embassy blinky for stm32g474

2026-06-28 16:21:27 -07:00 · 2026-06-28 16:21:27 -07:00 · b2cf4fd3bb
commit b2cf4fd3bb
10 changed files with 1737 additions and 0 deletions
--- a/.cargo/config.toml
+++ b/.cargo/config.toml
@ -0,0 +1,28 @@
+[target.'cfg(all(target_arch = "arm", target_os = "none"))']
+runner = ["probe-rs", "run", "--chip", "STM32G474RE", "--log-format=oneline"]
+# If you have an nRF52, you might also want to add "--allow-erase-all" to the list
+
+rustflags = [
+  "-C", "linker=flip-link",
+  "-C", "link-arg=-Tlink.x",
+  "-C", "link-arg=-Tdefmt.x",
+  # This is needed if your flash or ram addresses are not aligned to 0x10000 in memory.x
+  # See https://github.com/rust-embedded/cortex-m-quickstart/pull/95
+  "-C", "link-arg=--nmagic",
+]
+
+[build]
+# Select the correct target for your processor:
+# target = "thumbv6m-none-eabi"    # Cortex-M0 and Cortex-M0+
+# target = "thumbv7m-none-eabi"    # Cortex-M3
+# target = "thumbv7em-none-eabi"   # Cortex-M4 and Cortex-M7 (no FPU)
+target = "thumbv7em-none-eabihf" # Cortex-M4F and Cortex-M7F (with FPU)
+
+[env]
+DEFMT_LOG = "trace"
+
+[alias]
+# `cargo rb foo` will expand to `cargo run --bin foo`
+rb = "run --bin"
+# `cargo rrb foo` will expand to `cargo run --release --bin foo`
+rrb = "run --release --bin"
--- a/.gitignore
+++ b/.gitignore
@ -0,0 +1 @@
+/target
--- a/Cargo.lock
+++ b/Cargo.lock
--- a/Cargo.toml
+++ b/Cargo.toml
@ -0,0 +1,59 @@
+[package]
+authors = ["Joe Ardent <code@ardent.nebcorp.com>"]
+name = "treatbot-5k"
+edition = "2024"
+version = "50.0.0"
+
+default-run = "treatbot-5k"
+
+# To run all the tests via `cargo test` the tests need to be explicitly disabled for the binary targets
+# If you use a standard main.rs file the following is sufficient:
+[[bin]]
+name = "treatbot-5k"
+test = false
+
+[lib]
+harness = false
+
+# needed for each integration test
+[[test]]
+name = "integration"
+harness = false
+
+[dependencies]
+cortex-m = { version = "0.7", features = ["critical-section-single-core"] }
+cortex-m-rt = "0.7"
+defmt = "1.0"
+defmt-rtt = "1.0"
+embassy-executor = { version = "0.10.0", features = ["defmt", "platform-cortex-m", "executor-thread"] }
+embassy-futures = "0.1.2"
+embassy-stm32 = { version = "0.6.0", features = ["defmt", "stm32g474re", "memory-x", "unstable-pac", "exti", "dual-bank", "stm32-hrtim", "time-driver-any"] }
+embassy-sync = { version = "0.8.0", features = ["defmt"] }
+embassy-time = { version = "0.5.1", features = ["defmt", "defmt-timestamp-uptime", "tick-hz-32_768"] }
+panic-probe = { version = "1.0", features = ["print-defmt"] }
+semihosting = "0.1.20"
+# stm32g4xx-hal = { version = "0.1.0", features = ["defmt", "stm32g474", "hrtim"] }
+
+[dev-dependencies]
+defmt-test = "0.3"
+
+# cargo build/run
+[profile.dev]
+# default is opt-level = '0', but that makes very
+# verbose machine code
+opt-level = 's'
+# trade compile speed for slightly better optimisations
+codegen-units = 1
+
+# cargo build/run --release
+[profile.release]
+# default is opt-level = '3', but that makes quite
+# verbose machine code
+opt-level = 's'
+# trade compile speed for slightly better optimisations
+codegen-units = 1
+# Use Link Time Optimisations to further inline things across
+# crates
+lto = 'fat'
+# Leave the debug symbols in (default is no debug info)
+debug = 2
--- a/build.rs
+++ b/build.rs
@ -0,0 +1,35 @@
+//! This build script copies the `memory.x` file from the crate root into
+//! a directory where the linker can always find it at build time.
