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fishmore-publicdomainlibraryvol.ii1991xetec.iso
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enforcer.doc
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1991-02-14
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Enclosed is a majik tool for detecting invisible bugs in programs; _The
Enforcer_ uses the MMU to build a shroud of protection over anything that
is not legal memory. Any "empty holes" in the address space are marked as
illegal by _Enforcer_. Reads of the system ROMs are allowed, but not
writes. With the exception of longword reads of location 4, the lowest 1K
of memory is completely off-limits.
Enforcer runs on any Amiga or OS revision, as long a the MMU is not already
in use. This version of Enforcer also works on the A3000 under
SuperKickstart (V1.3 or 2.0). Under V1.3, enforcer requires SetPatch
version 1.38 or later.
When an illegal access is detected, the power LED will flash and a detailed
message will be sent out the serial port (at the default speed). Illegal
writes are aborted, illegal reads return NULL data. For example:
Program Counter (approximate)= 783C460 Fault address =DEADBEEF
User stack pointer = 7860ABC DOS Proccess address = 7839F98
Data: 00000001 01E0F0FB 00000FA0 0783AE18 00000001 01E0987F 01E0A93D 0783C3EC
Addr: 0783AE18 0785FB28 07810114 0783C3EC 07860AC0 00F8F56A 00F8F55E 078021D0
Status register =$8 Special status word =$729 (WRITE-WORD)
Data output buffer =$FFFFADEF (o)
Process/CLI = Background CLI ,"lawbreaker"
Hunk-O-Matic says: PC address is in hunk #0, near offset $70
CLI command "lawbreaker" has written the word value $ADEF to location
$DEADBEEF. The write was aborted. With the information given, it is
usually quite easy to figure out what went wrong.
Remote keystrokes:
^S - pause. You may have to press it more than once.
^Q - resume
^X - When in ^S, press ^X to suspend _Enforcer_ reporting.
Use ^Q to resume.
Command line options:
on
fprotect ;Same as on, but write protects $F00000-$F7FFFF
off
Notes:
If you don't have an external terminal, just use a modem & a terminal
program. Most modems will echo back characters at any baud rate. Else,
just set the baud rate to match the modem.
Illegal hits from CLI commands named "metascope" or "wack" are ignored.
Rebooting an A3000 running Enforcer causes the SuperKickstart to be
reloaded from scratch next time you boot. Some call this a feature.
This will, however, kill RAD:. When enforcer is off, SuperKickstart is
not reloaded.
The Alert() system call writes to locations in the $180-$1C0 area.