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NAMEWALK-COMPLETE: the directory-entry + name-walk machinery (L07, 006-S3FS)

Byte-verified carve of the complete name-resolution machinery that @ENTER-DIRECTORY uses: how a directory spec is parsed and how an object name is matched to an on-disk directory-entry index. This carves COLDE's name-walker callees fully - every path.

  • Disassembly source: ../../segments-ref/006-S3FS/006-S3FS.asm
  • Binary: ../../../segments/006-S3FS.bin (load base 26000B, big-endian)
  • sha256(006-S3FS.bin) = b4a563d0715a6304a35167ec5ff0090c92b0b99dd743aef159ac6b182e080585
  • Byte offset (decimal) of any address A = (A_oct - 26000B) * 2.
  • Companion files: NAMEWALK-COMPLETE.ASM, NAMEWALK-COMPLETE.pseudo.c.

All addresses/values are OCTAL. Every claim tagged VERIFIED (read from the bytes here), INFERRED, or OPEN.

This folder does not re-carve COLDE's entry split (that is in ../COLDE-CONNECT/) nor the block-0 device read (CHDSI->RXDIR->RCBLO, also in ../COLDE-CONNECT/). It carves the callees COLDE reaches while resolving the name.

1. Headline result

The whole name-walk family issues NO device transfer. It is pure in-core walking over two per-directory tables (VERIFIED - every callee's body only touches tables and resident helpers, never a driver vector):

Table 2-word entry accessor (read) write / default siblings
DIRECTORY table GDIRT 050124B PDIRT 050132B, GDDRT 050121B, PDDRT 050127B
NAME table GNAMT 050223B PNAMT 050231B, GDNMT 050220B, PDNMT 050226B

The block-0 read that the SCSI mount is missing is not in this machinery; it is CHDSI -> RXDIR -> RCBLO -> driver and the read-vs-fn42 fork lives in the SCSI disk driver (065-S3SIPIT). See ../COLDE-CONNECT/.

2. Full call graph (VERIFIED from resolved pointer words)

ENDIR 140176B  (@ENTER-DIRECTORY top; see ../ENTER-DIRECTORY/)
  |
  |-- CLPAR   044777B   parse/classify the spec's leading letter(s)
  |     |-- 003752B     resident enter/setup
  |     `-- GTTCH 030070B   get one spec character   (called x2)
  |
  |-- COLDE   132072B   cold-enter: DRIVE the name walk (NO device I/O)
  |     |-- 003752B     resident enter/setup
  |     |-- CLPAR  044777B   classify parameter
  |     |-- GDIRT  050124B   read directory-table entry (loop)
  |     |-- GNAMT  050223B   read name-table entry
  |     |-- 004735B    resident helper (COLDE-only; role OPEN)
  |     |-- GNAMI  047536B   pack ASCII name + probe name table
  |     |     `-- GNAMT 050223B   fetch name words
  |     `-- GNAMA  030235B   name-entry address arithmetic (leaf)
  |
  `-- GDIRE   131732B   resolve NAME -> directory-entry index (hash-chain walk)
        |-- 003752B     resident enter/setup
        |-- GNAMT  050223B   walk the NAME-table hash chain
        `-- GDIRT  050124B   read candidate DIRECTORY entries + confirm match

Shared leaves used by the accessors:
  GDIRA 030225B   directory-entry address arithmetic (leaf; byte-identical to GNAMA)
  GNAMA 030235B   name-entry address arithmetic       (leaf)
  GNEXM 050025B   scan directory table for NEXT matching entry (via GDIRT)

Pointer-word resolutions (the JPL/JMP indirection targets):

CLPAR : [045121]=003752 setup   [045122]=030070 GTTCH
        [045123]=040730 token-handler   [045124]=045650 return
GNAMI : [047643]=003752 setup   [047646]=050223 GNAMT
GDIRT-body : [050212]=003752 setup
GNEXM : [050112]=003752 setup   [050117]=050124 GDIRT
GDIRE : [132044]=003752 setup   [132046]=050223 GNAMT   [132052]=050124 GDIRT

3. What each helper does, and its paths

CLPAR 044777B - parse/classify the spec parameter

Reads two characters through GTTCH (030070B), then runs a decision tree matching them against ASCII letters {A B D F I L O P S U X} (octal 101,102,104,106,111,114,117,120,123,125,130). A recognised token jumps to the accepted-token handler ([045123]=040730); an unrecognised one rejects at 045125B.

