Bootloader, FW upload on HEX Cube Black

Hello all.
I have got some questions. Somebody help me please!

My ‘HEX Cube Black(FMUv3)’ has 2 chips(STM32F427, STM32F100)
I understood like below.

Main Chip : STM32F427

  • Bootloader File : px4fmuv3_bl.bin
  • Firmware File : px4_fmu-v3.bin

IO Chip : STM32F100

  • Bootloader File : px4io_bl.bin
  • Firmware File : px4_io-v2.bin

Question 1
If my understanding is right,
How to upload ‘px4_io-v2.bin’ (STM32F100’s firmware) to on HEX Cube Black?

Question 2
If my understanding is wrong,
STM32F100 doesn’t need ‘px4_io-v2.bin’ (STM32F100’s firmware) ?

I hope to know more about PX4, even if it takes so long time.
Reply Please. Thank you all.