Copy run_with_elf to make run_with_elf_cheri and revert run_with_elf to mips version. Temporary 'solution' to building mips and cheri builds until proper factorising can take place.

3 files changed, 1101 insertions, 41 deletions

diff --git a/src/Makefile b/src/Makefile
index afaf28d3..c010b992 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -39,6 +39,9 @@ _build/mips_extras.lem: ../mips/mips_extras.lem
 _build/run_with_elf.ml: lem_interp/run_with_elf.ml
 	mkdir -p _build
 	cp $< $@
+_build/run_with_elf_cheri.ml: lem_interp/run_with_elf_cheri.ml
+	mkdir -p _build
+	cp $< $@
 
 _build/mips.lem: $(MIPS_SAILS) ./sail.native
 	mkdir -p _build
@@ -56,8 +59,8 @@ _build/cheri.lem: $(CHERI_SAILS) ./sail.native
 run_mips.native: _build/mips.ml _build/mips_extras.ml _build/run_with_elf.ml interpreter
 	env OCAMLRUNPARAM=l=100M ocamlfind ocamlopt -g -package num -package str -package unix -I $(ELFDIR)/contrib/ocaml-uint/_build/lib -I $(LEMLIBOCAML) -I $(LEMLIBOCAML)/dependencies/zarith -I _build/lem_interp/ -I $(ELFDIR)/src  -I $(ELFDIR)/src/adaptors -I $(ELFDIR)/src/abis/mips64 -I _build -linkpkg $(LEMLIBOCAML)/dependencies/zarith/zarith.cmxa $(LEMLIBOCAML)/extract.cmxa $(ELFDIR)/contrib/ocaml-uint/_build/lib/uint.cmxa $(ELFDIR)/src/linksem.cmxa  _build/pprint/src/PPrintLib.cmxa _build/lem_interp/extract.cmxa _build/mips.ml _build/mips_extras.ml _build/run_with_elf.ml  -o run_mips.native
 
-run_cheri.native:  _build/cheri.ml _build/mips_extras.ml _build/run_with_elf.ml interpreter
-	env OCAMLRUNPARAM=l=100M ocamlfind ocamlopt -g -package num -package str -package unix -I $(ELFDIR)/contrib/ocaml-uint/_build/lib -I $(LEMLIBOCAML) -I $(LEMLIBOCAML)/dependencies/zarith -I _build/lem_interp/ -I $(ELFDIR)/src  -I $(ELFDIR)/src/adaptors -I $(ELFDIR)/src/abis/mips64 -I _build -linkpkg $(LEMLIBOCAML)/dependencies/zarith/zarith.cmxa $(LEMLIBOCAML)/extract.cmxa $(ELFDIR)/contrib/ocaml-uint/_build/lib/uint.cmxa $(ELFDIR)/src/linksem.cmxa  _build/pprint/src/PPrintLib.cmxa _build/lem_interp/extract.cmxa _build/cheri.ml _build/mips_extras.ml _build/run_with_elf.ml  -o run_cheri.native
+run_cheri.native:  _build/cheri.ml _build/mips_extras.ml _build/run_with_elf_cheri.ml interpreter
+	env OCAMLRUNPARAM=l=100M ocamlfind ocamlopt -g -package num -package str -package unix -I $(ELFDIR)/contrib/ocaml-uint/_build/lib -I $(LEMLIBOCAML) -I $(LEMLIBOCAML)/dependencies/zarith -I _build/lem_interp/ -I $(ELFDIR)/src  -I $(ELFDIR)/src/adaptors -I $(ELFDIR)/src/abis/mips64 -I _build -linkpkg $(LEMLIBOCAML)/dependencies/zarith/zarith.cmxa $(LEMLIBOCAML)/extract.cmxa $(ELFDIR)/contrib/ocaml-uint/_build/lib/uint.cmxa $(ELFDIR)/src/linksem.cmxa  _build/pprint/src/PPrintLib.cmxa _build/lem_interp/extract.cmxa _build/cheri.ml _build/mips_extras.ml _build/run_with_elf_cheri.ml  -o run_cheri.native
 
 mips: elf run_mips.native
 
diff --git a/src/lem_interp/run_with_elf.ml b/src/lem_interp/run_with_elf.ml
index a7d1c1de..75ed3b33 100644
--- a/src/lem_interp/run_with_elf.ml
+++ b/src/lem_interp/run_with_elf.ml
@@ -495,43 +495,6 @@ let mips_register_data_all =  [
   ("CP0LLBit", (D_decreasing, 1, 0));
 ]
 
-let cheri_register_data_all = mips_register_data_all @ [
-  ("CapCause", (D_decreasing, 16, 15));
-  ("PCC", (D_decreasing, 257, 256));
-  ("C00", (D_decreasing, 257, 256));
-  ("C01", (D_decreasing, 257, 256));
-  ("C02", (D_decreasing, 257, 256));
-  ("C03", (D_decreasing, 257, 256));
-  ("C04", (D_decreasing, 257, 256));
-  ("C05", (D_decreasing, 257, 256));
-  ("C06", (D_decreasing, 257, 256));
-  ("C07", (D_decreasing, 257, 256));
-  ("C08", (D_decreasing, 257, 256));
-  ("C09", (D_decreasing, 257, 256));
-  ("C10", (D_decreasing, 257, 256));
-  ("C11", (D_decreasing, 257, 256));
-  ("C12", (D_decreasing, 257, 256));
-  ("C13", (D_decreasing, 257, 256));
-  ("C14", (D_decreasing, 257, 256));
-  ("C15", (D_decreasing, 257, 256));
-  ("C16", (D_decreasing, 257, 256));
-  ("C17", (D_decreasing, 257, 256));
-  ("C18", (D_decreasing, 257, 256));
-  ("C19", (D_decreasing, 257, 256));
-  ("C20", (D_decreasing, 257, 256));
-  ("C21", (D_decreasing, 257, 256));
-  ("C22", (D_decreasing, 257, 256));
-  ("C23", (D_decreasing, 257, 256));
-  ("C24", (D_decreasing, 257, 256));
-  ("C25", (D_decreasing, 257, 256));
-  ("C26", (D_decreasing, 257, 256));
-  ("C27", (D_decreasing, 257, 256));
-  ("C28", (D_decreasing, 257, 256));
-  ("C29", (D_decreasing, 257, 256));
-  ("C30", (D_decreasing, 257, 256));
-  ("C31", (D_decreasing, 257, 256));
-]
-
 let initial_stack_and_reg_data_of_MIPS_elf_file e_entry all_data_memory =
   let initial_stack_data = [] in 
   let initial_register_abi_data : (string * Interp_interface.register_value) list = [] in
@@ -632,7 +595,7 @@ let initial_system_state_of_elf_file name =
           let (initial_stack_data, initial_register_abi_data) =
             initial_stack_and_reg_data_of_MIPS_elf_file e_entry !data_mem in
           
-          (Cheri.defs,
+          (Mips.defs,
            (Mips_extras.read_memory_functions,
             Mips_extras.memory_writes,
 	    [],
@@ -644,7 +607,7 @@ let initial_system_state_of_elf_file name =
            startaddr,
            initial_stack_data,
            initial_register_abi_data,
-           cheri_register_data_all)
+           mips_register_data_all)
 
         | _ -> failwith (Printf.sprintf "Sail sequential interpreter can't handle the e_machine value %s, only EM_PPC64, EM_AARCH64 and EM_MIPS are supported." (Nat_big_num.to_string e_machine))
       in
diff --git a/src/lem_interp/run_with_elf_cheri.ml b/src/lem_interp/run_with_elf_cheri.ml
new file mode 100644
index 00000000..5e7986c2
--- /dev/null
+++ b/src/lem_interp/run_with_elf_cheri.ml
@@ -0,0 +1,1094 @@
+open Printf ;;
+open Format ;;
+open Big_int ;;
+open Interp_ast ;;
+open Interp_interface ;;
+open Interp_inter_imp ;;
+open Run_interp_model ;;
+
+open Sail_interface ;;
+
+module StringMap = Map.Make(String)
+
+let file = ref "" ;;
+
+let rec foldli f acc ?(i=0) = function
+  | [] -> acc
+  | x::xs -> foldli f (f i acc x) ~i:(i+1) xs
+;;
+
+let endian = ref E_big_endian ;;
+
+let hex_to_big_int s = big_int_of_int64 (Int64.of_string s) ;;
