make this work with cpp

firmware/CMakeLists.txt

@@ -3,6 +3,7 @@
 # The following five lines of boilerplate have to be in your project's
 # CMakeLists in this exact order for cmake to work correctly
 cmake_minimum_required(VERSION 3.16)
+set(CMAKE_CXX_STANDARD 17)
 
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
-project(bmw-keyboard)
+project(initial-v)

firmware/components/crc/include/bmw_crc.h

@@ -1,3 +1,11 @@
 #include <stdint.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 uint8_t crc8(uint8_t crc, uint8_t const *buf, uint32_t len);
+
+#ifdef __cplusplus
+}
+#endif

firmware/components/shifter/include/shifter.h

@@ -5,6 +5,10 @@
 #include <driver/twai.h>
 #include <bmw_crc.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 static inline bool
 SHIFTER_BACK_P(twai_message_t message)
 {
@@ -29,4 +33,8 @@ void shifter_send_drive(bool moveable);
 void shifter_send_reset(void);
 void shifter_send_light(uint8_t counter);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif

firmware/main/CMakeLists.txt

@@ -1,2 +1,2 @@
-idf_component_register(SRCS "bmw-keyboard.c"
+idf_component_register(SRCS "initial-v.cpp"
                     INCLUDE_DIRS ".")

firmware/main/initial-v.cpp

@@ -139,7 +139,7 @@ timer_callback(TimerHandle_t pxTimer)
     xQueueSend(tx_task_queue, &tx_action, portMAX_DELAY);
 }
 
-void app_main(void)
+extern "C" void app_main(void)
 {
     ctrl_task_sem = xSemaphoreCreateBinary();
     tx_task_queue = xQueueCreate(1, sizeof(tx_task_action_t));