Changeset b4fa652 in mainline for kernel/genarch/src/fb/fb.c

Timestamp:

2006-08-04T08:21:30Z (18 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

b006a2c8

Parents:

d7e3fa66

Message:

Support 24bpp framebuffers with 4 pixelbytes (each pixel aligned on 32-bits).

At least on sparc64, the OpenFirmware linebytes property specifies the number
of pixels between consecutive scan lines of the display. Fix scanilne calculation,
including possible alignment.

Add note to 8bpp pixel functions pointing out drawbacks of that mode.

File:

• kernel/genarch/src/fb/fb.c (modified) (4 diffs)

kernel/genarch/src/fb/fb.c

@@ -135 +135 @@
 }
 
-/** Put pixel - 8-bit depth (3:2:3) */
+/** Put pixel - 8-bit depth (color palette/3:2:3)
+ *
+ * Even though we try 3:2:3 color scheme here, an 8-bit framebuffer
+ * will most likely use a color palette. The color appearance
+ * will be pretty random and depend on the default installed
+ * palette. This could be fixed by supporting custom palette
+ * and setting it to simulate the 8-bit truecolor.
+ */
 static void rgb_1byte(void *dst, int rgb)
 {
@@ -141 +148 @@
 }
 
-/** Return pixel color - 8-bit depth (3:2:3) */
+/** Return pixel color - 8-bit depth (color palette/3:2:3)
+ *
+ * See the comment for rgb_1byte().
+ */
 static int byte1_rgb(void *src)
 {
@@ -330 +340 @@
 /** Initialize framebuffer as a chardev output device
  *
- * @param addr Physical address of the framebuffer
- * @param x    Screen width in pixels
- * @param y    Screen height in pixels
- * @param bpp  Bits per pixel (8, 16, 24, 32)
- * @param scan Bytes per one scanline
- *
- */
-void fb_init(uintptr_t addr, unsigned int x, unsigned int y, unsigned int bpp, unsigned int scan)
+ * @param addr  Physical address of the framebuffer
+ * @param x     Screen width in pixels
+ * @param y     Screen height in pixels
+ * @param bpp   Bits per pixel (8, 16, 24, 32)
+ * @param scan  Bytes per one scanline
+ * @param align Request alignment for 24bpp mode.
+ */
+void fb_init(uintptr_t addr, unsigned int x, unsigned int y, unsigned int bpp, unsigned int scan, bool align)
 {
         switch (bpp) {
@@ -353 +363 @@
                         rgb2scr = rgb_3byte;
                         scr2rgb = byte3_rgb;
-                        pixelbytes = 3;
+                        if (align)
+                                pixelbytes = 4;
+                        else
+                                pixelbytes = 3;
                         break;
                 case 32: