mbv: i really though async would work this time

There's still a glitch/race somewhere.

mbv/apps/async/main.cc

@@ -11,11 +11,9 @@
 
 namespace {
 
-using async::AwaitableType;
 Timer* timer0;
 
 void Uart0Isr() {
-    ToggleLed(7);
     HandleUartIsr();
 }
 
@@ -48,16 +46,23 @@ void SetupInterrupts() {
 }
 
 async::task<> echo() {
-    async::task<uint8_t> reader = UartReadLoop();
+    async::task<std::byte> reader = UartReadLoop();
     async::gimme<std::span<const std::byte>> feeder;
     async::task<> writer = UartWriteLoop(feeder);
     writer.h.resume();  // advance to first yield
     while (1) {
         SetLed(1);
-        uint8_t c = co_await reader;
+        std::byte c = co_await reader;
         ClearLed(1);
-        ToggleLed(2);
-        feeder.feed(std::as_bytes(std::span{&c, 1}));
+        co_await feeder.feed(std::span{&c, 1});
+    }
+}
+
+async::task<> blink() {
+    while (1) {
+        co_await async::delay(500);
+        ToggleLed(0);
+        timer0->Pet();
     }
 }
 
@@ -65,25 +70,19 @@ async::task<> echo() {
 
 int main() {
     SetupUart();
-    UartWriteCrash("uart setup done\r\n");
+    UartWriteBlocking("uart setup done\r\n");
     SetupTimer();
-    UartWriteCrash("timer setup done\r\n");
+    UartWriteBlocking("timer setup done\r\n");
 
     gpio0->data = 0;
     SetupInterrupts();
 
     async::schedule(echo().h);
+    async::schedule(blink().h);
 
-    UartWriteCrash("init done. starting main loop\r\n");
+    UartWriteBlocking("init done. starting main loop\r\n");
 
-    async::main_loop([]() {
-        static int cnt = 0;
-        timer0->Pet();
-        if ((cnt++ % 100000) == 0) {
-            ToggleLed(0);
-        }
-        return false;
-    });
+    async::main_loop(nullptr);
     // should never get here
 }