From c8b231d48a37b0ab0d0cc6a721826915ae778be3 Mon Sep 17 00:00:00 2001
From: Fabien Freling <public@ffreling.com>
Date: Wed, 20 May 2015 16:37:56 +0200
Subject: [PATCH] Add CPU instructions.

---
 src/cpu.ml | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/src/cpu.ml b/src/cpu.ml
index 6948b18..f67bf2a 100644
--- a/src/cpu.ml
+++ b/src/cpu.ml
@@ -112,6 +112,15 @@ let run cpu (mem: Memory.map) =
   let opcode = read_pc_byte cpu mem |> char_of_int in
 (*  Hexa.print_slice cartridge.full_rom cpu.reg.pc (cpu.reg.pc + 7); *)
   match opcode with
+
+  (* 8-bit load *)
+  (* LD   r,(HL) *)
+  | '\x7E' -> printf "  LD \tA, (HL)\n";
+              let hl = merge_bytes cpu.reg.l cpu.reg.h in
+              cpu.reg.a <- Memory.get mem hl;
+              inc_cycles cpu 8;
+
+
   | '\x00' -> printf "  NOP\n";
               inc_cycles cpu 4
 
@@ -172,6 +181,15 @@ let run cpu (mem: Memory.map) =
                 inc_cycles cpu 8
               end
 
+  | '\x34' -> printf "  INC \t(HL)\n";
+              let hl = merge_bytes cpu.reg.l cpu.reg.h in
+              let v = Memory.get mem hl |> int_of_char in
+              cpu.flag.z <- v + 1 = 0;
+              cpu.flag.n <- false;
+              cpu.flag.h <- v = 0b00001111;
+              Memory.set mem hl (char_of_int (v + 1));
+              inc_cycles cpu 12
+
 
   | '\x3E' -> let n = read_pc_byte cpu mem in
               printf "  LD \tA, 0x%02X\n" n;
@@ -200,6 +218,12 @@ let run cpu (mem: Memory.map) =
               Memory.set mem (0xFF00 + n) cpu.reg.a;
               inc_cycles cpu 12
 
+  | '\xEA' -> let addr = read_pc_2bytes cpu mem in
+              printf "  LD \t(0X%04X), A\n" addr;
+              Memory.set mem addr cpu.reg.a;
+              inc_cycles cpu 16
+
+
   | '\xF0' -> let n = read_pc_byte cpu mem in
               printf "  LDH \tA, (0xFF%02X)\n" n;
               cpu.reg.a <- Memory.get mem (0xFF00 + n);
@@ -214,5 +238,10 @@ let run cpu (mem: Memory.map) =
               cmp_A cpu n;
               inc_cycles cpu 8
 
+  | '\xFB' -> printf "  EI\n";
+              (* enable interrupts, IME=1 *)
+              inc_cycles cpu 4
+
   |  x -> eprintf "opcode 0x%02X\n" (int_of_char x);
+          eprintf "#cycles: %d\n" cpu.cycles;
           failwith "Unimplemented opcode."