c79e274c7c
Use a statically allocated buffer on stack instead of using malloc for reading the random bytes. Using a local array is faster than allocating heap memory on every initiation of the command. Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org> Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Reviewed-by: Simon Glass <sjg@chromium.org> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
70 lines
1.3 KiB
C
70 lines
1.3 KiB
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;
|
|
|
|
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
|
|
);
|