Selection of STM32 startup file (determined by capacity)

         When writing a program for STM32, we need to add the startup file provided by the manufacturer to the project file (here we take the STMf10x series as an example), which contains the startup code. The startup code is a piece of assembly code related to the hardware. It is indispensable! The main functions of this code are as follows:

    1. Initialization of the stack (SP);

    2. Initialize the program counter (PC);

    3. Set the entry address of the vector table exception event;

    4. Call the main function.

    These are all preparations. It doesn’t matter if you don’t understand it at the moment. After all, the file is written in assembly language. . . . .

   Let's take a look at the three files provided by ST, which are used for STM32 chips of different capacities. These three files are:

     startup_stm32f10x_ld.s

     startup_stm32f10x_md.s

     startup_stm32f10x_hd.s

    Among them, ld.s is suitable for small-capacity products; md.s is suitable for medium-capacity products; hd.s is suitable for large-capacity products;

The capacity here refers to the size of FLASH. The judgment method is as follows:

    Small capacity: FLASH≤32K

    Medium capacity: 64K≤FLASH≤128K

    Large capacity: 256K≤FLASH

    In other words, you need to choose different startup files according to the size of your STM32 capacity, otherwise various errors will easily occur.