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| author | Peter Nelson <peter@peterdn.com> | 2020-12-30 18:07:35 +0000 |
|---|---|---|
| committer | Andreas Kling <kling@serenityos.org> | 2020-12-30 20:31:30 +0100 |
| commit | d0142779730d118cd3982239407bedc6103e2baa (patch) | |
| tree | a4d1c01563ab4e1452efc23ca37f189e30eddcc5 /Documentation | |
| parent | b3da5835f27f02c2454ec8f5f89b67c7c16d5f96 (diff) | |
| download | serenity-d0142779730d118cd3982239407bedc6103e2baa.zip | |
Docs: Update WSL notes with some workarounds for known issues
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/NotesOnWSL.md | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/Documentation/NotesOnWSL.md b/Documentation/NotesOnWSL.md index 9166c98dfd..409550f36c 100644 --- a/Documentation/NotesOnWSL.md +++ b/Documentation/NotesOnWSL.md @@ -64,6 +64,26 @@ To run SerenityOS in a WHPX-enabled QEMU VM: - `make run` as usual. +#### Known issues with WHPX + +##### Freeze on boot in Scheduler + +If Serenity freezes on boot with the log message: `Scheduler[0]: idle loop running` then you are likely missing some emulated CPU features. +Please ensure you have installed the most recent version of [QEMU for Windows](https://qemu.weilnetz.de/) and that you have followed the step above to enable the maximum feature set available: +`export SERENITY_QEMU_CPU="max,vmx=off"`. + +##### Illegal instruction on boot + +Using `SERENITY_QEMU_CPU="max"` can trigger a QEMU bug where the OSXSAVE CPUID flag is erroneously set, playing havoc with feature detection logic in libgcc and resulting in this error. + +To workaround this, first adjust the `SERENITY_QEMU_CPU` setting to emulate a more restricted feature set. `SERENITY_QEMU_CPU="qemu32"` appears to work in some cases, however in others causes the boot freeze issue above. +It's worth playing around with various different values here to see if you can find one that works for you. Running `qemu-system-i386.exe -cpu ?` will list the supported CPU configurations. + +If you cannot find a working CPU feature set, the next workaround is to patch libgcc in the Serenity toolchain build to remove the offending instruction. +Comment out the `if ((ecx & bit_OSXSAVE))` block in `Toolchain/Tarballs/gcc-<version>/libgcc/config/i386/cpuinfo.c`. In GCC 10.2.0 this is lines 282-297. + +Rebuild the toolchain using `Toolchain/BuildIt.sh` as normal, then rebuild Serenity. + ### Note on filesystems WSL2 filesystem performance for IO heavy tasks (such as compiling a large C++ project) on the host Windows filesystem is terrible. |