Initial commit.
diff --git a/inc/arch.h b/inc/arch.h
new file mode 100644
index 0000000..e12a8cf
--- /dev/null
+++ b/inc/arch.h
@@ -0,0 +1,12 @@
+#ifndef _ARCH_H
+#define _ARCH_H
+
+#include "cpu.h"
+#include "irq.h"
+
+void arch_init(struct cpu *cpu);
+void arch_irq_init_percpu(void);
+void arch_irq_config(uint32_t num, enum irq_trigger t, enum irq_polarity p);
+void arch_putchar(char c);
+
+#endif  /* _ARCH_H */