ReadReg            87 kernel/uart.c      if (ReadReg(LSR) & LSR_TX_IDLE) {
ReadReg           114 kernel/uart.c    while ((ReadReg(LSR) & LSR_TX_IDLE) == 0)
ReadReg           128 kernel/uart.c    if (ReadReg(LSR) & LSR_RX_READY) {
ReadReg           129 kernel/uart.c      return ReadReg(RHR);
ReadReg           141 kernel/uart.c    ReadReg(ISR); // acknowledge the interrupt
ReadReg           143 kernel/uart.c    if (ReadReg(LSR) & LSR_TX_IDLE) {