STM32F09x, when upon power-on reset it's FLASH is empty (which is a bit of an overstatement, it acutally checks only if 0x08000000 is 0xFFFFFFFF), it behaves as if BOOT0 is 1, i.e. maps system memory onto 0x00000000 and starts there. So far so good, it's described in RM0091 rev.9 in Empty check subchapter.
Note at the end of this subchapter says:
If the device is programmed for a first time but the Option bytes are not reloaded, the device
will still select System memory as a boot area after a System reset. The boot loader code is able to detect this situation and will change the boot memory mapping to Main Flash and perform a jump to user code programmed there.
I've just programmed a new STM32F091 and after any reset except power-on reset, it always went to bootloader and remained there; in other words, the last sentence above is not true.
Can ST please comment.
Thanks,
JW
