rpi: a backend for Raspberry Pi

Add a new backend for the Raspberry Pi.

This backend uses the DispmanX API to initialise the display, and create
an EGLSurface, so that GLESv2 rendering is shown on the "framebuffer".
No X server is involved. All compositing happens through GLESv2.

The created EGLSurface is specifically configured as buffer content
preserving, otherwise Weston wouuld show only the latest damage and
everything else was black. This may be sub-optimal, since we are not
alternating between two buffers, like the DRM backend is, and content
preserving may imply a fullscreen copy on each frame.

Page flips are not properly hooked up yet. The display update will
block, and we use a timer to call weston_output_finish_frame(), just
like the x11 backend does.

This backend handles the VT and tty just like the DRM backend does.
While VT switching works in theory, the display output seems to be
frozen while switched away from Weston. You can still switch back.

Seats and connectors cannot be explicitly specified, and multiple seats
are not expected.

Udev is used to find the input devices. Input devices are opened
directly, weston-launch is not supported at this time. You may need to
confirm that your pi user has access to input device nodes.

The Raspberry Pi backend is built by default. It can be build-tested
without the Raspberry Pi headers and libraries, because we provide stubs
in rpi-bcm-stubs.h, but such resulting binary is non-functional. If
using stubs, the backend is built but not installed.

VT and tty handling, and udev related code are pretty much copied from
the DRM backend, hence the copyrights. The rpi-bcm-stubs.h code is
copied from the headers on Raspberry Pi, including their copyright
notice, and modified.

Signed-off-by: Pekka Paalanen <ppaalanen@gmail.com>

configure.ac

@@ -128,6 +128,24 @@ if test x$enable_android_compositor = xyes; then
   PKG_CHECK_MODULES(ANDROID_COMPOSITOR, [mtdev >= 1.1.0])
 fi
 
+
+AC_ARG_ENABLE(rpi-compositor,
+	      AS_HELP_STRING([--disable-rpi-compositor],
+	                     [do not build the Raspberry Pi backend]),,
+	      enable_rpi_compositor=yes)
+AM_CONDITIONAL(ENABLE_RPI_COMPOSITOR, test "x$enable_rpi_compositor" = "xyes")
+have_bcm_host="no"
+if test x$enable_rpi_compositor = xyes; then
+  AC_DEFINE([BUILD_RPI_COMPOSITOR], [1], [Build the compositor for Raspberry Pi])
+  PKG_CHECK_MODULES(RPI_COMPOSITOR, [libudev >= 136 mtdev >= 1.1.0])
+  PKG_CHECK_MODULES(RPI_BCM_HOST, [bcm_host],
+                    [have_bcm_host="yes"
+                     AC_DEFINE([HAVE_BCM_HOST], [1], [have Raspberry Pi BCM headers])],
+                    [AC_MSG_WARN([Raspberry Pi BCM host libraries not found, will use stubs instead.])])
+fi
+AM_CONDITIONAL(INSTALL_RPI_COMPOSITOR, test "x$have_bcm_host" = "xyes")
+
+
 AC_ARG_WITH(cairo-glesv2,
             AS_HELP_STRING([--with-cairo-glesv2],
                            [Use GLESv2 cairo instead of full GL]))

src/Makefile.am

@@ -82,6 +82,12 @@ module_LTLIBRARIES =				\
 # The real backend is built by the Android build system.
 noinst_LTLIBRARIES = $(android_backend)
 
+if INSTALL_RPI_COMPOSITOR
+module_LTLIBRARIES += $(rpi_backend)
+else
+noinst_LTLIBRARIES += $(rpi_backend)
+endif
+
 if ENABLE_X11_COMPOSITOR
 x11_backend = x11-backend.la
 x11_backend_la_LDFLAGS = -module -avoid-version
@@ -145,6 +151,27 @@ android_backend_la_SOURCES =			\
 	android-framebuffer.h
 endif
 
