workspace-maintenance

name	workspace-maintenance
description	Use when maintaining the AGC-in-Rust workspace — Cargo.toml changes, feature flags, dependency hygiene, linting, formatting, bare-metal target configuration, probe-rs setup, or CI validation.
argument-hint	Describe the Cargo, workspace, dependency, or build maintenance task

Rust Workspace Maintenance — AGC-in-Rust

When To Use

• Add or adjust workspace members (agc-core, agc-sim, agc-test) or Cargo configuration
• Review dependency hygiene or feature flags
• Fix formatting, linting, or verification workflows
• Maintain embedded target setup (thumbv7em-none-eabihf, probe-rs, flip-link)
• Verify no_std compliance has not been broken by a dependency change
• Prepare CI checks

Procedure

1. Inspect workspace structure and relevant Cargo.toml files before making changes.
2. Keep dependency changes minimal. Prefer existing crates and the standard library.
3. Verify embedded target config: .cargo/config.toml must specify thumbv7em-none-eabihf as the default target for agc-core, probe-rs as the runner, and flip-link as the linker wrapper.
4. Treat feature flags as additive. Avoid features that silently remove behavior.
5. agc-core is always #![no_std]. The sim feature enables agc-sim to link against it with std.
6. Validate with the narrowest command first, then broaden to workspace-level.

Workspace Layout

agc-in-rust/
  Cargo.toml              workspace definition
  agc-core/               #![no_std], #![no_main] — flight software
  agc-sim/                std allowed — simulator + hosted HAL
  agc-test/               integration tests, VirtualAGC fixtures
  .cargo/config.toml      target triple, runner, linker

Feature Flags

# agc-core/Cargo.toml
[features]
default = ["sim"]
sim = ["std"]        # host simulation
bare-metal = []      # no std, no heap, hardware target

Required Dependencies (agc-core)

Crate	Role	Note
cortex-m	Mutex, interrupt::free, SysTick	Required for shared state pattern
cortex-m-rt	#[entry], #[exception]	Startup only; NOT the source of #[interrupt]
embedded-hal v1	HAL trait abstractions	Used inside bare-metal HAL structs
stm32f4 (or target PAC)	#[interrupt] with name verification	Re-exported as pub use stm32f4 as pac
cortex-m-semihosting	Dev-build panic logging	#[cfg(debug_assertions)] only
defmt	Structured probe logging	Dev builds only

Explicitly forbidden in agc-core: alloc, std, panic-halt, any RTOS crate, Vec, Box.

.cargo/config.toml

[build]
target = "thumbv7em-none-eabihf"

[target.thumbv7em-none-eabihf]
runner = "probe-rs run --chip STM32F405RGTx"
rustflags = [
  "-C", "link-arg=-Tlink.x",
  "-C", "link-arg=-flip-link",   # stack overflow detection
]

[profile.release]
opt-level = "s"
lto = true
codegen-units = 1

[profile.dev]
debug = true

Common Checks

cargo fmt --all
cargo clippy --workspace --all-targets -- -D warnings
cargo test --workspace
cargo build --target thumbv7em-none-eabihf -p agc-core   # bare-metal build must always pass
cargo doc --no-deps -p agc-core
cargo audit
cargo udeps --workspace                                   # when cleaning dependencies

no_std Compliance Verification

After adding any new dependency to agc-core:

cargo build --target thumbv7em-none-eabihf -p agc-core --no-default-features

If this fails with error[E0463]: can't find crate for 'std' on a transitive dependency, that dependency must be pinned to its default-features = false variant.

Delivery Checklist

• agc-core bare-metal build passes after changes
• No new std-only dependency added to agc-core
• No alloc or heap-allocating types introduced in agc-core
• Feature flags remain additive
• cargo clippy -- -D warnings clean across workspace
• cargo audit clean
• No dbg!, stray hprintln!, or commented-out code left in workspace