From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [PATCH 1/2] lib: Add early cpio decoder Date: Tue, 04 Sep 2012 10:00:09 -0700 Message-ID: <50463399.70506@zytor.com> References: <1346318957-5831-1-git-send-email-trenn@suse.de> <1346318957-5831-2-git-send-email-trenn@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1346318957-5831-2-git-send-email-trenn-l3A5Bk7waGM@public.gmane.org> Sender: initramfs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Thomas Renninger Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, lenb-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, robert.moore-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, Fenghua Yu , initramfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, bigeasy-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, vojcek-wYtBgQxc//8@public.gmane.org, eric.piel-VkQ1JFuSMpfAbQlEx87xDw@public.gmane.org, linux-acpi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, yinghai-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, "H. Peter Anvin" List-Id: linux-acpi@vger.kernel.org On 08/30/2012 02:29 AM, Thomas Renninger wrote: > From: "H. Peter Anvin" > > Add a simple cpio decoder without library dependencies for the purpose > of extracting components from the initramfs blob for early kernel > uses. Intended consumers so far are microcode and ACPI override. > > Signed-off-by: H. Peter Anvin > CC: Thomas Renninger > Link: http://lkml.kernel.org/r/201203261651.29640.trenn-l3A5Bk7waGM@public.gmane.org > Signed-off-by: Thomas Renninger I was trying to figure out if there is a way to do what you want (support for multiple files) without the problems of the callback interface. I think it is actually fairly straightforward; we need a prefix iterator (so you can give it a string like "kernel/acpi/" rather than a full filename) and it needs to be able to accept a "last" pointer so it can resume scanning at the point it last left off. That should be a pretty trivial change. The other thing we presumably want to do -- and this is generic -- is to be able to handle multiple sources for the initramfs; at the very least there is built in vs provided from the boot loader. I had originally intended to just handle that by calling the earlycpio function once per block, but the "last left off" bit makes that a little harder. Need to think about that a little bit. I am guessing that this may not need to be something we need from the very beginning, or am I wrong? -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.