+if ENABLE_RPI_COMPOSITOR
+rpi_backend = rpi-backend.la
+rpi_backend_la_LDFLAGS = -module -avoid-version
+rpi_backend_la_LIBADD = $(COMPOSITOR_LIBS)	\
+	$(RPI_COMPOSITOR_LIBS)			\
+	$(RPI_BCM_HOST_LIBS)			\
+	../shared/libshared.la
+rpi_backend_la_CFLAGS =				\
+	$(GCC_CFLAGS)				\
+	$(COMPOSITOR_CFLAGS)			\
+	$(RPI_COMPOSITOR_CFLAGS)		\
+	$(RPI_BCM_HOST_CFLAGS)
+rpi_backend_la_SOURCES =			\
+	compositor-rpi.c			\
+	rpi-bcm-stubs.h 			\
+	tty.c					\
+	evdev.c					\
+	evdev.h					\
+	evdev-touchpad.c
+endif
+
 if ENABLE_HEADLESS_COMPOSITOR
 headless_backend = headless-backend.la
 headless_backend_la_LDFLAGS = -module -avoid-version

src/compositor-rpi.c

@@ -0,0 +1,778 @@
+/*
+ * Copyright © 2008-2011 Kristian Høgsberg
+ * Copyright © 2011 Intel Corporation
+ * Copyright © 2012 Raspberry Pi Foundation
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and
+ * its documentation for any purpose is hereby granted without fee, provided
+ * that the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation, and that the name of the copyright holders not be used in
+ * advertising or publicity pertaining to distribution of the software
+ * without specific, written prior permission.  The copyright holders make
+ * no representations about the suitability of this software for any
+ * purpose.  It is provided "as is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+ * CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#define _GNU_SOURCE
+
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <math.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <libudev.h>
+
+#include "config.h"
+
+#ifdef HAVE_BCM_HOST
+#  include <bcm_host.h>
+#else
+#  include "rpi-bcm-stubs.h"
+#endif
+
+#include "compositor.h"
+#include "evdev.h"
+
+struct rpi_compositor;
+
+struct rpi_output {
+	struct rpi_compositor *compositor;
+	struct weston_output base;
+
+	struct weston_mode mode;
+	struct wl_event_source *finish_frame_timer;
+
+	DISPMANX_DISPLAY_HANDLE_T display;
+	EGL_DISPMANX_WINDOW_T egl_window;
+	DISPMANX_ELEMENT_HANDLE_T egl_element;
+};
+
+struct rpi_seat {
+	struct weston_seat base;
+	struct wl_list devices_list;
+
+	struct udev_monitor *udev_monitor;
+	struct wl_event_source *udev_monitor_source;
+	char *seat_id;
+};
+
+struct rpi_compositor {
+	struct weston_compositor base;
+	uint32_t prev_state;
+
+	struct udev *udev;
+	struct tty *tty;
+};
+
+static inline struct rpi_output *
+to_rpi_output(struct weston_output *base)
+{
+	return container_of(base, struct rpi_output, base);
+}
+
+static inline struct rpi_seat *
+to_rpi_seat(struct weston_seat *base)
+{
+	return container_of(base, struct rpi_seat, base);
+}
+
+static inline struct rpi_compositor *
+to_rpi_compositor(struct weston_compositor *base)
+{
+	return container_of(base, struct rpi_compositor, base);
+}
+
+static const char *
+egl_error_string(EGLint code)
+{
+#define MYERRCODE(x) case x: return #x;
+	switch (code) {
+	MYERRCODE(EGL_SUCCESS)
+	MYERRCODE(EGL_NOT_INITIALIZED)
+	MYERRCODE(EGL_BAD_ACCESS)
+	MYERRCODE(EGL_BAD_ALLOC)
+	MYERRCODE(EGL_BAD_ATTRIBUTE)
+	MYERRCODE(EGL_BAD_CONTEXT)
+	MYERRCODE(EGL_BAD_CONFIG)
+	MYERRCODE(EGL_BAD_CURRENT_SURFACE)
+	MYERRCODE(EGL_BAD_DISPLAY)
+	MYERRCODE(EGL_BAD_SURFACE)
+	MYERRCODE(EGL_BAD_MATCH)
+	MYERRCODE(EGL_BAD_PARAMETER)
+	MYERRCODE(EGL_BAD_NATIVE_PIXMAP)
+	MYERRCODE(EGL_BAD_NATIVE_WINDOW)
+	MYERRCODE(EGL_CONTEXT_LOST)
+	default:
+		return "unknown";
+	}
+#undef MYERRCODE
+}
+
+static void
+print_egl_error_state(void)