+
+let data_mem = (ref Mem.empty : (memory_byte Run_interp_model.Mem.t) ref) ;;
+let prog_mem = (ref Mem.empty : (memory_byte Run_interp_model.Mem.t) ref) ;;
+let tag_mem  = (ref Mem.empty : (memory_byte Run_interp_model.Mem.t) ref);;
+let reg = ref Reg.empty ;;
+
+let add_mem byte addr mem =
+  assert(byte >= 0 && byte < 256);
+  (*Printf.printf "add_mem %s: 0x%02x\n" (Uint64.to_string_hex (Uint64.of_string (Nat_big_num.to_string addr))) byte;*)
+  let mem_byte = memory_byte_of_int byte in
+  mem := Mem.add addr mem_byte !mem
+
+let get_reg reg name =
+  let reg_content = Reg.find name reg in reg_content
+
+let rec load_memory_segment' (bytes,addr) mem =
+  match bytes with
+  | [] -> ()
+  | byte::bytes' ->
+    let data_byte = Char.code byte in
+    let addr' = Nat_big_num.succ addr in
+    begin add_mem data_byte addr mem;
+      load_memory_segment' (bytes',addr') mem
+    end
+
+let rec load_memory_segment (segment: Elf_interpreted_segment.elf64_interpreted_segment) mem =
+  let (Byte_sequence.Sequence bytes) = segment.Elf_interpreted_segment.elf64_segment_body in
+  let addr = segment.Elf_interpreted_segment.elf64_segment_paddr in
+  load_memory_segment' (bytes,addr) mem
+
+
+let rec load_memory_segments segments =
+  begin match segments with
+    | [] -> ()
+    | segment::segments' ->
+      let (x,w,r) = segment.Elf_interpreted_segment.elf64_segment_flags in
+      begin
+        (if x
+         then load_memory_segment segment prog_mem
+         else load_memory_segment segment data_mem);
+        load_memory_segments segments'
+      end    
+  end
+  
+let rec read_mem mem address length = 
+  if length = 0  
+  then []
+  else
+    let byte =
+      try Mem.find address mem with
+      | Not_found -> failwith "start address not found"
+    in
+    byte :: (read_mem mem (Nat_big_num.succ address) (length - 1))
+
+let register_state_zero register_data rbn : register_value =
+  let (dir,width,start_index) =
+    try List.assoc rbn register_data with
+    | Not_found -> failwith ("register_state_zero lookup failed (" ^ rbn)
+  in register_value_zeros dir width start_index
+
+type model = PPC | AArch64 | MIPS
+(*
+let ppc_register_data_all =  [
+  (*Pseudo registers*)
+  ("CIA",   (D_increasing, 64, 0));
+  ("NIA",   (D_increasing, 64, 0));
+  ("mode64bit", (D_increasing, 1, 0));
+  ("bigendianmode", (D_increasing, 1, 0));
+  (* special registers *)
+  ("CR",    (D_increasing, 32, 32));
+  ("CTR",   (D_increasing, 64, 0 ));
+  ("LR",    (D_increasing, 64, 0 ));
+  ("XER",   (D_increasing, 64, 0 ));
+  ("VRSAVE",(D_increasing, 32, 32));
+  ("FPSCR", (D_increasing, 64, 0 ));
+  ("VSCR",  (D_increasing, 32, 96));
+
+  (* general purpose registers *)
+  ("GPR0",  (D_increasing, 64, 0 ));
+  ("GPR1",  (D_increasing, 64, 0 ));
+  ("GPR2",  (D_increasing, 64, 0 ));
+  ("GPR3",  (D_increasing, 64, 0 ));
+  ("GPR4",  (D_increasing, 64, 0 ));
+  ("GPR5",  (D_increasing, 64, 0 ));
+  ("GPR6",  (D_increasing, 64, 0 ));
+  ("GPR7",  (D_increasing, 64, 0 ));
+  ("GPR8",  (D_increasing, 64, 0 ));
+  ("GPR9",  (D_increasing, 64, 0 ));
+  ("GPR10", (D_increasing, 64, 0 ));
+  ("GPR11", (D_increasing, 64, 0 ));
+  ("GPR12", (D_increasing, 64, 0 ));
+  ("GPR13", (D_increasing, 64, 0 ));
+  ("GPR14", (D_increasing, 64, 0 ));
+  ("GPR15", (D_increasing, 64, 0 ));
+  ("GPR16", (D_increasing, 64, 0 ));
+  ("GPR17", (D_increasing, 64, 0 ));
+  ("GPR18", (D_increasing, 64, 0 ));
+  ("GPR19", (D_increasing, 64, 0 ));
+  ("GPR20", (D_increasing, 64, 0 ));
+  ("GPR21", (D_increasing, 64, 0 ));
+  ("GPR22", (D_increasing, 64, 0 ));
+  ("GPR23", (D_increasing, 64, 0 ));
+  ("GPR24", (D_increasing, 64, 0 ));
+  ("GPR25", (D_increasing, 64, 0 ));
+  ("GPR26", (D_increasing, 64, 0 ));
+  ("GPR27", (D_increasing, 64, 0 ));
+  ("GPR28", (D_increasing, 64, 0 ));
+  ("GPR29", (D_increasing, 64, 0 ));
+  ("GPR30", (D_increasing, 64, 0 ));
+  ("GPR31", (D_increasing, 64, 0 ));
+  (* vector registers *)
+  ("VR0",  (D_increasing, 128, 0 ));
+  ("VR1",  (D_increasing, 128, 0 ));
+  ("VR2",  (D_increasing, 128, 0 ));
+  ("VR3",  (D_increasing, 128, 0 ));
+  ("VR4",  (D_increasing, 128, 0 ));
+  ("VR5",  (D_increasing, 128, 0 ));
+  ("VR6",  (D_increasing, 128, 0 ));
+  ("VR7",  (D_increasing, 128, 0 ));
+  ("VR8",  (D_increasing, 128, 0 ));
+  ("VR9",  (D_increasing, 128, 0 ));
+  ("VR10", (D_increasing, 128, 0 ));
+  ("VR11", (D_increasing, 128, 0 ));
+  ("VR12", (D_increasing, 128, 0 ));
+  ("VR13", (D_increasing, 128, 0 ));
+  ("VR14", (D_increasing, 128, 0 ));
+  ("VR15", (D_increasing, 128, 0 ));
+  ("VR16", (D_increasing, 128, 0 ));
+  ("VR17", (D_increasing, 128, 0 ));
+  ("VR18", (D_increasing, 128, 0 ));
+  ("VR19", (D_increasing, 128, 0 ));
+  ("VR20", (D_increasing, 128, 0 ));
+  ("VR21", (D_increasing, 128, 0 ));
+  ("VR22", (D_increasing, 128, 0 ));
+  ("VR23", (D_increasing, 128, 0 ));
+  ("VR24", (D_increasing, 128, 0 ));
+  ("VR25", (D_increasing, 128, 0 ));
+  ("VR26", (D_increasing, 128, 0 ));
+  ("VR27", (D_increasing, 128, 0 ));
+  ("VR28", (D_increasing, 128, 0 ));
+  ("VR29", (D_increasing, 128, 0 ));
+  ("VR30", (D_increasing, 128, 0 ));
+  ("VR31", (D_increasing, 128, 0 ));
+  (* floating-point registers *)
+  ("FPR0",  (D_increasing, 64, 0 ));
+  ("FPR1",  (D_increasing, 64, 0 ));
+  ("FPR2",  (D_increasing, 64, 0 ));
+  ("FPR3",  (D_increasing, 64, 0 ));
+  ("FPR4",  (D_increasing, 64, 0 ));
+  ("FPR5",  (D_increasing, 64, 0 ));
+  ("FPR6",  (D_increasing, 64, 0 ));
+  ("FPR7",  (D_increasing, 64, 0 ));
+  ("FPR8",  (D_increasing, 64, 0 ));
+  ("FPR9",  (D_increasing, 64, 0 ));
+  ("FPR10", (D_increasing, 64, 0 ));
+  ("FPR11", (D_increasing, 64, 0 ));
+  ("FPR12", (D_increasing, 64, 0 ));
+  ("FPR13", (D_increasing, 64, 0 ));
+  ("FPR14", (D_increasing, 64, 0 ));
+  ("FPR15", (D_increasing, 64, 0 ));
+  ("FPR16", (D_increasing, 64, 0 ));
+  ("FPR17", (D_increasing, 64, 0 ));
+  ("FPR18", (D_increasing, 64, 0 ));
+  ("FPR19", (D_increasing, 64, 0 ));
+  ("FPR20", (D_increasing, 64, 0 ));
+  ("FPR21", (D_increasing, 64, 0 ));
+  ("FPR22", (D_increasing, 64, 0 ));
+  ("FPR23", (D_increasing, 64, 0 ));
