How does the ide driver loads ?

I`m trying to connect an ide harddisk to an embedded arm board. I
called the ide_register_hw() from my device driver, but after this not
much seem to happen in the kernel.

I wonder what the boot sequence is, when is the actual IDE hardware
being used for the first time ( f.i. reading the disk boot sector ) is
this already when the driver is called or does this happen later after
kernel startup ?

Any help or explanation on this subject would be welcome.

Best regards,

    Marcel G