+{
+	EGLint code;
+
+	code = eglGetError();
+	weston_log("EGL error state: %s (0x%04lx)\n",
+		   egl_error_string(code), (long)code);
+}
+
+static int
+rpi_finish_frame(void *data)
+{
+	struct rpi_output *output = data;
+
+	weston_output_finish_frame(&output->base,
+				   weston_compositor_get_time());
+	return 1;
+}
+
+static void
+rpi_output_repaint(struct weston_output *base, pixman_region32_t *damage)
+{
+	struct rpi_output *output = to_rpi_output(base);
+	struct rpi_compositor *compositor = output->compositor;
+
+	compositor->base.renderer->repaint_output(&output->base, damage);
+
+	/* FIXME: hook into page flip done */
+	wl_event_source_timer_update(output->finish_frame_timer, 10);
+}
+
+static void
+rpi_output_destroy(struct weston_output *base)
+{
+	struct rpi_output *output = to_rpi_output(base);
+	DISPMANX_UPDATE_HANDLE_T update;
+
+	wl_event_source_remove(output->finish_frame_timer);
+
+	eglDestroySurface(output->compositor->base.egl_display,
+			  output->base.egl_surface);
+
+	wl_list_remove(&output->base.link);
+	weston_output_destroy(&output->base);
+
+	update = vc_dispmanx_update_start(0);
+	vc_dispmanx_element_remove(update, output->egl_element);
+	vc_dispmanx_update_submit_sync(update);
+
+	/* XXX: how to destroy Dispmanx objects? */
+	vc_dispmanx_display_close(output->display);
+
+	free(output);
+}
+
+static int
+rpi_output_create(struct rpi_compositor *compositor)
+{
+	struct rpi_output *output;
+	DISPMANX_MODEINFO_T modeinfo;
+	DISPMANX_UPDATE_HANDLE_T update;
+	VC_RECT_T dst_rect;
+	VC_RECT_T src_rect;
+	int ret;
+	float mm_width, mm_height;
+	VC_DISPMANX_ALPHA_T alpharules = {
+		DISPMANX_FLAGS_ALPHA_FIXED_ALL_PIXELS,
+		255, /* opacity 0-255 */
+		0 /* mask resource handle */
+	};
+	struct wl_event_loop *loop;
+
+	output = calloc(1, sizeof *output);
+	if (!output)
+		return -1;
+
+	output->compositor = compositor;
+
+	output->display = vc_dispmanx_display_open(DISPMANX_ID_HDMI);
+	if (!output->display) {
+		weston_log("Failed to open dispmanx HDMI display.");
+		goto out_free;
+	}
+
+	ret = vc_dispmanx_display_get_info(output->display, &modeinfo);
+	if (ret < 0) {
+		weston_log("Failed to get display mode information.\n");
+		goto out_dmx_close;
+	}
+
+	vc_dispmanx_rect_set(&dst_rect, 0, 0, modeinfo.width, modeinfo.height);
+	vc_dispmanx_rect_set(&src_rect, 0, 0,
+			     modeinfo.width << 16, modeinfo.height << 16);
+
+	update = vc_dispmanx_update_start(0);
+	output->egl_element = vc_dispmanx_element_add(update,
+						  output->display,
+						  0 /* layer */,
+						  &dst_rect,
+						  0 /* src resource */,
+						  &src_rect,
+						  DISPMANX_PROTECTION_NONE,
+						  &alpharules,
+						  NULL /* clamp */,
+						  DISPMANX_NO_ROTATE);
+	vc_dispmanx_update_submit_sync(update);
+
+	output->egl_window.element = output->egl_element;
+	output->egl_window.width = modeinfo.width;
+	output->egl_window.height = modeinfo.height;
+
+	output->base.egl_surface =
+		eglCreateWindowSurface(compositor->base.egl_display,
+				       compositor->base.egl_config,
+				       (EGLNativeWindowType)&output->egl_window,
+				       NULL);
+	if (output->base.egl_surface == EGL_NO_SURFACE) {
+		print_egl_error_state();
+		weston_log("Failed to create output surface.\n");
+		goto out_dmx;
+	}
+
+	if (!eglSurfaceAttrib(compositor->base.egl_display,
+			      output->base.egl_surface,
+			      EGL_SWAP_BEHAVIOR, EGL_BUFFER_PRESERVED)) {
+		print_egl_error_state();
