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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
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. |
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.DSKWR | Disk write. System call to write blocks from memory onto a |
| disk. |
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.DSKCFIG | Disk conÞgure. This function allows you to change the |
| conÞguration of the speciÞed device. |
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.DSKFMT | Disk format. This function allows you to send a format |
| command to the speciÞed device. |
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.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. |
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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.)