cmd: add rng command
For the RNG uclass we currently only have a test working on the sandbox.
Provide a command to test the hardware random number generator on
non-sandbox systems.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/cmd/Kconfig b/cmd/Kconfig
index a6bfa87..7a78343 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -1672,6 +1672,13 @@
milliseconds. See also the 'bootstage' command which provides more
flexibility for boot timing.
+config CMD_RNG
+ bool "rng command"
+ depends on DM_RNG
+ select HEXDUMP
+ help
+ Print bytes from the hardware random number generator.
+
# TODO: rename to CMD_SLEEP
config CMD_MISC
bool "sleep"
diff --git a/cmd/Makefile b/cmd/Makefile
index 12e898d..8df39f3 100644
--- a/cmd/Makefile
+++ b/cmd/Makefile
@@ -117,6 +117,7 @@
obj-$(CONFIG_CMD_REGINFO) += reginfo.o
obj-$(CONFIG_CMD_REISER) += reiser.o
obj-$(CONFIG_CMD_REMOTEPROC) += remoteproc.o
+obj-$(CONFIG_CMD_RNG) += rng.o
obj-$(CONFIG_CMD_ROCKUSB) += rockusb.o
obj-$(CONFIG_SANDBOX) += host.o
obj-$(CONFIG_CMD_SATA) += sata.o
diff --git a/cmd/rng.c b/cmd/rng.c
new file mode 100644
index 0000000..36ca7a1
--- /dev/null
+++ b/cmd/rng.c
@@ -0,0 +1,56 @@
+// 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 <rng.h>
+
+static int do_rng(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+ size_t n = 0x40;
+ struct udevice *dev;
+ void *buf;
+ int ret = CMD_RET_SUCCESS;
+
+ if (uclass_get_device(UCLASS_RNG, 0, &dev) || !dev) {
+ printf("No RNG device\n");
+ return CMD_RET_FAILURE;
+ }
+
+ if (argc >= 2)
+ n = simple_strtoul(argv[1], NULL, 16);
+
+ buf = malloc(n);
+ if (!buf) {
+ printf("Out of memory\n");
+ return CMD_RET_FAILURE;
+ }
+
+ 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);
+ }
+
+ free(buf);
+
+ return ret;
+}
+
+#ifdef CONFIG_SYS_LONGHELP
+static char rng_help_text[] =
+ "[n]\n"
+ " - print n random bytes\n";
+#endif
+
+U_BOOT_CMD(
+ rng, 2, 0, do_rng,
+ "print bytes from the hardware random number generator",
+ rng_help_text
+);