P16-1166 : Optionally disable default fw path

* Users can now disable the default firmware search path
  by setting the environment variable PIXIE_DISABLE_SYSTEM_FIRMWARE
  to a true value.

sdk/include/pixie/utils/string.hpp

@@ -140,6 +140,13 @@ bool check_number(const std::string& s);
  */
 bool check_number_range(const std::string& s);
 
+/**
+ * @brief Check if a string is an affirmative value.
+ * @param[in] s the string that we'll check.
+ * @return @true if the string is affirmative else @false
+ */
+bool check_affirmative(const std::string& s);
+
 /**
  * @brief Token editor splits a string by a token separator allowing
  * you to add, edit or remove tokens. You can export the list as a

sdk/src/pixie/fw.cpp

@@ -1340,8 +1340,18 @@ void load_system_firmwares(system& firmwares) {
     if (sys_fw_path_env != nullptr) {
         system_firmware_path = sys_fw_path_env;
     }
-    xia_log(log::info) << "firmware: system: loading from " << system_firmware_path;
-    load_firmwares(firmwares, system_firmware_path, true);
+    auto disable_sys_fw_env = std::getenv("PIXIE_DISABLE_SYSTEM_FIRMWARE");
+    bool disable_sys_fw = false;
+    if (disable_sys_fw_env != NULL) {
+        std::string s(disable_sys_fw_env);
+        disable_sys_fw = util::string::check_affirmative(s);
+    }
+    if (!disable_sys_fw) {
+        xia_log(log::info) << "firmware: system: loading from " << system_firmware_path;
+        load_firmwares(firmwares, system_firmware_path, true);
+    } else {
+        xia_log(log::info) << "firmware: system: disabled";
+    }
 }
 
 void load_firmwares(system& firmwares, const std::string path, bool ignore_error) {

sdk/src/pixie/utils/string.cpp

@@ -123,6 +123,12 @@ bool check_number_range(const std::string& s) {
     throw std::runtime_error("invalid range: " + s);
 }
 
+bool check_affirmative(const std::string& s) {
+    std::string e(s);
+    util::string::tolower(e);
+    return (e == "true" || e == "t" || e == "yes" || e == "y" || e == "1");
+}
+
 token_editor::token_editor(const std::string& str, char separator_, bool sort_)
     : separator(separator_), sorted(sort_) {
     set(str);