From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Brown Subject: Re: [PATCH] x86, eboot: Support initrd loaded above 4G Date: Tue, 15 Jul 2014 16:24:21 +0100 Message-ID: <53C547A5.3030500@fensystems.co.uk> References: <1402773821-15995-1-git-send-email-yinghai@kernel.org> <20140618142819.GN24049@console-pimps.org> <20140709182651.GB15932@console-pimps.org> <20140711074029.GD5952@console-pimps.org> <20140715151025.GB32039@console-pimps.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20140715151025.GB32039-HNK1S37rvNbeXh+fF434Mdi2O/JbrIOy@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Matt Fleming , Yinghai Lu Cc: Matt Fleming , "H. Peter Anvin" , Ingo Molnar , linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Linux Kernel Mailing List , Ard Biesheuvel , Leif Lindholm List-Id: linux-efi@vger.kernel.org On 15/07/14 16:10, Matt Fleming wrote: > Going forward, I suspect any attempts to use the EFI File Protocol are > going to result in this kind of breakage, and that the only thing that > can be relied upon is the Disk I/O Protocol. > > But doing Disk I/O would necessitate adding the in-kernel FAT driver to > the EFI boot stub, which is a scary idea (though not without merit). Booting via iPXE will give you an EFI_SIMPLE_FILE_SYSTEM_PROTOCOL (providing access to the initrd previously downloaded by iPXE). It will also give you a dummy disk I/O protocol which always return EFI_NO_MEDIA. In those circumstances, only the EFI_SIMPLE_FILE_SYSTEM_PROTOCOL will work. Michael