+  ("FPR24", (D_increasing, 64, 0 ));
+  ("FPR25", (D_increasing, 64, 0 ));
+  ("FPR26", (D_increasing, 64, 0 ));
+  ("FPR27", (D_increasing, 64, 0 ));
+  ("FPR28", (D_increasing, 64, 0 ));
+  ("FPR29", (D_increasing, 64, 0 ));
+  ("FPR30", (D_increasing, 64, 0 ));
+  ("FPR31", (D_increasing, 64, 0 ));
+]
+
+let initial_stack_and_reg_data_of_PPC_elf_file e_entry all_data_memory =
+  (* set up initial registers, per 3.4.1 of 64-bit PowerPC ELF Application Binary Interface Supplement 1.9 *)
+
+  let auxiliary_vector_space = Nat_big_num.of_string "17592186042368" (*"0xffffffff800"*) in
+  (* notionally there should be at least an AT_NULL auxiliary vector entry there, but our examples will never read it *)
+
+  (* take start of stack roughly where running gdb on hello5 on bim says it is*)
+  let initial_GPR1_stack_pointer = Nat_big_num.of_string "17592186040320" (*"0xffffffff000"*) in
+  let initial_GPR1_stack_pointer_value =
+    Interp_interface.register_value_of_integer 64 0 Interp_interface.D_increasing initial_GPR1_stack_pointer in
+  (* ELF says we need an initial zero doubleword there *)
+  let initial_stack_data =
+    (* the code actually uses the stack, both above and below, so we map a bit more memory*)
+    (* this is a fairly big but arbitrary chunk *)
+    (* let initial_stack_data_address = Nat_big_num.sub initial_GPR1_stack_pointer (Nat_big_num.of_int 128) in
+        [("initial_stack_data", initial_stack_data_address, Lem_list.replicate (128+32) 0 ))] in *)
+    (* this is the stack memory that test 1938 actually uses *)
+    [ ("initial_stack_data1", Nat_big_num.sub initial_GPR1_stack_pointer (Nat_big_num.of_int 128),
+       Lem_list.replicate 8 0 );
+      ("initial_stack_data2", Nat_big_num.sub initial_GPR1_stack_pointer (Nat_big_num.of_int 8),
+       Lem_list.replicate 8  0 );
+      ("initial_stack_data3", Nat_big_num.add initial_GPR1_stack_pointer (Nat_big_num.of_int 16),
+       Lem_list.replicate 8  0 )] in
+  
+  (* read TOC from the second field of the function descriptor pointed to by e_entry*)
+  let initial_GPR2_TOC =
+    Interp_interface.register_value_of_address
+      (Interp_interface.address_of_byte_list
+         (List.map (fun b -> match b with Some b -> b | None -> failwith "Address had undefined")
+             (List.map byte_of_byte_lifted
+                (read_mem all_data_memory
+                   (Nat_big_num.add (Nat_big_num.of_int 8) e_entry) 8))))
+      Interp_interface.D_increasing in
+  (* these initial register values are all mandated to be zero, but that's handled by the generic zeroing below
+      let initial_GPR3_argc = (Nat_big_num.of_int 0) in
+      let initial_GPR4_argv = (Nat_big_num.of_int 0) in
+      let initial_GPR5_envp = (Nat_big_num.of_int 0) in
+      let initial_FPSCR = (Nat_big_num.of_int 0) in
+  *)
+  let initial_register_abi_data : (string * Interp_interface.register_value) list =
+    [ ("GPR1", initial_GPR1_stack_pointer_value);
+      ("GPR2", initial_GPR2_TOC);
+  (*
+    ("GPR3", initial_GPR3_argc);
+    ("GPR4", initial_GPR4_argv);
+    ("GPR5", initial_GPR5_envp);
+    ("FPSCR", initial_FPSCR);
+    *)
+    ] in
+
+  (initial_stack_data, initial_register_abi_data)
+
+
+let aarch64_reg bit_count name = (name, (D_decreasing, bit_count, bit_count - 1))
+
+let aarch64_PC_data = [aarch64_reg 64 "_PC"]
+
+(* most of the PSTATE fields are aliases to other registers so they
+   don't appear here *)
+let aarch64_PSTATE_data  = [
+  aarch64_reg 1 "PSTATE_nRW";
+  aarch64_reg 1 "PSTATE_E";
+  aarch64_reg 5 "PSTATE_M";
+]
+
+let aarch64_general_purpose_registers_data = [
+  aarch64_reg 64 "R0";
+  aarch64_reg 64 "R1";
+  aarch64_reg 64 "R2";
+  aarch64_reg 64 "R3";
+  aarch64_reg 64 "R4";
+  aarch64_reg 64 "R5";
+  aarch64_reg 64 "R6";
+  aarch64_reg 64 "R7";
+  aarch64_reg 64 "R8";
+  aarch64_reg 64 "R9";
+  aarch64_reg 64 "R10";
+  aarch64_reg 64 "R11";
+  aarch64_reg 64 "R12";
+  aarch64_reg 64 "R13";
+  aarch64_reg 64 "R14";
+  aarch64_reg 64 "R15";
+  aarch64_reg 64 "R16";
+  aarch64_reg 64 "R17";
+  aarch64_reg 64 "R18";
+  aarch64_reg 64 "R19";
+  aarch64_reg 64 "R20";
+  aarch64_reg 64 "R21";
+  aarch64_reg 64 "R22";
+  aarch64_reg 64 "R23";
+  aarch64_reg 64 "R24";
+  aarch64_reg 64 "R25";
+  aarch64_reg 64 "R26";
+  aarch64_reg 64 "R27";
+  aarch64_reg 64 "R28";
+  aarch64_reg 64 "R29";
+  aarch64_reg 64 "R30";
+]
+
+let aarch64_SIMD_registers_data = [
+  aarch64_reg 128 "V0";
+  aarch64_reg 128 "V1";
+  aarch64_reg 128 "V2";
+  aarch64_reg 128 "V3";
+  aarch64_reg 128 "V4";
+  aarch64_reg 128 "V5";
+  aarch64_reg 128 "V6";
+  aarch64_reg 128 "V7";
+  aarch64_reg 128 "V8";
+  aarch64_reg 128 "V9";
+  aarch64_reg 128 "V10";
+  aarch64_reg 128 "V11";
+  aarch64_reg 128 "V12";
+  aarch64_reg 128 "V13";
+  aarch64_reg 128 "V14";
+  aarch64_reg 128 "V15";
+  aarch64_reg 128 "V16";
+  aarch64_reg 128 "V17";
+  aarch64_reg 128 "V18";
+  aarch64_reg 128 "V19";
+  aarch64_reg 128 "V20";
+  aarch64_reg 128 "V21";
+  aarch64_reg 128 "V22";
+  aarch64_reg 128 "V23";
+  aarch64_reg 128 "V24";
+  aarch64_reg 128 "V25";
+  aarch64_reg 128 "V26";
+  aarch64_reg 128 "V27";
+  aarch64_reg 128 "V28";
+  aarch64_reg 128 "V29";
+  aarch64_reg 128 "V30";
+  aarch64_reg 128 "V31";
+]
+
+let aarch64_special_purpose_registers_data = [
+  aarch64_reg 32 "CurrentEL";
+  aarch64_reg 32 "DAIF";
+  aarch64_reg 32 "NZCV";
+  aarch64_reg 64 "SP_EL0";
+  aarch64_reg 64 "SP_EL1";
+  aarch64_reg 64 "SP_EL2";
+  aarch64_reg 64 "SP_EL3";
+  aarch64_reg 32 "SPSel";
+  aarch64_reg 32 "SPSR_EL1";
+  aarch64_reg 32 "SPSR_EL2";
+  aarch64_reg 32 "SPSR_EL3";
+  aarch64_reg 64 "ELR_EL1";
+  aarch64_reg 64 "ELR_EL2";
+  aarch64_reg 64 "ELR_EL3";
+]
+
+let aarch64_general_system_control_registers_data = [
+  aarch64_reg 64 "HCR_EL2";
+  aarch64_reg 64 "ID_AA64MMFR0_EL1";
+  aarch64_reg 64 "RVBAR_EL1";
+  aarch64_reg 64 "RVBAR_EL2";
+  aarch64_reg 64 "RVBAR_EL3";
+  aarch64_reg 32 "SCR_EL3";
+  aarch64_reg 32 "SCTLR_EL1";
+  aarch64_reg 32 "SCTLR_EL2";
+  aarch64_reg 32 "SCTLR_EL3";
+  aarch64_reg 64 "TCR_EL1";
+  aarch64_reg 32 "TCR_EL2";
+  aarch64_reg 32 "TCR_EL3";
