I'm working with a somewhat dated kernel (2.4.2+patches) and have discovered that there are problems with physical memory that does not map into KSEG0/KSEG1. I looked over the list archives (manually, I couldn't find a search interface) and it appears that this is still the case for current kernels (at least as of a note from last summer, the last time the issue seems to have come up.) Obviously, phys_to_virt() is going to be a problem but besides this I'm wondering what anybody may have done to support physical memory that is not always mapped into the virtual address space, so that I don't have to reinvent the wheel. When I tell the kernel about the memory above 0x20000000, userland fails to start; the kernel gets as far as execve()'ing init, but nothing happens (interrupts are enabled; I get echo on the console, but nothing from userland). Thanks, Kevin --