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land #58: C64 Ultimate support (stacked-merge follow-up) - #59

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docs/baseline-catchup-2026-07
Jul 20, 2026
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land #58: C64 Ultimate support (stacked-merge follow-up)#59
JC-000 merged 3 commits into
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docs/baseline-catchup-2026-07

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@JC-000JC-000 commented Jul 20, 2026

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Follow-up to land the already-approved #58 content onto master.

#58 was stacked on docs/baseline-catchup-2026-07 (per the baseline-catchup pattern); #57 merged first, so #58's squash (8c47854) landed on the baseline branch rather than master. This PR carries exactly that squash — the diff vs master is the 6-file C64U session change set already reviewed in #58. No new content.

🤖 Generated with Claude Code

JC-000and others added 3 commits May 23, 2026 17:10
CLAUDE.md was partially updated during the session that produced
PRs #51-#55; several sections survived with pre-bump claims that no
longer match reality. This commit refreshes them in one pass:
- Crypto ABI: bump x25519 sibling pin v0.4.0 -> v0.6.0; mark P-256
as c64-lib-contract SPEC-aligned with the make -C libs/<X>
lib-VARIANT integration pattern.
- MEMORY requirements: rename CRYPTO -> CRYPTO_HOT (UCI) /
CRYPTO_RESIDENT (ip65) per the W1 hot/cold split; cross-link
c64-lib-contract repo + docs/library-ingestion-architecture.md.
- Build vars: document USE_X25519_SIBLING + EMBED_P256_OVERLAY.
- UCI Memory layout: collapse to a pointer at the post-W1 table
below.
- Known issues: rewrite the X25519 sibling block for v0.6.0 + the
post-W1 split; replace MemoryPolicy note with the centralized
VICE helper (tools/_vice_helpers.py::default_vice_config).
- ECDSA P-256 wall-clock: update to 82.1 s under v0.3.0 (was 86.7 s
under v0.2.0); drop the v0.2.0-era defensive-init footnote.
- Memory layout: replace pre-W1 monolithic CRYPTO table with the
full UCI + ip65 post-W1 layout; document the ip65 CRYPTO_COLD_SHADOW
1,662 B overflow tracked at c64-nist-curves#54.
docs/library-ingestion-architecture.md gets a "Status as of 2026-05-23"
appendix snapshotting which §3 library-side issues and §4 c64-https-side
work items landed via PRs #51-#55 vs. are still in-flight (Task #12 /
P-384 wall-clock / CI bot).
No source / cfg / integration script / submodule changes.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
…ne (#58)
* fix(uci): widen uci_fence to keep 35% margin at 64 MHz
The C64 Ultimate tops out at 64 MHz, where the old 2525-cycle fence
(INNER=100, tuned for 48 MHz) shrinks to ~39.5 us — only ~4% over the
FPGA's ~38 us floor. Bump UCI_FENCE_INNER to 131 (~3300 cycles):
51.6 us at 64 MHz (35.7% margin), 68.8 us at 48 MHz, ~3.3 ms at
1 MHz. Still negligible for networking at every speed.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UZmMaxyyykvYbCvJAc4QVW
* feat(uci): interface-fallback DHCP acquire for C64 Ultimate WiFi
The C64 Ultimate has Ethernet AND WiFi; GET_IPADDR(iface=0) returns
0.0.0.0 when the box is on WiFi, which the old single-shot
net_dhcp_acquire surfaced as DHCP FAILED (UCI_ERR_NO_IP). Probe
interface indices 0..3 and take the first non-zero lease; clean up
(drain + ack) after a CMD_FAILED probe so the next one starts from
idle. Clear net_last_error on success so no-lease residue from
earlier probes doesn't sit next to a good acquire.
