I have a very newbie question about using merSDK.

I want to compile a compiler (ocalm) or something needed to compile another package. I did in the "traditional" way (make -> make install -> make clean). But then I realised that what I need is such compiler for the two different targets, so I should do it with mb2. I have never used mb2... what should i do? something like (for instance for the pc emulator i486):
mb2 -t SailfishOS-i486 build (or mb2 -t SailfishOS-i486 make?)
and then
mb2 -t SailfishOS-i486 install (or make install)
?

Is there any wiki or documentation that I can read about?