Motorola MVME197LE manual Disk I/O Support, Blocks Versus Sectors, Device Probe Function

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Debugger General Information

Disk I/O Support

197Bug can initiate disk input/output by communicating with intelligent disk controller modules over the VMEbus. Disk support facilities built into 197Bug

3consist of command-level disk operations, disk I/O system calls (only via one of the TRAP #496 instructions) for use by user programs, and defined data structures for disk parameters.

Parameters such as the address where the module is mapped and the type and number of devices attached to the controller module are kept in tables by 197Bug. Default values for these parameters are assigned at power-up and cold-start reset, but may be altered as described in the section on default parameters, later in this chapter.

Appendix B contains a list of the controllers presently supported, as well as a list of the default configurations for each controller.

Blocks Versus Sectors

The logical block defines the unit of information for disk devices. A disk is viewed by 197Bug as a storage area divided into logical blocks. By default, the logical block size is set to 256 bytes for every block device in the system. The block size can be changed on a per device basis with the IOT command.

The sector defines the unit of information for the media itself, as viewed by the controller. The sector size varies for different controllers, and the value for a specific device can be displayed and changed with the IOT command.

When a disk transfer is requested, the start and size of the transfer is specified in blocks. 197Bug translates this into an equivalent sector specification, which is then passed on to the controller to initiate the transfer. If the conversion from blocks to sectors yields a fractional sector count, an error is returned and no data is transferred.

Device Probe Function

A device probe with entry into the device descriptor table is done whenever a specified device is accessed; i.e., when system calls .DSKRD, .DSKWR,

.DSKCFIG, .DSKFMT, and .DSKCTRL, and debugger commands BH, BO, IOC, IOP, IOT, MAR, and MAW are used.

The device probe mechanism utilizes the SCSI commands “Inquiry” and “Mode Sense”. If the specified controller is non-SCSI, the probe simply returns a status of “device present and unknown”. The device probe makes an entry into the device descriptor table with the pertinent data. After an entry has been

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Installation Guide

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Contents MVME197LE Restricted Rights Legend Preface Document TerminologyBIT Related Documentation Document Title Motorola Publication NumberPage Page Safety Summary Safety Depends on YOU Contents Hardware Preparation and Installation Using the 197Bug Debugger Appendix a Configure and Environment Commands List of Figures Xiv List of Tables Xvi Introduction OverviewRequirements Features Block Diagram SpecificationsMVME197LE Specifications Block Diagram Bus Data Bus 256 BusSwitch MC88110 Address Data MUX AddressMezzanine Address Bus Memory ArrayFront Panel Switches and Indicators Functional DescriptionData Bus Structure MC88110 MPUFlash Memory Onboard DramBattery Backup RAM and Clock VMEbus InterfaceInterfaces Serial Port InterfacePrinter Interface Ethernet InterfaceScsi Interface Scsi TerminationPeripheral Resources Connectors Memory MapsInterrupt Sources Processor Bus Memory MapProcessor Bus Memory Map DramsizeAddress Range Devices Accessed Port Size Local Devices Memory MapVMEbus Memory Map VMEbus Accesses to the Local Peripheral BusVMEbus Short I/O Memory Map Unpacking Instructions Hardware PreparationHardware Preparation and Installation VMEbus Connector P1 Switch S1 Configuration SwitchesConfiguration Switch S1 General Information S1-1 to S1-8 OFF -- All Ones Factory Configuration Installation Instructions Switch S6MVME197LE Module Installation System Considerations MVME197LEIG/D1 Hardware Preparation and Installation Overview of M88000 Firmware Description of 197BugComparison With M68000-Based Firmware Installation and Start-up197Bug Implementation Terminal to make sure XON/XOFF handshaking is enabled OteAutoboot ROMboot Network BootReset Restarting the SystemAbort BreakSYSFAIL* Assertion/Negation Memory RequirementsMPU Clock Speed Calculation Terminal Input/Output Control DELBlocks Versus Sectors Disk I/O SupportDevice Probe Function Disk I/O via 197Bug Commands Disk I/O via 197Bug System Calls DskcfigDisk I/O Error Codes Default 197Bug Controller and Device ParametersNetwork I/O Support Bootp Protocol Module Physical Layer Manager Ethernet DriverUDP/IP Protocol Modules RARP/ARP Protocol ModulesNetwork Boot Control Module Network I/O Error CodesMultiprocessor Support Multiprocessor Control Register Mpcr MethodMpar Diagnostic Facilities Gcsr MethodDebugger General Information Entering Debugger Command Lines DebuggerSyntactic Variables Expression as a ParameterData Type Base Identifier Examples Address Formats Address as a ParameterOffset Registers Entering and Debugging Programs Port NumbersCalling System Utilities From User Programs Preserving The Debugger Operating Environment197Bug Vector Table and Workspace Hardware FunctionsFloating Point Support CPU/MPU RegistersDouble Precision Real Single Precision RealScientific Notation 197Bug Debugger Command Set Debugger CommandsNocm Noma Name Nioc RL Addrbhw Using the 197Bug Debugger Configure Board Information Block Cnfg MISet Environment to Bug/Operating System ENV DTable A-1. ENV Command Parameters ENV Parameter and Options Default Meaning of DefaultConfigure and Environment Commands Ffbffffc Table A-1. ENV Command Parameters Memory Requirement s 01FFFFFF Table A-1. ENV Command Parameters Efffffff FF7FFFFF Table A-1. ENV Command Parameters Table A-1. ENV Command Parameters Table A-1. ENV Command Parameters DISK/TAPE Controller Data Disk/Tape Controller Modules SupportedDisk/Tape Controller Default Configurations Single Board Computers 7 DevicesMVME320 4 Devices MVME323 4 DevicesMVME327A 9 Devices MVME328 14 DevicesMVME350 1 Device IOT Command Parameters for Supported Floppy Types IOT ParameterDisk/Tape Controller Data Network Controller Data Network Controller Modules SupportedNetwork Controller Data Symbols NumericsIN-2 IN-3 Nvram A-2 XON/XOFF Index
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