ld -A info please - (nf)

[stepp at uiuccsb.UUCP]

#N:uiuccsb:14900003:000:867
uiuccsb!stepp    Sep 20 08:27:00 1983

This is a request for a micro-tutorial on the unix loader and the -A option.
ld -A <file1> <file2> is a command for linking code in <file2> while
incorporating the symbol table from <file1>.  The origin address of the
module is (by default) set to start at the end of the code in <file1>.

It appears that this option produces a module (of <file2>) that can be
loaded during the execution of <file1> and which will contain resolved
references to objects in <file1>.  I suppose this might be used to create
user-managed overlays, and that is one interest in this feature.

I hope a knowledgeable wizard will respond to clear up my (mis)understanding
of this feature.  I also do not know how one causes the "overlay" produced
by the above ld command to actually be loaded by the system, without
destroying the executing program, to which it is linked by the -A option.