make_u32
reg0 = key[rkidx][0] ^ make_u32((u8)(x1[get_u8(reg0, 0)]),
reg1 = key[rkidx][1] ^ make_u32((u8)(x1[get_u8(reg1, 0)]),
reg2 = key[rkidx][2] ^ make_u32((u8)(x1[get_u8(reg2, 0)]),
reg3 = key[rkidx][3] ^ make_u32((u8)(x1[get_u8(reg3, 0)]),