The flip that makes the mount path the volume's content id. fat retires its
hardcoded fat_mounts: it reads its mount path from argv[2] (the volume manager
hands it the id-path, e.g. /volumes/fat-12345678, from the FAT serial), mounts
its volume root there, and installs the /system/configuration + /system/logs FHS
rewrites so /system/logs persistence stays decoupled from which volume backs it.
The rewrites are unconditional this increment (the single volume IS the boot
volume); S3 makes them content-conditional across N volumes. Every /volumes/usb
reference migrates to /volumes/fat-12345678 in one commit — the fat-test,
badge-scope-test, and vfs-test fixtures and the four QEMU regexes — plus a new
volume-identity-name case asserting the id-path mount and the /system/logs
rewrite. Discrimination: the regexes now require /volumes/fat-12345678, which the
old hardcoded fat never emitted (it mounted /volumes/usb). Full suite 128/128.
Daniel Samson
df61693065