+//! For many projects this is optional, as the linker always searches the
+//! project root directory -- wherever `Cargo.toml` is. However, if you
+//! are using a workspace or have a more complicated build setup, this
+//! build script becomes required. Additionally, by requesting that
+//! Cargo re-run the build script whenever `memory.x` is changed,
+//! updating `memory.x` ensures a rebuild of the application with the
+//! new memory settings.
+//!
+//! The build script also sets the linker flags to tell it which link script to use.
+
+use std::env;
+use std::fs::File;
+use std::io::Write;
+use std::path::PathBuf;
+
+fn main() {
+    // Put `memory.x` in our output directory and ensure it's
+    // on the linker search path.
+    let out = &PathBuf::from(env::var_os("OUT_DIR").unwrap());
+    File::create(out.join("memory.x"))
+        .unwrap()
+        .write_all(include_bytes!("memory.x"))
+        .unwrap();
+    println!("cargo:rustc-link-search={}", out.display());
+
+    // By default, Cargo will re-run a build script whenever
+    // any file in the project changes. By specifying `memory.x`
+    // here, we ensure the build script is only re-run when
+    // `memory.x` is changed.
+    println!("cargo:rerun-if-changed=memory.x");
+
+    // we're setting linker args in .cargo/config.toml via rustc flags
+}
--- a/generated.md
+++ b/generated.md
@ -0,0 +1,232 @@
+# `app-template`
+
+> Quickly set up a [`probe-rs`] + [`defmt`] + [`flip-link`] embedded project
+
+[`probe-rs`]: https://crates.io/crates/probe-rs
+[`defmt`]: https://github.com/knurling-rs/defmt
+[`flip-link`]: https://github.com/knurling-rs/flip-link
+
+## Dependencies
+
+### 1. `flip-link`:
+
+```bash
+cargo install flip-link
+```
+
+### 2. `probe-rs`:
+
+Install probe-rs by following the instructions at <https://probe.rs/docs/getting-started/installation/>.
+
+### 3. [`cargo-generate`]:
+
+```bash
+cargo install cargo-generate
+```
+
+[`cargo-generate`]: https://crates.io/crates/cargo-generate
+
+> *Note:* You can also just clone this repository instead of using `cargo-generate`, but this involves additional manual adjustments.
+
+## Setup
+
+### 1. Initialize the project template
+
+```bash
+cargo generate \
+    --git https://github.com/knurling-rs/app-template \
+    --branch main \
+    --name my-app
+```
+
+If you look into your new `my-app` folder, you'll find that there are a few `TODO`s in the files marking the properties you need to set.
+
+Let's walk through them together now.
+
+### 2. Set `probe-rs` chip
+
+Pick a chip from ` probe-rs chip list` and enter it into `.cargo/config.toml`.
+
+If, for example, you have a nRF52840 Development Kit as used in one of [our exercises], replace `{{chip}}` with `nRF52840_xxAA`.
+
+[our workshops]: https://rust-exercises.ferrous-systems.com
+
+```diff
+ # .cargo/config.toml
+-runner = ["probe-rs", "run", "--chip", "$CHIP", "--log-format=oneline"]
+runner = ["probe-rs", "run", "--chip", "nRF52840_xxAA", "--log-format=oneline"]
+```
+
+### 3. Adjust the compilation target
+
+In `.cargo/config.toml`, pick the right compilation target for your board.
+
+```diff
+ # .cargo/config.toml
+ [build]
+-target = "thumbv6m-none-eabi"    # Cortex-M0 and Cortex-M0+
+-# target = "thumbv7m-none-eabi"    # Cortex-M3
+-# target = "thumbv7em-none-eabi"   # Cortex-M4 and Cortex-M7 (no FPU)
+-# target = "thumbv7em-none-eabihf" # Cortex-M4F and Cortex-M7F (with FPU)
+target = "thumbv7em-none-eabihf" # Cortex-M4F (with FPU)
+```
+
+Add the target with `rustup`.
+
+```bash
+rustup target add thumbv7em-none-eabihf
+```
+
+### 4. Add a HAL as a dependency
+
+In `Cargo.toml`, list the Hardware Abstraction Layer (HAL) for your board as a dependency.
