# P15-006 Stage0 Decision

Status: `GO`; B07a is complete.

The authoritative baseline replay used commit
`6673f51152a5195a8a8903aa801f820abce7936e`.  This decision is independent of
the earlier P15-005 GO: P15-006 has its own corpus, model digest, source
extractors, byte encoding, and decision record.

The frozen corpus contains 80 map tuples and 13 device-resolution cases.  The
map tuples comprise 50 plain/inline/chunk producer cases and 30 compressed
explicit-extent cases.  They cover plain and inline boundaries, holes, raw
32-bit chunks, indexed 32-bit chunks, indexed 48-bit chunks, masked and
nonzero device IDs, all four explicit extent record sizes, fragments, partial
references, exact and post EOF, provider/metabox bounds, checked arithmetic
overflow, invalid formats and algorithms, and errors both before and after
metadata acquisition.  The device cases separately exercise primary,
multidevice, flat-device, unified-address, missing-provider, range, and
overflow behavior without changing GEOM ownership.

Expected records are produced by an independent arithmetic and on-disk record
decoder whose frozen SHA256 is
`effcf0b6cc6a6e916eae89a14ad52d7b96273a453556647b6eabf2926fcb4abb`.
The gate separately extracts the real `data.c` and `zmap.c` producer bodies
from the frozen BASE, compiles them with `-Werror`, and compares every
`m_la`, `m_pa`, `m_llen`, `m_plen`, `m_deviceid`, `m_flags`,
`m_algorithmformat`, positive errno, acquire count, and release count.  It
also packs those fields with fixed layout `<QQQQH2xIiiII`; the baseline tuple
bytes have SHA256
`8d3fec7ccbdfb7f7c851a494b6ecad02b8a019247bd9486188f8d37c169faedd`.
Two complete baseline replays produced byte-identical tuple, device, and
result files.

Protected hashes freeze the existing plain/chunk and compressed producers,
metadata acquire/put paths, physical I/O path, and device/GEOM mapping bodies.
The candidate replay additionally requires FULL and COMPACT dispatch to pass
all five map flag bits and all tuple fields through the new adapter.  Every
observed acquisition is balanced: the baseline contains 41 paths at 0:0, 30
at 1:1, seven at 2:2, and two at 3:3.  All successful non-EOF mappings have a
positive `m_llen`; Pre13 H07 remains closed.

This closes the specific Pre13 H01 oracle gaps for chunk, multidevice, bounds,
and overflow rather than reusing the old 26 plain/inline/hole tuples.  The
supplied G02 prep remains a non-authoritative prototype and was not used as
the tuple source.

The B07a implementation is commit
`141b11f0d847a63a47b6c6143e4c2913a1147a0f`.  Its authoritative host run
replayed all 80 tuples and 13 device cases against the frozen oracle.  The
4,480-byte tuple streams are byte-identical with SHA256
`8d3fec7ccbdfb7f7c851a494b6ecad02b8a019247bd9486188f8d37c169faedd`;
FULL and COMPACT dispatch preserve every tuple field and all five map flag
bits.  D and both K2 configurations pass, with no global or undefined symbol
delta from B06.

QEMU and the full feature suite were not run.  The final plan requires host
tuple replay, D, and K2 for B07a; it does not require a B07a QEMU fixture.
B07b is now dependency-unblocked for a separate batch.  B07c remains blocked
on B07b, and B08 remains blocked on B07c.  This decision neither implements
nor pre-accepts any of those later batches.