FreeRTOS sockets not connecting

rooneytoons wrote on Monday, July 16, 2018:

I am trying to create a simple client/server demo sending small packets across the network using a loopback interface on my EFM32 GG Cortex-M3 microcontroller.

I have copied verbatim the example code given on the freeros website here and here for sending and recieving.

In my main function I simply call the FreeRTOS_IPStart() function (which replaces the FreeRTOS_IPInit function) and then starts the threads, main function looks like this:

void main ( void )
    extern NetworkInterface_t *xLoopbackInterface;
    pxLoopback_FillInterfaceDescriptor(1, xLoopbackInterface);


	xTaskCreate(prvEchoClientRxTask, "rx", 300, NULL, 1U, &RXTask);
	xTaskCreate(vTCPSend, "tx", 300, NULL, 2U, &TXTask);
		puts("shouldnt be here");

I am unsure whether or not the way I have initialised the interface is right or not - I am using the FreeRTOS +TCP unofficial release with the loopback NetworkInterface.c

Stepping through, I meet my first problem in FreeRTOS_connect, when the prvConnectStart( pxSocket, pxAddress) is called the socket has not yet been bound, so goes into the condition that binds the socket…

		else if( socketSOCKET_IS_BOUND( pxSocket ) == pdFALSE )
			/* Bind the socket to the port that the client task will send from.
			Non-standard, so the error returned is that returned by bind(). */
			xResult = FreeRTOS_bind( ( Socket_t ) pxSocket, NULL, 0u );

xResult becomes zero here, indicating a successful bind.

Back in the connect function, xResult becomes equal to the return value of FreeRTOS_issocketconnected( pxSocket ); which is 0.

The code then finally gets stuck looping in the idle hook after xEventGroupWaitBits() is called.

I am using GCC compiler and am programming on Silicon labs’ IDE ‘Simplicity Studios’.

Thanks for any help!