sandbox_rng.c
996 Bytes
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) 2019, Linaro Limited
*/
#include <common.h>
#include <dm.h>
#include <rng.h>
#include <linux/string.h>
static int sandbox_rng_read(struct udevice *dev, void *data, size_t len)
{
unsigned int i, seed, random;
unsigned char *buf = data;
size_t nrem, nloops;
if (!len)
return 0;
nloops = len / sizeof(random);
seed = get_timer(0) ^ rand();
srand(seed);
for (i = 0, nrem = len; i < nloops; i++) {
random = rand();
memcpy(buf, &random, sizeof(random));
buf += sizeof(random);
nrem -= sizeof(random);
}
if (nrem) {
random = rand();
memcpy(buf, &random, nrem);
}
return 0;
}
static const struct dm_rng_ops sandbox_rng_ops = {
.read = sandbox_rng_read,
};
static const struct udevice_id sandbox_rng_match[] = {
{
.compatible = "sandbox,sandbox-rng",
},
{},
};
U_BOOT_DRIVER(sandbox_rng) = {
.name = "sandbox-rng",
.id = UCLASS_RNG,
.of_match = sandbox_rng_match,
.ops = &sandbox_rng_ops,
};