6 files changed, 92 insertions, 6 deletions
diff --git a/host/lib/transport/nirio/CMakeLists.txt b/host/lib/transport/nirio/CMakeLists.txt
index 6a33da6c5..5f12e91df 100644
--- a/host/lib/transport/nirio/CMakeLists.txt
+++ b/host/lib/transport/nirio/CMakeLists.txt
@@ -39,10 +39,8 @@ LIBUHD_APPEND_SOURCES(
 
 IF(WIN32)
     LIBUHD_APPEND_SOURCES(${CMAKE_CURRENT_SOURCE_DIR}/nirio_driver_iface_win.cpp)
-ELSE(WIN32)
-    IF(APPLE)
-        LIBUHD_APPEND_SOURCES(${CMAKE_CURRENT_SOURCE_DIR}/nirio_driver_iface_macos.cpp)
-    ELSE(APPLE)
-        LIBUHD_APPEND_SOURCES(${CMAKE_CURRENT_SOURCE_DIR}/nirio_driver_iface_linux.cpp)
-    ENDIF(APPLE)
+ELSEIF(${CMAKE_SYSTEM_NAME} STREQUAL "Linux") #Built-in variable encompasses all UNIX-like systems
+    LIBUHD_APPEND_SOURCES(${CMAKE_CURRENT_SOURCE_DIR}/nirio_driver_iface_linux.cpp)
+ELSE()
+    LIBUHD_APPEND_SOURCES(${CMAKE_CURRENT_SOURCE_DIR}/nirio_driver_iface_unsupported.cpp)
 ENDIF(WIN32)
diff --git a/host/lib/transport/nirio/nifpga_lvbitx.cpp b/host/lib/transport/nirio/nifpga_lvbitx.cpp
index 289a44d4a..b87d87a8d 100644
--- a/host/lib/transport/nirio/nifpga_lvbitx.cpp
+++ b/host/lib/transport/nirio/nifpga_lvbitx.cpp
@@ -16,6 +16,7 @@
 //
 
 #include <uhd/transport/nirio/nifpga_lvbitx.h>
+#include <cstdlib>
 #include <string>
 #include <iostream>
 #include <fstream>
@@ -109,6 +110,21 @@ std::string nifpga_lvbitx::_get_fpga_images_dir(const std::string search_paths)
     std::vector<std::string> search_path_vtr;
     boost::split(search_path_vtr, search_paths, boost::is_any_of(","));
 
+    //
+    // Add the value of the UHD_IMAGES_DIR environment variable to the list of
+    // directories searched for a LVBITX image.
+    //
+    char* uhd_images_dir;
+#ifdef UHD_PLATFORM_WIN32
+    size_t len;
+    errno_t err = _dupenv_s(&uhd_images_dir, &len, "UHD_IMAGES_DIR");
+    if(not err and uhd_images_dir != NULL) search_path_vtr.push_back(std::string(uhd_images_dir));
+    free(uhd_images_dir);
+#else
+    uhd_images_dir = getenv("UHD_IMAGES_DIR");
+    if(uhd_images_dir != NULL) search_path_vtr.push_back(std::string(uhd_images_dir));
+#endif
+
     std::string lvbitx_dir;
     //Traverse through the list of search paths. Priority: lexical
     BOOST_FOREACH(std::string& search_path, search_path_vtr) {
diff --git a/host/lib/transport/nirio/nirio_driver_iface_macos.cpp b/host/lib/transport/nirio/nirio_driver_iface_unsupported.cpp
index 1a1142525..1a1142525 100644
--- a/host/lib/transport/nirio/nirio_driver_iface_macos.cpp
+++ b/host/lib/transport/nirio/nirio_driver_iface_unsupported.cpp
diff --git a/host/lib/transport/nirio/niriok_proxy.cpp b/host/lib/transport/nirio/niriok_proxy.cpp
index 031623c9a..ac8faf0a4 100644
--- a/host/lib/transport/nirio/niriok_proxy.cpp
+++ b/host/lib/transport/nirio/niriok_proxy.cpp
@@ -293,6 +293,16 @@ namespace uhd { namespace niusrprio
     {
         return nirio_driver_iface::rio_munmap(map);
     }
+
+    nirio_status niriok_proxy::stop_all_fifos()
+    {
+        nirio_driver_iface::nirio_syncop_in_params_t in = {};
+        nirio_driver_iface::nirio_syncop_out_params_t out = {};
+
+        in.function = nirio_driver_iface::NIRIO_FUNC::FIFO_STOP_ALL;
+
+        return sync_operation(&in, sizeof(in), &out, sizeof(out));
+    }
 }}
 
