From mboxrd@z Thu Jan  1 00:00:00 1970
From: ishare <june.tune.sea@gmail.com>
Subject: Re: how does ld.so call ELF's entry?
Date: Sun, 7 Apr 2013 12:52:07 +0800
Message-ID: <20130407045207.GE9617@debian.localdomain>
References: <20130407021921.GA9462@debian.localdomain>
 <CAN0_x-Je1=2mtN8tY2mvBa-X7_P0dBoG9KRh0P63uW91eE5H2Q@mail.gmail.com>
 <20130407033913.GB9617@debian.localdomain>
 <6107E321-5746-4245-8C42-0C4E589BEE4A@ymail.com>
 <20130407034554.GC9617@debian.localdomain>
 <CAN0_x-J_7VOhzezQhWBZNAPfbREtoOkk3yMcS3kLzL5XFD5cwg@mail.gmail.com>
Mime-Version: 1.0
Return-path: <linux-assembly-owner@vger.kernel.org>
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=gmail.com; s=20120113;
        h=x-received:date:from:to:cc:subject:message-id:references
         :mime-version:content-type:content-disposition:in-reply-to
         :user-agent;
        bh=nuQmIlw36uGGYMTi+bDCyEos0DHyWdWLPUN8KIgG67A=;
        b=QiWXRiQl0HhnMdndrwbJz2seiDZpjmdYfrdckY+JqBMHwQNJfFtaq3PTihlIdVkYgO
         iM5b9j7nEqg4A/0pnnL7pIMrzE32b8P4bgAc65IbrqQtAFalci/YVIINDz4Eqioc1c14
         dZtHkcC40Kf5fWZb/mWrfQUkMAOMAL/kawWmovOvKPlG/PJ8zFm15wBy8jNjphJWkWaB
         Tnt66/bFbvgwYdUwD6Yt5299JeWlqHPW0gOq8R4xn0dOowuv5tgS5ZGskBCzie7AX0qm
         Gvy3F4L4v4uiIddCa3jxHzdSUy9zOdeNRegdxLIMh2WPYUPrWyrn3+uPYsS8OPMZqaT4
         kflQ==
Content-Disposition: inline
In-Reply-To: <CAN0_x-J_7VOhzezQhWBZNAPfbREtoOkk3yMcS3kLzL5XFD5cwg@mail.gmail.com>
Sender: linux-assembly-owner@vger.kernel.org
List-ID: <linux-assembly.vger.kernel.org>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: Sofiane Akermoun <akersof@gmail.com>
Cc: linux-assembly@vger.kernel.org

On Sun, Apr 07, 2013 at 06:45:58AM +0200, Sofiane Akermoun wrote:
> EntryPoint is set in the ELF Header at assembling/linking time.

  how does the interpreter know this address?

> 
> 2013/4/7 ishare <june.tune.sea@gmail.com>:
> > On Sat, Apr 06, 2013 at 08:43:16PM -0700, Chris Evans wrote:
> >> With a far jump to entry offset
> >
> >   How does it know the entry point's address?
> >
> >>
> >>
> >> Sent from my iPad
> >>
> >> On Apr 6, 2013, at 8:39 PM, ishare <june.tune.sea@gmail.com> wrote:
> >>
> >> > On Sun, Apr 07, 2013 at 05:11:28AM +0200, Sofiane Akermoun wrote:
> >> >> Hello,
> >> >>
> >> >>
> >> >> The interpreter is specified during linking process and the program header
> >> >> of your binary is filled with good values.
> >> >> Then when the operating system load your binary, he finds next the
> >> >> interpreter to use.
> >> >> The linker ld sets the good values by default but you can overwrite it or
> >> >> specify other values if you want.
> >> >> The steps are:
> >> >> 1)The operating system loads your binary
> >> >> 2)The program loader system execute the Interpreter specifiy in the binary
> >> >> 3)The interpreter gather all the dynamic libraries needed in memory
> >> >
> >> >
> >> >> 4)The Control is passed to the entry point of your program
> >> >
> >> >  How does  the step 4 been  done ?
> >> >
> >> >  thanks!
> >> >>
> >> >> The entry point is specified in your code source as a "global". And could
> >> >> be find in your object file by the linker.
> >> >> In theory there are some default tag to specify entry point, like "..start"
> >> >> for nasm, but you can also passed it to the linker.
> >> >>
> >> >> regards,
> >> >>
> >> >> Sofiane Akermoun
> >> >> akersof@gmail.com
> >> >>
> >> >>
> >> >>
> >> >>
> >> >>
> >> >> 2013/4/7 ishare <june.tune.sea@gmail.com>
> >> >>
> >> >>>
> >> >>>  For an ELF ,which needs a interpreter , how is it  been called by the
> >> >>> interpreter ?
> >> >>>
> >> >>>  As I know the interpreter is loaded first and do something essential
> >> >>> ,then call the main routine of ELF .
> >> >>>  How is this procedure implemented ?
> >> >>>
> >> >>>  Thanks!
> >> >>> --
> >> >>> To unsubscribe from this list: send the line "unsubscribe linux-assembly"
> >> >>> in
> >> >>> the body of a message to majordomo@vger.kernel.org
> >> >>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >> >>
> >> >>
> >> >>
> >> >> --
> >> >> Sofiane AKERMOUN
> >> >> akersof@gmail.com
> >> > --
> >> > To unsubscribe from this list: send the line "unsubscribe linux-assembly" in
> >> > the body of a message to majordomo@vger.kernel.org
> >> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-assembly" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
> 
> 
> -- 
> Sofiane AKERMOUN
> akersof@gmail.com