libfat/source/bit_ops.h

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2006-07-14 04:42:37 +02:00
/*
bit_ops.h
Functions for dealing with conversion of data between types
Copyright (c) 2006 Michael "Chishm" Chisholm
Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation and/or
other materials provided with the distribution.
3. The name of the author may not be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
2006-07-11 - Chishm
* Original release
*/
#ifndef _BIT_OPS_H
#define _BIT_OPS_H
/*-----------------------------------------------------------------
Functions to deal with little endian values stored in u8 arrays
-----------------------------------------------------------------*/
static inline u16 u8array_to_u16 (const u8* item, int offset) {
return ( item[offset] | (item[offset + 1] << 8));
}
static inline u32 u8array_to_u32 (const u8* item, int offset) {
return ( item[offset] | (item[offset + 1] << 8) | (item[offset + 2] << 16) | (item[offset + 3] << 24));
}
static inline void u16_to_u8array (u8* item, int offset, u16 value) {
item[offset] = (u8)value;
item[offset + 1] = (u8)(value >> 8);
}
static inline void u32_to_u8array (u8* item, int offset, u32 value) {
item[offset] = (u8)value;
item[offset + 1] = (u8)(value >> 8);
item[offset + 2] = (u8)(value >> 16);
item[offset + 3] = (u8)(value >> 24);
}
#endif // _BIT_OPS_H