Targets and features

The single reference for what the SDK builds for, and how.

Targets

Target	Chip	Cargo feature	Rust target	Commands
Host	developer machine	–	the host triple	`cargo test`, `cargo clippy`, `cargo doc`
ESP32-C3	ESP32-C3	`esp32c3`	`riscv32imc-unknown-none-elf`	`cargo check-esp32c3`, `cargo build-esp32c3`
ESP32-C6	ESP32-C6	`esp32c6`	`riscv32imac-unknown-none-elf`	`cargo check-esp32c6`, `cargo build-esp32c6`

cargo test                # host: portable crates and desktop tools (default-members)
cargo check-esp32c3
cargo check-esp32c6
cargo build-esp32c3
cargo build-esp32c6

The check-* / build-* aliases are defined in .cargo/config.toml and expand to cargo [check|build --release] -p altruist-urban --no-default-features --features <chip> --target <triple>. Examples: cargo check -p rohi-examples --no-default-features --features <chip> --target <triple>. CI additionally runs cargo fmt --all -- --check, cargo clippy --all-targets -- -D warnings on the host and clippy for the ESP packages per chip.

One chip at a time

Never validate with --all-features. esp32c3 and esp32c6 are mutually exclusive: the firmware features forward to chip-specific esp-hal features, and the build scripts / compile_error!s reject both (or none) at once. Check each chip in its own invocation. The repository has no default embedded target: a plain cargo command builds for the host and the chip is always explicit.

Host default members

cargo test and cargo clippy at the root run on default-members: crates/* and tools/*. The platform crates compile on the host without a chip feature (they are empty), so they are covered; firmware and examples are built per chip only.

Feature flags of the SDK crates

Crate	Feature	Meaning
`altruist-urban`	`esp32c3` / `esp32c6`	chip selection, forwarded to every `-esp` crate and `esp-` dependency
`rohi-hal-esp`, `rohi-config-esp`, `rohi-net-esp`	`esp32c3` / `esp32c6`	chip selection; no feature = empty crate
`rohi-net-esp`	`heap-stats`	track the minimum free wireless heap (small runtime overhead); enabled by the firmware
`rohi-net`	`testing`	in-memory `IpBackend` (`rohi_net::testing`) for host tests; not for firmware

Network stack features

embassy-net is built with tcp, udp, dns, dhcpv4, medium-ethernet (the Ethernet medium is what esp-radio uses). udp was added with the NTP time source (rohi-time-ntp), the first component that needs it.

Policy. Platform and network protocol features are enabled only when a current SDK component uses them. A work item that needs another feature (IPv6, mDNS, …) enables it together with the component and documents why.

Toolchain

rust-toolchain.toml pins the Rust toolchain, rust-src, rustfmt, clippy and both RISC-V targets; CI uses the same toolchain. protoc is needed to build rohi-control-proto, libdbus and pkg-config to build tools/rohi on Linux; the Nix development shell provides all of them.

Keyboard shortcuts