Costs ~38 B in NET_CODE — boundary with NET_BSS_TAIL shifted by $40
($1B26 -> $1B66); NET_BSS_TAIL occupancy is $625 so $75 slack
remains. Verified on C64 Ultimate firmware 1.1.0 (WiFi): phase2_check
PASS, IP acquired on iface 1.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UZmMaxyyykvYbCvJAc4QVW
* fix(uci): retune uci_fence for C64 Ultimate burst floor
The C64U (firmware 1.1.0, core 1.49) needs more inter-access time
than the U64E's empirical ~38 us, and only under sustained CMD_DATA
bursts: at 51.6 us spacing (INNER=131 @ 64 MHz) GET_IPADDR works but
TCP_CONNECT's ~15-byte hostname push is silently lost
(UCI_ERR_NO_SOCKET, no SYN ever leaves the box). Floor bracketed at
64 MHz: 51.6 us FAIL / 62.9 us PASS / 100 us PASS. Ship INNER=217
(5450 cycles = 85.2 us @ 64 MHz) for 35% margin over the worst-case
floor; 113.5 us @ 48 MHz, ~5.5 ms @ 1 MHz — negligible for
networking on both devices.
E2e verified on C64U: 64 MHz PASS (64.7 s), 48 MHz PASS (73.0 s).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UZmMaxyyykvYbCvJAc4QVW
* test(uci): set turbo before boot — C64U runtime-switch quirk
On the C64 Ultimate, a REST config CPU-speed change while the PRG is
running can glitch the UCI bridge so the next pushed command is
silently lost — reproduced 2x as UCI_ERR_NO_SOCKET on the first
TCP_CONNECT after a 1->64 MHz switch, even with a 100 us fence
(1->48 happened to survive). Move set_turbo_mhz before
reset/run_prg so the machine boots at target speed and never
switches mid-session; also makes boot speed deterministic instead
of inheriting the previous run's config.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UZmMaxyyykvYbCvJAc4QVW
* docs: C64 Ultimate notes + 48/64 MHz benchmarks
New bench device: C64 Ultimate Starlight (10.53.21.158, fw 1.1.0,
core 1.49, NTSC, WiFi). Documents the 64 MHz speed enum, the
runtime speed-switch quirk, the wider fence floor, multi-interface
GET_IPADDR, REU-disabled default + set_reu() incompatibility, and
the new P-256 e2e numbers: 73.0 s @ 48 MHz, 64.7 s @ 64 MHz.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UZmMaxyyykvYbCvJAc4QVW
* bench+docs: 48/64 MHz verify scaling analysis — REU DMA is the wall
bench_ecdsa_u64e.py: the post-W1 MemoryPolicy blocks the bench's DMA
writes of vector inputs into CRYPTO_BSS (now in CRYPTO_COLD_SHADOW);
pass override= with a reason instead of widening the policy.
Measured on C64U: ecdsa_verify_256 53.8 s @ 48 MHz / 47.4 s @ 64 MHz.
T(f) = D + C/f fits both e2e and verify pairs to 0.1 s:
verify D = 28.4 s speed-invariant vs C = 1.22 Gcycles CPU-scaled.
D matches fp_mul's REU row-fetch volume (~27 MB/verify) at the
stock ~1 MB/s DMA rate that turbo does not scale (consistent with
the 16 ms overlay-swap datapoint). e2e adds ~11.4 s of UCI/network
D. Conclusion documented in CLAUDE.md: >48 MHz clocks are mostly
wasted on this fp_mul; the fix is library-side.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UZmMaxyyykvYbCvJAc4QVW
---------
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
…E.md)
Resolves the squash-vs-original docs conflict by taking the session
tree's CLAUDE.md, which also restores the c64-nist-curves#69 link +
paragraph fix (633a972) that #58's squash predated.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UZmMaxyyykvYbCvJAc4QVW
@JC-000
JC-000 merged commit 80dff5b into masterJul 20, 2026
@JC-000
JC-000 deleted the docs/baseline-catchup-2026-07 branch July 20, 2026 01:59
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