Kernel: Implement basic MMIO functions

This is equivalent to IO.h except for memory mapped io instead of
IO ports

kernel/include/kernel/MMIO.h

@@ -0,0 +1,49 @@
+#pragma once
+
+#include <stdint.h>
+#include <stddef.h>
+
+namespace MMIO
+{
+
+	static inline void write8(uintptr_t addr, uint8_t val)
+	{
+		*(volatile uint8_t*)addr = val;
+	}
+
+	static inline void write16(uintptr_t addr, uint16_t val)
+	{
+		*(volatile uint16_t*)addr = val;
+	}
+
+	static inline void write32(uintptr_t addr, uint32_t val)
+	{
+		*(volatile uint32_t*)addr = val;
+	}
+
+	static inline void write64(uintptr_t addr, uint64_t val)
+	{
+		*(volatile uint64_t*)addr = val;
+	}
+
+	static inline uint8_t read8(uintptr_t addr)
+	{
+		return *(volatile uint8_t*)addr;
+	}
+
+	static inline uint16_t read16(uintptr_t addr)
+	{
+		return *(volatile uint16_t*)addr;
+	}
+
+	static inline uint32_t read32(uintptr_t addr)
+	{
+		return *(volatile uint32_t*)addr;
+	}
+
+	static inline uint64_t read64(uintptr_t addr)
+	{
+		return *(volatile uint64_t*)addr;
+	}
+
+}