-
Notifications
You must be signed in to change notification settings - Fork 488
Add patchAPIC conversion guide #26
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
Draft
khronokernel
wants to merge
5
commits into
master
Choose a base branch
from
apic-guide
base: master
Could not load branches
Branch not found: {{ refName }}
Loading
Could not load tags
Nothing to show
Loading
Are you sure you want to change the base?
Some commits from the old base branch may be removed from the timeline,
and old review comments may become outdated.
Draft
Changes from 1 commit
Commits
Show all changes
5 commits
Select commit
Hold shift + click to select a range
File filter
Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,71 @@ | ||
| # Patching the APIC table | ||
|
|
||
| An odd issue some HEDT users may experience is a kernel panic relating to more cores defined in APIC than actually present: | ||
|
|
||
| ``` | ||
| panic(cpu 0 caller 0x......): "x86_validate topology() 32 threads but 33 registered from MADT~0/... | ||
| ``` | ||
|
|
||
| The reason for this kernel panic is due to macOS's assumption that the first CPU in ACPI is always enabled, which on servers and HEDT systems may not always true. | ||
|
|
||
| To get around this, we want to patch our APIC table to point the first CPU entry to an active CPU. | ||
|
|
||
|
|
||
| ## Dumping your DSDT and APIC tables | ||
|
|
||
| Dumping your DSDT and APIC table is quite easy, however some of the methods mentioned in [Getting a copy of our DSDT](../Manual/dumpmd) may not provide you will all the needed files. Methods that will provide a full dump: | ||
khronokernel marked this conversation as resolved.
Outdated
Show resolved
Hide resolved
|
||
|
|
||
| * acpidump.exe | ||
| * Just run the program, don't give any specific arguments | ||
| * Clover's F4 | ||
| * UEFI Shell using acpidump.efi | ||
| * OpenCore's SysReport quirk | ||
|
|
||
| And don't forget to follow the decompile guide as well: [Compiling and decompiling ACPI Tables](../Manual/compile.md) | ||
|
|
||
|
|
||
| ## Examining our ACPI table | ||
|
|
||
| So lets take a look at our APIC table first: | ||
|
|
||
|  | ||
|
|
||
| Here we can see a list of all the CPU threads, and info about each one. Lets look at the first `[Processor Local APIC]` entry: | ||
|
|
||
| ``` | ||
| [02Ch 0044 1] Subtable Type : 00 [Processor Local APIC] | ||
| [02Dh 0045 1] Length : 08 | ||
| [02Eh 0046 1] Processor ID : 00 | ||
| [02Fh 0047 1] Local Apic ID : 02 | ||
| [030h 0048 4] Flags (decoded below) : 00000001 | ||
| Processor Enabled : 1 | ||
| Runtime Online Capable : 0 | ||
| ``` | ||
|
|
||
| Here we're given some important info, but the most important part: | ||
| ``` | ||
| Processor ID : 00 | ||
| ``` | ||
|
|
||
| This value is what matches up the APIC's table entry to your DSDT, and is passed to macOS to determine the first CPU entry. And here we get a glimpse into what might be causing our kernel panic. | ||
|
|
||
| Next open your DSDT and search for `Processor`: | ||
|
|
||
|  | ||
|
|
||
| Here we're given some important info regarding the first CPU: | ||
|
|
||
| ``` | ||
| Processor (C000, 0x80, 0x00000410, 0x06) | ||
| ``` | ||
|
|
||
| If we check the [ACPI Spec](https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf), section 19.6.108, we see the info is parsed as follows: | ||
|
|
||
| ``` | ||
| Processor (ProcessorName, ProcessorID, PBlockAddress, PblockLength) | ||
| ``` | ||
|
|
||
|
|
||
| Now if we look at the `ProcessorID` section, we notice it's `0x80`, but this doesn't match up with the first entry in our APIC table(`00`). Now we can get a clearer idea of what's wrong with out APIC table and why it kernel panics. | ||
khronokernel marked this conversation as resolved.
Outdated
Show resolved
Hide resolved
|
||
|
|
||
| ## Patching the APIC table | ||
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Uh oh!
There was an error while loading. Please reload this page.