.section .text
.globl _start

.equ UART_DATA, 0
.equ UART_STATUS, 1
.equ UART_RX_READY, 0b10
.equ UART_TX_READY, 0b01

_start:
    li a0, 0x1000

loop:
    lbu t0, UART_STATUS(a0)
    andi t0, t0, UART_RX_READY
    beqz t0, loop
    lbu t0, UART_DATA(a0)
    sb t0, UART_DATA(a0)
    j loop