RTOS/AM5728: UART Rx ring buffer

Thank you very much Rahul for this information, it helped me understand and figure out a little more of what was happening with my code. It appears that my second UART_read was obtaining the full packet, but my UART_write was not printing it all properly. I originally had 3 UART_writes in a row, with the third printing out what was received from UART_read but it was truncating the data. If I stepped through the writes it works correctly, or if I remove the first two writes then the third one prints correctly. I'll only need one write for my release version, but I was curious as to why having several in a row would cause issues?

I also had an issue that my very first read would not grab all the data correctly unless I manually cleared the RX FIFO register. But with the configuration below, everything appears to be working the way I was expecting. Here's a snippet of my uart_task and the rx callback function:

Void uart_test(UArg arg0, UArg arg1)
{
    char echoNewline[] = "\n\r";
    char echoPrompt[] = "\nuart driver example test:\n\r";
    char echoPrompt1[] = "\nData received is\n\r";

    while(1)
    {
        HW_WR_FIELD32(UART_BASE_ADDRESS + UART_FCR, UART_FCR_RX_FIFO_CLEAR, 1); // Clear Rx FIFO register

        UART_read(uart5_handle, rxUartBuf, 1);           // read first byte of packet: bytesToFollow
        Semaphore_pend(hSem, BIOS_WAIT_FOREVER);

        UART_read(uart5_handle, rxUartBuf, MAX_TX_PACKET_SIZE);  // read remaining bytes in packet
        Clock_start(clockUartReadTimeout);                  // start one-shot timer for UART_readCancel()
        Semaphore_pend(hSem, BIOS_WAIT_FOREVER);

        if(txPktSzError) {
            memset(txUartBuf, 0, MAX_RX_PACKET_SIZE);   // clear txBuf array
            memset(rxUartBuf, 0, MAX_TX_PACKET_SIZE);   // clear rxBuf array
            continue;
        }
        
        //UART_write(uart5_handle, echoNewline, sizeof(echoNewline));   // commented out so printing of txUartBuf works properly
        //UART_write(uart5_handle, echoPrompt1, sizeof(echoPrompt1));   // commented out so printing of txUartBuf works properly

        UART_write(uart5_handle, txUartBuf, txBytes);    // Display data received

        memset(txUartBuf, 0, MAX_RX_PACKET_SIZE);   // clear txBuf array
        memset(rxUartBuf, 0, MAX_TX_PACKET_SIZE);   // clear rxBuf array

        UART_write(uart5_handle, echoPrompt, sizeof(echoPrompt)); // Display prompt again
    }
}

static void uartRxCb(UART_Handle handle, void *buf, size_t count) {
    txPktSzError = 0;
    if(count == 1)
    {
        txBytes = rxUartBuf[0];
    }
    else
    {
        if(txBytes == count)
        {
            //Copy rxBuf to txBuf
            memset(txUartBuf, 0, MAX_RX_PACKET_SIZE);
            memcpy(txUartBuf, rxUartBuf, txBytes);
        }
        else
        {
            txPktSzError = 1;
        }
    }

    //Wake task to echo
    Semaphore_post(hSem);
}

Void uartReadTimeout(UArg arg)
{
    UART_readCancel(uart5_handle);
}

Thank you again!