Initial commit: Pico serial echo with BOOTSEL reboot

picomap.cpp

@@ -0,0 +1,16 @@
+#include <stdio.h>
+#include "pico/stdlib.h"
+#include "pico/bootrom.h"
+
+int main() {
+    stdio_init_all();
+
+    while (true) {
+        int c = getchar_timeout_us(100000);
+        if (c == 'p') {
+            printf("p");
+        } else if (c == 'b') {
+            reset_usb_boot(0, 0);
+        }
+    }
+}