hi Patrick,
On Mon, 16 Dec 2019 at 18:00, Patrick DELAUNAY patrick.delaunay@st.com wrote:
Hi,
From: U-Boot u-boot-bounces@lists.denx.de On Behalf Of Sughosh Ganu Sent: vendredi 13 décembre 2019 08:14
Add a sandbox driver for random number generation. Mostly aimed at
providing a
unit test for rng uclass.
Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org Reviewed-by: Patrice Chotard patrice.chotard@st.com
arch/sandbox/dts/test.dts | 4 ++++ drivers/rng/Kconfig | 7 +++++++ drivers/rng/Makefile | 1 + drivers/rng/sandbox_rng.c | 36 ++++++++++++++++++++++++++++++++++++ 4 files changed, 48 insertions(+) create mode 100644 drivers/rng/sandbox_rng.c
<snip>
a/drivers/rng/sandbox_rng.c b/drivers/rng/sandbox_rng.c new file mode
100644
index 0000000..c5be552 --- /dev/null +++ b/drivers/rng/sandbox_rng.c @@ -0,0 +1,36 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/*
- Copyright (c) 2019, Linaro Limited
- */
+#include <common.h> +#include <dm.h> +#include <rng.h>
+static unsigned long random = 0xdeadbeef;
+static int sandbox_rng_read(struct udevice *dev, void *data, size_t +len) {
Add protection on length I think: If (len != sizeof(random)) retrun - EINVAL;
Ok. Will add this check.
or treat the case len > 4 with loop ?
random ^= ~0UL;*(unsigned long *)data = random;return sizeof(random);Read is OK, so I think the correct return value is 0:
Ok. Will change.
return 0;NB: result (int) can be not enough to return the value read (size_t)
PS: it not really a random generator here but simple sequence 0xdeadbeef -> 0x21524110 -> 0xdeadbeef
It is enough for unitary test, but is is enough for sandbox ? we could reused PRNG code from lib/rand.c ?
I actually wrote this solely from the point of view of adding a unit test for the rng uclass. For which i think the simple sequence above should suffice. Do you have a strong opinion on this. If so, i can change the logic.
-sughosh