bus: send a weak ptr to io

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

include/bus.hh

@@ -2,41 +2,51 @@
 
 #include "header.hh"
 #include "io/io.hh"
+#include <memory>
 #include <optional>
 #include <span>
 #include <vector>
 
 namespace matar {
 class Bus {
+  private:
+    struct Private {
+        explicit Private() = default;
+    };
+
   public:
     static constexpr uint32_t BIOS_SIZE = 1024 * 16;
-    Bus(std::array<uint8_t, BIOS_SIZE>&& bios, std::vector<uint8_t>&& rom);
 
-    uint8_t read_byte(uint32_t address);
-    void write_byte(uint32_t address, uint8_t byte);
+    Bus(Private, std::array<uint8_t, BIOS_SIZE>&&, std::vector<uint8_t>&&);
 
-    uint16_t read_halfword(uint32_t address);
-    void write_halfword(uint32_t address, uint16_t halfword);
+    static std::shared_ptr<Bus> init(std::array<uint8_t, BIOS_SIZE>&&,
+                                     std::vector<uint8_t>&&);
 
-    uint32_t read_word(uint32_t address);
-    void write_word(uint32_t address, uint32_t word);
+    uint8_t read_byte(uint32_t);
+    void write_byte(uint32_t, uint8_t);
+
+    uint16_t read_halfword(uint32_t);
+    void write_halfword(uint32_t, uint16_t);
+
+    uint32_t read_word(uint32_t);
+    void write_word(uint32_t, uint32_t);
 
   private:
-    template<unsigned int N>
-    std::optional<std::span<const uint8_t>> read(uint32_t address) const;
+    template<unsigned int>
+    std::optional<std::span<const uint8_t>> read(uint32_t) const;
 
-    template<unsigned int N>
-    std::optional<std::span<uint8_t>> write(uint32_t address);
+    template<unsigned int>
+    std::optional<std::span<uint8_t>> write(uint32_t);
 
 #define MEMORY_REGION(name, start)                                             \
     static constexpr uint32_t name##_START = start;
 
 #define DECL_MEMORY(name, ident, start, end)                                   \
     MEMORY_REGION(name, start)                                                 \
-    std::array<uint8_t, end - start + 1> ident;
+    std::array<uint8_t, end - start + 1> ident = {};
 
     MEMORY_REGION(BIOS, 0x00000000)
-    std::array<uint8_t, BIOS_SIZE> bios;
+    std::array<uint8_t, BIOS_SIZE> bios = {};
 
     // board working RAM
     DECL_MEMORY(BOARD_WRAM, board_wram, 0x02000000, 0x0203FFFF)
@@ -61,9 +71,10 @@ class Bus {
 
 #undef MEMORY_REGION
     std::vector<uint8_t> rom;
+
+    std::unique_ptr<IoDevices> io;
+
     Header header;
     void parse_header();
-
-    IoDevices io;
 };
 }

include/cpu/cpu.hh

@@ -30,10 +30,10 @@ class Cpu {
     static constexpr uint8_t GPR_OLD_FIRST = 8;
 
     std::shared_ptr<Bus> bus;
-    std::array<uint32_t, GPR_COUNT> gpr; // general purpose registers
+    std::array<uint32_t, GPR_COUNT> gpr = {}; // general purpose registers
 
-    Psr cpsr; // current program status register
-    Psr spsr; // status program status register
+    Psr cpsr = {}; // current program status register
+    Psr spsr = {}; // status program status register
 
     static constexpr uint8_t SP_INDEX = 13;
     static_assert(SP_INDEX < GPR_COUNT);
@@ -56,7 +56,7 @@ class Cpu {
 
         // visible registers before the mode switch
         std::array<uint32_t, GPR_COUNT - GPR_OLD_FIRST - 1> old;
-    } gpr_banked; // banked general purpose registers
+    } gpr_banked = {}; // banked general purpose registers
 
     struct {
         Psr fiq;

include/io/io.hh

@@ -2,10 +2,14 @@
 #include "lcd.hh"
 #include "sound.hh"
 #include <cstdint>
+#include <memory>
 
 namespace matar {
+class Bus;
 class IoDevices {
   public:
+    IoDevices(std::weak_ptr<Bus>);
+
     uint8_t read_byte(uint32_t) const;
     void write_byte(uint32_t, uint8_t);
 
@@ -28,5 +32,7 @@ class IoDevices {
 
     struct lcd lcd     = {};
     struct sound sound = {};
+
+    std::weak_ptr<Bus> bus;
 };
 }