[sph]

Nothing stops you from having upward growing stacks in RISC-V, for example, as there are no dedicated stack instructions.

Instead of

  addi sp, sp, -16
  sd a0, 0(sp)
  sd a1, 8(sp)

Do:

  addi sp, sp, 16
  sd a0, -8(sp)
  sd a1, -16(sp)