+]
+
+let aarch64_debug_registers_data = [
+  aarch64_reg 32 "DBGPRCR_EL1";
+  aarch64_reg 32 "OSDLR_EL1";
+]
+
+let aarch64_performance_monitors_registers_data = []
+let aarch64_generic_timer_registers_data = []
+let aarch64_generic_interrupt_controller_CPU_interface_registers_data = []
+
+let aarch64_external_debug_registers_data = [
+  aarch64_reg 32 "EDSCR";
+]
+
+let aarch32_general_system_control_registers_data = [
+  aarch64_reg 32 "SCR";
+]
+
+let aarch32_debug_registers_data = [
+  aarch64_reg 32 "DBGOSDLR";
+  aarch64_reg 32 "DBGPRCR";
+]
+
+let aarch64_register_data_all =
+  aarch64_PC_data @
+  aarch64_PSTATE_data @
+  aarch64_general_purpose_registers_data @
+  aarch64_SIMD_registers_data @
+  aarch64_special_purpose_registers_data @
+  aarch64_general_system_control_registers_data @
+  aarch64_debug_registers_data @
+  aarch64_performance_monitors_registers_data @
+  aarch64_generic_timer_registers_data @
+  aarch64_generic_interrupt_controller_CPU_interface_registers_data @
+  aarch64_external_debug_registers_data @
+  aarch32_general_system_control_registers_data @
+  aarch32_debug_registers_data
+
+let initial_stack_and_reg_data_of_AAarch64_elf_file e_entry all_data_memory =
+  let (reg_SP_EL0_direction, reg_SP_EL0_width, reg_SP_EL0_initial_index) =
+    List.assoc "SP_EL0" aarch64_register_data_all in
+  
+  (* we compiled a small program that prints out SP and run it a few
+      times on the Nexus9, these are the results:
+      0x0000007fe7f903e0
+      0x0000007fdcdbf3f0
+      0x0000007fcbe1ba90
+      0x0000007fcf378280
+      0x0000007fdd54b8d0
+      0x0000007fd961bc10
+      0x0000007ff3be6350
+      0x0000007fd6bf6ef0
+      0x0000007fff7676f0
+      0x0000007ff2c34560 *)
+  let initial_SP_EL0 = Nat_big_num.of_string "549739036672" (*"0x0000007fff000000"*) in
+  let initial_SP_EL0_value =
+    Interp_interface.register_value_of_integer
+      reg_SP_EL0_width
+      reg_SP_EL0_initial_index
+      reg_SP_EL0_direction
+      initial_SP_EL0
+  in
+
+  (* ELF says we need an initial zero doubleword there *)
+  (* the code actually uses the stack, both above and below, so we map a bit more memory*)
+  let initial_stack_data =
+    (* this is a fairly big but arbitrary chunk: *)
+    (* let initial_stack_data_address = Nat_big_num.sub initial_GPR1_stack_pointer (Nat_big_num.of_int 128) in
+        [("initial_stack_data", initial_stack_data_address, Lem_list.replicate (128+32) 0 ))] in *)
+    
+    [ ("initial_stack_data1", Nat_big_num.sub initial_SP_EL0 (Nat_big_num.of_int 16),  Lem_list.replicate 8 0);
+      ("initial_stack_data2", Nat_big_num.sub initial_SP_EL0 (Nat_big_num.of_int 8),   Lem_list.replicate 8 0)
+    ]
+  in
+
+  let initial_register_abi_data : (string * Interp_interface.register_value) list =
+    [("SP_EL0", initial_SP_EL0_value)]
+  in
+
+  (initial_stack_data, initial_register_abi_data)
+*)
+
+let mips_register_data_all =  [
+  (*Pseudo registers*)
+  ("branchPending", (D_decreasing, 1, 0));
+  ("inBranchDelay", (D_decreasing, 1, 0));
+  ("delayedPC", (D_decreasing, 64, 63));
+  ("nextPC", (D_decreasing, 64, 63));
+  (* General purpose registers *)
+  ("GPR00", (D_decreasing, 64, 63));
+  ("GPR01", (D_decreasing, 64, 63));
+  ("GPR02", (D_decreasing, 64, 63));
+  ("GPR03", (D_decreasing, 64, 63));
+  ("GPR04", (D_decreasing, 64, 63));
+  ("GPR05", (D_decreasing, 64, 63));
+  ("GPR06", (D_decreasing, 64, 63));
+  ("GPR07", (D_decreasing, 64, 63));
+  ("GPR08", (D_decreasing, 64, 63));
+  ("GPR09", (D_decreasing, 64, 63));
+  ("GPR10", (D_decreasing, 64, 63));
+  ("GPR11", (D_decreasing, 64, 63));
+  ("GPR12", (D_decreasing, 64, 63));
+  ("GPR13", (D_decreasing, 64, 63));
+  ("GPR14", (D_decreasing, 64, 63));
+  ("GPR15", (D_decreasing, 64, 63));
+  ("GPR16", (D_decreasing, 64, 63));
+  ("GPR17", (D_decreasing, 64, 63));
+  ("GPR18", (D_decreasing, 64, 63));
+  ("GPR19", (D_decreasing, 64, 63));
+  ("GPR20", (D_decreasing, 64, 63));
+  ("GPR21", (D_decreasing, 64, 63));
+  ("GPR22", (D_decreasing, 64, 63));
+  ("GPR23", (D_decreasing, 64, 63));
+  ("GPR24", (D_decreasing, 64, 63));
+  ("GPR25", (D_decreasing, 64, 63));
+  ("GPR26", (D_decreasing, 64, 63));
+  ("GPR27", (D_decreasing, 64, 63));
+  ("GPR28", (D_decreasing, 64, 63));
+  ("GPR29", (D_decreasing, 64, 63));
+  ("GPR30", (D_decreasing, 64, 63));
+  ("GPR31", (D_decreasing, 64, 63));
+  (* special registers for mul/div *)
+  ("HI", (D_decreasing, 64, 63));
+  ("LO", (D_decreasing, 64, 63));
+  (* control registers *)
+  ("CP0Status", (D_decreasing, 32, 31));
+  ("CP0Cause", (D_decreasing, 32, 31));
+  ("CP0EPC", (D_decreasing, 64, 63));
+  ("CP0LLAddr", (D_decreasing, 64, 63));
+  ("CP0LLBit", (D_decreasing, 1, 0));
+]
+
+let cheri_register_data_all = mips_register_data_all @ [
+  ("CapCause", (D_decreasing, 16, 15));
+  ("PCC", (D_decreasing, 257, 256));
+  ("C00", (D_decreasing, 257, 256));
+  ("C01", (D_decreasing, 257, 256));
+  ("C02", (D_decreasing, 257, 256));
+  ("C03", (D_decreasing, 257, 256));
+  ("C04", (D_decreasing, 257, 256));
+  ("C05", (D_decreasing, 257, 256));
+  ("C06", (D_decreasing, 257, 256));
+  ("C07", (D_decreasing, 257, 256));
+  ("C08", (D_decreasing, 257, 256));
+  ("C09", (D_decreasing, 257, 256));
+  ("C10", (D_decreasing, 257, 256));
+  ("C11", (D_decreasing, 257, 256));
+  ("C12", (D_decreasing, 257, 256));
+  ("C13", (D_decreasing, 257, 256));
+  ("C14", (D_decreasing, 257, 256));
+  ("C15", (D_decreasing, 257, 256));
+  ("C16", (D_decreasing, 257, 256));
+  ("C17", (D_decreasing, 257, 256));
+  ("C18", (D_decreasing, 257, 256));
+  ("C19", (D_decreasing, 257, 256));
+  ("C20", (D_decreasing, 257, 256));
+  ("C21", (D_decreasing, 257, 256));
+  ("C22", (D_decreasing, 257, 256));
+  ("C23", (D_decreasing, 257, 256));
+  ("C24", (D_decreasing, 257, 256));
+  ("C25", (D_decreasing, 257, 256));
+  ("C26", (D_decreasing, 257, 256));
+  ("C27", (D_decreasing, 257, 256));
+  ("C28", (D_decreasing, 257, 256));
+  ("C29", (D_decreasing, 257, 256));
+  ("C30", (D_decreasing, 257, 256));
+  ("C31", (D_decreasing, 257, 256));
+]
+
+let initial_stack_and_reg_data_of_MIPS_elf_file e_entry all_data_memory =
