#define UART_BASE 0xc010
#define UART_DATA   ((volatile char*) (UART_BASE + 0x00))
#define UART_STATUS ((volatile char*) (UART_BASE + 0x02))

#define UART_STATUS_RXNE_pos 1
#define UART_STATUS_RXNE_msk (1 << UART_STATUS_RXNE_pos)
#define UART_STATUS_TXE_pos  0
#define UART_STATUS_TXE_msk  (1 << UART_STATUS_TXE_pos)

int uart_rx_available();
int uart_tx_available();
void uart_write(const char c);
char uart_read();