…de_packet,decode_packet} helpers

RFC 8331 wire-format math (10-bit-packed DID/SDID/DC/UDW[]/checksum,
ceil-to-byte, 4-byte align) and the header byte-swap dance are
duplicated across TX build, RX parse, gstreamer, RxTxApp and test
call sites. Add the primitives to st_ancillary.c / st40_api.h as a
pure addition, no call sites migrated yet (follow-up commits).

st40_get_udw()/st40_calc_checksum() are const-correct now (ABI
unchanged). encode_packet()/decode_packet() do the full
parity+checksum+advance dance in one call and reject udw_size > 255
(wire field is 8 bits) with -EINVAL. st_tx_ancillary_session.c
intentionally does not adopt the encoder: its TX_ANC_TEST_APPLY_PARITY
hook needs direct primitive access.

New tests: rfc8331_payload_bytes_test.cpp, rfc8331_codec_test.cpp.

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>

rx_anc_slot_parse_pkt() delegates per-ANC-subpacket wire parsing
(header decode, parity, checksum, UDW extraction) to
st40_rfc8331_decode_packet() instead of hand-rolling it inline.
Partial-success semantics and stat_anc_pkt_parse_err bumps are
preserved; meta_entry->udw_offset is set from the frame-relative
slot->udw_buffer_fill after each successful decode.

Two intentional behavior deltas vs the old inline parser: DID/SDID/DC
parity is now validated (previously wasn't), and the checksum is now
validated even for udw_size == 0 sub-packets (previously skipped,
though RFC 8331 defines the checksum over DID+SDID+DC+UDW regardless
of UDW length). Both are pinned by new tests: DecodeChecksumFailZeroUdw,
ChecksumFailureRecordedForEmptyAncPacket.

Also adds CrossPacketUdwOffsetThreadsAcrossRtpPackets, pinning that
udw_offset threads correctly across two separate RTP packets within
the same frame.

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>

tx_ancillary_session_build_packet()/build_rtp_packet() use
st40_rfc8331_payload_bytes() for the size formula and
st40_rfc8331_rtp_hdr_bswap()/payload_hdr_bswap() at all 9 htonl()
toggle sites in this file. Pure mechanical substitution, no behavior
change (314/314 unit tests pass unchanged).

TX still calls st40_set_udw()/tx_ancillary_apply_parity()/
st40_calc_checksum() directly rather than st40_rfc8331_encode_packet():
tx_ancillary_apply_parity()'s TX_ANC_TEST_APPLY_PARITY test hook needs
direct primitive access, which the single-call encoder can't
accommodate. Documented on encode_packet()'s doc comment so the gap
doesn't need git-archaeology to explain.

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>

Replace manual ntohl/htonl byte-swap pairs with
st40_rfc8331_payload_hdr_bswap() in gst_mtl_st40_rx.c, gst_mtl_st40p_tx.c,
rx_ancillary_app.c and tx_ancillary_app.c.

Also fixes two independent latent formula bugs found while migrating,
both undercounting the aligned payload size by 4 bytes at
udw_size % 16 == 12 (verified numerically over the full 0-255 range):
gst_mtl_st40_rx_shift_payload_hdr()'s bespoke WORD_10_BIT_ALIGN formula
misparses the next ANC sub-packet when triggered; RxTxApp's
floor-division formula sends 4 bytes of uninitialized mbuf tail on TX
and over-advances the payload pointer on RX. Both now use
st40_rfc8331_payload_bytes(), same bug class as 2082f10/c0f12995. New
test pins the exact divergence.

The gstreamer plugin cannot be compiled/tested in this environment
(gstreamer-1.0 dev package not installed); verified by code review and
the numeric proof instead. RxTxApp is covered by the production build.

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>

…pers

Replace manual ntohl/htonl byte-swap pairs and duplicated payload-size
formulas in st40_test.cpp, st40i_tests.cpp and st40_harness.c with
st40_rfc8331_payload_hdr_bswap()/st40_rfc8331_rtp_hdr_bswap()/
st40_rfc8331_payload_bytes().

st40_test.cpp's tx_anc_build_rtp_packet() and rx_handle_rtp() used a
floor-division variant of the size formula (missing the +7 before the
/8 ceil-division, and an alignment step that adds 4 extra bytes when
already 4-byte aligned instead of 0). Adopting the canonical helper
fixes this rather than reproducing the bug. st40i_tests.cpp already
had the correct ceil formula; st40_harness.c's ut40_anc_payload_bytes()
now delegates to the canonical helper instead of duplicating it.

Individual translation units for the two integration test files were
verified to compile cleanly (zero warnings under -Werror -Wall -Wvla);
a full KahawaiTest relink could not be completed in this environment
due to build/tests/ object files being repeatedly evicted between
shell invocations (reproduced on unrelated, unedited files too, so
this is an environment artifact, not a code issue -- see
/memories/repo/build-notes.md). st40_harness.c is covered by the full
unit suite: 314/314 pass.

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>

'From the ST40_TYPE_FRAME_LEVEL transport refactor onwards' describes
what changed rather than how the stat works today. stats_guide.md
documents current behavior, not history — drop the changelog phrasing,
keep the factual description.

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>

…run_gtest

Observed failure mode: an agent called run_gtest relying on port
auto-discovery without checking dpdk_devbind_status first, hit a bare PF
bound directly to vfio-pci (0 VFs, invalid for E810/E830), and spent many
extra tool calls diagnosing multicast-join/IGMP failures before finding
the real cause.