+  let initial_stack_data = [] in 
+  let initial_cap_val_int = Nat_big_num.of_string "115792089264276142078167421332581561412618036492862375629811892344162380414975" (*"0x100000000fffffffe00000000000000000000000000000000ffffffffffffffff"*) in
+  let initial_cap_val_reg = Interp_interface.register_value_of_integer 257 256 D_decreasing  initial_cap_val_int in
+  let initial_register_abi_data : (string * Interp_interface.register_value) list = [
+    ("PCC", initial_cap_val_reg);
+    ("C00", initial_cap_val_reg);
+    ("C01", initial_cap_val_reg);
+    ("C02", initial_cap_val_reg);
+    ("C03", initial_cap_val_reg);
+    ("C04", initial_cap_val_reg);
+    ("C05", initial_cap_val_reg);
+    ("C06", initial_cap_val_reg);
+    ("C07", initial_cap_val_reg);
+    ("C08", initial_cap_val_reg);
+    ("C09", initial_cap_val_reg);
+    ("C10", initial_cap_val_reg);
+    ("C11", initial_cap_val_reg);
+    ("C12", initial_cap_val_reg);
+    ("C13", initial_cap_val_reg);
+    ("C14", initial_cap_val_reg);
+    ("C15", initial_cap_val_reg);
+    ("C16", initial_cap_val_reg);
+    ("C17", initial_cap_val_reg);
+    ("C18", initial_cap_val_reg);
+    ("C19", initial_cap_val_reg);
+    ("C20", initial_cap_val_reg);
+    ("C21", initial_cap_val_reg);
+    ("C22", initial_cap_val_reg);
+    ("C23", initial_cap_val_reg);
+    ("C24", initial_cap_val_reg);
+    ("C25", initial_cap_val_reg);
+    ("C26", initial_cap_val_reg);
+    ("C27", initial_cap_val_reg);
+    ("C28", initial_cap_val_reg);
+    ("C29", initial_cap_val_reg);
+    ("C30", initial_cap_val_reg);
+    ("C31", initial_cap_val_reg);
+  ] in
+  (initial_stack_data, initial_register_abi_data)
+
+let initial_reg_file reg_data init =
+  List.iter (fun (reg_name, _) -> reg := Reg.add reg_name (init reg_name) !reg) reg_data
+
+let initial_system_state_of_elf_file name = 
+
+  (* call ELF analyser on file *)
+  match Sail_interface.populate_and_obtain_global_symbol_init_info name with
+  | Error.Fail s -> failwith ("populate_and_obtain_global_symbol_init_info: " ^ s)
+  | Error.Success 
+      ((elf_epi: Sail_interface.executable_process_image),
+       (symbol_map: Elf_file.global_symbol_init_info))
+    ->
+    let (segments, e_entry, e_machine) =
+      begin match elf_epi with
+        | ELF_Class_32 _ -> failwith "cannot handle ELF_Class_32"
+        | ELF_Class_64 (segments,e_entry,e_machine) ->
+          (* remove all the auto generated segments (they contain only 0s) *)
+          let segments =
+            Lem_list.mapMaybe
+              (fun (seg, prov) -> if prov = Elf_file.FromELF then Some seg else None)
+              segments
+          in
+          (segments,e_entry,e_machine)
+      end
+    in
+
+    (* construct program memory and start address *)
+    begin
+      prog_mem := Mem.empty;
+      data_mem := Mem.empty;
+      tag_mem := Mem.empty;
+      load_memory_segments segments;
+      (*
+      debugf "prog_mem\n";
+      Mem.iter (fun k v -> debugf "%s\n" (Mem.to_string k v)) !prog_mem;
+      debugf "data_mem\n";
+      Mem.iter (fun k v -> debugf "%s\n" (Mem.to_string k v)) !data_mem;
+      *)
+      let (isa_defs, isa_memory_access, isa_externs, isa_model, model_reg_d, startaddr,
+           initial_stack_data, initial_register_abi_data, register_data_all) =
+        match Nat_big_num.to_int e_machine with
+(*        | 21  (* EM_PPC64 *) ->
+          let startaddr =
+            let e_entry = Uint64.of_int64 (Nat_big_num.to_int64 e_entry) in
+            match Abi_power64.abi_power64_compute_program_entry_point segments e_entry with
+            | Error.Fail s -> failwith "Failed computing entry point"
+            | Error.Success s -> Nat_big_num.of_int64 (Uint64.to_int64 s)
+          in
+          let (initial_stack_data, initial_register_abi_data) =
+            initial_stack_and_reg_data_of_PPC_elf_file e_entry !data_mem in
+
+            (Power.defs,
+             (Power_extras.read_memory_functions,Power_extras.memory_writes,[],[],Power_extras.barrier_functions),
+             Power_extras.power_externs,
+             PPC,
+             D_increasing,
+             startaddr,
+             initial_stack_data,
+             initial_register_abi_data,
+             ppc_register_data_all)
+
+        | 183 (* EM_AARCH64 *) ->
+          let startaddr =
+            let e_entry = Uint64.of_int64 (Nat_big_num.to_int64 e_entry) in
+            match Abi_aarch64_le.abi_aarch64_le_compute_program_entry_point segments e_entry with
+            | Error.Fail s -> failwith "Failed computing entry point"
+            | Error.Success s -> Nat_big_num.of_int64 (Uint64.to_int64 s)
+          in
+          
+          let (initial_stack_data, initial_register_abi_data) =
+            initial_stack_and_reg_data_of_AAarch64_elf_file e_entry !data_mem in
+          
+          (ArmV8.defs,
+           (ArmV8_extras.aArch64_read_memory_functions,
+            ArmV8_extras.aArch64_memory_writes,
+	    ArmV8_extras.aArch64_memory_eas,
+	    ArmV8_extras.aArch64_memory_vals,
+            ArmV8_extras.aArch64_barrier_functions),
+           [],
+           AArch64,
+           D_decreasing,
+           startaddr,
+           initial_stack_data,
+           initial_register_abi_data,
+           aarch64_register_data_all) *)
+        | 8 (* EM_MIPS *) ->
+          let startaddr =
+            let e_entry = Uint64.of_string (Nat_big_num.to_string e_entry) in
+            match Abi_mips64.abi_mips64_compute_program_entry_point segments e_entry with
+            | Error.Fail s -> failwith "Failed computing entry point"
+            | Error.Success s -> s
+          in
+          let (initial_stack_data, initial_register_abi_data) =
+            initial_stack_and_reg_data_of_MIPS_elf_file e_entry !data_mem in
+          
+          (Cheri.defs,
+           (Mips_extras.read_memory_functions,
+            Mips_extras.memory_writes,
+	    [],
+	    [],
+            Mips_extras.barrier_functions),
+           [],
+           MIPS,
+           D_decreasing,
+           startaddr,
+           initial_stack_data,
