Making bootloader for STM32F427II

Hello, I have got a board with STM32F427II, instead of “classic” STM32F247VG. Difference is small - just more GPIO/ADC/SPI. So I thought that remaping of pins would make everything work, but I was wrong.

MCU Pins are here:

So I followed guide
Created new bootloader and tried to build new firmware with changed pins. I sucessfully flashed bootloader - I can see new COM-port, MP can flash firmware. But I cant see new comport when main firmware is loaded.

I forked latest master and commit my changes to code here:

I had to add new alternate functions to some pins, unlocked some pins in script and created new hwdef.dat file.

You should see that I commented some power flag pins, are they important?

Thank in advance.