+
+For the nRF52840 you'll want to use the [`nrf52840-hal`].
+
+[`nrf52840-hal`]: https://crates.io/crates/nrf52840-hal
+
+```diff
+ # Cargo.toml
+ [dependencies]
+-# some-hal = "1.2.3"
+nrf52840-hal = "0.14.0"
+```
+
+⚠️ Note for RP2040 users ⚠️
+
+You will need to not just specify the `rp-hal` HAL, but a BSP (board support crate) which includes a second stage bootloader. Please find a list of available BSPs [here](https://github.com/rp-rs/rp-hal-boards#packages).
+
+### 5. Import your HAL
+
+Now that you have selected a HAL, fix the HAL import in `src/lib.rs`
+
+```diff
+ // my-app/src/lib.rs
+-// use some_hal as _; // memory layout
+use nrf52840_hal as _; // memory layout
+```
+
+### (6. Get a linker script)
+
+Some HAL crates require that you manually copy over a file called `memory.x` from the HAL to the root of your project. For nrf52840-hal, this is done automatically so no action is needed. For other HAL crates, see their documentation on where to find an example file.
+
+The `memory.x` file should look something like:
+
+```text
+MEMORY
+{
+  FLASH : ORIGIN = 0x00000000, LENGTH = 1024K
+  RAM   : ORIGIN = 0x20000000, LENGTH = 256K
+}
+```
+
+The `memory.x` file is included in the `cortex-m-rt` linker script `link.x`, and so `link.x` is the one you should tell `rustc` to use (see the `.cargo/config.toml` file where we do that).
+
+### 7. Run!
+
+You are now all set to `cargo-run` your first `defmt`-powered application!
+There are some examples in the `src/bin` directory.
+
+Start by `cargo run`-ning `my-app/src/bin/hello.rs`:
+
+```console
+$ # `rb` is an alias for `run --bin`
+$ cargo rb hello
+    Finished `dev` profile [optimized + debuginfo] target(s) in 0.01s
+     Running `probe-rs run --chip nrf52840_xxaa --log-format=oneline target/thumbv6m-none-eabi/debug/hello`
+      Erasing ✔ 100% [####################]   8.00 KiB @  15.79 KiB/s (took 1s)
+  Programming ✔ 100% [####################]   8.00 KiB @  13.19 KiB/s (took 1s)                                                                                                                        Finished in 1.11s
+Hello, world!
+
+$ echo $?
+0
+```
+
+If you're running out of memory (`flip-link` bails with an overflow error), you can decrease the size of the device memory buffer by setting the `DEFMT_RTT_BUFFER_SIZE` environment variable. The default value is 1024 bytes, and powers of two should be used for optimal performance:
+
+```console
+$ DEFMT_RTT_BUFFER_SIZE=64 cargo rb hello
+```
+
+### (8. Set `rust-analyzer.linkedProjects`)
+
+If you are using [rust-analyzer] with VS Code for IDE-like features you can add following configuration to your `.vscode/settings.json` to make it work transparently across workspaces. Find the details of this option in the [RA docs].
+
+```json
+{
+    "rust-analyzer.linkedProjects": [
+        "Cargo.toml",
+        "firmware/Cargo.toml",
+    ]
+}
+```
+
+[RA docs]: https://rust-analyzer.github.io/manual.html#configuration
+[rust-analyzer]: https://rust-analyzer.github.io/
+
+## Running tests
+
+The template comes configured for running unit tests and integration tests on the target.
+
+Unit tests reside in the library crate and can test private API; the initial set of unit tests are in `src/lib.rs`.
+`cargo test --lib` will run those unit tests.
+
+```console
+$ cargo test --lib
+   Compiling example v0.1.0 (./knurling-rs/example)
+    Finished `test` profile [optimized + debuginfo] target(s) in 0.15s
+     Running unittests src/lib.rs (target/thumbv6m-none-eabi/debug/deps/example-2b0d0e25d141bf57)
+      Erasing ✔ 100% [####################]   8.00 KiB @  15.99 KiB/s (took 1s)
+  Programming ✔ 100% [####################]   8.00 KiB @  13.33 KiB/s (took 1s)                                                                                                                        Finished in 1.10s
+(1/1) running `it_works`...
