memory - Add bank device

Makeconf

@@ -3,6 +3,7 @@ modules := memory/device \
            memory/ram \
            memory/bootrom_overlay \
            memory/register \
+		   memory/bank \
            cpu/cpu \
            cpu/decoder
 

memory/bank.cpp

@@ -0,0 +1,44 @@
+#include <memory/bank.h>
+
+Bank::Bank()
+  : banks(), current_bank(nullptr)
+{}
+
+void Bank::addBank(u8 idx, Mem_device* dev)
+{
+  banks[idx] = dev;
+}
+
+void Bank::setBank(u8 idx)
+{
+  auto it = banks.find(idx);
+  if(it == banks.end())
+    current_bank = nullptr;
+  else
+    current_bank = it->second;
+}
+
+
+void Bank::write8(u16 addr, u8 data)
+{
+  if(current_bank == nullptr) return;
+  current_bank->write8(addr, data);
+}
+
+u8 Bank::read8(u16 addr)
+{
+  if(current_bank == nullptr) return 0xFFu;
+  return current_bank->read8(addr);
+}
+
+void Bank::write16(u16 addr, u16 data)
+{
+  if(current_bank == nullptr) return;
+  current_bank->write16(addr, data);
+}
+
+u16 Bank::read16(u16 addr)
+{
+  if(current_bank == nullptr) return 0xFFu;
+  return current_bank->read16(addr);
+}

memory/bank.h

@@ -0,0 +1,23 @@
+#pragma once
+
+#include <memory/device.h>
+
+#include <map>
+
+class Bank : public Mem_device {
+private:
+  Mem_device* current_bank;
+  std::map<u8, Mem_device*> banks;
+public:
+  Bank();
+
+  void addBank(u8 idx, Mem_device* dev);
+
+  void setBank(u8 bank);
+
+  void write8(u16 addr, u8 data);
+  u8 read8(u16 addr);
+
+  void write16(u16 addr, u16 data);
+  u16 read16(u16 addr);
+};