#include "led.h" #include "uart.h" #define uart0 ((struct uart*)0xc010) int main() { int c; int led = 0; while (1) { led_write(1 << led); c = uart_read(uart0); if (c == 'a') { led++; } else if (c == 'd') { led--; } if (led == 8) { led = 0; } else if (led < 0) { led = 7; } } }