+		weston_log("Failed to set swap behaviour to preserved.\n");
+		goto out_surface;
+	}
+
+	output->base.repaint = rpi_output_repaint;
+	output->base.destroy = rpi_output_destroy;
+	output->base.assign_planes = NULL;
+	output->base.set_backlight = NULL;
+	output->base.set_dpms = NULL;
+	output->base.switch_mode = NULL;
+
+	/* XXX: use tvservice to get information from and control the
+	 * HDMI and SDTV outputs. See:
+	 * /opt/vc/include/interface/vmcs_host/vc_tvservice.h
+	 */
+
+	/* only one static mode in list */
+	output->mode.flags =
+		WL_OUTPUT_MODE_CURRENT | WL_OUTPUT_MODE_PREFERRED;
+	output->mode.width = modeinfo.width;
+	output->mode.height = modeinfo.height;
+	output->mode.refresh = 60000;
+	wl_list_init(&output->base.mode_list);
+	wl_list_insert(&output->base.mode_list, &output->mode.link);
+
+	output->base.current = &output->mode;
+	output->base.origin = &output->mode;
+	output->base.subpixel = WL_OUTPUT_SUBPIXEL_UNKNOWN;
+	output->base.make = "unknown";
+	output->base.model = "unknown";
+
+	/* guess 96 dpi */
+	mm_width  = modeinfo.width * (25.4f / 96.0f);
+	mm_height = modeinfo.height * (25.4f / 96.0f);
+
+	weston_output_init(&output->base, &compositor->base,
+			   0, 0, round(mm_width), round(mm_height),
+			   WL_OUTPUT_TRANSFORM_NORMAL);
+	wl_list_insert(compositor->base.output_list.prev, &output->base.link);
+
+	loop = wl_display_get_event_loop(compositor->base.wl_display);
+	output->finish_frame_timer =
+		wl_event_loop_add_timer(loop, rpi_finish_frame, output);
+
+	weston_log("Raspberry Pi HDMI output %dx%d px\n",
+		   output->mode.width, output->mode.height);
+	weston_log_continue(STAMP_SPACE "guessing %d Hz and 96 dpi\n",
+			    output->mode.refresh / 1000);
+
+	return 0;
+
+out_surface:
+	eglDestroySurface(compositor->base.egl_display,
+			  output->base.egl_surface);
+
+out_dmx:
+	/* XXX: how to destroy Dispmanx objects? */
+
+out_dmx_close:
+	vc_dispmanx_display_close(output->display);
+
+out_free:
+	free(output);
+	return -1;
+}
+
+static void
+rpi_led_update(struct weston_seat *seat_base, enum weston_led leds)
+{
+	struct rpi_seat *seat = to_rpi_seat(seat_base);
+	struct evdev_device *device;
+
+	wl_list_for_each(device, &seat->devices_list, link)
+		evdev_led_update(device, leds);
+}
+
+static const char default_seat[] = "seat0";
+
+static void
+device_added(struct udev_device *udev_device, struct rpi_seat *master)
+{
+	struct evdev_device *device;
+	const char *devnode;
+	const char *device_seat;
+	int fd;
+
+	device_seat = udev_device_get_property_value(udev_device, "ID_SEAT");
+	if (!device_seat)
+		device_seat = default_seat;
+
+	if (strcmp(device_seat, master->seat_id))
+		return;
+
+	devnode = udev_device_get_devnode(udev_device);
+
+	/* Use non-blocking mode so that we can loop on read on
+	 * evdev_device_data() until all events on the fd are
+	 * read.  mtdev_get() also expects this. */
+	fd = open(devnode, O_RDWR | O_NONBLOCK | O_CLOEXEC);
+	if (fd < 0) {
+		weston_log("opening input device '%s' failed.\n", devnode);
+		return;
+	}
+
+	device = evdev_device_create(&master->base, devnode, fd);
+	if (!device) {
+		close(fd);
+		weston_log("not using input device '%s'.\n", devnode);
+		return;
+	}
+
+	wl_list_insert(master->devices_list.prev, &device->link);
+}
+
+static void
+evdev_add_devices(struct udev *udev, struct weston_seat *seat_base)
+{
+	struct rpi_seat *seat = to_rpi_seat(seat_base);
+	struct udev_enumerate *e;
+	struct udev_list_entry *entry;
+	struct udev_device *device;
