Not only removes a branch during normal operation, but also ensures
that, by initializing at the PRE_KERNEL_2 stage, and granting
privileges to all threads to the semaphore, this code will work in
early boot situations and in user mode.
This assumes that entropy drivers will all initialize during
PRE_KERNEL_1 stage. All in-tree drivers do that.
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
Semaphore state_sem initial count is set to 0 but k_sem_give()
is invoked first in sys_rand32_get() which will block the caller
forever.
Fix the issue by setting the initail count to count_limit.
Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
If there is a build setup problem where a device driver has not been
setup for the entropy driver then the call to device_get_binding()
will return a NULL value and the code will continue to use this NULL
value. The result is a hard fault later in code execution.
Note that CONFIG_ASSERT is by default off so one has to turn this
configuration on to catch this problem.
Signed-off-by: David Leach <david.leach@nxp.com>
Introducing CMake is an important step in a larger effort to make
Zephyr easy to use for application developers working on different
platforms with different development environment needs.
Simplified, this change retains Kconfig as-is, and replaces all
Makefiles with CMakeLists.txt. The DSL-like Make language that KBuild
offers is replaced by a set of CMake extentions. These extentions have
either provided simple one-to-one translations of KBuild features or
introduced new concepts that replace KBuild concepts.
This is a breaking change for existing test infrastructure and build
scripts that are maintained out-of-tree. But for FW itself, no porting
should be necessary.
For users that just want to continue their work with minimal
disruption the following should suffice:
Install CMake 3.8.2+
Port any out-of-tree Makefiles to CMake.
Learn the absolute minimum about the new command line interface:
$ cd samples/hello_world
$ mkdir build && cd build
$ cmake -DBOARD=nrf52_pca10040 ..
$ cd build
$ make
PR: zephyrproject-rtos#4692
docs: http://docs.zephyrproject.org/getting_started/getting_started.html
Signed-off-by: Sebastian Boe <sebastian.boe@nordicsemi.no>
This adds an implementation of Xoroshiro128+ PRNG, based on the
original implementation at [1]. This pseudorandom number generator
will use the entropy driver to obtain the seed.
While it uses only 128 bits of state, it's pretty robust for non-crypto
safe applications.
[1] http://vigna.di.unimi.it/xorshift/xoroshiro128plus.c
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
Instead of every hardware number generator driver providing an
implementation of this function, use the random device API to
centralize the implementation of this function.
This is a very simplistic function that can be seen as a stepping stone
to refactor the random number generation in Zephyr.
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
This should clear up some of the confusion with random number
generators and drivers that obtain entropy from the hardware. Also,
many hardware number generators have limited bandwidth, so it's natural
for their output to be only used for seeding a random number generator.
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
Some "random" drivers are not drivers at all: they just implement the
function `sys_rand32_get()`. Move those to a random subsystem in
preparation for a reorganization.
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
Leandro Pereira