On platforms like nrf5340 there are 2 CPUs:
- one is the cpu_net which takes care of the radio stuff and
owns the HW random generator
- one is the cpu_app which holds application data and polls
cpu_net through HCI commands when it needs some random data.
The PSA core implemented in Mbed TLS needs random data at initialization
time, which happens early in the boot process. If we wait for BT to
be ready before issuing the HCI command, then PSA core intialization
will fail. In facts there is no need for the BT to be completely
initialized just to ask for some random data from the cpu_app to
the cpu_net since the HW random generator will likely be already
functional in the cpu_net.
So let's just try the HCI command and, if something is not right,
it will fail anyway. There's no need to anticipate the failure.
Signed-off-by: Valerio Setti <vsetti@baylibre.com>
In order to bring consistency in-tree, migrate all drivers to the new
prefix <zephyr/...>. Note that the conversion has been scripted, refer
to #45388 for more details.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
In order to get rid of the duplication of the code that we had until now
in the tree, consolidate the handling of multiple calls to
bt_hci_cmd_send_sync(BT_HCI_OP_LE_RAND, ...) in a single location,
namely in hci_core.
This allows all of the users of this HCI command to use a single
implementation of the iterated sending of the HCI command to fill a
buffer with random bytes.
Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
bt_hci_cmd_send_sync() requires the caller to unref the buffer that is
sent back as a response. Add the missing call to net_buf_unref()
accordingly.
Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
Adds an entropy driver that uses Bluetooth HCI commands as its source
of randomness. As this method is blocking, the ISR API is not supported.
As this method will range from relatively slow (same core Bluetooth HCI
controller) to extremely slow (UART HCI Bluetooth controller), use the
xoshiro PRNG by default for RNG generation.
Implements #37186
Signed-off-by: Jordan Yates <jordan.yates@data61.csiro.au>
