xen: use the hvc console infrastructure for Xen console

Implement a Xen back-end for hvc console.

* * *
Add early printk support via hvc console, enable using
"earlyprintk=xen" on the kernel command line.

From: Gerd Hoffmann <kraxel@suse.de>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Olof Johansson <olof@lixom.net>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index 97bd71bc3aea..9e8f21410d2d 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -604,6 +604,14 @@ config HVC_BEAT
         help
           Toshiba's Cell Reference Set Beat Console device driver
 
+config HVC_XEN
+        bool "Xen Hypervisor Console support"
+        depends on XEN
+        select HVC_DRIVER
+        default y
+        help
+          Xen virtual console device driver
+
 config HVCS
         tristate "IBM Hypervisor Virtual Console Server support"
         depends on PPC_PSERIES