include/platform/random.h

/*
 * Copyright (c) 2021 Google, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#pragma once

#include <sys/types.h>
#include <compiler.h>

__BEGIN_CDECLS;

/**
 * platform_random_get_bytes() - Read bytes from random number source.
 * @buf: Buffer to receive the random bytes.
 * @len: How many bytes to put in the buffer.
 *
 * Reads "len" bytes from a random number source and stores them in "buf".
 *
 * Context: Can be called during early startup when interrupts are disabled
 *          or the scheduler is not started yet.
 */
void platform_random_get_bytes(uint8_t *buf, size_t len);

__END_CDECLS;