+static int uart_data_to_read(UART *uart)
+{
+ return uart->current < uart->len;
+}
+
+static char uart_pop(UART *uart)
+{
+ char ret;
+
+ if (uart->len == 0) {
+ uart->status &= ~UART_DATA_READY;
+ return 0;
+ }
+
+ ret = uart->buffer[uart->current++];
+
+ if (uart->current >= uart->len) {
+ /* Flush */
+ uart->len = 0;
+ uart->current = 0;
+ }
+
+ if (!uart_data_to_read(uart)) {
+ uart->status &= ~UART_DATA_READY;
+ }
+
+ return ret;
+}
+
+static void uart_add_to_fifo(UART *uart,
+ const uint8_t *buffer,
+ int length)
+{
+ if (uart->len + length > FIFO_LENGTH) {
+ abort();
+ }
+ memcpy(uart->buffer + uart->len, buffer, length);
+ uart->len += length;
+}
+