[Qemu-devel] Gives user ability to select endian format for video display - fixes Mac OS X guest color issue.

[Programmingkid]

This patches does the following:

- Allows user to select endian format of video display. 
This allows Mac OS X to be used as a guest and show all its colors
correctly. Just add -display-endian-big to the command line to use 
this feature. 

- Removes unneeded #ifdefs in drawRect: method. Correct method
selection is done at runtime instead of compile time. This makes one
binary work on more versions of Mac OS X rather than just the 
version that was used to compile it. It also makes the code
more efficient. Rather than setting the same variables over and over again, 
just do it once. 

- Adds runtime identification code for determining which version of the Mac
OS QEMU is running on.

Signed-off-by: John Arbuckle <address@hidden>

---
 ui/cocoa.m |   49 ++++++++++++++++++++++++++++++++++++++++++-------
 1 files changed, 42 insertions(+), 7 deletions(-)

diff --git a/ui/cocoa.m b/ui/cocoa.m
index 704d199..562fa29 100644
--- a/ui/cocoa.m
+++ b/ui/cocoa.m
@@ -64,6 +64,10 @@ static int last_buttons;
 int gArgc;
 char **gArgv;
 
+/* Used in drawRect:. Starts with little endian format. */
+static int bitmap_info = kCGBitmapByteOrder32Little | 
kCGImageAlphaNoneSkipFirst;
+SInt32 current_mac_os_version;
+
 // keymap conversion
 int keymap[] =
 {
@@ -238,7 +242,33 @@ static int cocoa_keycode_to_qemu(int keycode)
     return keymap[keycode];
 }
 
+/* Looks for the -display-endian-big option being sent to QEMU.
+   Fixes the issue with the colors not being displayed correctly with Mac OS X 
as the host.
+   It is normally assumed that the frame buffer has data in the little endian 
format.
+   Mac OS X uses the big endian format.
+*/
+static void scanForDisplayEndianOption(int argc, char * argv[])
+{
+       // search for the -display-endian-big option
+       for(int i = 0; i < argc; i++) {
+           if(strcmp(argv[i], "-display-endian-big") == 0) {
+            bitmap_info = kCGImageAlphaNoneSkipFirst;
+            // remove the option from the argv array
+            sprintf(argv[i], "%s", "-no-frame");  // no-frame does nothing in 
cocoa, so it is harmless
+            break;
+           }
+       }
+}
 
+/* Finds out what version of the Mac OS your computer is using. */
+static void determineMacOSVersion()
+{
+    OSErr err_num = Gestalt(gestaltSystemVersion, &current_mac_os_version);
+    if(err_num != noErr) {
+        current_mac_os_version = -1;
+        fprintf(stderr, "\nWarning: Failed to determine Mac OS version of your 
system!\n");
+    }
+}
 
 /*
  ------------------------------------------------------
@@ -257,6 +287,7 @@ static int cocoa_keycode_to_qemu(int keycode)
     BOOL isAbsoluteEnabled;
     BOOL isMouseDeassociated;
     NSDictionary * window_mode_dict; /* keeps track of the guest' graphic 
settings */
+    CGColorSpaceRef color_space;  /* used in drawRect: */
 }
 - (void) switchSurface:(DisplaySurface *)surface;
 - (void) grabMouse;
@@ -299,6 +330,13 @@ QemuCocoaView *cocoaView;
         screen.width = frameRect.size.width;
         screen.height = frameRect.size.height;
         [self updateWindowModeSettings];
+
+        if (current_mac_os_version >= MAC_OS_X_VERSION_10_4)
+            color_space = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);
+        else {
+            /* Using this in Mac OS 10.6 causes occasional crashes in 
drawRect:. */
+            color_space = CGColorSpaceCreateDeviceRGB();
+        }
     }
     return self;
 }
@@ -361,13 +399,8 @@ QemuCocoaView *cocoaView;
             screen.bitsPerComponent, //bitsPerComponent
             screen.bitsPerPixel, //bitsPerPixel
             (screen.width * (screen.bitsPerComponent/2)), //bytesPerRow
-#ifdef __LITTLE_ENDIAN__
-            CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB), //colorspace 
for OS X >= 10.4
-            kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipFirst,
-#else
-            CGColorSpaceCreateDeviceRGB(), //colorspace for OS X < 10.4 
(actually ppc)
-            kCGImageAlphaNoneSkipFirst, //bitmapInfo
-#endif
+            color_space,
+            bitmap_info,
             dataProviderRef, //provider
             NULL, //decode
             0, //interpolate
@@ -835,6 +868,7 @@ QemuCocoaView *cocoaView;
 
     self = [super init];
     if (self) {
+        determineMacOSVersion();
 
         // create a view and add it to the window
         cocoaView = [[QemuCocoaView alloc] initWithFrame:NSMakeRect(0.0, 0.0, 
640.0, 480.0)];
@@ -918,6 +952,7 @@ QemuCocoaView *cocoaView;
     COCOA_DEBUG("QemuCocoaAppController: startEmulationWithArgc\n");
 
     int status;
+    scanForDisplayEndianOption(argc, argv);
     status = qemu_main(argc, argv, *_NSGetEnviron());
     exit(status);
 }
-- 
1.7.5.4