Implement VGA simulation

1 files changed, 52 insertions, 4 deletions

diff --git a/tb/avalon.hpp b/tb/avalon.hpp
index a00ced0..8134677 100644
--- a/tb/avalon.hpp
+++ b/tb/avalon.hpp
@@ -1,7 +1,9 @@
-#ifndef AVALON_HPP
-#define AVALON_HPP
+#ifndef TALLER_AVALON_HPP
+#define TALLER_AVALON_HPP
 
+#include <cassert>
 #include <cstdint>
+#include <cstdio>
 #include <vector>
 
 namespace taller::avalon
@@ -9,11 +11,57 @@ namespace taller::avalon
 	class slave
 	{
 		public:
-			virtual std::uint32_t base_address() noexcept = 0;
-			virtual std::uint32_t address_mask() noexcept = 0;
+			inline slave(std::uint32_t base, std::uint32_t size, std::size_t word_size)
+			: base(base),
+			  mask(~(size - 1)),
+			  word(log2i(word_size))
+			{
+				assert(!((word_size - 1) & word_size));
+				assert(!(base & word_mask()) && !(size & word_mask()) && !((size - 1) & size));
+			}
+
+			inline std::uint32_t base_address() noexcept
+			{
+				return base;
+			}
+
+			inline std::uint32_t address_mask() noexcept
+			{
+				return mask;
+			}
+
+			inline std::uint32_t word_mask() noexcept
+			{
+				return (1 << word) - 1;
+			}
+
+			inline std::size_t word_size() noexcept
+			{
+				return 1 << word;
+			}
+
+			inline unsigned word_bits() noexcept
+			{
+				return word;
+			}
+
+			inline std::uint32_t address_span() noexcept
+			{
+				return ~mask + 1;
+			}
 
 			virtual bool read(std::uint32_t addr, std::uint32_t &data) = 0;
 			virtual bool write(std::uint32_t addr, std::uint32_t data, unsigned byte_enable) = 0;
+
+		private:
+			std::uint32_t base;
+			std::uint32_t mask;
+			unsigned      word;
+
+			static inline int log2i(int i)
+			{
+		    	return sizeof(int) * 8 - __builtin_clz(i) - 1;
+			}
 	};
 
 	template<class Platform>