<i>or maybe people just punch &quot;ARM Architecture Reference Manual&quot; into Google and grab one of the many slightly-outdated copies that are floating around on .edu servers</i><p>That&#x27;s what everyone does, and AFAIK the ARM ISA documentation is public. The lower-level details to do with the core hardware itself&#x2F;how to synthesise the core are NDA&#x27;d, however.