+	const char *path, *sysname;
+
+	e = udev_enumerate_new(udev);
+	udev_enumerate_add_match_subsystem(e, "input");
+	udev_enumerate_scan_devices(e);
+	udev_list_entry_foreach(entry, udev_enumerate_get_list_entry(e)) {
+		path = udev_list_entry_get_name(entry);
+		device = udev_device_new_from_syspath(udev, path);
+
+		sysname = udev_device_get_sysname(device);
+		if (strncmp("event", sysname, 5) != 0) {
+			udev_device_unref(device);
+			continue;
+		}
+
+		device_added(device, seat);
+
+		udev_device_unref(device);
+	}
+	udev_enumerate_unref(e);
+
+	evdev_notify_keyboard_focus(&seat->base, &seat->devices_list);
+
+	if (wl_list_empty(&seat->devices_list)) {
+		weston_log(
+			"warning: no input devices on entering Weston. "
+			"Possible causes:\n"
+			"\t- no permissions to read /dev/input/event*\n"
+			"\t- seats misconfigured "
+			"(Weston backend option 'seat', "
+			"udev device property ID_SEAT)\n");
+	}
+}
+
+static int
+evdev_udev_handler(int fd, uint32_t mask, void *data)
+{
+	struct rpi_seat *seat = data;
+	struct udev_device *udev_device;
+	struct evdev_device *device, *next;
+	const char *action;
+	const char *devnode;
+
+	udev_device = udev_monitor_receive_device(seat->udev_monitor);
+	if (!udev_device)
+		return 1;
+
+	action = udev_device_get_action(udev_device);
+	if (!action)
+		goto out;
+
+	if (strncmp("event", udev_device_get_sysname(udev_device), 5) != 0)
+		goto out;
+
+	if (!strcmp(action, "add")) {
+		device_added(udev_device, seat);
+	}
+	else if (!strcmp(action, "remove")) {
+		devnode = udev_device_get_devnode(udev_device);
+		wl_list_for_each_safe(device, next, &seat->devices_list, link)
+			if (!strcmp(device->devnode, devnode)) {
+				weston_log("input device %s, %s removed\n",
+					   device->devname, device->devnode);
+				evdev_device_destroy(device);
+				break;
+			}
+	}
+
+out:
+	udev_device_unref(udev_device);
+
+	return 0;
+}
+
+static int
+evdev_enable_udev_monitor(struct udev *udev, struct weston_seat *seat_base)
+{
+	struct rpi_seat *master = to_rpi_seat(seat_base);
+	struct wl_event_loop *loop;
+	struct weston_compositor *c = master->base.compositor;
+	int fd;
+
+	master->udev_monitor = udev_monitor_new_from_netlink(udev, "udev");
+	if (!master->udev_monitor) {
+		weston_log("udev: failed to create the udev monitor\n");
+		return 0;
+	}
+
+	udev_monitor_filter_add_match_subsystem_devtype(master->udev_monitor,
+			"input", NULL);
+
+	if (udev_monitor_enable_receiving(master->udev_monitor)) {
+		weston_log("udev: failed to bind the udev monitor\n");
+		udev_monitor_unref(master->udev_monitor);
+		return 0;
+	}
+
+	loop = wl_display_get_event_loop(c->wl_display);
+	fd = udev_monitor_get_fd(master->udev_monitor);
+	master->udev_monitor_source =
+		wl_event_loop_add_fd(loop, fd, WL_EVENT_READABLE,
+				     evdev_udev_handler, master);
+	if (!master->udev_monitor_source) {
+		udev_monitor_unref(master->udev_monitor);
+		return 0;
+	}
+
+	return 1;
+}
+
+static void
+evdev_disable_udev_monitor(struct weston_seat *seat_base)
+{
+	struct rpi_seat *seat = to_rpi_seat(seat_base);
+
+	if (!seat->udev_monitor)
+		return;
+
+	udev_monitor_unref(seat->udev_monitor);
+	seat->udev_monitor = NULL;
+	wl_event_source_remove(seat->udev_monitor_source);
+	seat->udev_monitor_source = NULL;
+}
+
+static void
+evdev_input_create(struct weston_compositor *c, struct udev *udev,
+		   const char *seat_id)
+{
+	struct rpi_seat *seat;
+
+	seat = malloc(sizeof *seat);
+	if (seat == NULL)
+		return;
+
