On Thu, Oct 18, 2012 at 08:56:34AM -0600, Khalid Aziz wrote: > On Thu, 2012-10-18 at 11:10 +0800, Dave Young wrote: > > In case efi booting, kdump need kernel parameter acpi_rsdp= to retrieve > > the acpi root table physical address. > > > > Add a function cmdline_add_efi to get the address from /sys/firmware/efi/systab > > If there's no such file or read fail the function will just do nothing. > > > > Tested efi boot Fedora 17 on thinkpad T420. > > > > Some background info for this issue: > > http://lists.infradead.org/pipermail/kexec/2010-March/003889.html > > > > [v1 -> v2]: > > Address comments from Khalid and Simon > > use fgets instead of read(2) to iterate the file > > do not add 'noefi' because kexec does not construct EFI signature > > in bootloader signature in boot_params, so kexec'd kernel will > > disable EFI automatically even without noefi. > > > > Signed-off-by: Dave Young <dyoung at redhat.com> > > --- > > kexec/arch/i386/crashdump-x86.c | 35 +++++++++++++++++++++++++++++++++++ > > 1 file changed, 35 insertions(+) > > > Looks good. > > Reviewed-by: Khalid Aziz <khalid at gonehiking.org> Khalid/Dave, Last time khalid mentioned that we are currently taking normal boot path in second kernel and that's why things are working even without "noefi"? If that's the case, then we don't need "acpi_rsdp" also? In normal boot path we used to just pass acpi memmap ranges in e820 map and second kernel could find those. So now I am full confused that howcome we require acpi_rsdp but not "noefi". This UEFI thing is a mess. We need to sort it out. I am primarily interested in making sure kdump works well with UEFI systems as more and more systems are going to adopt UEFI. Also this UEFI secure boot will make things very interesting. Now we can't trust the purgatory code prepared in user space. Thanks Vivek
