STM32G030F6P6_Evaluation/User/Main/Src/User_Main.cpp

extern "C"
{
#include "usart.h"
}

// 自定义函数入口
extern "C" void User_Main(void)
{
    HAL_UART_Transmit(&huart2, (const uint8_t *)"Hello world from C++ !!\r\n", 25, 1000);

    return;
}