linux/drivers/firmware/efi/libstub/random.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2016 Linaro Ltd;  <[email protected]>
 */

#include <linux/efi.h>
#include <asm/efi.h>

#include "efistub.h"

efi_rng_protocol_t;

efi_rng_protocol;

/**
 * efi_get_random_bytes() - fill a buffer with random bytes
 * @size:	size of the buffer
 * @out:	caller allocated buffer to receive the random bytes
 *
 * The call will fail if either the firmware does not implement the
 * EFI_RNG_PROTOCOL or there are not enough random bytes available to fill
 * the buffer.
 *
 * Return:	status code
 */
efi_status_t efi_get_random_bytes(unsigned long size, u8 *out)
{ … }

/**
 * efi_random_get_seed() - provide random seed as configuration table
 *
 * The EFI_RNG_PROTOCOL is used to read random bytes. These random bytes are
 * saved as a configuration table which can be used as entropy by the kernel
 * for the initialization of its pseudo random number generator.
 *
 * If the EFI_RNG_PROTOCOL is not available or there are not enough random bytes
 * available, the configuration table will not be installed and an error code
 * will be returned.
 *
 * Return:	status code
 */
efi_status_t efi_random_get_seed(void)
{ … }