Don't use interrupts reserved by esp-hal

Excluding the reserved interrupts fixes the task priorities. I also
considered refactoring `rtic/src/export/riscv_esp32c6.rs` to use esp-hal
instead of esp32c6 directly as it has code to do all the pointer
wrangling itself, but decided against it for now. It might be nice to
refactor both esp implentations to use it though.

2 files changed, 16 insertions, 38 deletions

diff --git a/rtic-macros/src/codegen/bindings/esp32c6.rs b/rtic-macros/src/codegen/bindings/esp32c6.rs
index 8e0af33..1d22466 100644
--- a/rtic-macros/src/codegen/bindings/esp32c6.rs
+++ b/rtic-macros/src/codegen/bindings/esp32c6.rs
@@ -13,11 +13,10 @@ mod esp32c6 {
     use std::collections::HashSet;
     use syn::{parse, Attribute, Ident};
 
-    // Section 1.6.2 technical reference manual specifies which interrupts can be configured.
-    const EXTERNAL_INTERRUPTS: [u8; 28] = [
-        1, 2, 5, 6, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,
-        28, 29, 30, 31,
-    ];
+    // esp-hal reserves interrupts 1-19:
+    // https://github.com/esp-rs/esp-hal/blob/esp-hal-v1.0.0-beta.0/esp-hal/src/interrupt/riscv.rs#L200
+    // https://github.com/esp-rs/esp-hal/blob/esp-hal-v1.0.0-beta.0/esp-hal/src/interrupt/riscv.rs#L725
+    const EXTERNAL_INTERRUPTS: [u8; 12] = [20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31];
 
     #[allow(clippy::too_many_arguments)]
     pub fn impl_mutex(
@@ -243,12 +242,9 @@ mod esp32c6 {
             )
             .zip(EXTERNAL_INTERRUPTS)
         {
-            // interrupt1...interrupt19 are already defined in esp_hal
-            if curr_cpu_id > 19 {
-                if *name == dispatcher_name {
-                    let ret = &("interrupt".to_owned() + &curr_cpu_id.to_string());
-                    stmts.push(quote!(#[export_name = #ret]));
-                }
+            if *name == dispatcher_name {
+                let ret = &("interrupt".to_owned() + &curr_cpu_id.to_string());
+                stmts.push(quote!(#[export_name = #ret]));
             }
         }
 
diff --git a/rtic/src/export/riscv_esp32c6.rs b/rtic/src/export/riscv_esp32c6.rs
index cf7ac3c..6789f26 100644
--- a/rtic/src/export/riscv_esp32c6.rs
+++ b/rtic/src/export/riscv_esp32c6.rs
@@ -1,5 +1,5 @@
 pub use esp32c6::{Interrupt, Peripherals};
-use esp32c6::{INTERRUPT_CORE0, INTPRI, PLIC_MX};
+use esp32c6::{INTERRUPT_CORE0, PLIC_MX};
 pub use riscv::interrupt;
 pub use riscv::register::mcause;
 
@@ -148,32 +148,14 @@ pub fn enable(int: Interrupt, prio: u8, cpu_int_id: u8) {
             .offset(int as isize)
             .write_volatile(cpu_int_id as u32);
 
-        match int {
-            Interrupt::FROM_CPU_INTR0
-            | Interrupt::FROM_CPU_INTR1
-            | Interrupt::FROM_CPU_INTR2
-            | Interrupt::FROM_CPU_INTR3 => {
-                // Set the interrupt's priority:
-                (*INTPRI::ptr())
-                    .cpu_int_pri(cpu_int_id as usize)
-                    .write(|w| w.bits(prio as u32));
-
-                // Finally, enable the CPU interrupt:
-                (*INTPRI::ptr())
-                    .cpu_int_enable()
-                    .modify(|r, w| w.bits((1 << cpu_int_id) | r.bits()));
-            }
-            _ => {
-                // Set the interrupt's priority:
-                (*PLIC_MX::ptr())
-                    .mxint_pri(cpu_int_id as usize)
-                    .write(|w| w.bits(prio as u32));
+        // Set the interrupt's priority:
+        (*PLIC_MX::ptr())
+            .mxint_pri(cpu_int_id as usize)
+            .write(|w| w.bits(prio as u32));
 
-                // Finally, enable the CPU interrupt:
-                (*PLIC_MX::ptr())
-                    .mxint_enable()
-                    .modify(|r, w| w.bits((1 << cpu_int_id) | r.bits()));
-            }
-        }
+        // Finally, enable the CPU interrupt:
+        (*PLIC_MX::ptr())
+            .mxint_enable()
+            .modify(|r, w| w.bits((1 << cpu_int_id) | r.bits()));
     }
 }