 #ifdef __GNUC__
diff --git a/host/lib/transport/nirio/niusrprio_session.cpp b/host/lib/transport/nirio/niusrprio_session.cpp
index a07bc4fdf..97d764736 100644
--- a/host/lib/transport/nirio/niusrprio_session.cpp
+++ b/host/lib/transport/nirio/niusrprio_session.cpp
@@ -77,6 +77,8 @@ nirio_status niusrprio_session::open(
         std::string lvbitx_checksum(_lvbitx->get_bitstream_checksum());
         boost::uint16_t download_fpga = (force_download || (_read_bitstream_checksum() != lvbitx_checksum)) ? 1 : 0;
 
+        nirio_status_chain(_ensure_fpga_ready(), status);
+
         nirio_status_chain(_rpc_client.niusrprio_open_session(
             _resource_name, bitfile_path, signature, download_fpga), status);
         _session_open = nirio_status_not_fatal(status);
@@ -196,4 +198,59 @@ nirio_status niusrprio_session::_write_bitstream_checksum(const std::string& che
     return status;
 }
 
+nirio_status niusrprio_session::_ensure_fpga_ready()
+{
+    nirio_status status = NiRio_Status_Success;
+    niriok_scoped_addr_space(_riok_proxy, BUS_INTERFACE, status);
+
+    //Verify that the Ettus FPGA loaded in the device. This may not be true if the
+    //user is switching to UHD after using LabVIEW FPGA. In that case skip this check.
+    boost::uint32_t pcie_fpga_signature = 0;
+    nirio_status_chain(_riok_proxy.peek(FPGA_PCIE_SIG_REG, pcie_fpga_signature), status);
+    //@TODO: Remove X300 specific constants for future products
+    if (pcie_fpga_signature != FPGA_X3xx_SIG_VALUE) {
+        return status;
+    }
+
+    boost::uint32_t reg_data = 0xffffffff;
+    nirio_status_chain(_riok_proxy.peek(FPGA_STATUS_REG, reg_data), status);
+    if (nirio_status_not_fatal(status) && (reg_data & FPGA_STATUS_DMA_ACTIVE_MASK))
+    {
+        //In case this session was re-initialized *immediately* after the previous
+        //there is a small chance that the server is still finishing up cleaning up
+        //the DMA FIFOs. We currently don't have any feedback from the driver regarding
+        //this state so just wait.
+        boost::this_thread::sleep(boost::posix_time::milliseconds(FPGA_READY_TIMEOUT_IN_MS));
+
+        //Disable all FIFOs in the FPGA
+        for (size_t i = 0; i < _lvbitx->get_input_fifo_count(); i++) {
+            _riok_proxy.poke(PCIE_RX_DMA_REG(DMA_CTRL_STATUS_REG, i), DMA_CTRL_DISABLED);
+        }
+        for (size_t i = 0; i < _lvbitx->get_output_fifo_count(); i++) {
+            _riok_proxy.poke(PCIE_TX_DMA_REG(DMA_CTRL_STATUS_REG, i), DMA_CTRL_DISABLED);
+        }
+
+        //Disable all FIFOs in the kernel driver
+        _riok_proxy.stop_all_fifos();
+
+        boost::posix_time::ptime start_time = boost::posix_time::microsec_clock::local_time();
+        boost::posix_time::time_duration elapsed;
+        do {
+            boost::this_thread::sleep(boost::posix_time::milliseconds(10)); //Avoid flooding the bus
+            elapsed = boost::posix_time::microsec_clock::local_time() - start_time;
+            nirio_status_chain(_riok_proxy.peek(FPGA_STATUS_REG, reg_data), status);
+        } while (
+            nirio_status_not_fatal(status) &&
+            (reg_data & FPGA_STATUS_DMA_ACTIVE_MASK) &&
+            elapsed.total_milliseconds() < FPGA_READY_TIMEOUT_IN_MS);
+
+        nirio_status_chain(_riok_proxy.peek(FPGA_STATUS_REG, reg_data), status);
+        if (nirio_status_not_fatal(status) && (reg_data & FPGA_STATUS_DMA_ACTIVE_MASK)) {
+            return NiRio_Status_FifoReserved;
+        }
+    }
+
+    return status;
+}
+
 }}
diff --git a/host/lib/transport/nirio/rpc/rpc_client.cpp b/host/lib/transport/nirio/rpc/rpc_client.cpp
index f8dc26b50..0c4b8fe3c 100644
--- a/host/lib/transport/nirio/rpc/rpc_client.cpp
+++ b/host/lib/transport/nirio/rpc/rpc_client.cpp
@@ -104,6 +104,11 @@ rpc_client::rpc_client (
     } catch (boost::exception&) {
         UHD_LOG << "rpc_client connection request cancelled/aborted." << std::endl;
         _exec_err.assign(boost::asio::error::connection_aborted, boost::asio::error::get_system_category());
+#if BOOST_VERSION < 104700
+    } catch (std::exception& e) {
+        UHD_LOG << "rpc_client connection error: " << e.what() << std::endl;
+        _exec_err.assign(boost::asio::error::connection_aborted, boost::asio::error::get_system_category());
+#endif
     }
 }