Moved 'build.board' property generation out of legacy package

Author: cmaglie

arduino/cores/packagemanager/package_manager.go

@@ -359,6 +359,13 @@ func (pme *Explorer) ResolveFQBN(fqbn *cores.FQBN) (
 	}
 	buildProperties.Set("runtime.os", properties.GetOSSuffix())
 	buildProperties.Set("build.library_discovery_phase", "0")
+
+	if buildProperties.Get("build.board") == "" {
+		architecture := board.PlatformRelease.Platform.Architecture
+		defaultBuildBoard := strings.ToUpper(architecture + "_" + board.BoardID)
+		buildProperties.Set("build.board", defaultBuildBoard)
+	}
+
 	// Deprecated properties
 	buildProperties.Set("tools.avrdude.path", "{runtime.tools.avrdude.path}")
 	buildProperties.Set("ide_version", "10607")

legacy/builder/target_board_resolver.go

@@ -50,12 +50,9 @@ func (s *TargetBoardResolver) Run(ctx *types.Context) error {
 		ctx.Info("")
 	}
 
-	if buildProperties.Get("build.board") == "" {
-		architecture := targetBoard.PlatformRelease.Platform.Architecture
-		defaultBuildBoard := strings.ToUpper(architecture + "_" + targetBoard.BoardID)
-		buildProperties.Set("build.board", defaultBuildBoard)
+	if !targetBoard.Properties.ContainsKey("build.board") {
 		ctx.Info(tr("Warning: Board %[1]s doesn't define a %[2]s preference. Auto-set to: %[3]s",
-			targetBoard.String(), "'build.board'", defaultBuildBoard))
+			targetBoard.String(), "'build.board'", buildProperties.Get("build.board")))
 	}
 
 	requiredTools, err := ctx.PackageManager.FindToolsRequiredForBuild(targetPlatform, buildPlatform)