Hi,
It seems there is a small problem of VGA palette corruption on EFI
machine. When the kernel initializes the architecture, it checks if the
machine is a EFI machine and if the memory at 0xa0000 is not tagged as
conventional memory, which should not be the case because this is VGA
memory. In that case, the kernel assumes that a VGA console can exist. I
would think that this assumption is correct.
When the kernel initialize the console in vgacon_startup it checks if it
can really use the VGA console. I think this is where a check is
missing. Currently, the function can fail if a VESA boot mode is
detected but not if a EFI boot mode was used. I think the code should be
modified like this :
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -377,7 +377,8 @@ static const char *vgacon_startup(void)
u16 saved1, saved2;
volatile u16 *p;
- if (screen_info.orig_video_isVGA == VIDEO_TYPE_VLFB) {
+ if (screen_info.orig_video_isVGA == VIDEO_TYPE_VLFB ||
+ screen_info.orig_video_isVGA == VIDEO_TYPE_EFI) {
no_vga:
#ifdef CONFIG_DUMMY_CONSOLE
conswitchp = &dummy_con;
In that case, the VGA console will fail and a dummy console will be
temporary used until the EFI driver get loaded. At that point the
console will be mapped to the EFI driver and graphics (splash screen and
penguins) will appear correctly.
Currently, the function vgacon_startup doesn't fail and initialize the
video card for a real VGA mode. This function change the first 16
entries of the VGA palette. When the efifb driver kick-in, the palette
is not restored to default ramp value, thus the 16 first entry remain in
a modified state.
Thanks,
Yannick Heneault