Thanks, Pasi.
I found out it about 7 hr ago and sent message to list.
"rhn_register" works just once and installs basic channel ( via server's session)
Afterwards one should login to rhn.redhat.com and change subscription
to "Optional"  inside account .

All your hackery works fine.
   I've also tried to rebuild Michael's xendom0  .32.25-172.src.rpm . It generates problem with kernel-firmware.rpm. I would not expect him to fix it , until CentOS 6.0 will be out.

Boris.
P.S. asciidoc dependency may be dropped during .32.25-172.src.rpm rebuild.

--- On Tue, 11/23/10, Pasi Kärkkäinen <pasik@iki.fi> wrote:

From: Pasi Kärkkäinen <pasik@iki.fi>
Subject: Re: [Xen-devel] Re: [Xen-users] [HOWTO] Running Xen 4.0 host (dom0) with Redhat Enterprise Linux 6 (RHEL6) xen fails to build
To: "Boris Derzhavets" <bderzhavets@yahoo.com>
Cc: "Michal Novotny" <minovotn@redhat.com>, "Digimer" <linux@alteeve.com>, xen-devel@lists.xensource.com, xen-users@lists.xensource.com
Date: Tuesday, November 23, 2010, 2:09 PM

On Tue, Nov 23, 2010 at 04:45:25AM -0800, Boris Derzhavets wrote:
>    It seems to be impossible reconnect to RHN to subscribe to optional
>    channel. During registration (30 days evaluation account) i was not given
>    any
>    option.
>

RHN channel subscriptions are changed from the RHN website,
not from the RHEL6 server..

So maybe that's the problem..

-- Pasi

>    Boris.
>
>    --- On Tue, 11/23/10, Michal Novotny <minovotn@redhat.com> wrote:
>
>      From: Michal Novotny <minovotn@redhat.com>
>      Subject: Re: [Xen-devel] Re: [Xen-users] [HOWTO] Running Xen 4.0 host
>      (dom0) with Redhat Enterprise Linux 6 (RHEL6) xen fails to build
>      To: "Boris Derzhavets" <bderzhavets@yahoo.com>
>      Cc: "Pasi Kärkkäinen" <pasik@iki.fi>, "Digimer" <linux@alteeve.com>,
>      xen-devel@lists.xensource.com, xen-users@lists.xensource.com
>      Date: Tuesday, November 23, 2010, 7:35 AM
>
>      If you're subscribed into Optional channel (and maybe some other channel
>      too) in RHN you should be able to download and install them using yum,
>      i.e.
>
>      # yum install texi2html dev86 pciutils-devel iasl
>
>      command. After that you should be able to recompile. In RHEL-6
>      environment you can always try either to google for the package or,
>      better, use `yum install` command to install the dependencies required.
>
>      Michal
>
>      On 11/23/2010 01:24 PM, Boris Derzhavets wrote:
>      > In meantime :-
>      >
>      > [root@Server6RH SPECS]# rpmbuild -bb ./xen.spec
>      > error: Failed build dependencies:
>      >     texi2html is needed by xen-4.0.1-6.el6.x86_64
>      >     dev86 is needed by xen-4.0.1-6.el6.x86_64
>      >     pciutils-devel is needed by xen-4.0.1-6.el6.x86_64
>      >     iasl is needed by xen-4.0.1-6.el6.x86_64
>      >
>      >
>      > Boris.
>      >
>      >
>      >
>      > _______________________________________________
>      > Xen-devel mailing list
>      > [1]Xen-devel@lists.xensource.com
>      > [2]http://lists.xensource.com/xen-devel
>
>      --
>      Michal Novotny<[3]minovotn@redhat.com>, RHCE
>      Virtualization Team (xen userspace), Red Hat
>
> References
>
>    Visible links
>    1. file:///mc/compose?to=Xen-devel@lists.xensource.com
>    2. http://lists.xensource.com/xen-devel
>    3. file:///mc/compose?to=minovotn@redhat.com