+	memset(seat, 0, sizeof *seat);
+	weston_seat_init(&seat->base, c);
+	seat->base.led_update = rpi_led_update;
+
+	wl_list_init(&seat->devices_list);
+	seat->seat_id = strdup(seat_id);
+	if (!evdev_enable_udev_monitor(udev, &seat->base)) {
+		free(seat->seat_id);
+		free(seat);
+		return;
+	}
+
+	evdev_add_devices(udev, &seat->base);
+}
+
+static void
+evdev_remove_devices(struct weston_seat *seat_base)
+{
+	struct rpi_seat *seat = to_rpi_seat(seat_base);
+	struct evdev_device *device, *next;
+
+	wl_list_for_each_safe(device, next, &seat->devices_list, link)
+		evdev_device_destroy(device);
+
+	if (seat->base.seat.keyboard)
+		notify_keyboard_focus_out(&seat->base);
+}
+
+static void
+evdev_input_destroy(struct weston_seat *seat_base)
+{
+	struct rpi_seat *seat = to_rpi_seat(seat_base);
+
+	evdev_remove_devices(seat_base);
+	evdev_disable_udev_monitor(&seat->base);
+
+	weston_seat_release(seat_base);
+	free(seat->seat_id);
+	free(seat);
+}
+
+static int
+rpi_init_egl(struct rpi_compositor *compositor)
+{
+	EGLint eglmajor, eglminor;
+	int ret;
+	EGLint num_config;
+
+	static const EGLint config_attrs[] = {
+		EGL_SURFACE_TYPE, EGL_WINDOW_BIT |
+				  EGL_SWAP_BEHAVIOR_PRESERVED_BIT,
+		EGL_RED_SIZE, 1,
+		EGL_GREEN_SIZE, 1,
+		EGL_BLUE_SIZE, 1,
+		EGL_ALPHA_SIZE, 0,
+		EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
+		EGL_NONE
+	};
+
+	compositor->base.egl_display = eglGetDisplay(EGL_DEFAULT_DISPLAY);
+	if (compositor->base.egl_display == EGL_NO_DISPLAY) {
+		weston_log("Failed to create EGL display.\n");
+		print_egl_error_state();
+		return -1;
+	}
+
+	ret = eglInitialize(compositor->base.egl_display, &eglmajor, &eglminor);
+	if (!ret) {
+		weston_log("Failed to initialise EGL.\n");
+		print_egl_error_state();
+		return -1;
+	}
+
+	ret = eglChooseConfig(compositor->base.egl_display, config_attrs,
+			      &compositor->base.egl_config, 1, &num_config);
+	if (ret < 0 || num_config != 1) {
+		weston_log("Failed to find an EGL config (found %d configs).\n",
+			   num_config);
+		print_egl_error_state();
+		return -1;
+	}
+
+	return 0;
+}
+
+static void
+rpi_fini_egl(struct rpi_compositor *compositor)
+{
+	gles2_renderer_destroy(&compositor->base);
+
+	eglMakeCurrent(compositor->base.egl_display,
+		       EGL_NO_SURFACE, EGL_NO_SURFACE,
+		       EGL_NO_CONTEXT);
+
+	eglTerminate(compositor->base.egl_display);
+	eglReleaseThread();
+}
+
+static void
+rpi_compositor_destroy(struct weston_compositor *base)
+{
+	struct rpi_compositor *compositor = to_rpi_compositor(base);
+	struct weston_seat *seat, *next;
+
+	wl_list_for_each_safe(seat, next, &compositor->base.seat_list, link)
+		evdev_input_destroy(seat);
+
+	/* destroys outputs, too */
+	weston_compositor_shutdown(&compositor->base);
+
+	rpi_fini_egl(compositor);
+	tty_destroy(compositor->tty);
+
+	bcm_host_deinit();
+	free(compositor);
+}
+
+static void
+vt_func(struct weston_compositor *base, int event)
+{
+	struct rpi_compositor *compositor = to_rpi_compositor(base);
+	struct weston_seat *seat;
+	struct weston_output *output;
+
+	switch (event) {
+	case TTY_ENTER_VT:
+		weston_log("entering VT\n");
+		compositor->base.focus = 1;
+		compositor->base.state = compositor->prev_state;
+		weston_compositor_damage_all(&compositor->base);
+		wl_list_for_each(seat, &compositor->base.seat_list, link) {
+			evdev_add_devices(compositor->udev, seat);
+			evdev_enable_udev_monitor(compositor->udev, seat);
+		}
+		break;
+	case TTY_LEAVE_VT:
+		weston_log("leaving VT\n");
