add endian helper

util/include/rusefi/endian.h

@@ -0,0 +1,95 @@
+#pragma once
+
+// http://en.wikipedia.org/wiki/Endianness
+
+#ifndef __BYTE_ORDER__
+	#error __BYTE_ORDER__ is not defined
+#endif
+
+#if defined(__BYTE_ORDER__)&&(__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
+	#define bigEndianHost true
+#endif
+#if defined(__BYTE_ORDER__)&&(__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
+	#define bigEndianHost false
+#endif
+
+/* TODO: already defined in efilib.h
+ * TODO: move here? */
+#if 0
+static inline uint16_t SWAP_UINT16(uint16_t x)
+{
+	return ((x << 8) | (x >> 8));
+}
+
+static inline uint32_t SWAP_UINT32(uint32_t x)
+{
+	return (((x >> 24) & 0x000000ff) | ((x <<  8) & 0x00ff0000) |
+			((x >>  8) & 0x0000ff00) | ((x << 24) & 0xff000000));
+}
+#endif
+
+template <typename T>
+class SwapEndian
+{
+	public:
+		struct IncompleteType;
+		SwapEndian() { }
+
+		constexpr operator typename std::conditional_t<sizeof(T) == 4, T, IncompleteType>() const {
+			return SWAP_UINT32(rep);
+		}
+
+		constexpr SwapEndian(std::conditional_t<sizeof(T) == 4, T, IncompleteType> val) {
+			rep = SWAP_UINT32(val);
+		}
+
+		constexpr operator typename std::conditional_t<sizeof(T) == 2, T, IncompleteType>() const {
+			return SWAP_UINT16(rep);
+		}
+
+		constexpr SwapEndian(std::conditional_t<sizeof(T) == 2, T, IncompleteType> val) {
+			rep = SWAP_UINT32(val);
+		}
+	private:
+		T rep;
+} __attribute__ ((packed));
+
+#if defined(__BYTE_ORDER__)&&(__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
+// Big endian storage types
+using beint16_t = SwapEndian<int16_t>;
+using beint32_t = SwapEndian<int32_t>;
+using beuint16_t = SwapEndian<uint16_t>;
+using beuint32_t = SwapEndian<uint32_t>;
+
+// Natine Little endian storage types
+using leint16_t = int16_t;
+using leint32_t = int32_t;
+using leuint16_t = uint16_t;
+using leuint32_t = uint32_t;
+#endif
+
+#if defined(__BYTE_ORDER__)&&(__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
+// Native Big endian storage types
+using beint16_t = int16_t;
+using beint32_t = int32_t;
+using beuint16_t = uint16_t;
+using beuint32_t = uint32_t;
+
+// Little endian storage types
+using leint16_t = SwapEndian<int16_t>;
+using leint32_t = SwapEndian<int32_t>;
+using leuint16_t = SwapEndian<uint16_t>;
+using leuint32_t = SwapEndian<uint32_t>;
+#endif
+
+//static_assert(sizeof(buint8_t) == 1);
+static_assert(sizeof(beint16_t) == 2);
+static_assert(sizeof(beint32_t) == 4);
+static_assert(sizeof(beuint16_t) == 2);
+static_assert(sizeof(beuint32_t) == 4);
+
+//static_assert(sizeof(luint8_t) == 1);
+static_assert(sizeof(leint16_t) == 2);
+static_assert(sizeof(leint32_t) == 4);
+static_assert(sizeof(leuint16_t) == 2);
+static_assert(sizeof(leuint32_t) == 4);