Files
thirdparty-littlefs/lfs_util.h
Christopher Haster ebc0d24211 Added conversion to/from little-endian on disk
Required to support big-endian processors, with the most notable being
the PowerPC architecture.

On little-endian architectures, these conversions can be optimized out
and have no code impact.

Initial patch provided by gmouchard
2018-02-15 16:33:03 -06:00

81 lines
2.2 KiB
C

/*
* lfs utility functions
*
* Copyright (c) 2017 ARM Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef LFS_UTIL_H
#define LFS_UTIL_H
#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
// Builtin functions, these may be replaced by more
// efficient implementations in the system
static inline uint32_t lfs_max(uint32_t a, uint32_t b) {
return (a > b) ? a : b;
}
static inline uint32_t lfs_min(uint32_t a, uint32_t b) {
return (a < b) ? a : b;
}
static inline uint32_t lfs_ctz(uint32_t a) {
return __builtin_ctz(a);
}
static inline uint32_t lfs_npw2(uint32_t a) {
return 32 - __builtin_clz(a-1);
}
static inline uint32_t lfs_popc(uint32_t a) {
return __builtin_popcount(a);
}
static inline int lfs_scmp(uint32_t a, uint32_t b) {
return (int)(unsigned)(a - b);
}
static inline uint32_t lfs_fromle32(uint32_t a) {
#if defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
return a;
#elif defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
return __builtin_bswap32(a);
#else
return (((uint8_t*)&a)[0] << 0) |
(((uint8_t*)&a)[1] << 8) |
(((uint8_t*)&a)[2] << 16) |
(((uint8_t*)&a)[3] << 24);
#endif
}
static inline uint32_t lfs_tole32(uint32_t a) {
return lfs_fromle32(a);
}
// CRC-32 with polynomial = 0x04c11db7
void lfs_crc(uint32_t *crc, const void *buffer, size_t size);
// Logging functions, these may be replaced by system-specific
// logging functions
#define LFS_DEBUG(fmt, ...) printf("lfs debug: " fmt "\n", __VA_ARGS__)
#define LFS_WARN(fmt, ...) printf("lfs warn: " fmt "\n", __VA_ARGS__)
#define LFS_ERROR(fmt, ...) printf("lfs error: " fmt "\n", __VA_ARGS__)
#endif