+all tests passed!
+```
+
+Integration tests reside in the `tests` directory; the initial set of integration tests are in `tests/integration.rs`.
+`cargo test --test integration` will run those integration tests.
+Note that the argument of the `--test` flag must match the name of the test file in the `tests` directory.
+
+```console
+$ cargo test --test integration
+   Compiling example v0.1.0 (./knurling-rs/example)
+    Finished `test` profile [optimized + debuginfo] target(s) in 0.10s
+     Running tests/integration.rs (target/thumbv6m-none-eabi/debug/deps/integration-aaaff41151f6a722)
+      Erasing ✔ 100% [####################]   8.00 KiB @  16.03 KiB/s (took 0s)
+  Programming ✔ 100% [####################]   8.00 KiB @  13.19 KiB/s (took 1s)                                                                                                                        Finished in 1.11s
+(1/1) running `it_works`...
+all tests passed!
+```
+
+Note that to add a new test file to the `tests` directory you also need to add a new `[[test]]` section to `Cargo.toml`.
+
+To run all the tests via `cargo test` the tests need to be explicitly disabled for all the existing binary targets.
+See `Cargo.toml` for details on how to do this.
+
+## Support
+
+`app-template` is part of the [Knurling] project, [Ferrous Systems]' effort at
+improving tooling used to develop for embedded systems.
+
+If you think that our work is useful, consider sponsoring it via [GitHub
+Sponsors].
+
+## License
+
+Licensed under either of
+
+- Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or
+  http://www.apache.org/licenses/LICENSE-2.0)
+
+- MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
+
+at your option.
+
+### Contribution
+
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in the work by you, as defined in the Apache-2.0 license, shall be
+licensed as above, without any additional terms or conditions.
+
+[Knurling]: https://knurling.ferrous-systems.com
+[Ferrous Systems]: https://ferrous-systems.com/
+[GitHub Sponsors]: https://github.com/sponsors/knurling-rs
--- a/memory.x
+++ b/memory.x
@ -0,0 +1,33 @@
+MEMORY
+{
+  /* NOTE 1 K = 1 KiBi = 1024 bytes */
+
+  FLASH : ORIGIN = 0x8000000, LENGTH = 256K
+  RAM : ORIGIN = 0x20000000, LENGTH = 80K
+}
+
+/* This is where the call stack will be allocated. */
+/* The stack is of the full descending type. */
+/* You may want to use this variable to locate the call stack and static
+   variables in different memory regions. Below is shown the default value */
+/* _stack_start = ORIGIN(RAM) + LENGTH(RAM); */
+
+/* You can use this symbol to customize the location of the .text section */
+/* If omitted the .text section will be placed right after the .vector_table
+   section */
+/* This is required only on microcontrollers that store some configuration right
+   after the vector table */
+/* _stext = ORIGIN(FLASH) + 0x400; */
+
+/* Example of putting non-initialized variables into custom RAM locations. */
+/* This assumes you have defined a region RAM2 above, and in the Rust
+   sources added the attribute `#[link_section = ".ram2bss"]` to the data
+   you want to place there. */
+/* Note that the section will not be zero-initialized by the runtime! */
+/* SECTIONS {
+     .ram2bss (NOLOAD) : ALIGN(4) {
+       *(.ram2bss);
+       . = ALIGN(4);
+     } > RAM2
+   } INSERT AFTER .bss;
+*/
--- a/src/lib.rs
+++ b/src/lib.rs
@ -0,0 +1,43 @@
+#![no_main]
+#![no_std]
+
+// use defmt_rtt as _; // global logger
+
+// use panic_probe as _;
+
+// same panicking *behavior* as `panic-probe` but doesn't print a panic message
+// this prevents the panic message being printed *twice* when `defmt::panic` is invoked
+#[defmt::panic_handler]
+fn panic() -> ! {
+    cortex_m::asm::udf()
+}
+
+/// Terminates the application and makes a semihosting-capable debug tool exit
+/// with status code 0.
+pub fn exit() -> ! {
+    semihosting::process::exit(0);
+}
+
+/// Hardfault handler.
