include "LIN/joint_LTL_LIN.ma".
include "joint/semanticsUtils.ma".

definition hw_reg_store ≝ λr,v,e. OK … (hwreg_store r v e).
definition hw_reg_retrieve ≝ λl,r. OK … (hwreg_retrieve l r).
definition hw_arg_retrieve ≝
  λl,a.match a with
  [ Reg r ⇒ hw_reg_retrieve l r
  | Imm b ⇒ OK … (BVByte b)
  ].

definition eval_registers_move ≝ λe,m.
match m with
[ from_acc r _ ⇒
  hw_reg_store r (hwreg_retrieve e RegisterA) e
| to_acc _ r ⇒
  hw_reg_store RegisterA (hwreg_retrieve e r) e
| int_to_reg r v ⇒
  hw_reg_store r (BVByte v) e
| int_to_acc _ v ⇒
  hw_reg_store RegisterA (BVByte v) e
].

definition LTL_LIN_state : sem_state_params ≝
  mk_sem_state_params
 (* framesT ≝ *) unit
 (* empty_framesT ≝ *) it
 (* regsT ≝ *) hw_register_env
 (* empty_regsT ≝ *) init_hw_register_env
 (* load_sp ≝ *) hwreg_retrieve_sp
 (* store_sp ≝ *) hwreg_store_sp.

(*CSC: XXXX, for external functions only*)
axiom ltl_lin_fetch_external_args: external_function → state LTL_LIN_state → ℕ → res (list val).
axiom ltl_lin_set_result: list val → unit → state LTL_LIN_state → res (state LTL_LIN_state).

definition LTL_LIN_save_frame : 
call_kind → unit → state_pc LTL_LIN_state → res(state LTL_LIN_state) ≝ 
λk.λ_.λst. match k with
[ PTR ⇒
  ! v ← Byte_of_val BadFunction
    (hwreg_retrieve (regs … st) RegisterA) ;
  if eq_bv … v (bv_zero …) then return (st_no_pc … st)
  else Error … [MSG BadFunction; MSG BadPointer]
| ID ⇒ push_ra … st (pc … st)
].

definition eval_LTL_LIN_ext_seq :
 ∀F.∀globals.∀ge : genv_gen F globals.ltl_lin_seq → ident → state LTL_LIN_state → res (state LTL_LIN_state) ≝
λF,globals,ge,s,curr_id,st.
match s with
[ SAVE_CARRY ⇒
  let regs ≝ hwreg_set_other … (carry … st) (regs … st) in
  return set_regs LTL_LIN_state regs st
| RESTORE_CARRY ⇒
  let carry ≝ other_bit (regs … st) in
  return set_carry LTL_LIN_state carry st
| LOW_ADDRESS l ⇒  ! pc_lab ← gen_pc_from_label … ge curr_id l;
                    let 〈addrl,addrh〉 ≝ beval_pair_of_pc pc_lab in
                    let regs ≝ hwreg_store RegisterA addrl (regs … st) in
                    return set_regs LTL_LIN_state regs st
| HIGH_ADDRESS l ⇒ ! pc_lab ← gen_pc_from_label … ge curr_id l;
                    let 〈addrl,addrh〉 ≝  beval_pair_of_pc pc_lab in
                    let regs ≝ hwreg_store RegisterA addrh (regs … st) in
                    return set_regs LTL_LIN_state regs st
].

definition LTL_LIN_semantics ≝
  λF.mk_sem_unserialized_params LTL_LIN F
  (* st_pars            ≝ *) LTL_LIN_state
  (* acca_store_        ≝ *) (λ_.hw_reg_store RegisterA)
  (* acca_retrieve_     ≝ *) (λe.λ_.hw_reg_retrieve e RegisterA)
  (* acca_arg_retrieve_ ≝ *) (λe.λ_.hw_reg_retrieve e RegisterA)
  (* accb_store_        ≝ *) (λ_.hw_reg_store RegisterB)
  (* accb_retrieve_     ≝ *) (λe.λ_.hw_reg_retrieve e RegisterB)
  (* accb_arg_retrieve_ ≝ *) (λe.λ_.hw_reg_retrieve e RegisterB)
  (* dpl_store_         ≝ *) (λ_.hw_reg_store RegisterDPL)
  (* dpl_retrieve_      ≝ *) (λe.λ_.hw_reg_retrieve e RegisterDPL)
  (* dpl_arg_retrieve_  ≝ *) (λe.λ_.hw_reg_retrieve e RegisterDPL)
  (* dph_store_         ≝ *) (λ_.hw_reg_store RegisterDPH)
  (* dph_retrieve_      ≝ *) (λe.λ_.hw_reg_retrieve e RegisterDPH) 
  (* dph_arg_retrieve_  ≝ *) (λe.λ_.hw_reg_retrieve e RegisterDPH)
  (* snd_arg_retrieve_  ≝ *) hw_arg_retrieve
  (* pair_reg_move_     ≝ *) eval_registers_move
(*  (* fetch_ra           ≝ *) (load_ra …)
  (* allocate_local     ≝ *) (λabs.match abs in void with [ ])
*)  (* save_frame         ≝ *) LTL_LIN_save_frame
  (* setup_call         ≝ *) (λ_.λ_.λ_.λst.return st)
  (* fetch_external_args≝ *) ltl_lin_fetch_external_args
  (* set_result         ≝ *) ltl_lin_set_result
  (* call_args_for_main ≝ *) 0
  (* call_dest_for_main ≝ *) it
  (* read_result        ≝ *) (λ_.λ_.λ_.
  λst.return map … (hwreg_retrieve (regs … st)) RegisterRets)
  (* eval_ext_seq       ≝ *) (eval_LTL_LIN_ext_seq ?)
  (* pop_frame          ≝ *) ((λ_.λ_.λ_.λ_.λst.pop_ra … st)).