1*025272a2SHeinrich Schuchardt // SPDX-License-Identifier: GPL-2.0+
2*025272a2SHeinrich Schuchardt /*
3*025272a2SHeinrich Schuchardt * The 'rng' command prints bytes from the hardware random number generator.
4*025272a2SHeinrich Schuchardt *
5*025272a2SHeinrich Schuchardt * Copyright (c) 2019, Heinrich Schuchardt <xypron.glpk@gmx.de>
6*025272a2SHeinrich Schuchardt */
7*025272a2SHeinrich Schuchardt #include <common.h>
8*025272a2SHeinrich Schuchardt #include <command.h>
9*025272a2SHeinrich Schuchardt #include <dm.h>
10*025272a2SHeinrich Schuchardt #include <hexdump.h>
11*025272a2SHeinrich Schuchardt #include <rng.h>
12*025272a2SHeinrich Schuchardt
do_rng(cmd_tbl_t * cmdtp,int flag,int argc,char * const argv[])13*025272a2SHeinrich Schuchardt static int do_rng(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
14*025272a2SHeinrich Schuchardt {
15*025272a2SHeinrich Schuchardt size_t n = 0x40;
16*025272a2SHeinrich Schuchardt struct udevice *dev;
17*025272a2SHeinrich Schuchardt void *buf;
18*025272a2SHeinrich Schuchardt int ret = CMD_RET_SUCCESS;
19*025272a2SHeinrich Schuchardt
20*025272a2SHeinrich Schuchardt if (uclass_get_device(UCLASS_RNG, 0, &dev) || !dev) {
21*025272a2SHeinrich Schuchardt printf("No RNG device\n");
22*025272a2SHeinrich Schuchardt return CMD_RET_FAILURE;
23*025272a2SHeinrich Schuchardt }
24*025272a2SHeinrich Schuchardt
25*025272a2SHeinrich Schuchardt if (argc >= 2)
26*025272a2SHeinrich Schuchardt n = simple_strtoul(argv[1], NULL, 16);
27*025272a2SHeinrich Schuchardt
28*025272a2SHeinrich Schuchardt buf = malloc(n);
29*025272a2SHeinrich Schuchardt if (!buf) {
30*025272a2SHeinrich Schuchardt printf("Out of memory\n");
31*025272a2SHeinrich Schuchardt return CMD_RET_FAILURE;
32*025272a2SHeinrich Schuchardt }
33*025272a2SHeinrich Schuchardt
34*025272a2SHeinrich Schuchardt if (dm_rng_read(dev, buf, n)) {
35*025272a2SHeinrich Schuchardt printf("Reading RNG failed\n");
36*025272a2SHeinrich Schuchardt ret = CMD_RET_FAILURE;
37*025272a2SHeinrich Schuchardt } else {
38*025272a2SHeinrich Schuchardt print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, buf, n);
39*025272a2SHeinrich Schuchardt }
40*025272a2SHeinrich Schuchardt
41*025272a2SHeinrich Schuchardt free(buf);
42*025272a2SHeinrich Schuchardt
43*025272a2SHeinrich Schuchardt return ret;
44*025272a2SHeinrich Schuchardt }
45*025272a2SHeinrich Schuchardt
46*025272a2SHeinrich Schuchardt #ifdef CONFIG_SYS_LONGHELP
47*025272a2SHeinrich Schuchardt static char rng_help_text[] =
48*025272a2SHeinrich Schuchardt "[n]\n"
49*025272a2SHeinrich Schuchardt " - print n random bytes\n";
50*025272a2SHeinrich Schuchardt #endif
51*025272a2SHeinrich Schuchardt
52*025272a2SHeinrich Schuchardt U_BOOT_CMD(
53*025272a2SHeinrich Schuchardt rng, 2, 0, do_rng,
54*025272a2SHeinrich Schuchardt "print bytes from the hardware random number generator",
55*025272a2SHeinrich Schuchardt rng_help_text
56*025272a2SHeinrich Schuchardt );
57