vgabios: Add support for vbe get/set line length function.

[seabios.git] / vgasrc / vgabios.c

diff --git a/vgasrc/vgabios.c b/vgasrc/vgabios.c
index d35cb0272293eb4dcfdc8743bd88b05d1a96c84e..d00016685f884f9fb49e254b00c4fd4e046ef274 100644 (file)
--- a/vgasrc/vgabios.c
+++ b/vgasrc/vgabios.c
@@ -63,6 +63,22 @@ struct pci_data rom_pci_data VAR16VISIBLE = {
  * Helper functions
  ****************************************************************/
 
+// Return the bits per pixel in system memory for a given mode.
+int
+vga_bpp(struct vgamode_s *vmode_g)
+{
+    switch (GET_GLOBAL(vmode_g->memmodel)) {
+    case MM_TEXT:
+        return 16;
+    case MM_PLANAR:
+        return 1;
+    }
+    u8 depth = GET_GLOBAL(vmode_g->depth);
+    if (depth > 8)
+        return ALIGN(depth, 8);
+    return depth;
+}
+
 u16
 calc_page_size(u8 memmodel, u16 width, u16 height)
 {