In a small company, "the boss" is the owner and there is no HR. If you don't get along with him, you leave.
In a large company, HR's job isn't to help you but to keep the company from getting sued. They will almost always side with management. You might make a dent in a manager's reputation and, if 5 or 6 people come forward with the same complaint about him, he might be "promoted away" into a role with less direct people management... but you're fired by that point, so it means nothing to you.
HR is not your friend.
Your best move if you have a bad boss is to work out a transfer behind his back, and leave on good terms. Find someone with more clout who will request sponsor you. Don't "apply for" transfer. Get requested. Never say anything bad about your boss in the process, just that you're looking for work that's more relevant to your skill set.
In a large company, HR's job isn't to help you but to keep the company from getting sued. They will almost always side with management. You might make a dent in a manager's reputation and, if 5 or 6 people come forward with the same complaint about him, he might be "promoted away" into a role with less direct people management... but you're fired by that point, so it means nothing to you.
HR is not your friend.
Your best move if you have a bad boss is to work out a transfer behind his back, and leave on good terms. Find someone with more clout who will request sponsor you. Don't "apply for" transfer. Get requested. Never say anything bad about your boss in the process, just that you're looking for work that's more relevant to your skill set.