After playing around with this a bit, it might even be easier to 
register your IO port routines with the ISAPNP manager.  The ISAPNP 
manager could then add/remove them from the global IO port list as 
necessary:

    isapnp_register_ioport_write(c, 0, 16, 1, ne2000_ioport_write, s);
    isapnp_register_ioport_read(c, 0, 16, 1, ne2000_ioport_read, s);


Note that c is the ISAPNP context from below and 0 is the first bank of 
IO port registers.

Matt.

Matthew Mastracci wrote:

>I was looking at how much work it would take to switch to using ISA-PNP
>for resource management.  I believe that it might simplify some of the
>QEMU internals, as well as make things like having multiple
>network/other devices much easier.  It may make moving to PCI (or having
>an option to boot with either ISAPNP or PCI on the fly) much easier.
>
>For anyone interested, the ISAPNP spec page is at:
>
> http://osdev.neopages.net/docs/PNP-ISA-v1.0a.pdf?the_id=54
>
>I believe the best way to implement ISA-PNP would be for each device to
>register an ISA-PNP context, then add specific resource requirements to
>the context as necessary.  The ISAPNP manager would then interact with
>the operating system and call the isapnp_configure method whenever the
>OS changes the setup.
>
>Perhaps something like this.  I would imagine that the ISAPNP resource
>manager would clear the IO port range back to the default IO port
>manager before calling the *_isapnp_configure routine:
>
>static void ne2000_isapnp_configure(void* opaque, ISAPNPContext *c)
>{
>    /* Get the first IO port as the base IO address */
>    int base = isapnp_get_ioport(c, 0);
>
>    register_ioport_write(base, 16, 1, ne2000_ioport_write, s);
>    register_ioport_read(base, 16, 1, ne2000_ioport_read, s);
>
>    register_ioport_write(base + 0x10, 1, 1, ne2000_asic_ioport_write,
>s);
>    register_ioport_read(base + 0x10, 1, 1, ne2000_asic_ioport_read, s);
>    register_ioport_write(base + 0x10, 2, 2, ne2000_asic_ioport_write,
>s);
>    register_ioport_read(base + 0x10, 2, 2, ne2000_asic_ioport_read, s);
>
>    register_ioport_write(base + 0x1f, 1, 1, ne2000_reset_ioport_write,
>s);
>    register_ioport_read(base + 0x1f, 1, 1, ne2000_reset_ioport_read,
>s);
>
>    s->irq = isapnp_get_irq(c, 0);
>
>    /* Perhaps this would happen below... (?) */
>    ne2000_reset();
>}
>
>void ne2000_init(int base, int irq, NetDriverState *nd)
>{
>    ISAPNPContext *c;
>    /* KTC2000 is an ISAPNP vendor ID for an NE2000 compatible card */
>    /* No serial number specified here, ISAPNP manager can autogenerate
>it */
>    c = isapnp_create_context("KTC", 2000, ne2000_isapnp_configure, s);
>
>    /* Need an edge-triggered IRQ, default is irq */
>    isapnp_register_irq(IRQ_MODE_EDGE, irq);
>
>    /* Need a block of 32 IO ports, default is base */
>    isapnp_register_ioport(32, base);
>}
>  
>