I have a standard PC104 rs232 serial card stacked on my Arcom Viper
PC104 SBC (single-board-computer) via the PC104 bus. Problem is I am
unable to access it like a normal serial port even though I configure
a serial device using setserial.

What I know:
- the Intel XScale PXA255 locates the second PCMCIA slot @ physical
address 0x30000000
- the linux kernel source maps the above physical address to virtual
address 0xf1000000 in arch/arm/mach-pxa/viper.c
- the Arcom Viper (physically) attaches the PC104 bus to the second
PCMCIA slot and we know that PC104 is really an ISA bus
- my PC104 serial card can select from irqs 3-7 and all the standard
COM ports up to COM8 (0x3f8, 0x2f8, ..., 0x2a0) via jumpers
- this platform (ARM) maps ISA irqs to different processor irqs. for
example, on bootup I'll see indicators which map ISA irq 7 to irq 108

What I thought would work:
- a simple setserial command with the virtual address of the PC104
bus + selected_port_on_serial_card with the mapped_irq on a standard
ttyS# device would allow me to use that device just like a normal
serial port. for example, if jumpers on the serial card selected port
0x2a8 (COM6) and (ISA) irq 7 (which maps to cpu irq 108), I would use:

# setserial /dev/ttyS1 port 0xf10002a8 irq 108 uart 16550a

This command returns instantly and the settings are in fact reflected,
but it's not really communicating with the port. A simple `echo 123 > /
dev/ttyS1` seems to hang for about 10 seconds before returning to the
shell.

What am I doing wrong? I have verified that the mapping takes place
during kernel init (arch/arm/mach-pxa/viper.c and generic.c). But if
Iwere to cat /proc/iomem the whole 0x30000000 block is excluded as if
it isn't mapped.

I think that if I can get the (physical) 0x30000000 range to show up
in /proc/iomem, that my other problems would be solved. How can I get
it to show up? Perhaps making a module (which I've never done)?

Thanks for any help.