Make SerialICE work on new hardware

Though it is designed to be as generic as possible the SerialICE shell needs a little bit of hardware specific initialization code for each supported mainboard. There is one file per mainboard with this initialization code in the mainboard/ directory.

The purpose of the initialization code is to get the machine far enough to be able to talk via serial console. This usually requires setup of the Super I/O chip and some southbridge registers. In some cases extra work may have to be done, like disabling a power-on watchdog timer, enabling a fan(!), or enabling some devices "on the path to the Super I/O".

Here is some simple example:

/* Hardware specific functions */

#define PMBASE 0x100
#define TCOBASE 0x60
#define TCO1_CNT 0x08

static void southbridge_init(void)
{
        /* Prevent the TCO timer from rebooting */
        /* Set ACPI base address (I/O space). */
        pci_write_config32(PCI_ADDR(0, 0x1f, 0, 0x40), (PMBASE | 1));
        /* Enable ACPI I/O. */
        pci_write_config8(PCI_ADDR(0, 0x1f, 0, 0x44), 0x10);
        /* Halt the TCO timer, preventing SMI and automatic reboot */
        outw(inw(PMBASE + TCOBASE + TCO1_CNT) | (1 << 11),
             PMBASE + TCOBASE + TCO1_CNT);
}

static void superio_init(void)
{
        /* Enter the configuration state. */
        pnp_enter_ext_func_mode_alt(0x2e);

        /* COM A */
        pnp_set_logical_device(0x2e, 4);
        pnp_set_enable(0x2e, 0);
        pnp_set_iobase0(0x2e, 0x3f8);
        pnp_set_irq0(0x2e, 4);
        pnp_set_enable(0x2e, 1);

        /* Exit the configuration state. */
        pnp_exit_ext_func_mode(0x2e);
}

static void chipset_init(void)
{
        southbridge_init();
        superio_init();
}