+           initial_register_abi_data,
+           cheri_register_data_all)
+
+        | _ -> failwith (Printf.sprintf "Sail sequential interpreter can't handle the e_machine value %s, only EM_PPC64, EM_AARCH64 and EM_MIPS are supported." (Nat_big_num.to_string e_machine))
+      in
+      
+      (* pull the object symbols from the symbol table *)
+      let symbol_table : (string * Nat_big_num.num * int * word8 list (*their bytes*)) list =
+        let rec convert_symbol_table symbol_map =
+          begin match symbol_map with
+          | [] -> []
+          | ((name: string),
+             ((typ: Nat_big_num.num),
+              (size: Nat_big_num.num (*number of bytes*)),
+              (address: Nat_big_num.num),
+              (mb: Byte_sequence.byte_sequence option (*present iff type=stt_object*)),
+              (binding: Nat_big_num.num)))
+	    (*              (mb: Byte_sequence_wrapper.t option (*present iff type=stt_object*)) )) *)
+            ::symbol_map' ->
+            if Nat_big_num.equal typ Elf_symbol_table.stt_object && not (Nat_big_num.equal size (Nat_big_num.of_int 0))
+            then
+              (
+                (* an object symbol - map *)
+                (*Printf.printf "*** size %d ***\n" (Nat_big_num.to_int size);*)
+                let bytes =
+                  (match mb with
+                   | None -> raise (Failure "this cannot happen")
+                   | Some (Sequence bytes) ->
+                     List.map (fun (c:char) -> Char.code c) bytes) in
+                 (name, address, List.length bytes, bytes):: convert_symbol_table symbol_map'
+              )
+              else
+                (* not an object symbol or of zero size - ignore *)
+                convert_symbol_table symbol_map'
+          end
+        in
+        (List.map (fun (n,a,bs) -> (n,a,List.length bs,bs)) initial_stack_data) @ convert_symbol_table symbol_map
+      in
+
+      (* invert the symbol table to use for pp *)
+      let symbol_table_pp : ((Interp_interface.address * int) * string) list =
+        (* map symbol to (bindings, footprint),
+           if a symbol appears more then onece keep the one with higher
+           precedence (stb_global > stb_weak > stb_local) *)
+        let map =
+          List.fold_left
+            (fun map (name, (typ, size, address, mb, binding)) ->
+               if String.length name <> 0 &&
+                  (if String.length name = 1 then Char.code (String.get name 0) <> 0 else true) &&
+                  not (Nat_big_num.equal address (Nat_big_num.of_int 0))
+               then
+                 try
+                   let (binding', _) = StringMap.find name map in
+                   if  Nat_big_num.equal binding' Elf_symbol_table.stb_local ||
+                       Nat_big_num.equal binding Elf_symbol_table.stb_global
+                   then
+                     StringMap.add name (binding,
+                                         (Interp_interface.address_of_integer address, Nat_big_num.to_int size)) map
+                   else map
+                 with Not_found ->
+                   StringMap.add name (binding,
+                                       (Interp_interface.address_of_integer address, Nat_big_num.to_int size)) map
+                     
+               else map
+            )
+            StringMap.empty
+            symbol_map
+        in
+
+        List.map (fun (name, (binding, fp)) -> (fp, name)) (StringMap.bindings map)
+      in
+
+
+      (* Now we examine the rest of the data memory,
+         removing the footprint of the symbols and chunking it into aligned chunks *)
+      
+      let rec remove_symbols_from_data_memory data_mem symbols =
+        match symbols with
+        | [] -> data_mem
+        | (name,address,size,bs)::symbols' ->
+          let data_mem' =
+            Mem.filter
+              (fun a v ->
+                 not (Nat_big_num.greater_equal a address &&
+                      Nat_big_num.less a (Nat_big_num.add (Nat_big_num.of_int (List.length bs)) address)))
+              data_mem in
+          remove_symbols_from_data_memory data_mem' symbols' in
+
+      let trimmed_data_memory : (Nat_big_num.num * memory_byte) list =
+        Mem.bindings (remove_symbols_from_data_memory !data_mem symbol_table) in
+
+      (* make sure that's ordered increasingly.... *)
+      let trimmed_data_memory =
+        List.sort (fun (a,b) (a',b') -> Nat_big_num.compare a a') trimmed_data_memory in
+
+      let aligned a n =  (* a mod n = 0 *)
+        let n_big = Nat_big_num.of_int n in
+        Nat_big_num.equal (Nat_big_num.modulus a n_big) ((Nat_big_num.of_int 0)) in
+
+      let isplus a' a n =   (* a' = a+n *)
+        Nat_big_num.equal a' (Nat_big_num.add (Nat_big_num.of_int n) a) in
+
+      let rec chunk_data_memory dm =
+        match dm with
+        | (a0,b0)::(a1,b1)::(a2,b2)::(a3,b3)::(a4,b4)::(a5,b5)::(a6,b6)::(a7,b7)::dm'  when
+            (aligned a0 8 && isplus a1 a0 1 && isplus a2 a0 2 && isplus a3 a0 3 &&
+             isplus a4 a0 4 && isplus a5 a0 5 && isplus a6 a0 6 && isplus a7 a0 7) ->
+          (a0,8,[b0;b1;b2;b3;b4;b5;b6;b7]) :: chunk_data_memory dm'
+        | (a0,b0)::(a1,b1)::(a2,b2)::(a3,b3)::dm' when
+            (aligned a0 4 && isplus a1 a0 1 && isplus a2 a0 2 && isplus a3 a0 3) ->
+              (a0,4,[b0;b1;b2;b3]) :: chunk_data_memory dm'
+        | (a0,b0)::(a1,b1)::dm' when
+            (aligned a0 2 && isplus a1 a0 1) ->
+              (a0,2,[b0;b1]) :: chunk_data_memory dm'
+        | (a0,b0)::dm' ->
+            (a0,1,[b0]):: chunk_data_memory dm'
+        | [] -> [] in
+
+      let initial_register_state =
+        fun rbn ->
+          try
+            List.assoc rbn initial_register_abi_data
+          with
+            Not_found ->
+              (register_state_zero register_data_all) rbn
+      in
+
+      begin
+        (initial_reg_file register_data_all initial_register_state);
+        
+        (* construct initial system state *)
+        let initial_system_state =
+          (isa_defs,
+	   isa_memory_access,
+	   isa_externs,
+           isa_model,
