cargo: use nightly and force target build

.github/workflows/build.yml

@@ -11,13 +11,16 @@ jobs:
       - name: Checkout sources
         uses: actions/checkout@v2
 
-      - name: Install stable toolchain
+      - name: Install nightly toolchain
         uses: actions-rs/toolchain@v1
         with:
           profile: minimal
-          toolchain: stable
+          toolchain: nightly
           override: true
 
+      - name: Add Cortex-M build target toolchain
+        run: rustup target add thumbv7em-none-eabihf
+
       - name: Run cargo check
         uses: actions-rs/cargo@v1
         continue-on-error: true  # WARNING: only for this example, remove it!
@@ -31,13 +34,16 @@ jobs:
       - name: Checkout sources
         uses: actions/checkout@v2
 
-      - name: Install stable toolchain
+      - name: Install nightly toolchain
         uses: actions-rs/toolchain@v1
         with:
           profile: minimal
-          toolchain: stable
+          toolchain: nightly
           override: true
 
+      - name: Add Cortex-M build target toolchain
+        run: rustup target add thumbv7em-none-eabihf
+
       - name: Run cargo build
         uses: actions-rs/cargo@v1
         with:
@@ -50,13 +56,17 @@ jobs:
       - name: Checkout sources
         uses: actions/checkout@v2
 
-      - name: Install stable toolchain
+      - name: Install nightly toolchain
         uses: actions-rs/toolchain@v1
         with:
           profile: minimal
-          toolchain: stable
+          toolchain: nightly
           override: true
 
+      - name: Add Cortex-M build target toolchain
+        run: rustup target add thumbv7em-none-eabihf
+
+
       - name: Run cargo test
         uses: actions-rs/cargo@v1
         with:

crates/ahab_stm32f11ve/.cargo/config.toml

@@ -1,2 +1,7 @@
+[target.'cfg(all(target_arch = "arm", target_os = "none"))']
+rustflags = [
+  "-C", "link-arg=-Tlink.x",
+]
+
 [build]
 target = "thumbv7em-none-eabihf"     # Cortex-M4F and Cortex-M7F (with FPU)

crates/ahab_stm32f11ve/Cargo.toml

@@ -1,15 +1,18 @@
+cargo-features = ["per-package-target"]
+
 [package]
 authors = ["Philip Linden <[email protected]>"]
 edition = "2021"
 readme = "README.md"
 name = "ahab_stm32f11ve"
 version = "0.1.0"
+forced-target = "thumbv7em-none-eabihf"
 
 [dependencies]
 cortex-m = { version = "0.7.6", features = ["critical-section-single-core"] }
 cortex-m-rt = { workspace = true }
 panic-halt = { workspace = true }
-rtt-target = { version = "0.6.1", features = ["log"] }
+rtt-target = { workspace = true }
 
 [[bin]]
 name = "ahab_stm32f11ve"

docs/SUMMARY.md

@@ -10,9 +10,11 @@
 
 # STM32F411VE
 
-- [getting started](docs/stm32/getting-started.md)
-- [debugging](docs/stm32/debugging.md)
+- [getting started](docs/stm32f411ve/getting-started.md)
+- [debugging](docs/stm32f411ve/debugging.md)
 
 ---
 
+# Development
+
 - [captain's log](captains-log.md)

docs/captains-log.md

@@ -96,4 +96,16 @@ re-use the template code if I need it, but building up from scratch is great
 practice to learn what all of these files do and how they fit together.
 
 Woohoo! I got a (dummy) program to compile for the STM32F411E board! Now to
-flash it...
+flash it... Nice, it worked!
+
+There is one hang up though. When I `cargo build` from the root, it tries to
+compile the embedded crates for the host arch. I want to edit `Cargo.toml` at
+the root to effectively do the same thing as specifying the target arch in
+`.cargo/config.toml` for each crate.
+
+https://doc.rust-lang.org/cargo/reference/unstable.html#per-package-target
+
+https://nnarain.github.io/2021/08/02/Setting-up-per-package-targets-in-Rust.html
+
+I had to add `cargo-features = ["per-package-target"]` to the `Cargo.toml` file,
+which is an unstable `nightly` feature.

rust-toolchain.toml

@@ -0,0 +1,5 @@
+[toolchain]
+channel = "nightly" # required for per-package-target
+
+[feature]
+per-package-target = ["true"]