io: i really ought to be working on the ppu and apu by now

Signed-off-by: Amneesh Singh <natto@weirdnatto.in>

include/io/io.hh

@@ -0,0 +1,32 @@
+#pragma once
+#include "lcd.hh"
+#include "sound.hh"
+#include <cstdint>
+
+namespace matar {
+class IoDevices {
+  public:
+    uint8_t read_byte(uint32_t) const;
+    void write_byte(uint32_t, uint8_t);
+
+    uint32_t read_word(uint32_t) const;
+    void write_word(uint32_t, uint32_t);
+
+    uint16_t read_halfword(uint32_t) const;
+    void write_halfword(uint32_t, uint16_t);
+
+  private:
+    struct {
+        using u16 = uint16_t;
+        bool post_boot_flag;
+        bool interrupt_master_enabler;
+        u16 interrupt_enable;
+        u16 interrupt_request_flags;
+        u16 waitstate_control;
+        bool low_power_mode;
+    } system = {};
+
+    struct lcd lcd     = {};
+    struct sound sound = {};
+};
+}