  • Paths: recognised token -> handler -> return; reject -> 045125B.
  • VERIFIED: it calls GTTCH and compares ASCII letters (bytes).
  • Naming discrepancy (OPEN): ../COLDE-CONNECT/ labelled CLPAR "clear parameter block". The bytes show a character parser, not a memory clear. The exact grammar it accepts is OPEN, but it is definitively a parser.

GDIRT 050124B / GNAMT 050223B - 2-word table-entry accessors

Each is the read/user stub of a 4-way BSET-split family that falls into one shared body (exactly the RDISK/WDISK and COLDE/DCOLD/XCOLD idiom):

SSM=1 SSK=0  get DEFAULT entry   (GDDRT 050121 / GDNMT 050220)
SSM=0 SSK=0  get USER    entry   (GDIRT 050124 / GNAMT 050223)   <- walk reads
SSM=1 SSK=1  put DEFAULT entry   (PDDRT 050127 / PDNMT 050226)
SSM=0 SSK=1  put USER    entry   (PDIRT 050132 / PNAMT 050231)

Shared directory body 050134B: enter_setup; compute entry address (index+1)*W + base; range-check against upper/lower bounds (error status 174B below-range); then copy exactly two words either table->params (GET) or params->table (PUT), selected by SSK. Name body 050233B is structurally identical.

  • Paths: GET (SSK=0), PUT (SSK=1); DEFAULT (SSM=1) vs USER (SSM=0); plus the above/below range-error arms.
  • VERIFIED: BSET flag ordering, 2-word copy, range checks, (index+1)*W+base.
  • INFERRED: SSM = default-vs-user (from the G*D* / G*I* naming).

GDIRA 030225B / GNAMA 030235B - leaf entry-address calculators

6-word leaf routines (no stack frame). Given base pointer in A and entry index in T, compute entry_addr = (index+1)*W and exchange into X. They are byte-identical (VERIFIED) - the directory table and name table share the same calculator and stride.

  • VERIFIED: (index+1)*W shape (MPY and ADD use the same operand), and that GDIRA == GNAMA byte-for-byte.
  • OPEN: the source of the stride operand W (P-relative constant vs caller B-relative) - not resolvable from these 6 words alone.

GNAMI 047536B - build/search the name index

Packs an ASCII object name (loop bounded at 7 chars) into name-table word form, then probes the NAME table (reading slots via GNAMT) with a 3-way result dispatch and returns the resolved slot:

  • Paths: free slot (047600B, advance buffer +16B, retry/insert; table-full check at 047606B, statuses 30B/31B); match (047627B); grow (047633B); error arm (047640B).
  • VERIFIED: char-pack loop, GNAMT probe, 3-way dispatch, statuses.
  • INFERRED: exact packed-word field layout.

GDIRE 131732B - GET DIRECTORY ENTRY BY NAME (the name-matcher)

The core name->entry resolver. Reads the NAME-table chain head via GNAMT, then hash-walks a chain: for each cursor it reads directory entry words via GDIRT, skips empty slots, strips a flag bit from the target name, folds the entry's hash bits and does a primary compare then a secondary masked compare. On full match it re-reads the entry (GDIRT), classifies the entry-type bits, and returns the matched index. Chain advance adds 30B to the hash bucket and ++cursor.

  • Paths: full match -> classify + return index (132015..132040B); primary mismatch / empty slot -> advance (132004B); chain exhausted -> status 33B "not found" (132011B); table-read error arm (132041B).
  • VERIFIED: GNAMT/GDIRT calls, hash-chain loop, dual compare, not-found 33B.
  • INFERRED: precise hash-fold semantics and the entry-type classification codes (147B/34B/26B).

GNEXM 050025B - scan for next matching directory entry

Linear scan of the directory table (entry stride 55B) via GDIRT, unsigned key compare, until match; status 43B on not-found. Part of the same family, used for enumeration rather than COLDE's primary lookup.

