# DF-2489 verification environment (QEMU/KVM guest, single-tenant)

## Stock (baseline) kernel
DragonFly dfbsd 6.5-DEVELOPMENT DragonFly 6.5-DEVELOPMENT #0: Thu Jul 2 06:02:54 UTC 2026
    root@dfbsd:/usr/obj/usr/src/sys/X86_64_GENERIC x86_64
kernel sha256 (stock) = 5dc83dac19ad09effd6241c33e0c0669d41b6497ee92d87d3a2e45f287bc22ad
kernel own ad_attach (nm, local t) = 0xffffffff80328d30
trap IP go2/go3 = 0xffffffff80328f7b = ad_attach+0x24b  (divq, ata-disk.c:147)
nata (ata-*.c incl. ata-disk.c, atapi-cam.c) is BUILT INTO the kernel
(only ehci.ko/xhci.ko + the rig at boot); root disk is virtio (vbd0s1a),
no ad* devices exist on the guest, unit 0 is free for the funnel.

## Source under test
guest /usr/src/sys/dev/disk/nata/ata-disk.c
baseline sha256  8773a2dfc4cfc372b1d2be6c2775fd72e0445e56cdc974615fb94654f6b78de1
                 (== audited sys/ tree, checker-verified in build.log)
patched (fix validation) sha256  0145d54bcb711f82912772515ceecfca64f3f5f9757caa432126927ea2a9f452

## Fixed kernel (fix validation)
built: cd /usr/src && make -j6 nativekernel KERNCONF=X86_64_GENERIC &&
       make installkernel KERNCONF=X86_64_GENERIC        (fix_build.log)

## Rig build
cc (DragonFly) -O2 -std=gnu11 -Werror -DKLD_MODULE, KLD dfrig2489.ko,
loaded AT BOOT via /boot/loader.conf (dfrig2489_load="YES"); on this
INVARIANTS guest runtime kldload GPFs (per audit-guest guidance).
Scenarios fired from a dedicated kernel worker thread holding the MP
token (the boot-attach context; the built-in atapicam driver's attach
asserts it).

## Hardware gating note
No physical ATA channel exists under this QEMU (root is virtio-blk);
the rig replaces only the hardware-facing seams (channel device graph,
IDENTIFY/data/CONTROL answers via hw.begin_transaction, the ata_if
DEFAULT setmode/locking methods) -- the entire path from the IDENTIFY
bytes through ata_getparam/ata_identify/newbus/ad_probe/ad_attach to
the faulting division is production code, kernel-binary for go1/2/3.