arm: add host uart driver tests

All host tests currently pass
Some async refactors may not work well on device, will try later

arm/main.cc

@@ -30,7 +30,7 @@ void SetupUart() {
 }
 
 void SetupTimer() {
-    timer0->SetupAsWdt(100000 * 4000);
+    timer0->SetupAsWdt(100000 * 1); //4000);
     timer0->EnableT1();
 
     _vector_table[16 + Timer0_IRQn] = reinterpret_cast<uint32_t>(Timer0Isr);
@@ -38,7 +38,7 @@ void SetupTimer() {
 }
 
 
-#if 0 // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101133
+#if 1 // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101133
 async::task<> echo() {
     async::task<uint8_t> reader = UartReadLoop();
     async::gimme<std::span<const std::byte>> feeder;
@@ -52,8 +52,7 @@ async::task<> echo() {
         co_await feeder.feed(std::as_bytes(std::span{&c, 1}));
     }
 }
-#endif
-
+#else
 async::task<> echo() {
     async::task<uint8_t> reader = UartReadLoop();
     while (1) {
@@ -64,7 +63,9 @@ async::task<> echo() {
         co_await UartWrite(std::as_bytes(std::span{&c, 1}));
     }
 }
+#endif
 
+[[maybe_unused]]
 async::task<> dump_trace() {
     while (1) {
         co_await async::delay(5000);
@@ -86,7 +87,7 @@ int main() {
     UartWriteBlocking("timer setup done\r\n");
 
     async::schedule(echo().h);
-    async::schedule(dump_trace().h);
+//    async::schedule(dump_trace().h);
 
     tracing::trace(tracing::TraceEvent::kUartIsr);
     tracing::trace(tracing::TraceEvent::kUartIsr);