From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933001AbXHDSwY (ORCPT ); Sat, 4 Aug 2007 14:52:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1765195AbXHDSwO (ORCPT ); Sat, 4 Aug 2007 14:52:14 -0400 Received: from an-out-0708.google.com ([209.85.132.245]:21964 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1765107AbXHDSwO (ORCPT ); Sat, 4 Aug 2007 14:52:14 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=Wy7hfTFvo6crMPjG3BPMQbnHQjqYTZ5ss86/rGdh3mVO7VCQ14s0w/DOkKfvTqAwH/lnDBU6XwtS/MzcL68p3adMZdvCYJEbhdriPSEACAk9LJQ7usbyngHTt3bHWikzWJYv+enFBIJ4y5uvwFH04ZI5QWVWsUm1g6OgD2mdLS0= Message-ID: <9a8748490708041152g2ae1b8cag2a42ee6909ce8ee5@mail.gmail.com> Date: Sat, 4 Aug 2007 20:52:12 +0200 From: "Jesper Juhl" To: "Rob Landley" Subject: Re: [PATCH] Documentation/make/headers_install.txt Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, "David Woodhouse" In-Reply-To: <200708041307.18578.rob@landley.net> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200708041307.18578.rob@landley.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 04/08/07, Rob Landley wrote: > From: Rob Landley > > Signed-off-by: Rob Landley > > Some documentation for "make headers_install". > > --- > > Earlier discussion was at http://lkml.org/lkml/2007/6/22/7 and I > believe I've responded to all of David's comments. > > --- /dev/null 2007-04-23 10:59:00.000000000 -0500 > +++ linux-2.6/Documentation/make/headers_install.txt 2007-08-04 13:04:51.000000000 -0500 > @@ -0,0 +1,46 @@ > +Exporting kernel headers for use by userspace > +============================================= > + > +The "make headers_install" command exports the kernel's header files in a > +form suitable for use by userspace programs. > + > +The linux kernel's exported header files describe the API for user space > +programs attempting to use kernel services. These kernel header files are > +used by the system's C library (such as glibc or uClibc) to define available > +system calls, as well as constants and structures to be used with these > +system calls. The C library's header files include the kernel header files > +from the "linux" subdirectory. The system's libc headers are usually > +installed at the default location /usr/include and the kernel headers in > +subdirectories under that (most notably /usr/include/linux and > +/usr/include/asm). > + > +Kernel headers are backwards compatible, but not forwards compatible. This Perhaps change the text "are backwards compatible" into "try very hard to be backwards compatible" ... ? > +means that a program built against a C library using older kernel headers > +should run on a newer kernel (although it may not have access to new > +features), but a program built against newer kernel headers may not work on an > +older kernel. > + > +The "make headers_install" command can be run in the top level directory of the > +kernel source code (or using a standard out-of-tree build). It takes two > +optional arguments: > + > + make headers_install ARCH=i386 INSTALL_HDR_PATH=/usr/include > + > +ARCH indicates which architecture to produce headers for, and defaults to the > +current architecture. The linux/asm directory of the exported kernel headers > +is platform-specific, to see a complete list of supported architectures use > +the command: how about s/"the command"/"the following command from inside a kernel source tree"/ ? > + > + ls -d include/asm-* | sed 's/.*-//' > + > +INSTALL_HDR_PATH indicates where to install the headers. It defaults to > +"./usr/include". > + > +The command "make headers_install_all" exports headers for all architectures > +simultaneously. (This is mostly of interest to distribution maintainers, > +who create an architecture-independent tarball from the resulting include > +directory.) Remember to provide the appropriate linux/asm directory via "mv" > +or "ln -s" before building a C library with headers exported this way. > + > +The kernel header export infrastructure is maintained by David Woodhouse > +. > Overall, looks good. Acked by: Jesper Juhl -- Jesper Juhl Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html Plain text mails only, please http://www.expita.com/nomime.html