+		wl_list_for_each(seat, &compositor->base.seat_list, link) {
+			evdev_disable_udev_monitor(seat);
+			evdev_remove_devices(seat);
+		}
+
+		compositor->base.focus = 0;
+		compositor->prev_state = compositor->base.state;
+		compositor->base.state = WESTON_COMPOSITOR_SLEEPING;
+
+		/* If we have a repaint scheduled (either from a
+		 * pending pageflip or the idle handler), make sure we
+		 * cancel that so we don't try to pageflip when we're
+		 * vt switched away.  The SLEEPING state will prevent
+		 * further attemps at repainting.  When we switch
+		 * back, we schedule a repaint, which will process
+		 * pending frame callbacks. */
+
+		wl_list_for_each(output,
+				 &compositor->base.output_list, link) {
+			output->repaint_needed = 0;
+		}
+
+		break;
+	};
+}
+
+static void
+rpi_restore(struct weston_compositor *base)
+{
+	struct rpi_compositor *compositor = to_rpi_compositor(base);
+
+	tty_reset(compositor->tty);
+}
+
+static void
+switch_vt_binding(struct wl_seat *seat, uint32_t time, uint32_t key, void *data)
+{
+	struct rpi_compositor *ec = data;
+
+	tty_activate_vt(ec->tty, key - KEY_F1 + 1);
+}
+
+static struct weston_compositor *
+rpi_compositor_create(struct wl_display *display, int argc, char *argv[],
+		      const char *config_file, int tty)
+{
+	struct rpi_compositor *compositor;
+	struct weston_output *output;
+	const char *seat = default_seat;
+	uint32_t key;
+
+	weston_log("initializing Raspberry Pi backend\n");
+
+	compositor = calloc(1, sizeof *compositor);
+	if (compositor == NULL)
+		return NULL;
+
+	if (weston_compositor_init(&compositor->base, display, argc, argv,
+				   config_file) < 0)
+		goto out_free;
+
+	compositor->udev = udev_new();
+	if (compositor->udev == NULL) {
+		weston_log("Failed to initialize udev context.\n");
+		goto out_compositor;
+	}
+
+	compositor->tty = tty_create(&compositor->base, vt_func, tty);
+	if (!compositor->tty) {
+		weston_log("Failed to initialize tty.\n");
+		goto out_udev;
+	}
+
+	compositor->base.destroy = rpi_compositor_destroy;
+	compositor->base.restore = rpi_restore;
+
+	compositor->base.focus = 1;
+	compositor->prev_state = WESTON_COMPOSITOR_ACTIVE;
+
+	for (key = KEY_F1; key < KEY_F9; key++)
+		weston_compositor_add_key_binding(&compositor->base, key,
+						  MODIFIER_CTRL | MODIFIER_ALT,
+						  switch_vt_binding, compositor);
+
+	bcm_host_init();
+
+	if (rpi_init_egl(compositor) < 0)
+		goto out_tty;
+
+	if (rpi_output_create(compositor) < 0)
+		goto out_egl;
+
+	if (gles2_renderer_init(&compositor->base) < 0)
+		goto out_output;
+
+	evdev_input_create(&compositor->base, compositor->udev, seat);
+
+	return &compositor->base;
+
+out_output:
+	wl_list_for_each(output, &compositor->base.output_list, link)
+		rpi_output_destroy(output);
+
+out_egl:
+	rpi_fini_egl(compositor);
+
+out_tty:
+	tty_destroy(compositor->tty);
+
+out_udev:
+	udev_unref(compositor->udev);
+
+out_compositor:
+	weston_compositor_shutdown(&compositor->base);
+
+out_free:
+	bcm_host_deinit();
+	free(compositor);
+
+	return NULL;
+}
+
+WL_EXPORT struct weston_compositor *
+backend_init(struct wl_display *display, int argc, char *argv[],
+	     const char *config_file)
+{
+	int tty = 0; /* default to current tty */
+
+	const struct weston_option rpi_options[] = {
+		{ WESTON_OPTION_INTEGER, "tty", 0, &tty },
+	};
+
+	parse_options(rpi_options, ARRAY_LENGTH(rpi_options), argc, argv);
+
+	return rpi_compositor_create(display, argc, argv, config_file, tty);
+}

