stm32: remove last use of python at build time

embassy-stm32/build.rs

@@ -1,6 +1,6 @@
 use std::env;
+use std::fs;
 use std::path::PathBuf;
-use std::process::Command;
 
 fn main() {
     let chip_name = env::vars_os()
@@ -11,17 +11,72 @@ fn main() {
         .unwrap()
         .to_ascii_lowercase();
 
+    struct Peripheral {
+        kind: String,
+        name: String,
+    }
+
+    let mut peripherals: Vec<Peripheral> = Vec::new();
+    stm32_metapac::peripherals!(
+        ($kind:ident, $name:ident) => {
+            peripherals.push(Peripheral{
+                kind: stringify!($kind).to_string(),
+                name: stringify!($name).to_string(),
+            });
+        };
+    );
+
+    let mut singletons: Vec<String> = Vec::new();
+    for p in peripherals {
+        match p.kind.as_str() {
+            // Generate singletons per pin, not per port
+            "gpio" => {
+                println!("{}", p.name);
+                let port_letter = p.name.strip_prefix("GPIO").unwrap();
+                for pin_num in 0..16 {
+                    singletons.push(format!("P{}{}", port_letter, pin_num));
+                }
+            }
+
+            // No singleton for these, the HAL handles them specially.
+            "exti" => {}
+
+            // We *shouldn't* have singletons for these, but the HAL currently requires
+            // singletons, for using with RccPeripheral to enable/disable clocks to them.
+            //"rcc" => {}
+            //"dbgmcu" => {}
+            //"syscfg" => {}
+            //"dma" => {}
+            //"bdma" => {}
+            //"dmamux" => {}
+
+            // For other peripherals, one singleton per peri
+            _ => singletons.push(p.name.clone()),
+        }
+    }
+
+    // One singleton per EXTI line
+    for pin_num in 0..16 {
+        singletons.push(format!("EXTI{}", pin_num));
+    }
+
+    // One singleton per DMA channel
+    stm32_metapac::dma_channels! {
+        ($channel_peri:ident, $dma_peri:ident, $version:ident, $channel_num:expr, $ignore:tt) => {
+            singletons.push(stringify!($channel_peri).to_string());
+        };
+    }
+
     let out_dir = &PathBuf::from(env::var_os("OUT_DIR").unwrap());
     let out_file = out_dir.join("generated.rs").to_string_lossy().to_string();
-
-    let exit_code = Command::new("python3")
-        .args(&["gen.py", &chip_name, &out_file])
-        .status()
-        .expect("failed to execute gen.py");
-
-    if !exit_code.success() {
-        panic!("gen.py exited with {:?}", exit_code)
-    }
+    fs::write(
+        out_file,
+        format!(
+            "embassy_hal_common::peripherals!({});",
+            singletons.join(",")
+        ),
+    )
+    .unwrap();
 
     stm32_metapac::peripheral_versions!(
         ($peri:ident, $version:ident) => {