Rinat Sadretdinow wrote in a message to Peter Fitzsimmons:

 AZ>> Is there anything to compress/encrypt OS/2 execubles
 AZ>> like PKLite, Diet, or Protect?

 RS> No, there are not such compressors existed for OS/2. It's
 RS> rather difficult to create stub that unpacks exe code, maps
 RS> all the segments, relocates them and so on like PkLite does.
 RS> But it is possible. Guess no one will produce such
 RS> compressor, except he's crazy 

Since code is loaded into read-only memory, and is both shareable and
discardable, any code compression facility must be built into the operating
system.  If applications try to do their own code compression, then very
bad things will happen.

 PF> On devcon 8,  there is a program called REPACK to pack already-linked
 PF> programs.

 RS> Yes, but unfortunately REPACK does not pack all programs
 RS> properly. Sometimes it turns them into unexecutable stuff
 RS> without possibility to restore original code :-(

This is the first I've heard of this.  I've had some extensive discussions
with IBM about REPACK, and they are not aware of any such problems.  Can
you provide an example?

 PF> The caveat is that the new packing method is only for OS/2 3.0+.

 RS> Wrong, exe page type #5 is not supported by OS/2 system
 RS> loader prior 2.99 only. So very first OS/2 WARP versions can
 RS> execute those files also. But 2.0 and 2.11 cannot.

Technically, no.  If you apply the CSDs to 2.11 that came out after Warp,
then it will also support the Iterated-II segment type.  I think that the
latest is FixPak 98 (XR_B098), which installs on top of a 2.11 system
(XR_6200) and brings the kernel build level to 6.665.
 
-- Mike


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