Motorola MVME177 Disk I/O via 177Bug Commands IOI Input/Output Inquiry, IOP Physical I/O to Disk

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Debugger General Information

The device probe mechanism utilizes the SCSI commands ÒInquiryÓ and ÒMode SenseÓ. If the specified controller is non-SCSI, the probe simply returns a status of Òdevice present and unknownÓ. The device probe makes an entry into the device descriptor table with the pertinent data. After an entry has been made, the next time a probe is done it simply returns with Òdevice presentÓ status (pointer to the device descriptor).

Disk I/O via 177Bug Commands

The 177Bug commands listed in the following paragraphs are provided for disk I/O. Detailed instructions for their use are found in the Debugging Package for Motorola 68K CISC CPUs User's Manual. When a command is issued to a particular controller LUN and device LUN, these LUNs are remembered by 177Bug so that the next disk command defaults to use the same controller and device.

IOI (Input/Output Inquiry)

This command probes the system for all possible CLUN/DLUN combinations and displays inquiry data for devices which support it. The device descriptor table has space for a maximum of 16 device descriptors. Use the IOI command to view the table or clear it if necessary.

IOP (Physical I/O to Disk)

IOP allows you to:

❏Read blocks of data

❏Write blocks of data

❏Format a specified device in a certain way

IOP creates a command packet from the arguments you have specified, then invokes the proper system call function to carry out the operation.

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