From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: EFI mode after running kexec Date: Thu, 29 Aug 2013 12:15:43 -0700 Message-ID: <20130829191543.GA11624@kroah.com> References: <20130829022632.GA26862@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Josh Boyer Cc: "linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-efi@vger.kernel.org On Thu, Aug 29, 2013 at 08:18:39AM -0400, Josh Boyer wrote: > On Wed, Aug 28, 2013 at 10:26 PM, Greg KH wrote: > > Hi all, > > > > I've been messing with UEFI booting a kernel and then later on, using > > kexec to boot another kernel, and noticed that the kexec'ed kernel is > > not really in EFI mode, although the EFI framebuffer seems present and > > able to be used. > > > > Is this to be expected? I'd think that the EFI framebuffer wouldn't be > > around anymore. Odds are this is a BIOS bug, given that the machine I'm > > using is a really old UEFI mode (i.e. before secure boot mode ever > > showed up), but should it work this way? > > AFAIK, it's to be expected at this point. kexec doesn't work as it > should with UEFI. How "should" it work? It seems to boot a kernel just fine, although not in EFI mode, which makes sense (I had forgotten about the BootServices stuff.) > I believe Matthew and/or Matt can elaborate further, but it has to do > with only being able to call ExitBootServices once and providing > mappings to the UEFI Runtime services functions. That makes sense. thanks, greg k-h