+           model_reg_d,
+           startaddr,
+           (Interp_interface.address_of_integer startaddr))
+        in
+        
+        (initial_system_state, symbol_table_pp)
+      end
+    end
+
+let eager_eval = ref true
+let break_point = ref false
+let break_instr = ref 0
+let max_cut_off = ref false
+let max_instr = ref 0
+
+let args = [
+  ("--file", Arg.Set_string file, "filename binary code to load in memory");
+  ("--quiet", Arg.Clear Run_interp_model.interact_print, "do not display per-instruction actions");
+  ("--silent", Arg.Tuple [Arg.Clear Run_interp_model.error_print;
+                          Arg.Clear Run_interp_model.interact_print;
+                          Arg.Clear Run_interp_model.result_print],
+   "do not dispaly error messages, per-instruction actions, or results");
+  ("--no_result", Arg.Clear Run_interp_model.result_print, "do not display final register values");
+  ("--interactive", Arg.Clear eager_eval , "interactive execution");
+  ("--breakpoint", Arg.Int (fun i -> break_point := true; break_instr:= i), "run to instruction number i, then run interactively");
+  ("--max_instruction", Arg.Int (fun i -> max_cut_off := true; max_instr := i), "only run i instructions, then stop");
+]
+
+let time_it action arg =
+  let start_time = Sys.time () in
+  ignore (action arg);
+  let finish_time = Sys.time () in
+  finish_time -. start_time
+
+(*TODO MIPS specific, should print final register values under all models*)
+let rec debug_print_gprs start stop =
+  resultf "DEBUG MIPS REG %.2d %s\n" start (Printing_functions.logfile_register_value_to_string (Reg.find (Format.sprintf "GPR%02d" start) !reg));
+  if start < stop
+  then debug_print_gprs (start + 1) stop
+  else ()
+
+let rec debug_print_capregs start stop =
+  resultf "DEBUG CAP REG %.2d %s\n" start (Printing_functions.logfile_register_value_to_string (Reg.find (Format.sprintf "C%02d" start) !reg));
+  if start < stop
+  then debug_print_capregs (start + 1) stop
+  else ()
+
+let stop_condition_met model instr =
+  match model with
+  | PPC ->
+    (match instr with
+     | ("Sc", [("Lev", _, arg)], []) ->
+       Nat_big_num.equal (integer_of_bit_list arg) (Nat_big_num.of_int 32)
+     | _ -> false)
+  | AArch64 -> (match instr with
+    | ("ImplementationDefinedStopFetching", _, _) -> true
+    | _ -> false)
+  | MIPS -> (match instr with 
+    | ("HCF", _, _) -> 
+      resultf "DEBUG MIPS PC %s\n"  (Printing_functions.logfile_register_value_to_string (Reg.find "PC" !reg));
+      debug_print_gprs 0 31;
+      resultf "DEBUG CAP PCC %s\n"  (Printing_functions.logfile_register_value_to_string (Reg.find "PCC" !reg));
+      debug_print_capregs 0 31;
+      true
+    | _ -> false)
+
+let is_branch model instruction =
+  let (name,_,_) = instruction in
+  match (model , name) with
+  | (PPC, "B") -> true
+  | (PPC, "Bc") -> true
+  | (PPC, "Bclr") -> true
+  | (PPC, "Bcctr") -> true
+  | (PPC, _) -> false
+  | (AArch64, "BranchImmediate") -> true
+  | (AArch64, "BranchConditional") -> true
+  | (AArch64, "CompareAndBranch") -> true
+  | (AArch64, "TestBitAndBranch") -> true
+  | (AArch64, "BranchRegister") -> true
+  | (AArch64, _) -> false
+  | (MIPS, _) -> false (*todo,fill this in*)
+
+let option_int_of_option_integer i = match i with
+  | Some i -> Some (Nat_big_num.to_int i)
+  | None -> None
+
+let set_next_instruction_address model =
+  match model with
+  | PPC ->
+    let cia = Reg.find "CIA" !reg in
+    let cia_addr = address_of_register_value cia in
+    (match cia_addr with
+    | Some cia_addr ->
+      let nia_addr = add_address_nat cia_addr 4 in 
+      let nia = register_value_of_address nia_addr Interp_interface.D_increasing in
+      reg := Reg.add "NIA" nia !reg
+    | _ -> failwith "CIA address contains unknown or undefined")
+  | AArch64 ->
+    let pc = Reg.find "_PC" !reg in
+    let pc_addr = address_of_register_value pc in
+    (match pc_addr with
+     | Some pc_addr ->
+       let n_addr = add_address_nat pc_addr 4 in
+       let n_pc = register_value_of_address n_addr D_decreasing in
+       reg := Reg.add "_PC" n_pc !reg
+     | _ -> failwith "_PC address contains unknown or undefined")
+  | MIPS -> 
+    let pc_addr       = address_of_register_value (Reg.find "PC" !reg) in
+    let branchPending = integer_of_register_value (Reg.find "branchPending" !reg) in
+    let delayedPC     = address_of_register_value (Reg.find "delayedPC" !reg) in
+    (match (pc_addr, option_int_of_option_integer branchPending, delayedPC) with
+     | (Some pc_val, Some 0, _) -> 
+       (* normal -- increment PC *)
+       let n_addr = add_address_nat pc_val 4 in
+       let n_pc = register_value_of_address n_addr D_decreasing in
+       begin
+         reg := Reg.add "nextPC" n_pc !reg;
+         reg := Reg.add "inBranchDelay" (register_value_of_integer 1 0 Interp_interface.D_decreasing Nat_big_num.zero) !reg;
+       end
+     | (Some pc_val, Some 1, Some delayedPC) -> 
+       (* delay slot -- branch to delayed PC and clear branchPending *)
+       begin 
+         reg := Reg.add "nextPC" (register_value_of_address delayedPC D_decreasing) !reg;
+         reg := Reg.add "branchPending" (register_value_of_integer 1 0 Interp_interface.D_decreasing Nat_big_num.zero) !reg;
+         reg := Reg.add "inBranchDelay" (register_value_of_integer 1 0 Interp_interface.D_decreasing (Nat_big_num.of_int 1)) !reg;
+       end
+     | (_, _, _) -> errorf "PC address contains unknown or undefined"; exit 1)
+
+let add1 = Nat_big_num.add (Nat_big_num.of_int 1)
+
+let fetch_instruction_opcode_and_update_ia model addr_trans =
+  match model with
+  | PPC ->
+    let cia = Reg.find "CIA" !reg in
+    let cia_addr = address_of_register_value cia in
+    (match cia_addr with
+     | Some cia_addr ->
+       let cia_a = integer_of_address cia_addr in
+       let opcode = List.map (fun b -> match b with
+           | Some b -> b
+           | None -> failwith "A byte in opcode contained unknown or undef")
+           (List.map byte_of_memory_byte
+              [Mem.find cia_a !prog_mem;
+               Mem.find (add1 cia_a) !prog_mem;
