This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


Re: [Xen-devel] [Q] GRUB -> __start_xen?

To: xen-devel@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-devel] [Q] GRUB -> __start_xen?
From: Josh Triplett <josht@xxxxxxxxxx>
Date: Fri, 24 Jun 2005 11:54:32 -0700
Delivery-date: Fri, 24 Jun 2005 18:53:38 +0000
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <20050624182542.GC339769@xxxxxxxxxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <20050624182542.GC339769@xxxxxxxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
On Fri, 2005-06-24 at 14:25 -0400, Bharadwaj Yadavalli wrote:
> I am trying to understand the internals of Xen.
> On x86 (and may be other architectures), it appears to me 
> that xen's entry point is 
>          void __init __start_xen(multiboot_info_t *mbi)
> that lives in xeno-unstable.bk/xen/arch/x86/setup.c.
> 1. Who builds the structure mbi and calls __start_xen?

The Grub bootloader creates the structure, and calls a Xen startup
function defined in xen/arch/x86/boot/x86_32.S .  That assembly code
does some minimal setup and then calls the C startup function, passing
the structure pointer.

> 2. How is __satrt_xen registered as the entry point?

The Xen image booted by GRUB has a well-specified format which includes
the location of the entry point.

> Is there a place that I can read to understand the transfer
> of control from multiboot GRUB to xen's entry point?


- Josh Triplett

Xen-devel mailing list

<Prev in Thread] Current Thread [Next in Thread>