[J-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 <[email protected]>
 */
#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;

	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));

	if (dm_rng_read(dev, buf, n)) {
		printf("Reading RNG failed\n");
		ret = CMD_RET_FAILURE;
	} else {
		print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, buf, n);
	}

	return ret;
}

#ifdef CONFIG_SYS_LONGHELP
static char rng_help_text[] =
	"[dev [n]]\n"
	"  - print n random bytes(max 64) read from dev\n";
#endif

U_BOOT_CMD(
	rng, 3, 0, do_rng,
	"print bytes from the hardware random number generator",
	rng_help_text
);
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 <[email protected]>
	6	*/
	7	#include <common.h>
	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;
4f24ac08 HS	20	int ret = CMD_RET_SUCCESS;
4f24ac08 HS	21
87ab234c SG	22	switch (argc) {
	23	case 1:
	24	devnum = 0;
	25	n = 0x40;
	26	break;
	27	case 2:
	28	devnum = hextoul(argv[1], NULL);
	29	n = 0x40;
	30	break;
	31	case 3:
	32	devnum = hextoul(argv[1], NULL);
	33	n = hextoul(argv[2], NULL);
	34	break;
	35	default:
	36	return CMD_RET_USAGE;
	37	}
	38
	39	if (uclass_get_device_by_seq(UCLASS_RNG, devnum, &dev) \|\| !dev) {
4f24ac08 HS	40	printf("No RNG device\n");
	41	return CMD_RET_FAILURE;
	42	}
	43
c79e274c SG	44	if (!n)
	45	return 0;
	46
	47	n = min(n, sizeof(buf));
4f24ac08 HS	48
	49	if (dm_rng_read(dev, buf, n)) {
	50	printf("Reading RNG failed\n");
	51	ret = CMD_RET_FAILURE;
	52	} else {
	53	print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, buf, n);
	54	}
	55
4f24ac08 HS	56	return ret;
	57	}
	58
	59	#ifdef CONFIG_SYS_LONGHELP
	60	static char rng_help_text[] =
87ab234c	61	"[dev [n]]\n"
c79e274c	62	" - print n random bytes(max 64) read from dev\n";
4f24ac08 HS	63	#endif
	64
	65	U_BOOT_CMD(
87ab234c	66	rng, 3, 0, do_rng,
4f24ac08 HS	67	"print bytes from the hardware random number generator",
	68	rng_help_text
	69	);