Support ARM Builds for Raspberry Pi, NextThing CHIP, etc.

[sci-phi]

I am interested in using LibUI via Go, Ruby, or Python to build GUI executables for "Maker" boards with ARM SOCs like Raspberry Pi, NextThingCo CHIP (PocketCHIP especially) and whatever other IoT varietals crop up. The leading platforms are based on Debian OS variants, so Go and CMake are installable.

How difficult do you expect it would be to modify libui to work on ARM ? Would you be willing to provide support and accept the PR if this work was attempted?

[andlabs]

libui works out of the box. For the Go package you would just need to create a link_linux_arm.go and respective libui_linux_arm.a file, the latter coming from a static libui build.

[sci-phi]

Thanks, I had a struggle with getting CMAKE > 3.1, but I finally managed to produce "libui.a" on the pocketCHIP itself using the static build advice ("cmake .. -DBUILD_SHARED_LIBS=OFF")

Is there any more documentation on the next steps I would need to take?

[andlabs]

Go into $GOPATH/github.com/andlabs/ui. You would just need to copy that libui.a file into the Go repository, preferably as libui_linux_arm.a, set up the link_linux_arm.go file (you can just copy libui_linux_386.go and edit it as appropriate), and then go install github.com/andlabs/ui (note the use of go install here, NOT go get).

BTW, I've switched the build system to meson, so the build instructions are slightly different. I've outlined them in the README in much clearer terms though.