diff --git a/book/en/src/by-example/app.md b/book/en/src/by-example/app.md index 00e0051987..2450c59ab3 100644 --- a/book/en/src/by-example/app.md +++ b/book/en/src/by-example/app.md @@ -106,7 +106,7 @@ mut` variables are safe to use within a hardware task. $ cargo run --example hardware {{#include ../../../../ci/expected/hardware.run}}``` -So far all the RTFM applications we have seen look no different that the +So far all the RTFM applications we have seen look no different than the applications one can write using only the `cortex-m-rt` crate. From this point we start introducing features unique to RTFM. @@ -115,7 +115,7 @@ we start introducing features unique to RTFM. The static priority of each handler can be declared in the `task` attribute using the `priority` argument. Tasks can have priorities in the range `1..=(1 << NVIC_PRIO_BITS)` where `NVIC_PRIO_BITS` is a constant defined in the `device` -crate. When the `priority` argument is omitted the priority is assumed to be +crate. When the `priority` argument is omitted, the priority is assumed to be `1`. The `idle` task has a non-configurable static priority of `0`, the lowest priority. @@ -140,12 +140,12 @@ $ cargo run --example preempt Note that the task `gpiob` does *not* preempt task `gpioc` because its priority is the *same* as `gpioc`'s. However, once `gpioc` terminates the execution of -task `gpiob` is prioritized over `gpioa`'s due to its higher priority. `gpioa` +task, `gpiob` is prioritized over `gpioa` due to its higher priority. `gpioa` is resumed only after `gpiob` terminates. One more note about priorities: choosing a priority higher than what the device supports (that is `1 << NVIC_PRIO_BITS`) will result in a compile error. Due to -limitations in the language the error message is currently far from helpful: it +limitations in the language, the error message is currently far from helpful: it will say something along the lines of "evaluation of constant value failed" and the span of the error will *not* point out to the problematic interrupt value -- we are sorry about this!