From 04fcb000a161362c15becc14ef037e9e69bf1e0e Mon Sep 17 00:00:00 2001
From: Alex Janka <alex@alexjanka.com>
Date: Mon, 13 Feb 2023 10:51:52 +1100
Subject: [PATCH] initial apu

---
 src/processor/apu.rs    | 7 +++++++
 src/processor/memory.rs | 7 ++++++-
 src/processor/mod.rs    | 5 ++++-
 3 files changed, 17 insertions(+), 2 deletions(-)
 create mode 100644 src/processor/apu.rs

diff --git a/src/processor/apu.rs b/src/processor/apu.rs
new file mode 100644
index 0000000..bb95584
--- /dev/null
+++ b/src/processor/apu.rs
@@ -0,0 +1,7 @@
+pub(super) struct Apu {}
+
+impl Apu {
+    pub(super) fn init() -> Self {
+        Self {}
+    }
+}
diff --git a/src/processor/memory.rs b/src/processor/memory.rs
index 7f058ae..1741309 100644
--- a/src/processor/memory.rs
+++ b/src/processor/memory.rs
@@ -101,6 +101,7 @@ pub struct Memory {
     io: [u8; 76],
     pub(super) user_mode: bool,
     joypad: Joypad,
+    pub(super) apu_enabled: bool,
 }
 
 impl Memory {
@@ -120,6 +121,7 @@ impl Memory {
             io: [0xFF; 76],
             user_mode: false,
             joypad: Joypad::default(),
+            apu_enabled: true,
         }
     }
 
@@ -227,7 +229,10 @@ impl Memory {
                 0xFF1C => self.masked_io(addr_l, data, 0b1100000),
                 0xFF20 => self.masked_io(addr_l, data, 0b111111),
                 0xFF23 => self.io[addr_l] = (self.io[addr_l] & 0b10111111) | (data & 0b01000000),
-                0xFF26 => self.io[addr_l] = (self.io[addr_l] & 0b1111111) | (data & 0b10000000),
+                0xFF26 => {
+                    self.io[addr_l] = (self.io[addr_l] & 0b1111111) | (data & 0b10000000);
+                    self.apu_enabled = self.io[addr_l] & 0b10000000 == 0b10000000
+                }
                 0xFF11 | 0xFF14 | 0xFF16 | 0xFF19 | 0xFF1E => {
                     // sound
                     self.io[addr_l] = data;
diff --git a/src/processor/mod.rs b/src/processor/mod.rs
index b064df3..8b7e615 100644
--- a/src/processor/mod.rs
+++ b/src/processor/mod.rs
@@ -1,4 +1,4 @@
-use self::{gpu::Gpu, memory::Memory, timer::Timers};
+use self::{apu::Apu, gpu::Gpu, memory::Memory, timer::Timers};
 use crate::{
     util::{clear_bit, get_bit},
     verbose_println,
@@ -6,6 +6,7 @@ use crate::{
 use gilrs::Gilrs;
 use minifb::Window;
 
+mod apu;
 pub mod gpu;
 mod instructions;
 pub mod memory;
@@ -35,6 +36,7 @@ pub struct Cpu {
     halted: bool,
     timers: Timers,
     gamepad_handler: Gilrs,
+    apu: Apu,
 }
 
 // Hz
@@ -62,6 +64,7 @@ impl Cpu {
             halted: false,
             timers: Timers::init(),
             gamepad_handler,
+            apu: Apu::init(),
         }
     }