[display] Refactor to avoid implicit framebuffer allocation.

platform/armemu/display.c

 /*
  * Copyright (c) 2010 Travis Geiselbrecht
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files
  * (the "Software"), to deal in the Software without restriction,
  * including without limitation the rights to use, copy, modify, merge,
  * publish, distribute, sublicense, and/or sell copies of the Software,
  * and to permit persons to whom the Software is furnished to do so,
  * subject to the following conditions:
@@ skipping 10 matching lines @@
  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 #include <err.h>
 #include <debug.h>
 #include <platform.h>
 #include "platform_p.h"
 #include <platform/armemu.h>
 #include <dev/display.h>
 #include <lib/gfx.h>
 #include <reg.h>
+#include <assert.h>
 
 #define DRAW_TEST_PATTERN 0
 
 static int display_w, display_h;
 static void *display_fb;
 
 inline static int has_display(void)
 {
     return *REG32(SYSINFO_FEATURES) & SYSINFO_FEATURE_DISPLAY;
 }
 
 void platform_init_display(void)
 {
     if (!has_display())
         return;
 
     display_fb = (void *)DISPLAY_FRAMEBUFFER;
     display_w = *REG32(DISPLAY_WIDTH);
     display_h = *REG32(DISPLAY_HEIGHT);
 
 #if DRAW_TEST_PATTERN
     gfx_draw_pattern();
 #endif
 }
 
+status_t display_get_framebuffer(struct display_framebuffer *fb)
+{
+    DEBUG_ASSERT(fb);
+    if (!has_display())
+        return ERR_NOT_FOUND;
+
+    fb->image.format = IMAGE_FORMAT_RGB_x888;
+    fb->image.pixels = display_fb;
+    fb->image.width = display_w;
+    fb->image.height = display_h;
+    fb->image.stride = display_w;
+    fb->image.rowbytes = display_w * 4;
+    fb->flush = NULL;
+    fb->format = DISPLAY_FORMAT_RGB_x888;
+
+    return NO_ERROR;
+}
+
 status_t display_get_info(struct display_info *info)
 {
+    DEBUG_ASSERT(info);
     if (!has_display())
         return ERR_NOT_FOUND;
 
-    info->framebuffer = display_fb;
-    info->format = GFX_FORMAT_RGB_x888;
+    info->format = DISPLAY_FORMAT_RGB_x888;
     info->width = display_w;
     info->height = display_h;
-    info->stride = display_w;
-    info->flush = NULL;
 
     return NO_ERROR;
 }