Method read

devices/src/legacy/serial.rs:287–315

(&mut self, _base: u64, offset: u64, data: &mut [u8])

impl BusDevice for Serial {
    fn read(&mut self, _base: u64, offset: u64, data: &mut [u8]) {
        if data.len() != 1 {
            return;
        }

        data[0] = match offset as u8 {
            DLAB_LOW if self.is_dlab_set() => self.baud_divisor as u8,
            DLAB_HIGH if self.is_dlab_set() => (self.baud_divisor >> 8) as u8,
            DATA => {
                self.del_intr_bit(IIR_RECV_BIT);
                if self.in_buffer.len() <= 1 {
                    self.line_status &= !LSR_DATA_BIT;
                }
                self.in_buffer.pop_front().unwrap_or_default()
            }
            IER => self.interrupt_enable,
            IIR => {
                let v = self.interrupt_identification | IIR_FIFO_BITS;
                self.iir_reset();
                v
            }
            LCR => self.line_control,
            MCR => self.modem_control,
            LSR => self.line_status,
            MSR => self.modem_status,
            SCR => self.scratch,
            _ => 0,
        };
    }

    fn write(&mut self, _base: u64, offset: u64, data: &[u8]) -> Option<Arc<Barrier>> {
        if data.len() != 1 {