RTOS/AM5728: UART printf issue

/*
 *  ======== main.c ========
 */

#include <xdc/std.h>

#include <xdc/runtime/Error.h>
#include <xdc/runtime/System.h>

#include <ti/sysbios/BIOS.h>

#include <ti/sysbios/knl/Task.h>

/* UART header files */
#include <ti/drv/uart/UART.h>
#include <ti/drv/uart/UART_stdio.h>

#include <ti/board/board.h>
#include <ti/board/board_cfg.h>

/*
 *  ======== taskFxn ========
 */
Void taskFxn(UArg a0, UArg a1)
{
    System_printf("enter taskFxn()\n");

    UART_puts("DSP1 - Invalid Memory section", -1);
    //UART_printf("TASK Test Start...\n");

    Task_sleep(10);

    System_printf("exit taskFxn()\n");

    System_flush(); /* force SysMin output to console */
}

/*
 *  ======== main ========
 */
Int main()
{ 
    Task_Handle task;
    Error_Block eb;
    Task_Params taskParams;

    /* Call board init functions */
    Board_initCfg boardCfg;

    boardCfg = BOARD_INIT_PINMUX_CONFIG |
        BOARD_INIT_MODULE_CLOCK |
        BOARD_INIT_UART_STDIO;

    //boardCfg = BOARD_INIT_PINMUX_CONFIG ;
    Board_init(boardCfg);

    UART_printf("GPMC Test Start...\n");

    System_printf("enter main()\n");

    Error_init(&eb);

    /* Create 1 task with priority 15 */
    //Task_Params_init(&taskParams);
    //taskParams.stackSize = 1024;
    //taskParams.priority = 15;
    //taskParams.instance -> name = "Task1";

    task = Task_create(taskFxn, NULL, &eb);
    if (task == NULL) {
        System_printf("Task_create() failed!\n");
        BIOS_exit(0);
    }

    BIOS_start();    /* does not return */
    return(0);
}