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const.h

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/*!     \file include/const.h
 *      \brief Global constants definition.
 *      \author Andrea Righi <drizzt@inwind.it>
 *      \date Last update:\n
 *              2003-12-16 Andrea Righi:
 *                      Added pid_t typedef.\n
 *              2004-13-01 Andrea Righi:
 *                      New kernel style.\n
 *      \note Copyright (&copy;) 2003 Andrea Righi
 */

#ifndef CONST_H
#define CONST_H

#include <kernel/config.h>
#include <types.h>

// --- Global constants ----------------------------------------------- //

//! Logical value of TRUE.
#define TRUE    1
//! Logical value of FALSE.
#define FALSE   0
//! NULL constant.
#define NULL    0

//! Little endian architecture.
#define __LITTLE_ENDIAN__       1234
//! Big endian architecture.
#define __BIG_ENDIAN__          4321
//! The current architecture.
#define __BYTE_ORDER__          __LITTLE_ENDIAN__

// --- Useful macros -------------------------------------------------- //

//! This macro returns the minimum value between \a a and \a b.
#define MIN(a, b)       ((a) < (b) ? (a) : (b))
//! This macro returns the maximum value between \a a and \a b.
#define MAX(a, b)       ((a) > (b) ? (a) : (b))
//! This macro returns the absolute value of \a a.
#define ABS(a)          ((a) < 0 ? -(a) : (a))
//! This macro truncates \a addr to the \a align boundary.
#define TRUNC(addr, align)      ((addr) & ~((align) - 1))
//! This macro rounds down \a addr to the \a align boundary.
#define ALIGN_DOWN(addr, align) TRUNC(addr, align)
//! This macro rounds up \a addr to the \a align boundary.
#define ALIGN_UP(addr, align)   ( ((addr) + (align) - 1) & (~((align) - 1)) )

#endif

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