The ap.core file is created automatically in the directory, /usr/tmp, when either a machine abort occurs (for example, bus errors, segmentation violations, and so on), or by requesting the monitor debugger d command.
This file is a regular UNIX file, which can be written to tape using UNIX utilities, such as tar or cpio, and can be sent to Customer Support for investigating a problem. The apcrash command can be used to examine the core file with commands similar to the D3 monitor Virtual Debugger.
The core file is made of segments, each representing part of the memory at the time the dump occurred. These segments have a 16 byte header as illustrated:
start | Start address |
size | Size in bytes |
data | Optional data filed |
pib | PIB number of the process |
ty | Segment type |
The actual size of the segment is rounded up to the nearest 4-byte boundary.
This table lists the segment types and the meaning of the other fields, where applicable:
0 | PCB |
B | Buffer table |
F | Virtual Frame—Data is the FID |
G | Global segment—Start is the value of the GM register ra |
L | Local segment—Start is the value of the GM register ral |
M | Monitor version—Data is the frame size in bytes |
P | PIBs table—Data is the PIB size in bytes |
R | Hardware registers |
S | Main shared memory—Data is the starting offset of the dump |
V | Virtual buffers |