EK-TM4C1294XL: Issues with UART to SSH Data Formatting and Partial Transmissions

#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "driverlib/debug.h"
#include "driverlib/gpio.h"
#include "driverlib/interrupt.h"
#include "driverlib/pin_map.h"
#include "driverlib/rom.h"
#include "driverlib/rom_map.h"
#include "driverlib/sysctl.h"
#include "driverlib/uart.h"

//*****************************************************************************
//
//! \addtogroup example_list
//! <h1>UART Echo (uart_echo)</h1>
//!
//! This example application utilizes the UART to echo text.  The first UART
//! (connected to the USB debug virtual serial port on the evaluation board)
//! will be configured in 115,200 baud, 8-n-1 mode.  All characters received on
//! the UART are transmitted back to the UART.
//
//*****************************************************************************

//****************************************************************************
//
// System clock rate in Hz.
//
//****************************************************************************
uint32_t g_ui32SysClock;

//*****************************************************************************
//
// The error routine that is called if the driver library encounters an error.
//
//*****************************************************************************
#ifdef DEBUG
void
__error__(char *pcFilename, uint32_t ui32Line)
{
}
#endif

//*****************************************************************************
//
// The UART interrupt handler.
//
//*****************************************************************************
void
UARTIntHandler(void)
{
    uint32_t ui32Status;

    //
    // Get the interrrupt status.
    //
    ui32Status = MAP_UARTIntStatus(UART0_BASE, true);

    //
    // Clear the asserted interrupts.
    //
    MAP_UARTIntClear(UART0_BASE, ui32Status);

    //
    // Loop while there are characters in the receive FIFO.
    //
    while(MAP_UARTCharsAvail(UART0_BASE))
    {
        //
        // Read the next character from the UART and write it back to the UART.
        //
        MAP_UARTCharPutNonBlocking(UART0_BASE,
                                   MAP_UARTCharGetNonBlocking(UART0_BASE));
    }
}

//*****************************************************************************
//
// Send a string to the UART.
//
//*****************************************************************************
void
UARTSend(const uint8_t *pui8Buffer, uint32_t ui32Count)
{
    //
    // Loop while there are more characters to send.
    //
    while(ui32Count--)
    {
        //
        // Write the next character to the UART.
        //
        MAP_UARTCharPutNonBlocking(UART0_BASE, *pui8Buffer++);
    }
}

//*****************************************************************************
//
// This example demonstrates how to send a string of data to the UART.
//
//*****************************************************************************
int
main(void)
{
    //
    // Run from the PLL at 120 MHz.
    // Note: SYSCTL_CFG_VCO_240 is a new setting provided in TivaWare 2.2.x and
    // later to better reflect the actual VCO speed due to SYSCTL#22.
    //
    g_ui32SysClock = MAP_SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ |
                                             SYSCTL_OSC_MAIN |
                                             SYSCTL_USE_PLL |
                                             SYSCTL_CFG_VCO_240), 120000000);
                                             
    //
    // Enable the GPIO port that is used for the on-board LED.
    //
    MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPION);

    //
    // Enable the GPIO pins for the LED (PN0).
    //
    MAP_GPIOPinTypeGPIOOutput(GPIO_PORTN_BASE, GPIO_PIN_0);

    //
    // Enable the peripherals used by this example.
    //
    MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);
    MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);

    //
    // Enable processor interrupts.
    //
    MAP_IntMasterEnable();

    //
    // Set GPIO A0 and A1 as UART pins.
    //
    MAP_GPIOPinConfigure(GPIO_PA0_U0RX);
    MAP_GPIOPinConfigure(GPIO_PA1_U0TX);
    MAP_GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);

    //
    // Configure the UART for 115,200, 8-N-1 operation.
    //
    MAP_UARTConfigSetExpClk(UART0_BASE, g_ui32SysClock, 115200,
                            (UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE |
                             UART_CONFIG_PAR_NONE));

    //
    // Enable the UART interrupt.
    //
    MAP_IntEnable(INT_UART0);
    MAP_UARTIntEnable(UART0_BASE, UART_INT_RX | UART_INT_RT);

    //
    // Prompt for text to be entered.
    //
    UARTSend((uint8_t *)"\033[2JEnter text: ", 16);

    //
    // Loop forever echoing data through the UART.
    //
    while(1)
    {
    }
}

void PhyUART4Init(uint32_t baudrate) {
    uint32_t ui32SysClk = 120000000; // System clock frequency

    // Enable GPIOK and UART4 peripherals
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOK);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_UART4);

    // Wait for the peripherals to be ready
    while (!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOK));
    while (!SysCtlPeripheralReady(SYSCTL_PERIPH_UART4));

    // Configure GPIO pins for UART4
    GPIOPinConfigure(GPIO_PK0_U4RX); // PK0 as U4RX
    GPIOPinConfigure(GPIO_PK1_U4TX); // PK1 as U4TX
    GPIOPinTypeUART(GPIO_PORTK_BASE, GPIO_PIN_0 | GPIO_PIN_1);

    // Set UART4 configuration
    UARTConfigSetExpClk(UART4_BASE, ui32SysClk, baudrate,
                        UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE | UART_CONFIG_PAR_NONE);

    // Enable the UART FIFO
    UARTFIFOEnable(UART4_BASE);
    UARTFIFOLevelSet(UART4_BASE, UART_FIFO_TX1_8, UART_FIFO_RX1_8);

    // Register and enable UART interrupts
    UARTIntRegister(UART4_BASE, UART4IntHandler);
    UARTIntEnable(UART4_BASE, UART_INT_RX);
    IntEnable(INT_UART4);

    // Enable the UART for operation
    UARTEnable(UART4_BASE);

    // Debug: Log UART configuration completion
    TRACE_INFO("UART4 configured with baud rate: %u\n", baudrate);
}

void UART4IntHandler(void) {
    uint32_t ui32Status;
    BaseType_t xHigherPriorityTaskWoken = pdFALSE;
    char data;

    ui32Status = UARTIntStatus(UART4_BASE, true);
    UARTIntClear(UART4_BASE, ui32Status);

    if (ui32Status & UART_INT_RX) {
        while (UARTCharsAvail(UART4_BASE)) {
            data = (char)UARTCharGetNonBlocking(UART4_BASE);
            xQueueSendToBackFromISR(qUART4, &data, &xHigherPriorityTaskWoken);
        }
    }

    if (xHigherPriorityTaskWoken == pdTRUE) {
        portYIELD();
    }
}