NAME

core − format of core image file

DESCRIPTION

UNIX writes out a core image of a terminated process when any of various errors occur.  See "signal (II)" for the list of reasons; the most common are memory violations, illegal instructions, bus errors, and user-generated quit signals.  The core image is called “core” and is written in the process’s working directory (provided it can be; normal access controls apply).  The first 1024 bytes of the core image are a copy of the system’s per-user data for the process, including the registers as they were at the time of the fault. The remainder represents the actual contents of the user’s core area when the core image was written. If the text segment is write-protected and shared, it is not dumped; otherwise the entire address space is dumped. The format of the information in the first 1024 bytes is described by the user structure of the system.  The important stuff not detailed therein is the locations of the registers.  Here are their offsets.  The parenthesized numbers for the floating registers are used if the floating-point hardware is in single precision mode, as indicated in the status register. 

fpsr0004

fr00006  (0006)

fr10036  (0022)

fr20046  (0026)

fr30056  (0032)

fr40016  (0012)

fr50026  (0016)

r01772

r11766

r21750

r31752

r41754

r51756

sp1764

pc1774

ps1776

In general the debuggers "db (I)" and "cdb (I)" are sufficient to deal with core images. 

SEE ALSO

cdb (I), db (I), signal (II)