From mboxrd@z Thu Jan  1 00:00:00 1970
Return-path: <barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org>
Received: from 3.mo1.mail-out.ovh.net ([46.105.60.232]
 helo=mo1.mail-out.ovh.net)
 by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux))
 id 1TtHOb-0002Nh-4b
 for barebox@lists.infradead.org; Thu, 10 Jan 2013 12:38:10 +0000
Received: from mail615.ha.ovh.net (gw6.ovh.net [213.251.189.206])
 by mo1.mail-out.ovh.net (Postfix) with SMTP id B08CEFF8772
 for <barebox@lists.infradead.org>; Thu, 10 Jan 2013 13:51:45 +0100 (CET)
Date: Thu, 10 Jan 2013 13:36:34 +0100
From: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Message-ID: <20130110123634.GB22953@game.jcrosoft.org>
References: <CAJfOKBzoXNvQu38qXXu9w9fyBuWqC_kAmHUqw2Z5B=8d9ymejg@mail.gmail.com>
MIME-Version: 1.0
Content-Disposition: inline
In-Reply-To: <CAJfOKBzoXNvQu38qXXu9w9fyBuWqC_kAmHUqw2Z5B=8d9ymejg@mail.gmail.com>
List-Id: <barebox.lists.infradead.org>
List-Unsubscribe: <http://lists.infradead.org/mailman/options/barebox>,
 <mailto:barebox-request@lists.infradead.org?subject=unsubscribe>
List-Archive: <http://lists.infradead.org/pipermail/barebox/>
List-Post: <mailto:barebox@lists.infradead.org>
List-Help: <mailto:barebox-request@lists.infradead.org?subject=help>
List-Subscribe: <http://lists.infradead.org/mailman/listinfo/barebox>,
 <mailto:barebox-request@lists.infradead.org?subject=subscribe>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Sender: barebox-bounces@lists.infradead.org
Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org
Subject: Re: GCC question
To: Franck Jullien <franck.jullien@gmail.com>
Cc: barebox <barebox@lists.infradead.org>

On 10:02 Wed 09 Jan     , Franck Jullien wrote:
> Hi,
> 
> I have a question not directly related to Barebox but I think I can
> find some answer here: )
> 
> I would like to use initcalls in a Linux user's land program on a x86 target.
> 
> I'm doing something like this:
> 
> #ifndef _INIT_H
> #define _INIT_H
> 
> typedef int (*initcall_t)(void);
> 
> extern initcall_t __start_target, __stop_target;
> 
> #define target_initcall(fn)	static initcall_t _##fn \
> 				__attribute__((used)) \
> 				__attribute__ ((section("target"))) = fn
> 
> #endif
> 
> then:
> 
> 	initcall_t *initcall;
> 
> 	for (initcall = &__start_target;
> 			initcall < &__stop_target; initcall++) {
> 		printf("initcall-> %p\n", *initcall);
> 		ret = (*initcall)();
> 		if (ret)
> 			printf("initcall %p failed: %d\n", *initcall, ret);
> 	}
> 
> Everything looks fine except the linker removes the function
> "initcalled" because it is not
> referenced anywhere and this is normal.
> 
> I have not modified the linker script (I'm using the default one). I'm
> using auto generated
> __start_target and __stop_target symbols generated by the linker.
> 
> My question is: why does it work in barebox ? For example, in
> nios2/generic.c we have only
> static function and initcalls. So why the linker does optimize out
> those functions ? Is it
> because we have initcall corresponding sections in the linker script ?
on userspace you can use directly the contructor

Best Regards,
J.

_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox