Sorry, I can't check with Linux, but i guess it's probably similar with all OS.
Have you checked the "Target platform" of your project ?
Project -> Project Options -> Config and Target (see capture.png).
Anyway, I guess these options are also (i.e. also for Linux) stored into the .lpi file of the project: stored, if not the "Default" value are selected inside the "Target platform", of course.
For instance:
<CodeGeneration>
<TargetCPU Value="powerpc"/>
<TargetOS Value="linux"/>
<Optimizations>
<OptimizationLevel Value="3"/>
</Optimizations>
</CodeGeneration>