Re: [Xen-devel] Xen Unikernel: from zero to Hello World!

[Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>]

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@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel