does sercon-port support for memory mapped MMIO 32bit address?

[Gerd Hoffmann]

Hi,
> But I can't turn on the  sercon port for boot menu. Seems that address for
>    sercon is u16, only take 16bit address. I use 16bit serial port address
>    for coreboot 0x3e8, it is not working.
>
> How to turn on MMIO serial console for boot menu?

Not supported right now.  Needs non-trivial changes, sercon code might
have to switch to 32bit mode for mmio access, the registers are
out-of-reach in real mode.

cheers,
  Gerd