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Debugger General Information

BH (Bootstrap and Halt)

BH reads an operating system or control program from a specified device into memory, and then returns control to 187Bug. It is used as a debugging tool.

Disk I/O via 187Bug System Calls

All operations that actually access the disk are done directly or indirectly by 187Bug TRAP #496 system calls. (The command-level disk operations provide a convenient way of using these system calls without writing and executing a program.)

The following system calls are provided to allow user programs to do disk I/O:

.DSKRD

Disk read. System call to read blocks from a disk into

 

memory.

 

 

.DSKWR

Disk write. System call to write blocks from memory onto a

 

disk.

 

 

.DSKCFIG

Disk conÞgure. This function allows you to change the

 

conÞguration of the speciÞed device.

 

 

.DSKFMT

Disk format. This function allows you to send a format

 

command to the speciÞed device.

 

 

.DSKCTRL

Disk control. This function is used to implement any

 

special device control functions that cannot be

 

accommodated easily with any of the other disk functions.

 

 

Refer to the Debugging Package for Motorola 88K RISC CPUs User's Manual for information on using these and other system calls.

Controller Command Packets

To perform a disk operation, 187Bug must eventually present a particular disk controller module with a controller command packet which has been especially prepared for that type of controller module. (This is accomplished in the respective controller driver module.)

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Motorola MVME187 manual Disk I/O via 187Bug System Calls, BH Bootstrap and Halt, Controller Command Packets