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/*
* Copyright (C) 2017 Freie Universität Berlin
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup sys_luid
* @{
*
* @file
* @brief LUID module implementation
*
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
*
* @}
*/
#include <stdint.h>
#include <string.h>
#include "assert.h"
#include "periph/cpuid.h"
#include "luid.h"
static uint8_t lastused = 1;
void luid_get(void *buf, size_t len)
{
luid_base(buf, len);
((uint8_t *)buf)[0] ^= lastused++;
}
void luid_custom(void *buf, size_t len, int gen)
{
luid_base(buf, len);
for (size_t i = 0; i < sizeof(gen); i++) {
((uint8_t *)buf)[i % len] ^= ((gen >> (i * 8)) & 0xff);
}
}
void luid_base(void *buf, size_t len)
{
assert(buf && (len > 0));
memset(buf, LUID_BACKUP_SEED, len);
#if CPUID_LEN
uint8_t *out = (uint8_t *)buf;
uint8_t cid[CPUID_LEN];
cpuid_get(cid);
for (size_t i = 0; i < CPUID_LEN; i++) {
out[i % len] ^= cid[i];
}
#endif
}