+///
+/// Terminates the application and makes a semihosting-capable debug tool exit
+/// with an error. This seems better than the default, which is to spin in a
+/// loop.
+#[cortex_m_rt::exception]
+unsafe fn HardFault(_frame: &cortex_m_rt::ExceptionFrame) -> ! {
+    semihosting::process::exit(1);
+}
+
+// defmt-test 0.3.0 has the limitation that this `#[tests]` attribute can only be used
+// once within a crate. the module can be in any file but there can only be at most
+// one `#[tests]` module in this library crate
+#[cfg(test)]
+#[defmt_test::tests]
+mod unit_tests {
+    use defmt::assert;
+
+    #[test]
+    fn it_works() {
+        assert!(true)
+    }
+}
--- a/src/main.rs
+++ b/src/main.rs
@ -0,0 +1,89 @@
+#![no_std]
+#![no_main]
+
+use defmt::{info, unwrap};
+use embassy_executor::Spawner;
+use embassy_stm32::flash::{Flash, InterruptHandler};
+use embassy_stm32::gpio::{AnyPin, Level, Output, Speed};
+use embassy_stm32::{bind_interrupts, Peri};
+use embassy_time::Timer;
+use {defmt_rtt as _, panic_probe as _};
+
+bind_interrupts!(struct Irqs {
+    FLASH => InterruptHandler;
+});
+
+#[embassy_executor::main]
+async fn main(spawner: Spawner) {
+    let p = embassy_stm32::init(Default::default());
+    info!("Hello Flash!");
+
+    // Led should blink uninterrupted during erase operation
+    spawner.spawn(unwrap!(blinky(p.PA5.into())));
+
+    // let mut f = Flash::new(p.FLASH, Irqs);
+    // // Test on bank 2 so the CPU doesn't stall (code runs from bank 1).
+    // // G474RE in dual-bank mode: bank 2 starts at 256KB offset.
+    // // Erase 4KB (2 pages at 2KB each in dual-bank mode).
+    // test_flash(&mut f, 256 * 1024, 4 * 1024).await;
+
+    //treatbot_5k::exit()
+}
+
+#[embassy_executor::task]
+async fn blinky(p: Peri<'static, AnyPin>) {
+    let mut led = Output::new(p, Level::High, Speed::Low);
+
+    loop {
+        info!("high");
+        led.set_high();
+        Timer::after_millis(300).await;
+
+        info!("low");
+        led.set_low();
+        Timer::after_millis(300).await;
+    }
+}
+
+async fn _test_flash(f: &mut Flash<'_>, offset: u32, size: u32) {
+    info!("Testing offset: {=u32:#X}, size: {=u32:#X}", offset, size);
+
+    info!("Reading...");
+    let mut buf = [0u8; 32];
+    unwrap!(f.blocking_read(offset, &mut buf));
+    info!("Read: {=[u8]:x}", buf);
+
+    info!("Erasing...");
+    unwrap!(f.erase(offset, offset + size).await);
+
+    info!("Reading...");
+    let mut buf = [0u8; 32];
+    unwrap!(f.blocking_read(offset, &mut buf));
+    info!("Read after erase: {=[u8]:x}", buf);
+
+    info!("Writing...");
+    unwrap!(
+        f.write(
+            offset,
+            &[
+                1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,
+                24, 25, 26, 27, 28, 29, 30, 31, 32
+            ]
+        )
+        .await
+    );
+
+    info!("Reading...");
+    let mut buf = [0u8; 32];
+    unwrap!(f.blocking_read(offset, &mut buf));
+    info!("Read: {=[u8]:x}", buf);
+    assert_eq!(
+        &buf[..],
+        &[
+            1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24,
+            25, 26, 27, 28, 29, 30, 31, 32
+        ]
+    );
+
+    info!("Flash async test passed!");
+}
--- a/tests/integration.rs
+++ b/tests/integration.rs
@ -0,0 +1,16 @@
+#![no_std]
+#![no_main]
+
+use treatbot_5k as _; // memory layout + panic handler
+
+// See https://crates.io/crates/defmt-test/0.3.0 for more documentation (e.g. about the 'state'
+// feature)
+#[defmt_test::tests]
+mod tests {
+    use defmt::assert;
+
+    #[test]
+    fn it_works() {
+        assert!(true)
+    }
+}