From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: Xen Unikernel: from zero to Hello World! Date: Tue, 27 Oct 2015 15:59:35 -0400 Message-ID: <20151027195935.GD29620@l.oracle.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Carl Patenaude Poulin Cc: xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On Tue, Oct 27, 2015 at 03:42:19PM -0400, Carl Patenaude Poulin wrote: > Hi all, > > Thanks to Andrew Cooper's priceless help, I've managed to put > together a Xen PV kernel that does nothing except loop forever. I'm > going to try making it print "Hello, world!". > > I was hoping someone could fact-check my research. What I've dug up > is: > * I need to load my unikernel with `xl -c` to get console output. > * My kernel currently refuses to load with the `-c` option. From > what I've read online, this is because I need to implement a console > device driver, similar to Mini-OS's xencons_ring.c. /me nods. > * On Xen debug builds, I don't need a console device driver, I can > just do HYPERVISOR_console_io hypercalls. Right. > > What strategy would you use to debug this early in the development > process? Is there a debugger I should be using? You can use gdbsx - and then gdb. See http://www.slideshare.net/xen_com_mgr/from-printk-to-qemu-xenlinux-kernel-debugging slide 15. > > I'd appreciate any information and any links to information, even > when it's only tangentially relevant. > > Thanks in advance, > > Carl Patenaude Poulin > B Eng Software undergraduate at McGill University > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel