569f05debc
All six validation scripts (xhci-irq, msix, ps2, timer, iommu, usb-storage) booted build/<arch>/<config>/harddrive.img, which is only produced by older make-all flows and goes stale (the Jul-17 image). Running them against it measured the wrong tree — the same trap that produced the false '+rb0.3.0' bootloader reading and the first hub-test failure. Each now prefers build/<arch>/<config>.iso via -cdrom and only falls back to harddrive.img when no ISO exists. extra.img and usb-storage.img remain as data drives in both modes.