switching to dfu without reset

[Ron]

Hi,

My system needs to maintain certain gpio at their state at all times, including when switching to bootloader,

I understand that reset will also return my gpios to input mode,

Is there a solution ? 

Maybe a way to switch to dfu/bootloader without reset ?

I would appreciate some insights/ideas/examples on this issue

Thanks

Eran

[Dmitry]

I don't know your schematics, but why external pull-up is not an option? When MCU is powered up, your pin will be tied to power line (I mean output of the regulator, not battery) through a pull-up all the time, and you can switch off by setting GPIO to 0.

[Ron]

Definitely an option, but we already have the hardware,,, 

Why is it such a "perilous" thing to do ?

I would appreciate your insights

Eran