rajamesandClaude Opus 5.5
01c447f9ab
A v4 node no longer reads its own command line or prints a prompt. Its host puts a line of text in the node's input buffer and starts it at (LINE); the node interprets it and stops at (IDLE), leaving in (LINE-STATUS) how it ended: completed, an error, or QUIT. The host says " ok" or " ERROR" and prompts, as the kernel's REPL does for a v3 VM. A line may be 1024 characters, a block, as v3's. Ruled 2026-10-05 (V3-PARITY.md 1b); design ENGINE.md 3.1. - quit.v4: (REPL), the node's prompt loop, is gone; (LINE) (IDLE) (DONE) - image.h/.c: v4_line_begin, v4_line_done, v4_line_status; the node is idle at switch-on - boot.c: v4_boot_line, the one loop the hosted binary, the kernel and the capsule loader hand a line with; the code that took " ok" and the prompt back out of the node's output is gone - hosted.c, sk_v4.c: the prompt and the line editing are the host's - test_host_quit.c: the tests are the node's host; two tests of the old 80-character prompt line now test a whole line, 1024 and 1025 characters Verified: make -C v4 test passes at both widths; hosted-check passes on three ISAs; clean qemu with STARFORTH_V4=1 on amd64, aarch64 and riscv64 passes POST (550 of 550) with the same hashes as hosted, and three lines typed at each bare-metal prompt through the serial port are answered correctly (logs/20261005-180922, -181152, -181541). Still the lone node: kernel_main.c starts it before the fleet tables. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
v4/
StarForth v4: the 32-instruction F18-derived core. The design lives in
docs/v4.0.0/JUSTIFICATION.md (why) and docs/v4.0.0/DECOMPOSITION.md
(every v3 word mapped to a v4 fate).
The first deliverable is the hosted C99 golden model (JUSTIFICATION.md §10,
step 1). It must pass POST and hold K≡1.0 with 32- and 64-bit cells on all
three host ISAs.
Acceptance (JUSTIFICATION.md §16): v4 must be equivalent to v3 at any point
in time, with the same vocabularies and behaviour, on the F18-derived engine;
and every ISA, hosted and bare metal, must still reach its ok prompt.
make -C v4 test passing is a development check, not acceptance.
What exists so far is the single node: registers, circular stacks, memory, all
32 opcodes, per-opcode and per-call-target heat, and three console
registers (CONSOLE-TX, which captures output, and CONSOLE-RX and CONSOLE-STATUS, which hand out
input a test feeds) standing in for the console node until the mesh exists. The tests load definitions
onto a node either opcode by opcode (v4/include/v4/asm.h) or as text in the notation DECOMPOSITION.md
uses (v4/include/v4/text.h). make -C v4 test builds
and runs the tests at both cell widths; make -C v4 sanitize repeats them
under ASan and UBSan. There is no POST and no K measurement yet.
The system: nucleus, capsules, prompt
docs/v4.0.0/NUCLEUS.md is the design. A v4 system is four things:
| Part | Where | What it is |
|---|---|---|
| Engine | v4/src |
The golden model of the 32-opcode node |
| Nucleus | v4/capsule/*.v4, built by v4/tools/mkimage.c |
The assembled words, as a memory image linked into the binary |
| Capsules | capsules/v4/*.4th, baked by tools/mkcapsule.c |
FORTH source, loaded when the system comes up |
| Boot | v4/system/boot.c |
Starts the nucleus, checks and loads each capsule, prints the parity lines, gives the prompt |
Two products link the same four and differ only in the console:
- Hosted Linux,
v4/tools/hosted.c:make -C v4 hostedbuildsv4/build/starforth4-amd64,-aarch64and-riscv64, static, 64-bit cells. - Bare metal,
kernel/src/v4/sk_v4.c:make -f kernel/Makefile ARCH=<arch> STARFORTH_V4=1.
A boot prints:
PARITY:V4_NUCLEUS words=292 image_hash=0x...
