[syslinux] non-standard (PCI) Serial port

Tue Jun 28 12:08:12 PDT 2016

 I'm trying to get isolinux serial port working on a system.  Using
 UEFI boot mode but system does not have Legacy Serial port (3f8, etc)
 enabled.  Serial port devices are PCI devices, memory mapped I/O with
 32-bit offset.  Using linux kernel command line
 console=uart8250,mmio32,xxxx,115200n8 works.  However I do not see
 syslinux/isolinux boot menu.

 Looking through the code it looks like syslinux assumes serial ports
 are I/O only and do not use EFI boot services Serial Port?