Merge #562

562: Replace default WFI with simpler NOP r=korken89 a=AfoHT

As noted by #561 there are multiple issues with various hardware implementations and debugging together with sleep modes.

As RTIC strives to be a generic framework (even though this is an implementation targeting cortex-m) the decision having `WFI` as the default `idle` task causes issues in some hardware, raising the barrier to entry.

This changes the default behaviour to do a simple `NOP` instead, adding documentation how to provide a custom `idle` task achieving the old default behaviour. Also removes the automatic setting of SLEEPONEXIT bit when no `idle` was provided, delegating this to the user.

This was discussed on the weekly meeting 2021-12-14 and this was the favoured solution.

Fixes #561 

Co-authored-by: Henrik Tjäder <henrik@grepit.se>

1 files changed, 1 insertions, 1 deletions

diff --git a/macros/src/codegen/idle.rs b/macros/src/codegen/idle.rs
index d6539316..0dededa4 100644
--- a/macros/src/codegen/idle.rs
+++ b/macros/src/codegen/idle.rs
@@ -85,7 +85,7 @@ pub fn codegen(
             vec![],
             None,
             quote!(loop {
-                rtic::export::wfi()
+                rtic::export::nop()
             }),
         )
     }