Appendix A: AMIBIOS POST Checkpoint Codes92Additional Bus CheckpointsWhile control is inside the different bus routines, additionalcheckpoints are output to I/O port address 0080h as word to identifythe routines being executed.These are word checkpoints. The low byte of checkpoint is the systemBIOS checkpoint where control is passed to the different bus routines.The high byte of checkpoint indicates that the routine is beingexecuted in different buses.High ByteThe high byte of these checkpoints includes the following information:Bits DescriptionBits 7-4 0000 Function 0. Disable all devices on the bus.0001 Function 1. Initialize static devices on the bus.0010 Function 2. Initialize output devices on the bus.0011 Function 3. Initialize input devices on the bus.0100 Function 4. Initialize IPL devices on the bus.0101 Function 5. Initiate general devices on the bus.0110 Function 6. Initialize error reporting on the bus.0111 Function 7. Initialize add-on ROMs for all buses.Bits 3-0 Specify the bus0 Generic DIM Device Initialization Manager.1 Onboard System devices.2 ISA devices.3 EISA devices.4 ISA PnP devices.5 PCI devices.
