PC_EFI/Chameleon Refresh Rate Issue

[banini_jeque]

I've been trying to set 75Hz in my "Graphics Mode", but it still runs at 60.

 

I did some research and found that long ago an error had been found where the bootloader would constantly reboot/crash if a > 60Hz refresh rate were specified, so they commented out the code that sets that up in order to ignore the refresh rate.

 

Then I found this post: VESA 3 fix for boot sector.

 

So, I uncommented out the generateCRTCTiming section and added his patch.

 

if ( (vesaVersion >> 8) >= 3 && refreshRate >= 60 &&
(gBootMode & kBootModeSafe) == 0 )
{
VBECRTCInfoBlock timing;

// added by TRAC because of SSE bug in boot2
// activates SSE support by CPU
__asm__ ("movl %cr4,%eax \n"
"orl $1536,%eax \n"
"movl %eax,%cr4 \n");

// Generate CRTC timing for given refresh rate.

generateCRTCTiming( minfo.XResolution, minfo.YResolution,
refreshRate, kCRTCParamRefreshRate,
&timing );

 

I used the graphics.c source from PC_EFI v10.5, compiled it, installed the new "boot" file, and PC_EFI still works, but it also still ignores my refresh rates.

 

I thought I would post this and see if anyone thought it was interesting, and if it could be taken further so that refresh rates were finally working.