Using STM8S's own BootLoader_1

This article will record in detail how to use the STM8S built-in BootLoader to implement program updates.

Preparation: 

1. ST support document UM0560 (explains how to use BootLoader) 

2. ST official download software STMFlashLoader Demo.exe 

3. IAR Embedded Workbench 、ST Visual Programmer 

4. 2 STM8S105K6, used to implement the update operation.

Practical operation: 

1. 使用STVP -> OPTION BYTE -> ROP ->Read Out Protection OFF 

STVP -> OPTION BYTE -> BOOTLOADER ENABLE ->BootLoader Enable 

This article only records how to use BootLoader. If read protection is enabled, it is not discussed in this article (UM0560 mentions how to deal with it). Why these two bytes of option words need to be processed is explained in UM0560. If you do not do this, you cannot enter the BootLoader program. After the MCU is reset, if it detects that these two option bytes do not match, it will jump to the user application area 0x8000 address.

Additional notes: 

Enable BootLoader to use library functions to write byte option words.

FLASH_Unlock(FLASH_MEMTYPE_DATA);       //解锁Flash

FLASH_ProgramOptionByte(0x487E, 0x55); //Enable BootLoader

FLASH_Lock(FLASH_MEMTYPE_DATA); //Lock Flash and write code here

Read protection cannot be written using library functions.

Use UART to communicate with PC 

Open STMFlashLoader Demo.exe on the PC and connect the serial port. 

Within 1 second after the MCU is reset, click Next. 

If you cannot enter the interface above, check from 3 aspects: 

1. Step 1, whether the two-byte option word has been configured. 

2. Are the serial port TX and RX connected correctly? 

3. Is the MCU power supply normal? 

Select the MCU density capacity, which corresponds to the firmware version 1.3, which is read from the Boot area by the host computer. Click Next.

Next, enter the erase, download, and update interface. I won’t say much about erase, you will understand what it means after you operate it. Updata means reading the MCU program and saving it as a file. Let’s focus on the download operation. 

Before downloading, you need to execute label 1. The key point here is label 2, do not load the HEX file. If the HEX file is loaded, label 3 cannot be operated and the write address cannot be selected. The reason is that the HEX file itself contains the write address information, so it cannot be changed. In IAR, you can edit OPTION and select Generate Bin file. Only after the Bin file is generated can you select the address. 

The address I choose here is 0xA000, which is determined by the developer. APP1.bin contains the firmware information to be updated, that is, the program to be copied to the target board slave.

At this point, the BootLoader has completed half of its task. The next article will describe how the host MCU shakes hands with the slave, and then how the host updates the slave's program.

When I was operating, I was thinking about how to put the firmware and application programs into the host's flash separately. I went to various forums for help but didn't get a satisfactory answer. I accidentally loaded a Bin file and the problem was solved. I wrote it down specially, hoping to help people with the same confusion.