Adopt proper embedded tooling for the blank-screen debug (user has a Pi Debug Probe):
- flip-link linker (baked into pm-rust:2): stack overflow faults cleanly instead of
silently corrupting .bss/.data (the SPI buffer -> black screen class of bug).
- defmt + defmt-rtt + panic-probe: firmware logs boot/heap-free/display/parse/loop
heartbeat over RTT; panics print message+location. .cargo runner = probe-rs run.
- Restore the full live metronome (from 08b0940) as the instrumented target.
- deploy + serve pm-kit.elf (probe-rs decodes defmt strings from the ELF).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
First per-board binary. rust/pm-kit/ is a minimal rp235x-hal firmware that blinks
GP25 on the Pico 2 — proves the toolchain, RP2350 boot block (ImageDef), memory
layout, and flash before we add any drivers.
- src/main.rs + memory.x + build.rs + .cargo/config.toml: rp235x-hal blink, builds
for thumbv8m.main-none-eabihf.
- build.sh + uf2.py: one command builds the ELF in the container, objcopies to a raw
image, and packs pm-kit.uf2 (rp2350-arm-s family). Drag onto the Pico 2 in BOOTSEL.
Verified: builds clean; produces a valid 6-block UF2. Runtime (does it blink?) is the
on-device check. Next: drivers (display first) + link pm-core.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
