Up until recently, Haiku builds for ARM have targetted individual ARM boards. The compile process for ARM images required two things: an architecture, and a target board (such as the Raspberry Pi 2). This board setting adjusted a large number of defines throughout Haiku at compile time to set the operating system up for the target ARM device. The board selection also handled placing all the propriety bits (a lot of which have sketchy licensing) into the Haiku image during compile. Haiku would then have to distribute these files. (sketchy licensing and all)
Over the past few years, FranÃ§ois Revol, Ithamar R. Adema, and others have worked to add Flat Device Tree (FDT) support to Haiku. FDT’s enable operating systems to obtain core knowledge of the devices they run on by simply swapping one or more compiled binary files. These files describe critical things the operating system needs to know about the hardware they run on. Really important things such as what devices exist at what memory locations. (Think video frame buffers, serial ports, etc)
In a series of cryptic commits in July 2017, I removed these board-centric build steps with grand plans of making testing (and running) Haiku on ARM devices easier.
No, this does not mean Haiku now runs on ARM, as it has been able to do that for a while now. The goal of these changes and improvements is to speed up development of Haiku’s ARM build, and to simplify the distribution of ARM builds into a single, generic ARMv7 image.