DATA_DIR override with environment variable (#333)

src/altera.cpp

@@ -9,6 +9,7 @@
 
 #include <string>
 
+#include "common.hpp"
 #include "jtag.hpp"
 #include "device.hpp"
 #include "epcq.hpp"
@@ -181,12 +182,11 @@ bool Altera::load_bridge()
 			return false;
 		}
 
-		// DATA_DIR is defined at compile time.
-		bitname = DATA_DIR "/openFPGALoader/spiOverJtag_";
+		bitname = get_shell_env_var("OPENFPGALOADER_SOJ_DIR", DATA_DIR "/openFPGALoader");
 #ifdef HAS_ZLIB
-		bitname += _device_package + ".rbf.gz";
+		bitname += "/spiOverJtag_" + _device_package + ".rbf.gz";
 #else
-		bitname += _device_package + ".rbf";
+		bitname += "/spiOverJtag_" + _device_package + ".rbf";
 #endif
 	}
 

src/common.cpp

@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+ * Copyright (C) 2023 Gwenhael Goavec-Merou <[email protected]>
+ */
+
+
+#include "common.hpp"
+
+#include <string>
+#include <cstdlib>
+
+/*!
+ * \brief return shell environment variable value
+ * \param[in] key: variable name
+ * \return variable value or ""
+ */
+const std::string get_shell_env_var(const char* key,
+		const char *def_val) noexcept {
+	const char* ret = std::getenv(key);
+	return std::string(ret ? ret : def_val);
+}

src/common.hpp

@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+ * Copyright (C) 2023 Gwenhael Goavec-Merou <[email protected]>
+ */
+
+#ifndef SRC_COMMON_HPP_
+#define SRC_COMMON_HPP_
+
+#include <string>
+
+/*!
+ * \brief return shell environment variable value
+ * \param[in] key: variable name
+ * \param[in] def_val: value to return when not found
+ * \return variable value or def_val
+ */
+const std::string get_shell_env_var(const char* key,
+	const char *def_val="") noexcept;
+
+#endif  // SRC_COMMON_HPP_

src/xilinx.cpp

@@ -13,6 +13,7 @@
 
 #include "jtag.hpp"
 #include "bitparser.hpp"
+#include "common.hpp"
 #include "configBitstreamParser.hpp"
 #include "jedParser.hpp"
 #include "mcsParser.hpp"
@@ -468,9 +469,8 @@ bool Xilinx::load_bridge()
 			return false;
 		}
 
-		// DATA_DIR is defined at compile time.
-		bitname = DATA_DIR "/openFPGALoader/spiOverJtag_";
-		bitname += _device_package + ".bit.gz";
+		bitname = get_shell_env_var("OPENFPGALOADER_SOJ_DIR", DATA_DIR "/openFPGALoader");
+		bitname += "/spiOverJtag_" + _device_package + ".bit.gz";
 	}
 
 #if defined (_WIN64) || defined (_WIN32)