port-cats/18026 cats fails to dump kernel core

Hi,

Just thought I'd let people know I've managed to dig into this one a bit.

The issue looks to be related to the memory map in some way.  When doing
the memory dump cats use DMA to do the transfers, having enabled dma
debugging and some pciide debugging, it seems that the hang probably
isn't a bug in the dma code, but something else.

Basically when the code attempts to dump the memory page at 0xB8000 the
system hangs.   It doesn't matter how big the DMAs are, if it's the
first page that we attempted to dump, it always hangs.

Searching google seems to show that 0xb8000 is a common address for vga
on x86.  I'm wondering if the M1543 chip has decided that address is
special (as it's a x86 southbridge) and gets itself confused, and hangs
the system.

Does anyone know if that's possible?

Thanks,
Chris