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// SPDX-License-Identifier: GPL-2.0+
/*
* Library for freestanding binary
*
* Copyright 2019, Heinrich Schuchardt <xypron.glpk@gmx.de>
*
* GCC requires that freestanding programs provide memcpy(), memmove(),
* memset(), and memcmp().
*/
#include <common.h>
/**
* memcmp() - compare memory areas
*
* @s1: pointer to first area
* @s2: pointer to second area
* @n: number of bytes to compare
* Return: 0 if both memory areas are the same, otherwise the sign of the
* result value is the same as the sign of the difference between
* the first differing pair of bytes taken as u8.
*/
int memcmp(const void *s1, const void *s2, size_t n)
{
const u8 *pos1 = s1;
const u8 *pos2 = s2;
for (; n; --n) {
if (*pos1 != *pos2)
return *pos1 - *pos2;
++pos1;
++pos2;
}
return 0;
}
/**
* memcpy() - copy memory area
*
* @dest: destination buffer
* @src: source buffer
* @n: number of bytes to copy
* Return: pointer to destination buffer
*/
void *memmove(void *dest, const void *src, size_t n)
{
u8 *d = dest;
const u8 *s = src;
if (d >= s) {
for (; n; --n)
*d++ = *s++;
} else {
d += n;
s += n;
for (; n; --n)
*--d = *--s;
}
return dest;
}
/**
* memcpy() - copy memory area
*
* @dest: destination buffer
* @src: source buffer
* @n: number of bytes to copy
* Return: pointer to destination buffer
*/
void *memcpy(void *dest, const void *src, size_t n)
{
return memmove(dest, src, n);
}
/**
* memset() - fill memory with a constant byte
*
* @s: destination buffer
* @c: byte value
* @n: number of bytes to set
* Return: pointer to destination buffer
*/
void *memset(void *s, int c, size_t n)
{
u8 *d = s;
for (; n; --n)
*d++ = c;
return s;
}
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