Move C++ tree into firmware/

.gitignore

@@ -1 +1 @@
-build
+firmware/build

cmd/load/main.go

@@ -17,7 +17,7 @@ func main() {
 		fmt.Fprintf(os.Stderr, "error: %v\n", err)
 		os.Exit(1)
 	}
-	buildDir := filepath.Join(wd, "build")
+	buildDir := filepath.Join(wd, "firmware", "build")
 
 	if err := run(buildDir); err != nil {
 		fmt.Fprintf(os.Stderr, "error: %v\n", err)
@@ -27,7 +27,7 @@ func main() {
 
 func run(buildDir string) error {
 	fmt.Println("Configuring...")
-	cmake := exec.Command("cmake", "-B", buildDir)
+	cmake := exec.Command("cmake", "-S", filepath.Join(filepath.Dir(buildDir)), "-B", buildDir)
 	cmake.Stdout = os.Stdout
 	cmake.Stderr = os.Stderr
 	if err := cmake.Run(); err != nil {