I’ve updated https://github.com/beagleboard/beaglebone-black/blob/master/BBB_SRM.pdf such that we can use it as a template for future SRMs as well as to accept community edits.
Source is at https://github.com/beagleboard/beaglebone-black/wiki/System-Reference-Manual in asciidoc format. PDF conversion done with asciidoctor-pdf. Looking to move to asciidoctor.js in the future.