Porting wine to amd64 on NetBSD, second evaluation report

This report was written by Naveen Narayanan as part of Google Summer of Code 2019.

This report encompasses the progress of the project during the second coding period.

WINE on amd64

As getting Wine to work with WoW64 support was of foremost importance, my focus was on compat32 dependency packages without which Wine's functionality would be limited and more importantly untestable. Initially, being unaware of what to expect, I just wanted Wine to run, at the earliest. So, with outmost support from mentors, the consensus was to install libs from 32-bit packages to ${PREFIX}/lib/32 and ignore everything else that came with the respective packages.

I had most of the compat32 packages ready after a couple of days. And it was time we gave Wine a whirl. Well, the build was successful. However, I had problems with 32-bit Xorg. The applications which came packaged with Wine worked fine, but, other Microsoft Windows applications like notepad++, Mario etc had a hard time running. Additionally, I noticed that fontconfig went wild and crashed spewing errors symptomatic of Wine (32-bit) not playing nice with the fontconfig lib that came with 32-bit Xorg package. On top of this, I found that build failed on certain machines due to unavailability of headers. This made us reconsider our decision to install 32-bit libs to ${PREFIX}/lib/32 and ignore everything else which included headers and binaries.

Ultimately, we realized that it was time we found a proper solution to the problem of where 32-bit packages should be installed on NetBSD amd64 and then, we eventually settled on ${PREFIX}/emul/netbsd32/. It seemed logical, and I got on with the task of adapting the respective Makefiles of dependency packages to install to ${PREFIX}/emul/netbsd32/. Additionally, I packaged fontconfig (32-bit) in high hopes that Wine would behave appropriately with the former. Wine build was successful. However, I noticed that Wine wasn't linking against the fontconfig libs from my package but against the ones which came with 32-bit Xorg package. Later, I realized, after consulting with mentors, that pkgsrc doesn't search for pkgconfig files (*.pc) in ${PREFIX}/emul/netbsd32/lib by default. pkgsrc sets _PKG_CONFIG_LIBDIR appropriately based on ${LIBABISUFFIX}. As you can see, it doesn't search for .pc files in ${PREFIX}/emul/netbsd32/lib and hence, pkgconfig couldn't get the right flags for fontconfig package. On the other hand, Wine configure script found fontconfig libs provided by 32-bit Xorg package against which it linked wine. A kludgy workaround was to use configure args for the respective libs thereby, obviating configure from finding the wrong libs. Finally, with the help of aforementioned kludgy workarounds, we were able to build Wine and successfully run Mario and Lua (32-bit binaries).

How to run Wine on NetBSD -current

• Build -current distribution.
• Compile -current kernel with USER_LDT enabled and SVS disabled.
• Install kernel and distribution.
• Clone wip repo.
• cd /usr/pkgsrc/wip/wine64; make install
• export LD_LIBRARY_PATH=/usr/pkg/emul/netbsd32/lib; wine mario.exe

Future Plans

Wine requires the kernel option USER_LDT to be able to run 32-bit applications on amd64 - facilitated by WoW64. Presently, this feature isn't enabled by default on NetBSD and hence, the kernel has to be compiled with USER_LDT enabled. This also warrants the kernel option SVS to be disabled currently owing to compatability issues. Work is being done to resolve the conflict which would apparently allow USER_LDT to be enabled by default in the GENERIC kernel.

pkgsrc can be made to search for pkgconf config files in ${PREFIX}/emul/netbsd32/lib by setting _PKG_CONFIG_LIBDIR to ${BUILDLINK_DIR}${LIBABIPREFIX}/lib${LIBABISUFFIX} as per @maya's suggestion. It might take some more thought and time before we finalize it.

Summary

Presently, Wine on amd64 is in test phase. It seems to work fine with caveats like LD_LIBRARY_PATH which has to be set as 32-bit Xorg libs don't have ${PREFIX}/emul/netbsd32/lib in its rpath section. The latter is due to us extracting 32-bit libs from tarballs in lieu of building 32-bit Xorg on amd64. As previously stated, pkgsrc doesn't search for pkgconfig files in ${PREFIX}/emul/netbsd32/lib which might have inadvertent effects that I am unaware of as of now. I shall be working on these issues during the final coding period. I would like to thank @leot, @maya and @christos for saving me from shooting myself in the foot many a time. I, admittedly, have had times when multiple approaches, which all seemed right at that time, perplexed me. I believe those are times when having a mentor counts, and I have been lucky enough to have really good ones. Once again, thanks to Google for this wonderful opportunity.