RTOS/MSP432P401R: UART interrupt failed when entering custom BSL from TI RTOS

#define TASKSTACKSIZE      4096

Task_Struct task1Struct;
Char task1Stack[TASKSTACKSIZE];

#define BSL_PARAM       0x7C48DF90 //0xFFFFDFFF  // Interface selection = UART
#define BSL_API_ADDR    0x00202000  // Address of BSL API table
#define BSL_FUNCTION    (*((UIntT *)BSL_API_ADDR))

UART_Handle xPort;

void jumptoBSL(Int val) {
    uint8_t locDelay;
    UART_close(xPort);

    Hwi_disable();
    NVIC->ICER[0] = 0xFFFF;
    NVIC->ICPR[0] = 0xFFFF;
    NVIC->ICER[1] = 0xFFFF;
    NVIC->ICPR[1] = 0xFFFF;

    for (locDelay = 0; locDelay < 10; locDelay++)
    {
        __delay_cycles(2000000);
    }

    // call the bootloader
    ((void (*)())BSL_FUNCTION)((UIntT)BSL_PARAM);

}



Void echoFxn(UArg arg0, UArg arg1)
{
    UART_Params uartParams;
    UART_Params_init(&uartParams);
    uartParams.writeDataMode = UART_DATA_BINARY;
    uartParams.readDataMode = UART_DATA_BINARY;
    uartParams.readReturnMode = UART_RETURN_FULL;
    uartParams.readEcho = UART_ECHO_OFF;
    uartParams.readTimeout = 1000; // mS
    uartParams.baudRate = 9600;
    xPort = UART_open(Board_UART0, &uartParams);

    BIOS_exit(1);

    while(1) {
    }
}

/*
 *  ======== main ========
 */
int main(void)
{

    Task_Params taskParams;

    /* Call board init functions */
    Board_initGeneral();
    Board_initGPIO();
    Board_initUART();

    /* Construct heartBeat Task  thread */
    Task_Params_init(&taskParams);
    taskParams.arg0 = 1000;

    taskParams.stackSize = TASKSTACKSIZE;
    taskParams.stack = &task1Stack;
    taskParams.priority = 1;
    taskParams.instance->name = "echo";
    Task_construct(&task1Struct, (Task_FuncPtr)echoFxn, &taskParams, NULL);

    System_atexit(jumptoBSL);
    /* Start BIOS */
    BIOS_start();

    return (0);
}