Add simple endianness supporting write function, and, for now, only one
shortcut helper, write16le().
Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx>
---
kms++util/inc/kms++util/endian.h | 46 ++++++++++++++++++++++++++++++++
1 file changed, 46 insertions(+)
create mode 100644 kms++util/inc/kms++util/endian.h
diff --git a/kms++util/inc/kms++util/endian.h b/kms++util/inc/kms++util/endian.h
new file mode 100644
index 0000000..ea09065
--- /dev/null
+++ b/kms++util/inc/kms++util/endian.h
@@ -0,0 +1,46 @@
+#pragma once
+
+#include <type_traits>
+#include <byteswap.h>
+#include <stdint.h>
+
+static_assert((__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) ||
+ (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__),
+ "Unable to detect endianness");
+
+enum class endian {
+ little = __ORDER_LITTLE_ENDIAN__,
+ big = __ORDER_BIG_ENDIAN__,
+ native = __BYTE_ORDER__
+};
+
+template<typename T>
+constexpr T byteswap(T value) noexcept
+{
+ static_assert(std::is_integral<T>(), "Type is not integral");
+ static_assert(sizeof(T) == 2 ||
+ sizeof(T) == 4 ||
+ sizeof(T) == 8,
+ "Illegal value size");
+
+ switch (sizeof(T)) {
+ case 2: return bswap_16(value);
+ case 4: return bswap_32(value);
+ case 8: return bswap_64(value);
+ }
+}
+
+template<endian E, typename T>
+static void write_endian(T val, T* dst)
+{
+ if constexpr (E != endian::native)
+ val = byteswap(val);
+
+ *dst = val;
+}
+
+[[maybe_unused]]
+static void write16le(uint16_t val, uint16_t* dst)
+{
+ write_endian<endian::little, uint16_t>(val, dst);
+}
--
2.34.1
