Building Marlin for STM32: Unsupported Platform! (no replies)

Hi,

I try to build git branch Marlin-bugfix-2.1.x for the STM32F103RE_creality
The Ender mainboard. Version 4.2.7.
Configurations-bugfix-2.1.x/config/examples/Creality/Ender-5/CrealityV427

But it does not want to build. With platformIO I get these error messages:

$ pio check
Checking STM32F103RE_creality > cppcheck (board: genericSTM32F103RE; platform: ststm32@~12.1)
Marlin/src/HAL/platforms.h:58: [high:error] #error Unsupported Platform! [preprocessorErrorDirective]

But there are STM32 in the list, so why doesn't it work?

With ArduinoIDE it crashes with strange library errors. Wrong version?
I tried u8glib-HAL 0.5.4, 0.5.3 and 0.5.2

Marlin-bugfix-2.1.x/Marlin/src/HAL/AVR/u8g_com_HAL_AVR_sw_spi.cpp: In function 'void u8g_com_arduino_init_shift_out(uint8_t, uint8_t)':
Marlin-bugfix-2.1.x/Marlin/src/HAL/AVR/u8g_com_HAL_AVR_sw_spi.cpp:71:15: error: cannot convert 'volatile uint32* {aka volatile long unsigned int*}' to 'volatile uint8_t* {aka volatile unsigned char*}' in assignment
   u8g_outData = portOutputRegister(digitalPinToPort(dataPin));
               ^
/media/DATEN/home/jan/Home/Build/Marlin-bugfix-2.1.x/Marlin/src/HAL/AVR/u8g_com_HAL_AVR_sw_spi.cpp:72:16: error: cannot convert 'volatile uint32* {aka volatile long unsigned int*}' to 'volatile uint8_t* {aka volatile unsigned char*}' in assignment
   u8g_outClock = portOutputRegister(digitalPinToPort(clockPin));
                ^
exit status 1
Compilation error: cannot convert 'volatile uint32* {aka volatile long unsigned int*}' to 'volatile uint8_t* {aka volatile unsigned char*}' in assignment

btw, how can I read the stock firmware from the board using avrdude?

thanks

JPT

PS: The forum documented it's 10 years since I fiddled with the MendelMax 2. Now I am back ;)