I have a bunch of Blue Pill boards I'm re-animating (ye olde chippe shortage, y'know). Attacking them with stm32flash reports a flash size of 128 kBytes. On the other hand, 0x1FFFF7E0 contains 0x40, indicating 64 kBytes of flash as per ST's RM0008 reference manual.
Now, which of these is correct? if it's the former, how can the code running on the board discover that fact?