Refactor how display drivers are selected

My previous commit, f92f8afebe,  broke -vnc (spotted by Glauber Costa).  This
is because it's necessary to tell when the no special display parameters have
been passed and default to SDL or VNC appropriately.

This refactors the display selection logic to be less complicated which has
the effect of fixing the regression mentioned above.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 10 insertions, 1 deletions

diff --git a/sysemu.h b/sysemu.h
index 7d65804b69..4063533f2b 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -86,6 +86,15 @@ int tap_win32_init(VLANState *vlan, const char *model,
 /* SLIRP */
 void do_info_slirp(Monitor *mon);
 
+typedef enum DisplayType
+{
+    DT_DEFAULT,
+    DT_CURSES,
+    DT_SDL,
+    DT_VNC,
+    DT_NOGRAPHIC,
+} DisplayType;
+
 extern int bios_size;
 extern int cirrus_vga_enabled;
 extern int std_vga_enabled;
@@ -94,7 +103,7 @@ extern int xenfb_enabled;
 extern int graphic_width;
 extern int graphic_height;
 extern int graphic_depth;
-extern int nographic;
+extern DisplayType display_type;
 extern const char *keyboard_layout;
 extern int win2k_install_hack;
 extern int rtc_td_hack;