console: add user console daemon

This adds a first draft of systemd-consoled. This is still missing a lot
of features and does some rather primitive rendering. However, it shows
the direction this code is going and serves as basis for further testing.

The systemd-consoled binary should be run as `systemd --user' unit. It
automatically picks up any session marked as Desktop=SYSTEMD-CONSOLE.
Therefore, you can use any login-manager you want (ranging from /bin/login
to gdm) to create sessions for systemd-consoled. However, the sessions
managers must be prepared to set the Desktop= variable properly.

The user-session is called `systemd-console', only the daemon providing
the terminal environment is called `systemd-consoled' (mind the 'd').

So far, only a single terminal session is provided on each opened
user-session. However, we support multiple user-sessions (even across
multiple seats) just fine. In the future, the workspace logic will get
extended so you can have multiple terminal sessions in a single
user-session for easier access.

Note that this is still experimental! Instructions on how to run it will
follow shortly.

1 files changed, 82 insertions, 0 deletions

diff --git a/src/console/consoled-display.c b/src/console/consoled-display.c
new file mode 100644
index 0000000000..a30a2f1022
--- /dev/null
+++ b/src/console/consoled-display.c
@@ -0,0 +1,82 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2014 David Herrmann <dh.herrmann@gmail.com>
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <inttypes.h>
+#include <stdlib.h>
+#include "consoled.h"
+#include "grdev.h"
+#include "list.h"
+#include "macro.h"
+#include "util.h"
+
+int display_new(Display **out, Session *s, grdev_display *display) {
+        _cleanup_(display_freep) Display *d = NULL;
+
+        assert(out);
+        assert(s);
+        assert(display);
+
+        d = new0(Display, 1);
+        if (!d)
+                return -ENOMEM;
+
+        d->session = s;
+        d->grdev = display;
+        d->width = grdev_display_get_width(display);
+        d->height = grdev_display_get_height(display);
+        LIST_PREPEND(displays_by_session, d->session->display_list, d);
+
+        grdev_display_enable(display);
+
+        *out = d;
+        d = NULL;
+        return 0;
+}
+
+Display *display_free(Display *d) {
+        if (!d)
+                return NULL;
+
+        LIST_REMOVE(displays_by_session, d->session->display_list, d);
+        free(d);
+
+        return NULL;
+}
+
+void display_refresh(Display *d) {
+        assert(d);
+
+        d->width = grdev_display_get_width(d->grdev);
+        d->height = grdev_display_get_height(d->grdev);
+}
+
+void display_render(Display *d, Workspace *w) {
+        const grdev_display_target *target;
+
+        assert(d);
+        assert(w);
+
+        GRDEV_DISPLAY_FOREACH_TARGET(d->grdev, target) {
+                if (workspace_draw(w, target))
+                        grdev_display_flip_target(d->grdev, target);
+        }
+}