From d82f57772459d9bf12bb2c935e3ebc9b93368f51 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Henrik=20Tj=C3=A4der?= Date: Wed, 22 Feb 2023 19:03:51 +0100 Subject: [PATCH] Book: Fix links, proofread targets and starting_a_project --- book/en/src/by-example/starting_a_project.md | 4 ++-- book/en/src/internals/targets.md | 15 ++++++--------- 2 files changed, 8 insertions(+), 11 deletions(-) diff --git a/book/en/src/by-example/starting_a_project.md b/book/en/src/by-example/starting_a_project.md index 8638f9064d..86d7e71d60 100644 --- a/book/en/src/by-example/starting_a_project.md +++ b/book/en/src/by-example/starting_a_project.md @@ -3,14 +3,14 @@ A recommendation when starting a RTIC project from scratch is to follow RTIC's [`defmt-app-template`]. -If you are targeting ARMv6-M or ARMv8-M-base architecture, check out the section [Target Architecture](../internals/targets.md) for more information on hardware limitations to be aware of. +If you are targeting ARMv6-M or ARMv8-M-base architecture, check out the section [Target Architecture](../internals/targets.md) for more information on hardware limitations to be aware of. [`defmt-app-template`]: https://github.com/rtic-rs/defmt-app-template This will give you an RTIC application with support for RTT logging with [`defmt`] and stack overflow protection using [`flip-link`]. There is also a multitude of examples provided by the community: -For inspiration you may look at the below resources. For now they cover RTIC 1.0.x, but will be updated with RTIC 2.0.x examples over time. +For inspiration, you may look at the below resources. For now, they cover RTIC v1.x, but will be updated with RTIC v2.x examples over time. - [`rtic-examples`] - Multiple projects - [https://github.com/kalkyl/f411-rtic](https://github.com/kalkyl/f411-rtic) diff --git a/book/en/src/internals/targets.md b/book/en/src/internals/targets.md index 04fd592203..efad15005f 100644 --- a/book/en/src/internals/targets.md +++ b/book/en/src/internals/targets.md @@ -1,7 +1,7 @@ # Target Architecture -While RTIC can currently target all Cortex-m devices there are some key architecure differences that -users should be aware of. Namely the absence of Base Priority Mask Register (`BASEPRI`) which lends +While RTIC can currently target all Cortex-m devices there are some key architecture differences that +users should be aware of. Namely, the absence of Base Priority Mask Register (`BASEPRI`) which lends itself exceptionally well to the hardware priority ceiling support used in RTIC, in the ARMv6-M and ARMv8-M-base architectures, which forces RTIC to use source masking instead. For each implementation of lock and a detailed commentary of pros and cons, see the implementation of @@ -29,7 +29,7 @@ Table 1 below shows a list of Cortex-m processors and which type of critical sec ## Priority Ceiling -This implementation is covered in depth by the [Critical Sections][critical_sections] page of this book. +This is covered by the [Resources][resources] page of this book. ## Source Masking @@ -55,17 +55,14 @@ with B. ``` At time *t1*, task B locks the shared resource by selectively disabling (using the NVIC) all other -tasks which have a priority equal to or less than any task which shares resouces with B. In effect -this creates a virtual priority ceiling, miroring the `BASEPRI` approach described in the -[Critical Sections][critical_Sections] page. Task A is one such task that shares resources with +tasks which have a priority equal to or less than any task which shares resources with B. In effect +this creates a virtual priority ceiling, mirroring the `BASEPRI` approach. Task A is one such task that shares resources with task B. At time *t2*, task A is either spawned by task B or becomes pending through an interrupt condition, but does not yet preempt task B even though its priority is greater. This is because the -NVIC is preventing it from starting due to task A being being disabled. At time *t3*, task B +NVIC is preventing it from starting due to task A being disabled. At time *t3*, task B releases the lock by re-enabling the tasks in the NVIC. Because task A was pending and has a higher priority than task B, it immediately preempts task B and is free to use the shared resource without risk of data race conditions. At time *t4*, task A completes and returns the execution context to B. Since source masking relies on use of the NVIC, core exception sources such as HardFault, SVCall, PendSV, and SysTick cannot share data with other tasks. - -[critical_sections]: https://github.com/rtic-rs/cortex-m-rtic/blob/master/book/en/src/internals/critical-sections.md