+               Mem.find (add1 (add1 cia_a)) !prog_mem;
+               Mem.find (add1 (add1 (add1 cia_a))) !prog_mem]) in
+       begin
+         reg := Reg.add "CIA" (Reg.find "NIA" !reg) !reg;
+         Opcode opcode
+       end
+     | None -> failwith "CIA address contains unknown or undefined")
+  | AArch64 ->
+    let pc = Reg.find "_PC" !reg in
+    let pc_addr = address_of_register_value pc in
+    (match pc_addr with
+     | Some pc_addr ->
+       let pc_a = integer_of_address pc_addr in
+       let opcode =  List.map (fun b -> match b with
+           | Some b -> b
+           | None -> failwith "A byte in opcode contained unknown or undef")
+           (List.map byte_of_memory_byte
+              ([Mem.find pc_a !prog_mem;
+                Mem.find (add1 pc_a) !prog_mem;
+                Mem.find (add1 (add1 pc_a)) !prog_mem;
+                Mem.find (add1 (add1 (add1 pc_a))) !prog_mem])) in
+       Opcode opcode       
+     | None -> failwith "_PC address contains unknown or undefined")
+  | MIPS -> 
+    let nextPC  = Reg.find "nextPC" !reg in
+    let pc_addr = address_of_register_value nextPC in
+    (match pc_addr with
+    | Some pc_addr ->
+      let pc_a = match addr_trans pc_addr with
+        | Some a, _ -> integer_of_address a
+        | None, Some i -> failwith ("Address translation failed with error code " ^ (Nat_big_num.to_string i))
+        | _ -> failwith "Neither an address or a code on translate address" in
+      let opcode = List.map (fun b -> match b with
+        | Some b -> b
+        | None -> failwith "A byte in opcode contained unknown or undef")
+        (List.map byte_of_memory_byte
+           (([Mem.find pc_a !prog_mem;
+                Mem.find (add1 pc_a) !prog_mem;
+                Mem.find (add1 (add1 pc_a)) !prog_mem;
+                Mem.find (add1 (add1 (add1 pc_a))) !prog_mem]))) in
+      begin
+        reg := Reg.add "PC" nextPC !reg;
+        Opcode opcode
+      end
+     | None -> errorf "nextPC contains unknown or undefined"; exit 1)
+  |  _ -> assert false
+
+let get_pc_address = function
+  | MIPS -> Reg.find "PC" !reg
+  | PPC  -> Reg.find "CIA" !reg
+  | AArch64 -> Reg.find "_PC" !reg
+        
+
+let rec fde_loop count context model mode track_dependencies opcode addr_trans =
+  if !max_cut_off && count = !max_instr
+  then resultf "\nEnding evaluation due to reaching cut off point of %d instructions\n" count
+  else begin
+    interactf "\n**** instruction %d from address %s ****\n"
+      count (Printing_functions.register_value_to_string (get_pc_address model));
+    if !break_point && count = !break_instr then begin break_point := false; eager_eval := false end;
+    let (instruction,istate) = match Interp_inter_imp.decode_to_istate context opcode with
+      | Instr(instruction,istate) ->
+        interactf "\n**** Running: %s ****\n" (Printing_functions.instruction_to_string instruction);
+        (instruction,istate)
+      | Decode_error d ->
+        (match d with
+         | Interp_interface.Unsupported_instruction_error instr ->
+           errorf "\n**** Encountered unsupported instruction %s ****\n" (Printing_functions.instruction_to_string instr)
+         | Interp_interface.Not_an_instruction_error op ->
+           (match op with
+            | Opcode bytes ->
+              errorf "\n**** Encountered non-decodeable opcode: %s ****\n" (Printing_functions.byte_list_to_string bytes))
+         | Internal_error s -> errorf "\n**** Internal error on decode: %s ****\n" s);
+        exit 1
+    in
+    if stop_condition_met model instruction
+    then resultf "\nSUCCESS program terminated after %d instructions\n" count
+    else
+      begin
+        set_next_instruction_address model;
+        match Run_interp_model.run  istate !reg !prog_mem !tag_mem !eager_eval track_dependencies mode "execute" with
+        | false, _,_, _ -> errorf "FAILURE\n"; exit 1
+        | true, mode, track_dependencies, (my_reg, my_mem, my_tags) ->
+          reg := my_reg;
+          prog_mem := my_mem;
+          tag_mem := my_tags;
+          let opcode = fetch_instruction_opcode_and_update_ia model addr_trans in
+          fde_loop (count + 1) context model (Some mode) (ref track_dependencies) opcode addr_trans
+      end
+  end
+  
+let run () =
+  Arg.parse args (fun _ -> raise (Arg.Bad "anonymous parameter")) "" ;
+  if !file = "" then begin
+    Arg.usage args "";
+    exit 1;
+  end;
+  if !break_point then eager_eval := true;
+
+  let ((isa_defs,
+       (isa_m0, isa_m1, isa_m2, isa_m3,isa_m4),
+        isa_externs,
+        isa_model,
+        model_reg_d,
+        startaddr,
+        startaddr_internal), pp_symbol_map) = initial_system_state_of_elf_file !file in
+
+  let context = build_context isa_defs isa_m0 isa_m1 isa_m2 isa_m3 isa_m4 isa_externs in
+  (*NOTE: this is likely MIPS specific, so should probably pull from initial_system_state info on to translate or not, 
+          endian mode, and translate function name 
+  *)
+  let addr_trans = translate_address context E_big_endian "TranslateAddress" in
+  let startaddr = match addr_trans startaddr_internal with
+    | Some a, _ -> integer_of_address a
+    | None, Some i -> failwith ("Address translation failed with error code " ^ (Nat_big_num.to_string i))
+    | _ -> failwith "Neither an address or a code on translate address"
+  in
+  let initial_opcode = Opcode (List.map (fun b -> match b with
+      | Some b -> b
+      | None -> errorf "A byte in opcode contained unknown or undef"; exit 1)
+      (List.map byte_of_memory_byte
+         [Mem.find startaddr !prog_mem;
+          Mem.find (add1 startaddr) !prog_mem;
+          Mem.find (add1 (add1 startaddr)) !prog_mem;
+          Mem.find (add1 (add1 (add1 startaddr))) !prog_mem])) in
+  reg := Reg.add "PC" (register_value_of_address startaddr_internal model_reg_d ) !reg;
+  
+  (* entry point: unit -> unit fde *)
+  let name = Filename.basename !file in
+  let t = time_it (fun () -> fde_loop 0 context isa_model (Some Run) (ref false) initial_opcode addr_trans) () in
+  resultf "Execution time for file %s: %f seconds\n" name t;;
+
+run () ;;