From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752147Ab2JDJxW (ORCPT ); Thu, 4 Oct 2012 05:53:22 -0400 Received: from smtp.nue.novell.com ([195.135.221.5]:46356 "EHLO smtp.nue.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751713Ab2JDJxU (ORCPT ); Thu, 4 Oct 2012 05:53:20 -0400 Subject: Re: [PATCH] efi: add efivars kobject to efi sysfs folder From: joeyli To: Matt Fleming Cc: linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, glin@suse.com, Jeremy Kerr , Matthew Garrett , "H. Peter Anvin" , Peter Jones In-Reply-To: <1349340875.15966.18.camel@mfleming-mobl1.ger.corp.intel.com> References: <1349317486-30006-1-git-send-email-jlee@suse.com> <1349340875.15966.18.camel@mfleming-mobl1.ger.corp.intel.com> Content-Type: text/plain; charset="UTF-8" Date: Thu, 04 Oct 2012 17:46:24 +0800 Message-ID: <1349343984.24232.147.camel@linux-s257.site> Mime-Version: 1.0 X-Mailer: Evolution 2.28.2 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 於 四，2012-10-04 於 09:54 +0100，Matt Fleming 提到： > On Thu, 2012-10-04 at 10:24 +0800, Lee, Chun-Yi wrote: > > UEFI variable filesystem need a new mount point, so this patch add > > efivars kobject to efi_kobj for create a /sys/firmware/efi/efivars > > folder. > > > > Cc: Matt Fleming > > Cc: Jeremy Kerr > > Cc: Matthew Garrett > > Cc: H. Peter Anvin > > Signed-off-by: Lee, Chun-Yi > > --- > > drivers/firmware/efivars.c | 11 +++++++++++ > > include/linux/efi.h | 1 + > > 2 files changed, 12 insertions(+), 0 deletions(-) > > Actually, shouldn't the new filesystem be called "efivarfs", or "efifs" > to make it more explicit that it is a filesystem? I used "efivars" because this folder generated by efivars. But, I like your suggestion for use "efivarfs", it's better then "efivars". > > We also need something in Documentation/filesystems/ describing the old > EFI variable method, why it's no longer any good, and why the new > filesystem is favoured. Does anybody have anything to add to the > following? > > diff --git a/Documentation/filesystems/00-INDEX b/Documentation/filesystems/00-INDEX > index 8c624a1..ddf5a83 100644 > --- a/Documentation/filesystems/00-INDEX > +++ b/Documentation/filesystems/00-INDEX > @@ -38,6 +38,8 @@ dnotify_test.c > - example program for dnotify > ecryptfs.txt > - docs on eCryptfs: stacked cryptographic filesystem for Linux. > +efivars.txt > + - info for the efivars filesystem. > exofs.txt > - info, usage, mount options, design about EXOFS. > ext2.txt > diff --git a/Documentation/filesystems/efivars.txt b/Documentation/filesystems/efivars.txt > new file mode 100644 > index 0000000..4350c1a > --- /dev/null > +++ b/Documentation/filesystems/efivars.txt > @@ -0,0 +1,16 @@ > + > +efivars - a (U)EFI variable filesystem > + > +The efivars filesystem was created to address the shortcomings of > +using entries in sysfs to maintain EFI variables. The old sysfs EFI > +variables code only supported variables of up to 1024 bytes. This > +limitation existed in version 0.99 of the EFI specification, but was > +removed before any full releases. Since variables can now be larger > +than a single page, sysfs isn't the best interface for this. > + > +Variables can be created, deleted and modified with the efivars > +filesystem. > + > +The efivars filesystem is typically mounted like this, > + > + mount -t efivars none /sys/firmware/efi/efivars > The above documentation is really good! Thanks a lot! Joey Lee