4. How a directory name is parsed and matched (end to end)

  1. Parse. CLPAR tokenises the spec's leading letter(s) via GTTCH, recognising a small keyword/type-code set (VERIFIED it is a parser).
  2. Pack. GNAMI turns the ASCII object name into the packed name-table word form, probing the NAME table (via GNAMT) for a slot.
  3. Match. GDIRE hash-walks the NAME table (GNAMT) and cross-checks the DIRECTORY table (GDIRT) until the matching directory-entry index is found, or returns 33B = not found.
  4. Underneath, GDIRT/GNAMT (with their default/put siblings) are the shared 2-word entry accessors, and GDIRA/GNAMA are the shared leaf address calculators.

Only after the name is resolved does ENDIR reach the single block-0 device read (CHDSI->RXDIR->RCBLO, carved in ../COLDE-CONNECT/). Nothing in this name-walk touches a device.

5. VERIFIED / INFERRED / OPEN

# Claim Status
1 GDIRT/GNAMT are the read/user stubs of 4-way BSET splits (SSM,SSK) into one shared body VERIFIED
2 Shared body copies exactly 2 words, GET vs PUT by SSK, with range checks (174B below-range) VERIFIED
3 Entry address = (index+1)*W + base (dir body) / (index+1)*55B (GNEXM) VERIFIED
4 GDIRA and GNAMA are 6-word leaves, byte-identical, compute (index+1)*W VERIFIED
5 GDIRE resolves NAME->entry index by hash-walking NAME(GNAMT)+DIRECTORY(GDIRT) tables VERIFIED
6 GDIRE "not found" == status 33B; classifies matched entry type before return VERIFIED
7 CLPAR reads 2 chars via GTTCH and matches ASCII letters VERIFIED
8 GNAMI packs the ASCII name (<=7 chars) + 3-way name-table probe (free/match/grow), via GNAMT VERIFIED
9 Whole family issues NO device transfer (only tables + resident helpers) VERIFIED
10 SSM selects DEFAULT vs USER table INFERRED (from G*D*/G*I* naming)
11 CLPAR's exact accepted grammar / the token set semantics OPEN
12 Source of GDIRA/GNAMA stride operand W (P-rel constant vs B-rel) OPEN
13 GNAMI packed-word field layout; GDIRE hash-fold + type-code meanings (147B/34B/26B) INFERRED / OPEN
14 resident 004735B (COLDE-only helper) role; 003752B = common enter/setup OPEN / INFERRED
15 CLPAR = "clear parameter block" (prior label) vs parser (bytes) CONTRADICTED - it is a parser

6. dd byte proofs (big-endian .bin)

All reproduced with dd if=006-S3FS.bin bs=1 skip=<off> count=2 | od -An -tx1:

CLPAR  044777B  off 15358 = 22 51   (021121 STD I 121)
GNAMI  047536B  off 18108 = 22 44   (021104 STD I 104)
GDIRT  050124B  off 18600 = f8 38   (174070 BSET ZRO SSM)
GNAMT  050223B  off 18726 = f8 38   (174070 BSET ZRO SSM)
GDIRA  030225B  off  2346 = cc 6f   (146157 RADD CLD SA DX)
GNAMA  030235B  off  2362 = cc 6f   (146157 RADD CLD SA DX)
GDIRE  131732B  off 69556 = 22 49   (021111 STD I 111)

Each opcode word matches the disassembly in ../../segments-ref/006-S3FS/006-S3FS.asm at the same address. GDIRA and GNAMA share the same first word (cc 6f), consistent with the VERIFIED byte-identity of the two leaves.

  • ../COLDE-CONNECT/ - COLDE/DCOLD/XCOLD entry split; the block-0 read path CHDSI->RXDIR->RCBLO->driver (this folder carves COLDE's name-walker callees).
  • ../ENTER-DIRECTORY/ - ENDIR top level, MON 124B PRSRV, the device seam.
  • ../FUNCTION-42-RETURN/, ../SCSDISK-TRANSFER/, ../SCSI-DRIVER/, ../SMD-DRIVER-BASELINE/, ../RCBLO/ - the device-driver half (out of the name walk).
  • Symbols: ../../segments-ref/006-S3FS/006-S3FS.symbols.txt (FILSYS-SYMBOLS).