Over the weekend I experimented with
AptioMemoryFix and various
slide values (including no
slide parameter at all). What I found was baffling and inscrutable. I took a lot of notes which I can summarize later, but the key observations were as follows:
Setting up the Experiment:
- My configuration:
- SMBIOS Macmini8,1
- IGFX enabled and Platform ID 0x3E980003 (headless).
- Fenvi FV-T919 in bottom PCIe x1 slot.
- RX 580 GPU in Slot 1.
- I created 20 different config.plist files, named config-1.plist through config-20.plist.
- config-1.plist specified slide=1
- config-2.plist specified slide=2
- ...
- config-20.plist specified slide=20
- At the Clover Boot Menu we can select the Options option (ha!) and pick from any of the .plist files in the CLOVERfolder.
- This is very handy because we can quickly cycle between all 20 values of slide without having to go through the whole tedium of booting into macOS, mounting EFI, modifying config.plist, etc.
- I also tried a random set of much larger values of slide, such as slide=167.
- I ran memmap several times (with several reboots) to make sure that the map was the same or very nearly the same each time.
- And sure enough, the memory map was the same after each reboot.
Expectations:
- Based on the information we have seen from vit9696 and others regarding calculation of slide values, I fully expected each slide value to generate a consistent, repeatable memory address.
- For example, if I use slide=1, I expected macOS kernel to allocate a block of memory at the same memory address on each and every reboot (as long as memmap was the same, which it was).
- So I selected config-1.plist and I immediately received a Couldn't allocate runtime area error, along with a memory address and size.
- So I made a note of the memory address and rebooted/repeated the same experiment with the same slide value.
- Surprisingly, the memory address changed...
- Each time I repeated the experiment, I got a different memory address.
- So I switched to slide=2, then slide=3, then slide=4, and so on. And I repeated the experiment multiple times with each slide value.
Overall Observations:
- As we increase slide from 1 to 20 and then to 167 we expect the base memory address to increase.
- But I did not observe any such behavior.
- When I used slide=167 I found that macOS was attempting to allocate memory in the same region as slide=5 or slide=7.
- When I used slide=15 I found that macOS was attempting to allocate memory in the same region as slide=1 or slide=167 or slide=12.
- In other words, the value of slide did not seem to make any difference.
- After spending a couple of hours on this, I was exhausted and happily went back to OsxAptioFix2Drv-free2000.
If you have also experimented with Slide values, did you observe the same behavior? If not, what did you observe?