Apologies, my experience is SysV-centric for amd64, as described here[0] under the Parameter Passing section, which is a clustrfuck compared to the simplicity of the 386 SysV ABI as described here[1]:

  > Argument words are pushed onto the stack in reverse order (that is, the
  > rightmost argument in C call syntax has the highest address), preserving the
  > stack’s word alignment. All incoming arguments appear on the stack, resid-
  > ing in the stack frame of the caller.

Both links were found @ https://wiki.osdev.org/System_V_ABI

[0] https://www.uclibc.org/docs/psABI-x86_64.pdf

[1] https://www.sco.com/developers/devspecs/abi386-4.pdf