Re: [lwip-users] best approach to lwip using FreeRTOS

[Sergio Sider]

Hi Richard & All,

Thank you all for your help!

> I have just sent you some files.  They might be the same as you already
> have.
> Regards,
> Richard.

Yes, it´s the same I already have. Thanks anyway!


Well, I made some tests using the lwip 1.3.0 implementation from
Luminary. It´s NO_SYS=1 and SYS_LIGHTWEIGHT_PROT=1.
The timeout counters were implemented in a timer ISR each 10ms, and
the Ethernet ISR just sets a flag to be polled by the main
application, that called lwip to process the packets and re-enables
the ethernet interrupt.

So, I did the following to adapt to FreeRTOS

1) Created a task to mimic the timer interrupt for processing the lwip
timeout counters

void vLWIPTimerTask (void* pvParameters)
{
        portTickType xLastWakeTime = xTaskGetTickCount();
        for (;;)
        {
        lwIPServiceTimers(10);  //luminary´s procs the lwip counters
                vTaskDelayUntil (&xLastWakeTime, (10 / portTICK_RATE_MS)); 
//each 10ms
        }
}

2) created a thread for lwip, that initializes the stack and then
stays in a loop

...

while (1)  {

        ....other processing...

        if (HWREGBITW(&System_Flags,FLAG_RXPKT) ||
HWREGBITW(&System_Flags,FLAG_TXPKT)) {

                stellarisif_interrupt(&lwip_netif);
                HWREGBITW(&System_Flags,FLAG_RXPKT) = 0;
                HWREGBITW(&System_Flags,FLAG_TXPKT) = 0;

                EthernetIntEnable(ETH_BASE,ETH_INT_RX);
                EthernetIntEnable(ETH_BASE,ETH_INT_RX);

        //
        // Service any packets on the receive queue.
        //
        stellarisif_input(&lwip_netif);

        }

}

3) changed sys_arch_protect() and sys_arch_unprotect to call
VPortEnterCritical() and vPortExitCritical() instead of the original
disable & enable interrupts.


Well, it´s apparently working ok, although I did not have time to test
it in a 'real' application.

I have 2 questions:

1) Is it ok what I did ? Am I forgetting something ?

2) I was planing to do all ethernet stuff in the lwip thread. But, is
it possible & safe to use it from another thread?

Thanks again for all your help!
Sergio P. SIder