Rectangular ST7735 blocking controls — qualification pending

This next P3 slice extends crates/core/tests/st7735_sam_guest.rs, not the production model or PyBadge wiring. The existing four tests remain; a fifth authored Cortex-M test adds a nonzero, non-square controller-memory window and an intentionally wrong-axis negative, in ordinary and forced-legacy SPI paths. No local emulator execution or hosted passing result is claimed yet.

Literal vector and independent expectations

The reviewed public input is CODAL ST7735.cpp at 312ae57e, SHA256 d8aafbdd338c9501c314f33983eb1ceb1229bc0acfcd10c28a4d2527d756c805. Its setAddrWindow(7, 11, 3, 2) describes CASET 11..12 and RASET 7..9. The driver coordinates are not silently relabelled as physical columns/rows. With MADCTL at its zero reset value, the fixture's fixed controller-memory crop is columns 11..12 and rows 7..9 (2×3), not a deployed module aperture.

Ordinary, non-doubled indexed bytes 21 43 65 describe indices 1..6, lower nibble first. The literal RGB444 wire vector is 11 12 22 33 34 44 55 56 66. The guest uploads an independently authored, channel-distinct nonlinear LUT, not CODAL's production palette. Expected LUT addresses are literal R/G/B triples [1,33,97] through [6,38,102], in physical row-major order. Neither expected addresses nor wire bytes call the emulator's mapping/codec helpers. Every byte travels through guest SPI DATA and TXC polling, with CS paused between bytes, including within parameters and packed pixels.

The negative changes only window dimensions to three columns by two rows. SPI must still complete, but the declared crop must report four known and two unknown pixels and withhold frame bytes. This catches an axis/window error that the older symmetric 2×2 positive cannot expose. No host MMIO setup, pixel RAM injection, completion seeding or guest-controller replacement is used.

Acceptance and still-open work

Require all five guest tests to execute and pass in the hosted feature-on and feature-off jobs, plus all enabled exact-head checks. Record source and guest hashes, original failed results and tested/landed tree identities before merge. No floor, catalogue allowance, production descriptor, app pin or capture moves.

This source review and literal authored trace do not execute the compiled CODAL driver. Continue the full P3 follow-on contract: actual driver extraction/execution, all advertised orientations, odd-pixel command interruption, retained RAM under orientation/LUT/reset changes, deployed CF2/macros and module aperture/GM evidence. BGR/glass rendering, IRQ/DMA, native Arcade, active-frame RTx, new-panel WASM rendering and consumer adoption remain unqualified. A single passing rectangular guest must not mark P3 or CP14 done.

Referenced source notice

The vector is authored from the referenced public protocol layout; preserve the source's notice when carrying driver-derived material forward:

MIT License

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