VERIFY.md

Verification handoff

All code in this repo was written without sbt, zig or ngspice available, so nothing has been compiled or run. This file is the checklist for whoever verifies it first. Fix what breaks with minimal changes and report what you changed.

Run in order

cd rtl      && sbt test                       # Chisel 3.6.0 / chiseltest 0.6.2
cd rtl      && sbt run                        # emits rtl/generated/CcuMmio.v
cd firmware && zig build test                 # needs Zig 0.13.x
cd firmware && zig build                      # RV32IM freestanding ELF
cd spice    && ngspice -b nexus_nand.sp       # must print t_emergence

Highest-risk spots (my best guesses at what fails)

1. rtl/build.sbt: the addCompilerPlugin line and dependency versions (Chisel 3.6.0 needs the chisel3-plugin; check Scala 2.13.10 resolves).
2. CcuMmio.scala: switch/is with 0x00.U literals, and Elaborate using chisel3.stage.ChiselStage (deprecated but present in 3.6).
3. IntentNexusSpec.scala: the saturation test steps 300 cycles; the reset-on-bind test expects entropy to read 0 one cycle after passionBound.
4. firmware/build.zig: Zig build API moves between releases; written for 0.13 (b.path, resolveTargetQuery, cpu_features_add).
5. firmware/src/main.zig: callconv(.Naked) + inline asm _start, and the 0.13-style pub fn panic signature. The linker script entry symbol and section names (.text.init) must line up.
6. firmware/src/ccu.zig: fence() uses asm volatile ("fence iorw, iorw" ::: "memory"); the host test builds on x86/arm, where it compiles to nothing. The test's fake register block cannot react to writes (see below).
7. spice/nexus_nand.sp: .measure syntax differs across ngspice versions; models.lib is a level-1 placeholder, not a real 32nm PDK.

Known limitations (not bugs to "fix" silently)

• The Zig host test pre-loads the product into the fake register block, so it checks layout and error handling, not multiplication. RTL tests cover the math.
• Zig Registers offsets must match CcuMmio.scala (0x00/04/08/0C/10). A cross-check (e.g. a generated header) does not exist yet.
• SPICE timing numbers are meaningless without a real process library.

Report back

For each command above: pass/fail, the exact error, and the diff you applied. If CI (.github/workflows/ci.yml) disagrees with your local result, say which tool versions differ.