[thirdparty/u-boot.git] / cmd / rng.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * The 'rng' command prints bytes from the hardware random number generator.
 *
 * Copyright (c) 2019, Heinrich Schuchardt <xypron.glpk@gmx.de>
 */
#include <common.h>
#include <command.h>
#include <dm.h>
#include <hexdump.h>
#include <malloc.h>
#include <rng.h>

static int do_rng(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
	size_t n;
	u8 buf[64];
	int devnum;
	struct udevice *dev;
	int ret = CMD_RET_SUCCESS, err;

	if (argc == 2 && !strcmp(argv[1], "list")) {
		int idx = 0;

		uclass_foreach_dev_probe(UCLASS_RNG, dev) {
			idx++;
			printf("RNG #%d - %s\n", dev->seq_, dev->name);
		}

		if (!idx) {
			log_err("No RNG device\n");
			return CMD_RET_FAILURE;
		}

		return CMD_RET_SUCCESS;
	}

	switch (argc) {
	case 1:
		devnum = 0;
		n = 0x40;
		break;
	case 2:
		devnum = hextoul(argv[1], NULL);
		n = 0x40;
		break;
	case 3:
		devnum = hextoul(argv[1], NULL);
		n = hextoul(argv[2], NULL);
		break;
	default:
		return CMD_RET_USAGE;
	}

	if (uclass_get_device_by_seq(UCLASS_RNG, devnum, &dev) || !dev) {
		printf("No RNG device\n");
		return CMD_RET_FAILURE;
	}

	if (!n)
		return 0;

	n = min(n, sizeof(buf));

	err = dm_rng_read(dev, buf, n);
	if (err) {
		puts(err == -EINTR ? "Abort\n" : "Reading RNG failed\n");
		ret = CMD_RET_FAILURE;
	} else {
		print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, buf, n);
	}

	return ret;
}

U_BOOT_CMD(
	rng, 3, 0, do_rng,
	"print bytes from the hardware random number generator",
	"list         - list all the probed rng devices\n"
	"rng [dev] [n]    - print n random bytes(max 64) read from dev\n"
);
Commit	Line	Data
4f24ac08 HS	1	// SPDX-License-Identifier: GPL-2.0+
	2	/*
	3	* The 'rng' command prints bytes from the hardware random number generator.
	4	*
	5	* Copyright (c) 2019, Heinrich Schuchardt <xypron.glpk@gmx.de>
	6	*/
d678a59d	7	#include <common.h>
4f24ac08 HS	8	#include <command.h>
	9	#include <dm.h>
	10	#include <hexdump.h>
336d4615	11	#include <malloc.h>
4f24ac08 HS	12	#include <rng.h>
4f24ac08 HS	13
09140113	14	static int do_rng(struct cmd_tbl cmdtp, int flag, int argc, char const argv[])
4f24ac08	15	{
87ab234c	16	size_t n;
c79e274c	17	u8 buf[64];
87ab234c	18	int devnum;
c79e274c	19	struct udevice *dev;
144c0167	20	int ret = CMD_RET_SUCCESS, err;
4f24ac08	21
9a6e975c WO	22	if (argc == 2 && !strcmp(argv[1], "list")) {
	23	int idx = 0;
	24
	25	uclass_foreach_dev_probe(UCLASS_RNG, dev) {
	26	idx++;
	27	printf("RNG #%d - %s\n", dev->seq_, dev->name);
	28	}
	29
	30	if (!idx) {
	31	log_err("No RNG device\n");
	32	return CMD_RET_FAILURE;
	33	}
	34
	35	return CMD_RET_SUCCESS;
	36	}
	37
87ab234c SG	38	switch (argc) {
	39	case 1:
	40	devnum = 0;
	41	n = 0x40;
	42	break;
	43	case 2:
	44	devnum = hextoul(argv[1], NULL);
	45	n = 0x40;
	46	break;
	47	case 3:
	48	devnum = hextoul(argv[1], NULL);
	49	n = hextoul(argv[2], NULL);
	50	break;
	51	default:
	52	return CMD_RET_USAGE;
	53	}
	54
	55	if (uclass_get_device_by_seq(UCLASS_RNG, devnum, &dev) \|\| !dev) {
4f24ac08 HS	56	printf("No RNG device\n");
	57	return CMD_RET_FAILURE;
	58	}
	59
c79e274c SG	60	if (!n)
	61	return 0;
	62
	63	n = min(n, sizeof(buf));
4f24ac08	64
144c0167 MB	65	err = dm_rng_read(dev, buf, n);
	66	if (err) {
	67	puts(err == -EINTR ? "Abort\n" : "Reading RNG failed\n");
4f24ac08 HS	68	ret = CMD_RET_FAILURE;
	69	} else {
	70	print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, buf, n);
	71	}
	72
4f24ac08 HS	73	return ret;
	74	}
	75
4f24ac08	76	U_BOOT_CMD(
87ab234c	77	rng, 3, 0, do_rng,
4f24ac08	78	"print bytes from the hardware random number generator",
9a6e975c WO	79	"list - list all the probed rng devices\n"
9a6e975c WO	80	"rng [dev] [n] - print n random bytes(max 64) read from dev\n"
4f24ac08	81	);