[Info-vax] VMS Farewell message?

[John Reagan]

"Rich Alderson" <news at alderson.users.panix.com> wrote in message 
news:mddd3tynm3x.fsf at panix5.panix.com...
> Wayne <weblis at monsanto.com> writes:
>
>>  For the final shutdown we are having a farewell celebration and I
>> would like to change the final message to something more appropriate.
>> Is there any way to change this "SYSTEM SHUTDOWN COMPLETE" message or
>> add a message immediately before or after it?
>
> Two people have suggested patching the string present in EXECPTION.EXE.
>
> I would instead patch the instruction which references that string to 
> point
> to a different address (in the patch area) at which you place whatever 
> string
> you want.
>
> But maybe the VMS debugger is not sophisticated enough for that?
>

The code loads an address out of the $LINKAGE section.  The address in the 
$LINKAGE section might have been relocated at execlet load time.  (For those 
of you who didn't realize, but the execlet loader at boottime is pretty much 
is the same code as the image activator you know and love).

Plus even if you patch the relocation on the $LINKAGE section, you'll still 
have to find a place to put the string.  There is no patch area like there 
is on the VAX.  You'd have to see the various compiler listing files and 
link map for EXCEPTION.EXE to see if there is some slop in some of the 
literal psects to put the string you want.  Remember that the linker will 
append each module's $LITERAL psect into a larger image section.  They are 
probably 16-byte aligned if I remember correctly so you might only have 15 
bytes of free space between one module's strings and the next module's 
strings.

You probably can find the calling sequence using SDA.

John