Add a VF-binding check before the first run_gtest call, and a dedicated
"Multicast join / IGMP failure" decision-tree entry.

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>

tx_ancillary_session_build_packet() and build_rtp_packet() built each
ANC sub-packet by hand (did/sdid/data_count/UDW/checksum) because the
BAD_PARITY test hook needed to intercept every parity-encoded field.
Both now call the shared st40_rfc8331_encode_packet() codec instead;
TX_ANC_TEST_APPLY_PARITY is replaced by TX_ANC_TEST_CORRUPT_PARITY, a
post-encode corrective pass on the finished wire buffer.

Deriving room from the accumulated payload offset exposed an unsigned
underflow once the running byte count reached max_pkt_len (the prior
loop-entry break only estimated UDW bit cost, not per-packet fixed
overhead), which wrapped room to a huge value and defeated the new
bounds check. Both loops now bail out via the existing
STI_FRAME_ANC_TOO_LARGE path before the subtraction can wrap, and the
break heuristic uses the exact per-packet byte size instead.

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>

install_dependencies, dpdk_build, ice_driver_rebuild, build_mtl, and the
ecosystem/eBPF build tools returned entire build logs (hundreds to
thousands of lines) inline in the tool result. Add _summarize_output(),
reusing the existing _save_test_log() log-file convention from
run_gtest, to save the full output to build/logs/ and return only the
log path, line count, and last 40 lines. run_gtest now uses the same
helper instead of its own inline tail/log-path logic.

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>

tx_ancillary_test_drop_pkt() called dbg() without a visible
declaration when this header was pulled into a translation unit
that doesn't already include mt_log.h (e.g. the ST40 TX unit-test
harness), failing the debug build with -Werror=implicit-function-
declaration.

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>

St20p/St30p/St40p unit harnesses embed the production RX pipeline
.c files and relied on --allow-multiple-definition to let their
fake transport functions (e.g. ut20p_rx_put_framebuff) override
the real ones. Debug link ordering instead selected the real
st20_rx_put_framebuff(), which dereferenced the harness's fake
transport handle and crashed in mt_handle_acquire().

Each harness now #defines the transport calls to its own stub
names while compiling the included pipeline source, so the
harness never depends on which duplicate symbol the linker
happens to pick.

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>

gst_mtl_st40p_rx (pipeline API) is the correct ST2110-40 RX
element: gst_mtl_st40_rx used ST40P_RX_FLAG_BLOCK_GET, which
reintroduces a preroll-timeout bug the pipeline-API plugin
deliberately avoids with non-blocking polling, and its
include-metadata-in-buffer path truncated multi-bit RFC8331
header fields (line_number, hori_offset, the packed c/s/stream_num
byte) into single bytes. It has no capability gst_mtl_st40p_rx
lacks, so it is removed rather than kept as a second, worse
option.

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>

Adds a `unit` mode to build.sh that configures the root project with
-Denable_unit_tests=true in build_unit/, builds it with ninja, and runs
tests/unit/UnitTest. Reuses the existing buildtype/enable_asan flags
(e.g. `./build.sh debug unit` builds and runs the suite under ASan via
LD_PRELOAD), instead of introducing a separate script with its own env
vars.

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>

dma_dev is a gchar[MTL_PORT_MAX_LEN] member, so its address can
never be NULL. GCC's -Waddress flagged the check in
gst_mtl_common_parse_general_arguments() as always true; keep
only the strlen() emptiness check.

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>

rx_anc_slot_parse_pkt narrows the running udw_buffer_fill sum into
the public st40_meta.udw_offset (uint16_t). The value is currently
bounded by ST40_MAX_META entries of at most 0xFF wire bytes each, well
under UINT16_MAX, but nothing enforced that relationship if
ST40_MAX_META were ever raised. Fail the build instead of silently
truncating the offset.

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>

st40_rx_put_framebuff only checked s_impl->type before dereferencing
s_impl->impl, with no refcount protection against a concurrent
st40_rx_free() destroying the session underneath it. Use
MT_HANDLE_GUARD/MT_HANDLE_RELEASE, the pattern already used elsewhere
for this handle type, to close the use-after-free race.

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>

st20_rx_ops, st22_rx_ops, st30_rx_ops, st40_rx_ops and st41_rx_ops
(notify_rtp_ready), plus the matching TX ops structs
(notify_rtp_done), documented these RTP-level callbacks as Optional.
Each lib create() path actually rejects session creation with -EINVAL
when the callback is unset in RTP_LEVEL mode, so the callback is
mandatory. Also corrects st30_rx_ops which referenced the wrong enum
(ST20_TYPE_RTP_LEVEL instead of ST30_TYPE_RTP_LEVEL).

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>

st40_rx_create() logged "st_rx_audio_ops_check fail" on failure, a
copy-paste leftover from the audio session code path. It actually
calls rx_ancillary_ops_check().

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>

Update the agent routing table, MTL Developer (TDD) and MTL System Admin
agent descriptions, the mtl-build and mtl-write-test skills, and the unit
test README to reference `./build.sh unit` instead of the stale
`./build/tests/unit/UnitTest` path and the manual meson/ninja invocation.

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>

Three st40 unit test files were added with a stale 2025 copyright year;
update to 2026.

Signed-off-by: Kasiewicz, Marek <marek.kasiewicz@intel.com>