From d103f7adad9db03b0a13878ad9f80bd02b54b4c1 Mon Sep 17 00:00:00 2001 From: Stephen Glancy Date: Thu, 30 Aug 2018 15:54:28 -0500 Subject: Adds endian_swap to fapi2 Change-Id: Ie076098cd05ea0ae768d8da142df1b933ab7eb07 Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/65525 Dev-Ready: STEPHEN GLANCY Tested-by: Jenkins Server Tested-by: HWSV CI Tested-by: PPE CI Tested-by: Hostboot CI Reviewed-by: Louis Stermole Reviewed-by: ANDRE A. MARIN Reviewed-by: Matt K. Light Reviewed-by: Daniel M. Crowell Reviewed-by: Jennifer A. Stofer Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/65527 Tested-by: FSP CI Jenkins Reviewed-by: Sachin Gupta --- src/import/hwpf/fapi2/include/utils.H | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'src') diff --git a/src/import/hwpf/fapi2/include/utils.H b/src/import/hwpf/fapi2/include/utils.H index fcbde482..c45e410c 100644 --- a/src/import/hwpf/fapi2/include/utils.H +++ b/src/import/hwpf/fapi2/include/utils.H @@ -38,6 +38,33 @@ namespace fapi2 { + +/// +/// @brief Endian swapping +/// @tparam T input type +/// @param[in,out] io_input integral input +/// @note https://stackoverflow.com/questions/105252/how-do-i-convert-between-big-endian-and-little-endian-values-in-c +/// This function does not take into account the system's endianness, but just does the endian swap +/// +template < typename T > +void endian_swap(T& io_input) +{ + constexpr size_t MIN_BYTES = 2; + static_assert(sizeof(T) >= MIN_BYTES, "Byte swapping requires at least 2 bytes of data"); + + uint8_t* l_varArray = reinterpret_cast(&io_input); + + for(size_t i = 0; i < sizeof(io_input) / 2; i++) + { + const size_t BYTE_SWAP_INDEX = sizeof(io_input) - 1 - i; + + // Rolling our own swap as certain downstream libraries do not have std::swap enabled + const auto l_temp = l_varArray[BYTE_SWAP_INDEX]; + l_varArray[BYTE_SWAP_INDEX] = l_varArray[i]; + l_varArray[i] = l_temp; + } +} + #ifndef __PPE__ /// /// @brief Enable/Disable special wakeup on processor chip core(s) -- cgit v1.2.1