Retail PS2 Games with Debugging Symbols

I think any decent ELF loader shouldn't copy the debug sections to memory, so it wouldn't matter (well, much. There'd be some more seeking on the DVD compared to a stripped file...). No idea what the PS2 is doing though...

 

I don't think so. More likely to do with the disc layout and the actual game ID/logo data.

PS2 discs have two woobles instead of just one. The drive controller checks for the existence of the second wooble. Also, the logo display code needs the second wooble to retrieve a 8bit value which is then used in a XOR operation de-obfuscate the "PlayStation 2" logo bitmap. Without that the thing would hang at a black screen even if a fake disc managed to get that far.

Means it's impossible to make it display anything different of the PlayStation2 logo on a non tampered console during a disc boot. I'd say these are the reasons why they need to reuse bits of original discs. And they likely choose which discs to use based on how it's easy to "attach" a different data groove to the existing index of a licensed game they managed to dupe.