1 files changed, 85 insertions, 0 deletions
diff --git a/rtic-macros/src/codegen/pre_init.rs b/rtic-macros/src/codegen/pre_init.rs
new file mode 100644
index 00000000..28ba29c0
--- /dev/null
+++ b/rtic-macros/src/codegen/pre_init.rs
@@ -0,0 +1,85 @@
+use crate::syntax::ast::App;
+use proc_macro2::TokenStream as TokenStream2;
+use quote::quote;
+
+use crate::{analyze::Analysis, codegen::util};
+
+/// Generates code that runs before `#[init]`
+pub fn codegen(app: &App, analysis: &Analysis) -> Vec<TokenStream2> {
+    let mut stmts = vec![];
+
+    let rt_err = util::rt_err_ident();
+
+    // Disable interrupts -- `init` must run with interrupts disabled
+    stmts.push(quote!(rtic::export::interrupt::disable();));
+
+    stmts.push(quote!(
+        // To set the variable in cortex_m so the peripherals cannot be taken multiple times
+        let mut core: rtic::export::Peripherals = rtic::export::Peripherals::steal().into();
+    ));
+
+    let device = &app.args.device;
+    let nvic_prio_bits = quote!(#device::NVIC_PRIO_BITS);
+
+    // check that all dispatchers exists in the `Interrupt` enumeration regardless of whether
+    // they are used or not
+    let interrupt = util::interrupt_ident();
+    for name in app.args.dispatchers.keys() {
+        stmts.push(quote!(let _ = #rt_err::#interrupt::#name;));
+    }
+
+    let interrupt_ids = analysis.interrupts.iter().map(|(p, (id, _))| (p, id));
+
+    // Unmask interrupts and set their priorities
+    for (&priority, name) in interrupt_ids.chain(app.hardware_tasks.values().filter_map(|task| {
+        if util::is_exception(&task.args.binds) {
+            // We do exceptions in another pass
+            None
+        } else {
+            Some((&task.args.priority, &task.args.binds))
+        }
+    })) {
+        let es = format!(
+            "Maximum priority used by interrupt vector '{name}' is more than supported by hardware"
+        );
+        // Compile time assert that this priority is supported by the device
+        stmts.push(quote!(
+            const _: () =  if (1 << #nvic_prio_bits) < #priority as usize { ::core::panic!(#es); };
+        ));
+
+        stmts.push(quote!(
+            core.NVIC.set_priority(
+                #rt_err::#interrupt::#name,
+                rtic::export::logical2hw(#priority, #nvic_prio_bits),
+            );
+        ));
+
+        // NOTE unmask the interrupt *after* setting its priority: changing the priority of a pended
+        // interrupt is implementation defined
+        stmts.push(quote!(rtic::export::NVIC::unmask(#rt_err::#interrupt::#name);));
+    }
+
+    // Set exception priorities
+    for (name, priority) in app.hardware_tasks.values().filter_map(|task| {
+        if util::is_exception(&task.args.binds) {
+            Some((&task.args.binds, task.args.priority))
+        } else {
+            None
+        }
+    }) {
+        let es = format!(
+            "Maximum priority used by interrupt vector '{name}' is more than supported by hardware"
+        );
+        // Compile time assert that this priority is supported by the device
+        stmts.push(quote!(
+            const _: () =  if (1 << #nvic_prio_bits) < #priority as usize { ::core::panic!(#es); };
+        ));
+
+        stmts.push(quote!(core.SCB.set_priority(
+            rtic::export::SystemHandler::#name,
+            rtic::export::logical2hw(#priority, #nvic_prio_bits),
+        );));
+    }
+
+    stmts
+}