non variant field repr

Author: burrbull

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/).
 - Fix new `mismatched-lifetime-syntaxes` lint warnings
 - Adapt RISC-V specific codegen for `riscv-peripheral` v0.3.0 rework
 - Include `riscv-peripheral` peripherals in `Peripherals` struct
+- `repr(transparent)` for field wrapper
 - Ensure `__INTERRUPTS` are `#[no_mangle]` on Xtensa.
 - Add `base_isa` field to `riscv_config` to allow the `riscv_rt::core_interrupt`
   macro to properly generate start trap assembly routines in vectored mode.

src/generate/register.rs

@@ -1497,12 +1497,6 @@ fn add_with_no_variants(
         .as_ref()
         .map(|feature| quote!(#[cfg_attr(feature = #feature, derive(defmt::Format))]));
 
-    let cast = if fty == "bool" {
-        quote! { val.0 as u8 != 0 }
-    } else {
-        quote! { val.0 as _ }
-    };
-
     let desc = if let Some(rv) = reset_value {
         format!("{desc}\n\nValue on reset: {rv}")
     } else {
@@ -1513,11 +1507,12 @@ fn add_with_no_variants(
         #[doc = #desc]
         #defmt
         #[derive(Clone, Copy, Debug, PartialEq, Eq)]
+        #[repr(transparent)]
         pub struct #pc(#fty);
         impl From<#pc> for #fty {
             #[inline(always)]
             fn from(val: #pc) -> Self {
-                #cast
+                val.0
             }
         }
     });