src/rpi-bcm-stubs.h

@@ -0,0 +1,184 @@
+/*
+Copyright (c) 2012, Broadcom Europe Ltd
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+    * Neither the name of the copyright holder nor the
+      names of its contributors may be used to endorse or promote products
+      derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY
+DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+/*
+ * This file provides just enough types and stubs, so that the rpi-backend
+ * can be built without the real headers and libraries of the Raspberry Pi.
+ *
+ * This file CANNOT be used to build a working rpi-backend, it is intended
+ * only for build-testing, when the proper headers are not available.
+ */
+
+#ifndef RPI_BCM_STUBS
+#define RPI_BCM_STUBS
+
+#include <stdint.h>
+
+/* from /opt/vc/include/bcm_host.h */
+
+static inline void bcm_host_init(void) {}
+static inline void bcm_host_deinit(void) {}
+
+/* from /opt/vc/include/interface/vctypes/vc_display_types.h */
+
+typedef enum
+{
+	VCOS_DISPLAY_INPUT_FORMAT_INVALID = 0,
+} DISPLAY_INPUT_FORMAT_T;
+
+/* from /opt/vc/include/interface/vctypes/vc_image_types.h */
+
+typedef struct tag_VC_RECT_T {
+	int32_t x;
+	int32_t y;
+	int32_t width;
+	int32_t height;
+} VC_RECT_T;
+
+typedef enum {
+	VC_IMAGE_ROT0,
+} VC_IMAGE_TRANSFORM_T;
+
+/* from /opt/vc/include/interface/vmcs_host/vc_dispmanx_types.h */
+
+typedef uint32_t DISPMANX_DISPLAY_HANDLE_T;
+typedef uint32_t DISPMANX_UPDATE_HANDLE_T;
+typedef uint32_t DISPMANX_ELEMENT_HANDLE_T;
+typedef uint32_t DISPMANX_RESOURCE_HANDLE_T;
+typedef uint32_t DISPMANX_PROTECTION_T;
+
+#define DISPMANX_NO_HANDLE 0
+#define DISPMANX_PROTECTION_NONE  0
+#define DISPMANX_ID_HDMI      2
+
+typedef enum {
+	/* Bottom 2 bits sets the alpha mode */
+	DISPMANX_FLAGS_ALPHA_FROM_SOURCE = 0,
+	DISPMANX_FLAGS_ALPHA_FIXED_ALL_PIXELS = 1,
+	DISPMANX_FLAGS_ALPHA_FIXED_NON_ZERO = 2,
+	DISPMANX_FLAGS_ALPHA_FIXED_EXCEED_0X07 = 3,
+
+	DISPMANX_FLAGS_ALPHA_PREMULT = 1 << 16,
+	DISPMANX_FLAGS_ALPHA_MIX = 1 << 17
+} DISPMANX_FLAGS_ALPHA_T;
+
+typedef struct {
+	DISPMANX_FLAGS_ALPHA_T flags;
+	uint32_t opacity;
+	DISPMANX_RESOURCE_HANDLE_T mask;
+} VC_DISPMANX_ALPHA_T;
+
+typedef struct {
+	int32_t width;
+	int32_t height;
+	VC_IMAGE_TRANSFORM_T transform;
+	DISPLAY_INPUT_FORMAT_T input_format;
+} DISPMANX_MODEINFO_T;
+
+typedef enum {
+	DISPMANX_NO_ROTATE = 0,
+} DISPMANX_TRANSFORM_T;
+
+typedef struct {
+	uint32_t dummy;
+} DISPMANX_CLAMP_T;
+
+/* from /opt/vc/include/interface/vmcs_host/vc_dispmanx.h */
+
+static inline int
+vc_dispmanx_rect_set(VC_RECT_T *rect, uint32_t x_offset, uint32_t y_offset,
+		     uint32_t width, uint32_t height)
+{
+	rect->x = x_offset;
+	rect->y = y_offset;
+	rect->width = width;
+	rect->height = height;
+	return 0;
+}
+
+static inline DISPMANX_DISPLAY_HANDLE_T
+vc_dispmanx_display_open(uint32_t device)
+{
+	return -1;
+}
+
+static inline int
+vc_dispmanx_display_close(DISPMANX_DISPLAY_HANDLE_T display)
+{
+	return -1;
+}
+
+static inline int
+vc_dispmanx_display_get_info(DISPMANX_DISPLAY_HANDLE_T display,
+			     DISPMANX_MODEINFO_T *pinfo)
+{
+	return -1;
+}
+
+static inline DISPMANX_UPDATE_HANDLE_T
+vc_dispmanx_update_start(int32_t priority)
+{
+	return -1;
+}
+
+static inline DISPMANX_ELEMENT_HANDLE_T
+vc_dispmanx_element_add(DISPMANX_UPDATE_HANDLE_T update,
+			DISPMANX_DISPLAY_HANDLE_T display,
+			int32_t layer,
+			const VC_RECT_T *dest_rect,
+			DISPMANX_RESOURCE_HANDLE_T src,
+			const VC_RECT_T *src_rect,
+			DISPMANX_PROTECTION_T protection,
+			VC_DISPMANX_ALPHA_T *alpha,
+			DISPMANX_CLAMP_T *clamp,
+			DISPMANX_TRANSFORM_T transform)
+{
+	return -1;
+}
+
+static inline int
+vc_dispmanx_element_remove(DISPMANX_UPDATE_HANDLE_T update,
+			   DISPMANX_ELEMENT_HANDLE_T element)
+{
+	return -1;
+}
+
+static inline int
+vc_dispmanx_update_submit_sync(DISPMANX_UPDATE_HANDLE_T update)
+{
+	return -1;
+}
+
+/* from /opt/vc/include/EGL/eglplatform.h */
+
+typedef struct {
+	DISPMANX_ELEMENT_HANDLE_T element;
+	int width;
+	int height;
+} EGL_DISPMANX_WINDOW_T;
+
+#endif /* RPI_BCM_STUBS */