user manual

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Debugger General Information
4
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:
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.)
.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.