mbv: minor cleanup

mbv/hal/bios.h

@@ -0,0 +1,12 @@
+#pragma once
+
+#include <cstdint>
+
+extern "C" {
+
+uint8_t BiosUartRead();
+void BiosUartWrite(uint8_t);
+void BiosWozmon();
+void BiosUartWriteNibble(uint8_t);
+
+}

mbv/hal/gpio.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#include <cstdint>
+
+struct Gpio {
+    volatile uint32_t data;
+
+    static Gpio* Instance(uint32_t base) {
+        return reinterpret_cast<Gpio*>(base);
+    }
+};