Generating Warp Charge

This question was brought to my attention last gaming session. I was never a fan of psyker but many people are and some really depends on it, even building their tactics around it sometimes.

The rule book says that Warp Charge was generated automatically at the start of the turn.
So, if a Librarian comes in from reserves, will he generate any Warp Charge?

I would say yes, but not very confidently. What about you guys?

any rules that says at the start of turn is up to the active player to decide the sequence. so the player can come in reserve first then only declare generate warp charge which I don't think any sane player would do so la.

Don't quite understand. But I take it as a YES from you?

is in the FAQ if i remember correctly. yes, you can generate warp charge after come in from reserves but cannot cast blessing/malediction powers though.

I can't find it.. That's why not so confident. Let us here what others would say.