[bug#35493] [PATCH 3/3] doc: Document 'display' and 'vt' fields of 'slim-configuration'.

[Diego Nicola Barbato]

>From a17223fd626d0039259053ff412fbe56c9cdc78c Mon Sep 17 00:00:00 2001
From: Diego Nicola Barbato <address@hidden>
Date: Sun, 28 Apr 2019 22:18:28 +0200
Subject: [PATCH 3/3] doc: Document 'display' and 'vt' fields of
 'slim-configuration'.

* doc/guix.texi (X Window): Mention 'display' and 'vt' fields of
  'slim-configuration' and explain how to use them to add multiple SLiM
  services to system services.
---
 doc/guix.texi | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/doc/guix.texi b/doc/guix.texi
index 4f43db3443..6ac76c18f6 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -13450,6 +13450,33 @@ This is the type for the SLiM graphical login manager 
for X11.
 Like GDM, SLiM looks for session types described by @file{.desktop} files and
 allows users to choose a session from the log-in screen using @kbd{F1}.  It
 also honors @file{~/.xsession} files.
+
+Unlike GDM, SLiM does not spawn the user session on a different VT after
+logging in, which means that you can only start one graphical session.  If you
+want to be able to run multiple graphical sessions at the same time you have
+to add multiple SLiM services to your system services.  The following example
+shows how to replace the default GDM service with two SLiM services on tty7
+and tty8.
+
address@hidden
+(use-modules (gnu services)
+             (gnu services desktop)
+             (gnu services xorg)
+             (srfi srfi-1))  ;for 'remove'
+
+(operating-system
+  ;; ...
+  (services (cons* (service slim-service-type (slim-configuration
+                                               (display ":0")
+                                               (vt "vt7")))
+                   (service slim-service-type (slim-configuration
+                                               (display ":1")
+                                               (vt "vt8")))
+                   (remove (lambda (service)
+                             (eq? (service-kind service) gdm-service-type))
+                           %desktop-services))))
address@hidden lisp
+
 @end defvr
 
 @deftp {Data Type} slim-configuration
@@ -13487,6 +13514,12 @@ false, you will be unable to log in.
 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
 Configuration of the Xorg graphical server.
 
address@hidden @code{display} (default @code{":0"})
+The display on which to start the Xorg graphical server.
+
address@hidden @code{vt} (default @code{"vt7"})
+The VT on which to start the Xorg graphical server.
+
 @item @code{xauth} (default: @code{xauth})
 The XAuth package to use.
 
-- 
2.21.0