The OS isn't running at all, so it cannot access the hardware.
Maybe there are some hardware registers which has to be written to (Find out which and what value if you want to access the LED :-P).

Yeah, I read it but I can't make use of that now, as we don't have any driver for the touchpd.
In nspire emus source I grepped "touchpad" and could only find GPIO 1 +3.
I'll search for that address.
But if the touchpad is connected to the GPIOs on the non-CX, you could test my git fork:
http://github.com/Vogtinator/linux (branch testing)

IRQ domain add legacy failed on boottime with a huge stack backtrace because of a warning on line 23, which gets shown if the irqs couldn't get reserved.
It still fails with nr_irqs 128..
But with irq_set_chained_handler  it seems to work but still crashes if I enable interrupts on GPIO 21. I"ll try both, like mach-at91/gpio.c.
If I regiser the chained handler for the timer int, /proc/interrupts shows
18: GPIO timer
and the system is VERY slow (what makes sense, but it still works).

Levak: Sadly useless.. Does still run in foreground. If I poll the touchpad the function returns after it has the data..

Edit 2: If I enable int's for GPIO21 (the floating one), the kernel hangs. No soft-lockup, hard-lockup.
What could be the reasons? For the other GPIOs it works fine (they're not changing).
irq = request_irq(controller->irq, nspire_gpio_irq, 0, "gpio", controller);

static irqreturn_t nspire_gpio_irq(int irq, void *data)
{
    uint8_t pin, port;
    uint16_t status_val;
    uint16_t __iomem *status = NSPIRE_GPIO(0, INT_MASKED_STATUS);
    for (port = 0; port < controller->chip.ngpio; port += 8) {
        status_val = readw(status);
        /* Ack interrupt */
        writew(0xFF, status + (NSPIRE_GPIO_INT_STATUS_OFFSET
        - NSPIRE_GPIO_INT_MASKED_STATUS_OFFSET));
        status += NSPIRE_GPIO_SECTION_SIZE;
        //if(!status_val)
            continue;
        //Rest cut out
    }
    return IRQ_HANDLED;
}
Do I have to do some other calls for registering my IRQ? I think request_irq should do it.

Well, of course i2c isn't still running in the background OS: You completely replaced it. Nothing is running in the background except what Linux knows to do

No, im reading the GPIO registers with a C program started with ndless.

Is there a driver for the i2c protocol implemented yet?

Yes, i2c-gpio.

Maybe we'll get lucky and find out the touchpad itself is already supported, and just the adapter needed a driver.

If not, I think the serial mouse driver in linux will be a good example and it will be easy to port it to i²c.
Could be a bit harder if it uses interrupts, tough.

I'm currently testing GPIOs with ndless. The binary (input) value of all ports toggles randomly between 0x59d00bf and 0x5bdoobf.
(Could also be periodically, sample rate is highest possible)
What is GPIO 21(0x020000)?
Also, the output value (0x80132d) doesn't vary at all. Isn't the touchpad connected to GPIOs 1 + 3?

Edit: Can I use GPIOs both as input and output? Example:
GPIO1 configured as output=HIGH, connected to ground through resistor.
Can I read input=LOW?

Edit2: With linux the gpio input still toggles randomly.
Should I implement an irq_chip for this? Directly setting, getting and changing direction are working. (At least the right values in the registers change)

Edit3: Could someone please test GPIOs? I don't know how.
http://dl.dropbox.com/u/105478372/zImagetest.tns
With useless i2c-gpio:
http://dl.dropbox.com/u/105478372/zImagetesti2c.tns

Is SZ_4K =1 because the size has to be in pages?
I'll change it, test it and send you a new patch.
Does X and directfb work on click and touchpads?
If not, you have to add cx_clcd_check to your classic clcd panel struct.

And what is in the second RAM?

There's the SRAM (flip-flops, fast) and the SDRAM (slow, has to be refreshed dynamically)

But how knows nClock the right time after any softreboot (linucx, chrash on calc etc.)?

I think it CAN be that linucx doesn't override that value in RAM, but that's random.
The ram doesn't get cleared by linux.

BTW: We should choose a new name, linucx is outdated and wrong. Maybe linspire?

You have to write it on a usb-stick using "dd if=rootfs.ext2 of=/dev/sdb".
Also, you are using the wrong image, the only images with X are my builds and I use only tar.bz2.

The ADC works perfectly with ndless, but not my linux kernel driver..
What am I doing wrong?
My changes in nspire_mmio.h:
#define NSPIRE_ADC_PHYS_BASE 0xC4000000
#define NSPIRE_ADC_SIZE 0x000001DF
#define NSPIRE_ADC_VIRT_BASE 0xfed7ee21 //0x1df before BOOT1
common.c:
struct map_desc nspire_io_regs[] __initdata = {
IOTABLE_ENTRY(ADC),
IOTABLE_ENTRY(APB),
IOTABLE_ENTRY(BOOT1),
IOTABLE_ENTRY(INTERRUPT),
};
Then im accessing it with:
adc[0] = readl(IOMEM(NSPIRE_ADC_VIRT_BASE + 0x110));What am I doing wrong?