olm3ca

@Jake Lo - It's been a while, but I have a fun update for you: a very recent discovery in WhateverGreen has broken past the barrier of using Mojave only. I can confirm Big Sur works with graphics acceleration now! And probably even more recent versions like Monterey. The fix will be coming out soon in a public release, with the boot arg -igfxnotelemetryload - thought you (and others here) would like to know!

Following up on this, @flyingfishfinger - it appears a developer has identified a fix in WhateverGreen for this, and it isn't MEI related as some of us thought after all. More details in the Chrultrabook Discord #hackintosh group if you're still interested. This will mean big improvements for the Coreboot hackintosh users out there...

I'll be interested in seeing if 256mb helps, or an older version of Coreboot. As Flyingfishfinger mentioned, it's an issue that has plagued Coreboot users like us Chromebook / chrultrabook folks. @Hervé and others here have tried to help with this in the past for the Galaxy Chromebook, 10th Gen Comet Lake also with the UHD 620. It would be so great to figure out what is broken between Coreboot and Catalina / Big Sur / Monterey. On the Galaxy Chromebook, Comet Lake + UHD 620 should be supported, but we are stuck at 31mb vram no matter what values are used.

Not really something I can do with Coreboot. It's build into the firmware. I know I have MATs support, and on the Pixelbook we got it working on Mojave but not Catalina+...

Really appreciate the reply @Jake Lo. I've tried these and still no luck. Another strange occurrence right now is that itlwm and Airportitlwm are failing. I used to be able to use Airportitlwm, but gave up and switched to itwlm with Heliport. Now itwlm is also failing. One thing about these Chromebooks is that nvram never works the way it should, so I wonder if something is up there. Anyway, if you have any other ideas, I'll be trying as many combinations as I can think of for this iGPU. On a normal machine it would have worked by now, I'm sure!

Thanks. It's being quite stubborn. I've tried a lot of combinations and thus far it remains at 31mb. Out of curiosity, @Jake Lo - how did you figure out the framebuffer args for the Pixelbook last time? Was it something you gathered from Hackintool or another method?

@Hervé Thanks so much for the fast response. I can report that, for the first time, I can use a device-id without a kernel panic! Unfortunately I still have 31mb, but just to confirm the following: Yes, the hardware ID of the chip is 8086:9B41 => i5-10210U (Mobile UHD 620). Your post on this iGPU was really helpful. I'm using SMBIOS MacBookPro16,3 as it seems to be slightly more aligned with my hardware platform-id is 0900A53E and device-id is 9B3E0000. Boots with 31mb VRAM I'm using the framebuffer args from the OC guide (fbmem, stolenmem). I can also boot without them, so they don't appear to be having any effect. Any other suggestions are welcome! Getting closer, thank you again.

@Hervé and @Leon With your help, we got Mojave working on the Google Pixelbook. I've since started on a new project, the Samsung Galaxy Chromebook. It's very similar to the Samsung Galaxy Flex, but I'm having some difficulty again with graphics acceleration and was wondering if you wouldn't mind giving this a look. Here are the specs of the machine: CPU: Intel i5-10210U GPU: Intel UHD 620 Catalina installed, with the following working: Wifi / bt, internal NVMe SSD, battery percentage. Touchpad, touchscreen, and audio not working but this is secondary. Custom DSDTs generated from DSDT.aml intead of prebuilts. I have also used OC guide prebuilts with same result below. I've attached my ioreg and the current EFI I'm working with. Following the OC guide for Comet Lake, the platform-id 00009B3E gives 31mb VRAM. I've tried all of the framebuffers listed on Whatevergreen's wiki for CFL / CML. None result in full 1536 VRAM. This machine has a 4K screen, I've also tried the dpcd-max-link-rate of 14000000 but you'll see I have that commented out for now in the config. One peculiar thing is the device-id gives a kernel panic unless I use an invalid one. So the guide specifically states "An UHD620 in a Comet Lake CPU requires device-id=9B3E0000" however this results in a panic. If I use 12345678 or no device-id at all, it will boot with 31mb VRAM. My question is, like with the Pixelbook, are there specific framebuffer arguments for the UHD 620 on Comet Lake that would help me to get it to boot? Or any other tips for getting the UHD 620 to work on Comet Lake? Thanks so much! olm3ca’s SGC.ioreg EFI.zip

We definitely do! What really helped with the config.plist you shared was the enable-dpcd-max-link-rate-fix and the dpcd-max-link-rate (highlights from the config are below). Without those, it wouldn't get to the GUI. For some reason though, this exact same EFI does not boot to the GUI on Catalina. We're still trying to figure out why. the install procedure and more details are on the repo here: https://github.com/olm3ca/PixelbookOSX/blob/main/README.md AAPL,ig-platform-id / Data / 00001E59 framebuffer-patch-enable / Data / 01000000 framebuffer-fbmem / Data / 00009000 framebuffer-stolenmem / Data / 00003001 enable-dpcd-max-link-rate-fix / Data / 01000000 dpcd-max-link-rate / Data / 1E000000

I got it working! @Jake Lo it turns out the config.plist you shared with me on Mojave works like a charm The problem was Catalina, and I think it's related to the firmware on this Pixelbook, it's not a regular BIOS. Something prevented graphics acceleration on Catalina but now it's working on Mojave. So - thanks so much to you and @Hervé for the support! Note: once I iron out a few more problems I'll gladly share any details. Still more to be done.

Happy new year to everyone and thanks again for the help provided previously. As an update on this: DVMT is confirmed as set to 128mb. Unfortunately, after many (many!) tries of every possible framebuffer / platform-id / device-id combinations for the HD615, I'm seeing that this is a problem with MrChromebox's UEFI firmware on ChromeOS devices and Mac OS Catalina. This post on InsanelyMac is from a year ago, and details exactly the same problem I've been having. Whenever framebuffer args are used, the system locks up at [IGPU] Render Compression for IOSurface is Enabled. Other users (Reddit post) with this graphics card, HD615, have also reported similar problems in Catalina. As I've stalled out on Catalina, I've started the process to get Mojave running. Right now, the initial installer locking up at "disk is not convertible to apfs" even after going to Disk Utility, show all devices, format as APFS with GUID. I've tried many different types of drives (SSD, external HD, etc) and none are working. It always happens when there are 2 minutes remaining in the install. Thanks for the support once again.

As an update on this... Windows reports the dedicated video memory is 128mb. We're going to see about adjusting the DVMT at the firmware level - it's possible...

I'm asking the developer of the Pixelbook firmware (MrChromebox) to see if we can change that, there are no settings I can manipulate myself. Meanwhile, no other attempts have yielded any results - the only two platform-ids that work continue to be 16590000 or 01001659.

Thank you! Just tried it, looks like it hangs on Render Compression for IOSurface is Enabled. I'll try the other platform ID of 01001E59 and will report back.

Thank you so much, @Jake Lo - got it now. @Hervé attached is the requested file. PixelbookOSX.zip