Amber ARM-compatible core

I am not sure if it is bug, I thought " push = i_req && ..." should be "push = in_wreq && ...". Because I saw some non-zero wbuf_used_r value in the icache wishbone_buf2 instance.

However this simple substitution doesn't work out.

Please don't create bug reports because you do not understand how the code works. Only post a bug report when you find some behaviour which is illegal. Then it would be helpful if you actually work out the issue and post a patch file. Or at least post a sequence of assembly code which does not execute correctly because of the bug.