diff options
| -rw-r--r-- | book/en/src/by-example/app.md | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/book/en/src/by-example/app.md b/book/en/src/by-example/app.md index c84f7a41..e8e1d7a6 100644 --- a/book/en/src/by-example/app.md +++ b/book/en/src/by-example/app.md @@ -6,6 +6,32 @@ This is the smallest possible RTIC application: {{#include ../../../../examples/smallest.rs}} ``` +All RTIC applications use the [`app`] attribute (`#[app(..)]`). This attribute +must be applied to a `mod`-item. The `app` attribute has a mandatory `device` +argument that takes a *path* as a value. This must be a full path pointing to a +*peripheral access crate* (PAC) generated using [`svd2rust`] **v0.14.x** or +newer. More details can be found in the [Starting a new project](./new.md) +section. + +The `app` attribute will expand into a suitable entry point so it's not required +to use the [`cortex_m_rt::entry`] attribute. + +[`app`]: ../../../api/cortex_m_rtic_macros/attr.app.html +[`svd2rust`]: https://crates.io/crates/svd2rust +[`cortex_m_rt::entry`]: ../../../api/cortex_m_rt_macros/attr.entry.html + +## `init` + +Within the `app` module the attribute expects to find an initialization +function marked with the `init` attribute. This function must have +signature `fn(init::Context) -> (init::LateResources, init::Monotonics)`. + +This initialization function will be the first part of the application to run. +The `init` function will run *with interrupts disabled* and has exclusive access +to Cortex-M where the `bare_metal::CriticalSection` token is available as `cs`. +And optionally, device specific peripherals through the `core` and `device` fields +of `init::Context`. + `static mut` variables declared at the beginning of `init` will be transformed into `&'static mut` references that are safe to access. Notice, this feature may be deprecated in next release, see `task_local` resources. @@ -31,7 +57,6 @@ $ cargo run --example init > triple to cargo (e.g `cargo run --example init --target thumbv7m-none-eabi`) or > configure a device to be used by default when building the examples in `.cargo/config.toml`. > In this case, we use a Cortex M3 emulated in QEMU so the target is `thumbv7m-none-eabi`. -> See [`Starting a new project`](./new.md) for more info. ## `idle` |