Problems entering bootloader mode on STM32F072 with readout protection level 1.

[ECarm.1]

I'm developing firmware update for an application based on a STM32F072, using the built-in bootloader via UART1.

The method to enter bootloader is jump to Bootloader addres (as found on ST community discussions).

I managed to get Bootloader commands working with readout protection level 0 (for debugging); after setting RDP to level 1, the STM32 seems not to enter Bootloader mode any more: it seems being stuck in the loop waiting for boot interface selection, as I get no answer (neither 0x79 nor 0x1f) when sending 0x7f pattern on UART1 (user application not starting also).

Thanks in advance for any help.