PARITY:V4_CAPSULE name=v4:forth79.4th capsule_id=0x... capsule_hash=0x... dict_hash=0x...
PARITY:OK
ok>
Every build of one commit prints the same hashes. make -C v4 hosted-check
boots the three hosted binaries (the two foreign ones under user-mode QEMU)
and fails unless their output is identical and ends in PARITY:OK.
A capsule line the node does not answer ok to ends the boot, naming the
capsule, block and line, with PARITY:FAIL and POST: FAILED.
State, 2026-10-05, after ENGINE.md step 1: all six builds start the nucleus,
load v4:forth79.4th, pass POST and reach ok>, with the same lines:
PARITY:V4_NUCLEUS words=295 image_hash=0x3b5a9a7a2f7c5361
PARITY:V4_CAPSULE name=v4:forth79.4th capsule_id=... dict_hash=0xc45c4db43ea0b1f1
PARITY:V4_POST tests=550 pass=550 fail=0
PARITY:V4_CAPSULE name=v4:post79.4th capsule_id=... dict_hash=0x88df0873060da73e
PARITY:OK
POST: PASSED
ok>
Bare-metal logs: logs/20261005-180922/amd64/, logs/20261005-181152/aarch64/,
logs/20261005-181541/riscv64/. On each, three lines were then typed at the
prompt through the serial port — a definition, its use with the capsule's
U*, and an unknown word — and each answered as the hosted binary does. The
capsules were unsigned (no signing key on this machine).
A node is handed a line (docs/v4.0.0/ENGINE.md 3.1). It does not read
its own command line and prints no prompt. Its host puts the text in the
node's input buffer and starts it at (LINE); the node interprets the text
and stops at (IDLE), leaving in (LINE-STATUS) how it ended. The host says
ok or ERROR and prompts, as the kernel's REPL does for a v3 VM. A line
may be 1024 characters, a block. v4_line_begin, v4_line_done and
v4_line_status (v4/include/v4/image.h) are that interface;
v4_boot_line (v4/system/boot.c) is the one loop the hosted binary, the
kernel and the capsule loader all run it with.
This is still the lone node. On bare metal kernel_main.c starts it
before the fleet tables, beside the kernel's own system and not in the VM's
place. ENGINE.md sets out the steps from here; step 1 is the only one
done. V3-PARITY.md records the rulings it is built from.
What this does not yet show. forth79.4th holds two definitions, U*
and U/MOD. Every other word is still in the assembled nucleus, so POST is
so far a test of the assembled words. Moving them to the capsule, a group at
a time with POST after each, is the next step (NUCLEUS.md section 8).
POST
capsules/v4/post79.4th: 550 cases in blocks 7000 up, covering 126 of the
130 words of the FORTH-79 Required Word Set. 443 are v3's cases with what
the hosted v3 binary did as the expected result. The other 107, and the 27
v3 cases left out, are listed with reasons in docs/v4.0.0/POST79.md.
make -C v4 postboots the amd64 system: the quick check after a change.make -C v4 hosted-checkboots all three hosted ISAs and compares them.make -C v4 post79writes the capsule again (tools/mkpost.py,tools/post79_rules.py); it needs the hosted v3 binary.
POST is FORTH: a harness of FORTH-79 words and two nucleus hooks, (CATCH)
and (EMIT-HOOK). It forgets itself when it has finished. The boot passes
only on seeing POST's tally line with fail=0 (v4/system/boot.c). A colon
definition broken on purpose (U/MOD without its last SWAP) fails five
cases and the boot stops with POST: FAILED.
Not tested: KEY, EXPECT, QUERY (the keyboard) and QUIT (it returns
without ok).
Open: PAD 42 OVER ! faults on v4, because PAD is a byte address and !
takes a cell address (D-1). FORTH-79 expects it to work. The v3 case for it
is left out until that is ruled.
The Required Word Set list in tools/mkpost.py was written from memory of
the standard and has not been checked against the document.