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Add Cpu.read_pc_byte

master
Fabien Freling 2015-03-25 16:19:54 +01:00
parent f72d8ece56
commit 5789fe145f
1 changed files with 42 additions and 26 deletions
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68
src/cpu.ml
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@ -93,15 +93,23 @@ let cmp_A cpu n =
cpu.flag.c <- diff > 0xFF || diff < 0;
update_flag_reg cpu
let read_pc_byte cpu mem =
let b = Memory.get mem cpu.reg.pc in
inc_pc cpu 1;
int_of_char b
let read_pc_2bytes cpu mem =
let word = read_2B mem cpu.reg.pc in
inc_pc cpu 2;
word
(**
http://imrannazar.com/GameBoy-Z80-Opcode-Map
https://github.com/sinamas/gambatte/blob/master/libgambatte/src/cpu.cpp
*)
let run cpu (mem: Memory.map) =
let opcode = Memory.get mem cpu.reg.pc in
inc_pc cpu 1;
let n = Memory.get mem cpu.reg.pc |> int_of_char in
let nn = Memory.get mem (cpu.reg.pc + 1) |> int_of_char in
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
| '\x00' -> printf " NOP\n";
@ -111,38 +119,43 @@ let run cpu (mem: Memory.map) =
inc_BC cpu;
inc_cycles cpu 8
| '\x18' -> printf " JP\t 0x%02X\n" n;
inc_pc cpu n; inc_cycles cpu 12
| '\x18' -> let n = read_pc_byte cpu mem in
printf " JP\t 0x%02X\n" n;
inc_pc cpu (n - 1); inc_cycles cpu 12
| '\x20' -> printf " JR\t NZ, 0x%02X\n" n;
| '\x20' -> let n = read_pc_byte cpu mem in
printf " JR\t NZ, 0x%02X\n" n;
if cpu.flag.z = false then
begin
inc_pc cpu n; inc_cycles cpu 12
inc_pc cpu (n - 1); inc_cycles cpu 12
end else
begin
inc_pc cpu 1; inc_cycles cpu 8
inc_cycles cpu 8
end
| '\x21' -> let addr = read_2B mem cpu.reg.pc in
printf " LD\t HL, 0x%04X\n" addr;
cpu.reg.h <- char_of_int nn;
cpu.reg.l <- char_of_int n;
| '\x21' -> let nn = read_pc_2bytes cpu mem in
printf " LD\t HL, 0x%04X\n" nn;
let high, low = split_2B nn in
cpu.reg.h <- high;
cpu.reg.l <- low;
inc_cycles cpu 12
| '\x28' -> printf " JR\t Z, 0x%02X\n" n;
| '\x28' -> let n = read_pc_byte cpu mem in
printf " JR\t Z, 0x%02X\n" n;
if cpu.flag.z = true then
begin
inc_pc cpu n; inc_cycles cpu 12
inc_pc cpu (n - 1); inc_cycles cpu 12
end else
begin
inc_pc cpu 1; inc_cycles cpu 8
inc_cycles cpu 8
end
| '\x3E' -> printf " LD \tA, 0x%02X\n" n;
cpu.reg.a <- char_of_int(n);
inc_pc cpu 1; inc_cycles cpu 8
| '\x3E' -> let n = read_pc_byte cpu mem in
printf " LD \tA, 0x%02X\n" n;
cpu.reg.a <- char_of_int n;
inc_cycles cpu 8
| '\xAF' -> printf " XOR \tA, A\n";
let int_A = int_of_char cpu.reg.a in
@ -157,25 +170,28 @@ let run cpu (mem: Memory.map) =
end else
inc_cycles cpu 8
| '\xC3' -> let addr = read_2B mem cpu.reg.pc in
| '\xC3' -> let addr = read_pc_2bytes cpu mem in
printf " JP \t0x%04X\n" addr;
cpu.reg.pc <- addr; inc_cycles cpu 16
| '\xE0' -> printf " LDH \t(0xFF%02X), A\n" n;
| '\xE0' -> let n = read_pc_byte cpu mem in
printf " LDH \t(0xFF%02X), A\n" n;
Memory.set mem (0xFF00 + n) cpu.reg.a;
inc_pc cpu 1; inc_cycles cpu 12
inc_cycles cpu 12
| '\xF0' -> printf " LDH \tA, (0xFF%02X)\n" n;
| '\xF0' -> let n = read_pc_byte cpu mem in
printf " LDH \tA, (0xFF%02X)\n" n;
cpu.reg.a <- Memory.get mem (0xFF00 + n);
inc_pc cpu 1; inc_cycles cpu 12
inc_cycles cpu 12
| '\xF3' -> printf " DI\n";
(* fixme *)
inc_cycles cpu 4
| '\xFE' -> printf " CP\t0x%02X\n" n;
| '\xFE' -> let n = read_pc_byte cpu mem in
printf " CP\t0x%02X\n" n;
cmp_A cpu n;
inc_pc cpu 1; inc_cycles cpu 8
inc_cycles cpu 8
| x -> eprintf "opcode 0x%02X\n" (int_of_char x);
failwith "Unimplemented opcode."