I have been unable to boot my CoreExpress Atom Z530 based board from flash, because my 2.6.31.6 kernel does not seem to have support for the (US15W chipset) IDE controller configured. I have read many web links that point to CONFIG_PATA_SCH as the key, but that does not work for me.

I _can_ boot RedHat 2.6.18-164.e15 which does not have CONFIG_PATA_SCH configured, but I believe they are using initrd.
The board manufacturer, Lippert, suggested CONFIG_ATA_PIIX and CONFIG_ATA_GENERIC as well. Neither helped.

Thanks in advance
MS

What makes you think the US15W is the cause ?.
And what does "unable to boot" mean - exactly ?. Do you get a boot menu, can you select anything, any messages.
Nothing (and I mean *nothing*) at all maybe ?.

What I burn onto the CF contains a RedHat kernel image, and a 2.6.31.6 kernel. I do see both from the Grub menu. If I select Redhat, I believe the initrd file provides support for the IDE controller that lets me see the CF and therefore the RedHat image, and I boot that successfully.
On the other hand, the 2.6.31.6 kernel doesn't seem to see the CF and therefore never sees the boot image. It ends up failing when it assumes the kernel image must be on the network somewhere.
I am not an expert on the initrd file, but I believe this will be my key and I am pursuing information on how those are created and used.

Could you, please, show your grub configuration, which is used to load 2.6.31 kernel. Is there on your CF an initrd file for this kernel?

Thanks for your interest guys, but I am losing this board today so I'll have to end this thread.