FireWolf Pl.

A Place of Freedom

@FireWolf2 months ago

08/23
01:19
macOS Catalina

Ice Lake Intel Iris Plus Graphics on macOS Catalina: A solution to the kernel panic due to unsupported core display clock frequencies in the framebuffer driver

Hi folks! I haven’t updated my blog for a long time, but today I have something new about the graphics driver for Ice Lake platforms on macOS Catalina 10.15.6 to share with you. It’s time to write a new blog post.

If this page looks strange due to font or layout issues, you could find a pretty-printed version at here.

>> Introduction

It has been quite a while since Apple released the graphics driver for Intel Ice Lake platforms. While we expect that it should not be difficult to make the integrated graphics card on an Ice Lake-based laptop work under macOS Catalina, a large number of people has encountered a kernel panic due to an unsupported Core Display Clock frequency. Core Display Clock (CDCLK) is one of the primary clocks used by the display engine to do its work. Apple’s graphics driver expects that the EFI firmware has already set the clock frequency to either 652.8 MHz or 648 MHz, but quite a few laptops set it to a much lower value (e.g. 172.8 MHz), and hence a kernel panic is triggered. In the following sections, I will focus on how the graphics driver verifies and configures the Core Display Clock and how we add support for these valid yet unsupported frequencies.

Read More →

Ice Lake Intel Iris Plus Graphics on macOS Catalina: A solution to the kernel panic due to unsupported core display clock frequencies in the framebuffer driver

@FireWolf2 years ago

11/10
23:28
macOS Mojave

Coffee Lake Intel UHD Graphics 630 on macOS Mojave: A nearly ultimate solution to the kernel panic due to division by zero in the framebuffer driver

Hi folks! Times goes fast. I have some new findings to share with you. Now it’s time to write a new post.

If this page looks strange due to font or layout issues, you can find a pretty-printed GitBook version at here.

>> Introduction

Nowadays, it might not be easy to make the integrated graphics card, namely Intel UHD Graphics 630, fully work on Apple’s latest macOS Mojave without any issues on a Coffee Lake-based laptop. In addition to the minimum requirement of DVMT pre-allocated memory that I identified three years ago, some built-in displays may not report valid values of certain capabilities, resulting in the graphics driver failing to verify those values and reporting a fatal error by triggering a kernel panic.

Read More →

Coffee Lake Intel UHD Graphics 630 on macOS Mojave: A nearly ultimate solution to the kernel panic due to division by zero in the framebuffer driver

@FireWolf2 years ago

10/3
19:58
macOS Mojave

Coffee Lake Intel UHD Graphics 630 on macOS Mojave: A compromise solution to the kernel panic due to division by zero in the framebuffer driver

Hi folks! Long time no see.

Finally, I have some time to write this post…

>> Introduction

So recently I was working on installing macOS Mojave on my laptop.
It is equipped with a Core i7 8750H processor and a gorgeous 4K display.

As usual, the first thing right after the installation is to make the integrated graphics card working.

Some of you may have already known that DVMT pre-allocated memory is an “annoying” issue on non-Apple laptop, because Apple has raised the limit as of Broadwell.
(Read the post I published three years ago if you want to know more about this issue.)

Thankfully, the DVMT pre-allocated memory is set to 64 MB by default in BIOS.
This looks reasonable to me since 32 MB DVMT is not enough to power the builtin 4K display.
Besides, I needed to patch the `CoreDisplay` framework to unlock the pixel clock limitation.
So I thought this should be relatively easy, but it turned out that I was “too young and native”.

Read More →

Coffee Lake Intel UHD Graphics 630 on macOS Mojave: A compromise solution to the kernel panic due to division by zero in the framebuffer driver