Do Buddhist texts record or comment on the then-prevalent varna or caste systems?

Do Buddhist ancient scriptures/texts record or comment on: 1. The then-prevalent varna system? or 2. The then-prevalent caste system (clan-like system)? I understand that Buddhism is based on equality, i.e. I am not saying that Buddhism accepted the caste system. In particular, what I am asking is whether buddhist text: - Records any wrong-doings based on caste system or varna system - Records whether or not the varna system was birth-based at that time - Explicitly says that it rejects birth-based varna system/caste system. Please provide references from such text.