Support for Bare metal/single task/thread

[amitv87]

Multi task environment for simple applications like beacon/eddystone is kind of overkill and increases ROM/RAM requirements.
Also porting the lib to some new OS becomes challenging when time is scarce.

I would love to have an option to run the entire host stack in single task/thread (similar to LWIP in NO_SYS mode).
Here is the pseudo code that I am after.

int main(){
  AppInit();                                  // initialize system
  NimbleHostInit(conf, transport, callbacks); // initialize nimble host

  while (true) {
    AppTask();    // handle all system operations here
    NimbleTask(); // handle all nimble host operations here like read from/write to transport
  }
  return 0;
}

[sjanc]

Currently we don't have any plans for bare metal support in NimBLE host, but I don't see a reason to block this if anyone is willing to work on that.

BTW upcoming Nimble 1.5 release have much improved ram/rom usage when unused BLE roles are disabled.
Eg this is for advertiser sample app (beacon):

FLASH RAM
9990 1518 @apache-mynewt-nimble_nimble_controller.a
3372 710 @apache-mynewt-nimble_nimble_drivers_nrf51.a
8522 1153 @apache-mynewt-nimble_nimble_host.a
80 32 @apache-mynewt-nimble_nimble_host_services_gap.a
599 5596 @apache-mynewt-nimble_nimble_transport.a

And you should be able to tune it further down as this is using stack's defaults for transport buffers...