On Mon, Oct 06, 2008 at 09:24:03AM -0600, Bjorn Helgaas wrote: > The EFI Runtime Services Table contains pointers to ia64 function > descriptors. On existing, pre-Tiano, firmware, SetVirtualAddressMap() > converts *all* these pointers from physical to virtual. On Tiano-based > firmware, the pointer to the SetVirtualAddressMap() function descriptor > is not converted, so it remains a physical pointer. > > The ia64 kexec purgatory patches the SetVirtualAddressMap() function > descriptor so that when the new kernel calls SetVirtualAddressMap(), it > never reaches firmware. Instead, it calls a dummy function that just > returns success. > > Purgatory runs in physical mode, so it must convert the pointer from the > RuntimeServicesTable to a physical address. This patch makes that > conversion work both for old firmware (where the pointer is an identity- > mapped virtual address) and new Tiano firmware (where the pointer is a > physical address). > > Without this patch, kexec on Tiano firmware causes an MCA because > ia64_env_setup() subtracts PAGE_OFFSET from a physical address and ends > up with an invalid physical address. Referencing that address causes > the MCA. > > Signed-off-by: Bjorn Helgaas <bjorn.helgaas at hp.com> Thanks Bjorn, applied. -- Simon Horman VA Linux Systems Japan K.K., Sydney, Australia Satellite Office H: www.vergenet.net/~horms/ W: www.valinux.co.jp/en
