hw/m68k: Set graphic display dimensions generically

If a dimension is not set, have the machine init code
(q800_machine_init) set the default values.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-Id: <20260216213121.47122-6-philmd@linaro.org>

hw/m68k/q800.c

@@ -560,9 +560,9 @@ static void q800_machine_init(MachineState *machine)
                             TYPE_NUBUS_MACFB);
     dev = DEVICE(&m->macfb);
     qdev_prop_set_uint32(dev, "slot", 9);
-    qdev_prop_set_uint32(dev, "width", graphic_width);
-    qdev_prop_set_uint32(dev, "height", graphic_height);
-    qdev_prop_set_uint8(dev, "depth", graphic_depth);
+    qdev_prop_set_uint32(dev, "width", graphic_width ?: 800);
+    qdev_prop_set_uint32(dev, "height", graphic_height ?: 600);
+    qdev_prop_set_uint8(dev, "depth", graphic_depth ?: 8);
     qdev_realize(dev, BUS(nubus), &error_fatal);
 
     macfb_mode = (NUBUS_MACFB(dev)->macfb).mode;

system/globals-target.c

@@ -14,9 +14,9 @@ int graphic_width = 1024;
 int graphic_height = 768;
 int graphic_depth = 8;
 #elif defined(TARGET_M68K)
-int graphic_width = 800;
-int graphic_height = 600;
-int graphic_depth = 8;
+int graphic_width;
+int graphic_height;
+int graphic_depth;
 #else
 int graphic_width = 800;
 int graphic_height = 600;