // Convert between 32-bit big-endian and native order
  168. static inline uint32_t lfs_frombe32(uint32_t a) {
  169. #if !defined(LFS_NO_INTRINSICS) && ( \
  170. (defined( BYTE_ORDER ) && defined( ORDER_LITTLE_ENDIAN ) && BYTE_ORDER == ORDER_LITTLE_ENDIAN ) || \
  171. (defined(__BYTE_ORDER ) && defined(__ORDER_LITTLE_ENDIAN ) && __BYTE_ORDER == __ORDER_LITTLE_ENDIAN ) || \
  172. (defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__))
  173. return __builtin_bswap32(a);
  174. #elif !defined(LFS_NO_INTRINSICS) && ( \
  175. (defined( BYTE_ORDER ) && defined( ORDER_BIG_ENDIAN ) && BYTE_ORDER == ORDER_BIG_ENDIAN ) || \
  176. (defined(__BYTE_ORDER ) && defined(__ORDER_BIG_ENDIAN ) && __BYTE_ORDER == __ORDER_BIG_ENDIAN ) || \
  177. (defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))
  178. return a;
  179. #else
  180. return (((uint8_t*)&a)[0] << 24) |
  181. (((uint8_t*)&a)[1] << 16) |
  182. (((uint8_t*)&a)[2] << 8) |
  183. (((uint8_t*)&a)[3] << 0);
  184. #endif
  185. }
  186. static inline uint32_t lfs_tobe32(uint32_t a) {
  187. return lfs_frombe32(a);
  188. }
  189. // Calculate CRC-32 with polynomial = 0x04c11db7
  190. uint32_t lfs_crc(uint32_t crc, const void *buffer, size_t size);
  191. // Allocate memory, only used if buffers are not provided to littlefs
  192. // Note, memory must be 64-bit aligned
  193. static inline void *lfs_malloc(size_t size) {
  194. #ifndef LFS_NO_MALLOC
  195. return malloc(size);
  196. #else
  197. (void)size;
  198. return NULL;
  199. #endif
  200. }
  201. // Deallocate memory, only used if buffers are not provided to littlefs
  202. static inline void lfs_free(void *p) {
  203. #ifndef LFS_NO_MALLOC
  204. free(p);
  205. #else
  206. (void)p;
  207. #endif
  208. }
  209. #ifdef __cplusplus
  210. } /* extern "C" */
  211. #endif
  212. #endif
  213. #endif