On Fri, May 23, 2014 at 11:54:27AM -0400, Vivek Goyal wrote: > On Fri, May 23, 2014 at 09:47:08AM -0400, Dave Young wrote: > > Hi, > > > > Vivek, replying with webmail, sorry for the formatting issue. > > > > Another way is export the mapping scheme in sysfs. So if kernel boot > > with efi=old_map we can detect it as well. OTOH in future there's probably > > other quirk system. > > > > So kexec-tools can switch to use old way if kernel use ioremap. > > Exporting type of mapping being used in current kernel and automatically > deciding that whether to boot with efi or noefi sounds reasonable to me. > I am assuming that once type of mapping got fixed in first kernel boot > it can't be changed in subsequent kernel boots? Right, 2nd kernel will continue to use the original mapping because we can only call the firmware function once to enter virtual mode. Thanks Dave
