Echo of data in UART through interrupts in LM3S811 Qemu Simulation - arm

Question

I am trying to transmit and receive characters in UART through interrupts in LM3S811 using Qemu Simulation. I wrote this code with the help of this https://www.electronicwings.com/arm7/lpc2148-uart0. I am not sure whether it is correct and it does not work. Could someone suggest how to get the task done.
startup code :
.thumb
.global start
start:
.word 0x20001000
.word main
flash.ld
MEMORY
{
FLASH (rx) : ORIGIN = 0x00000000, LENGTH = 0x00010000
SRAM (rxw) : ORIGIN = 0x20000000, LENGTH = 0x00002000
}
SECTIONS
{
.text : {
*(.vectors);
*(.text);
etext = .;
} > FLASH
.rodata : {
*(.rodata);
} > FLASH
.data : {
sdata = .;
*(.data);
edata = .;
} > SRAM AT > FLASH
.bss: {
sbss = .;
*(.bss);
ebss = .;
} > SRAM
}
main.c
#define UARTDR (*((volatile unsigned int *) 0x4000C000)) // Data register for UART...
#define UARTIFLS (*((volatile unsigned int *) 0x40000034)) // Interrupt identification register...
#define UARTFR (*((volatile unsigned int *) 0x4000C018)) // Register which holds the status of the FIFO...
char rx;
_irq void UART0_Inerrupt(void)
{
int iir_value;
iir_value = UARTIFLS // Interrupt Identification register...
if (iir_value & 0x00) { // If interrupt is received, i.e data is present...
rx = UARTDR;
}
UARTDR = rx; // Write to data register for writing to transmit FIFO...
while ( (UARTFR & 0x20) == 1) continue;
}
int main(void)
{
NVICVectAddr0 = (unsigned) UART0_Inerrupt;
while(1);
}
``