Thx, but this is obviously not the solution....
You changed everything to now only support the F4...

Didn't look at all the code changes, but your version seems to be a bit older:

• still uses rcc_peripheral_enable_clock instead of rcc_periph_clock_enable
• doesn't use desig_get_unique_id_as_string

See also #6

I know. But at this point I don't have resources to pursue the proper solution (and there "exists" a working MX bootloader), I at least wanted to share the code so somebody else can easily pick it up.