[mammoth] Create a method for getting initial caps.

lib/mammoth/include/mammoth/init.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#include <stdint.h>
+#include <zerrors.h>
+
+extern uint64_t gSelfProcCap;
+extern uint64_t gSelfVmasCap;
+
+extern uint64_t gBootDenaliVmmoCap;
+
+z_err_t ParseInitPort(uint64_t init_port_cap);

lib/mammoth/include/mammoth/port.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#include <stdint.h>
+#include <zerrors.h>
+
+class Port {
+ public:
+  Port(uint64_t port_cap);
+
+  z_err_t PollForIntCap(uint64_t* msg, uint64_t* cap);
+
+ private:
+  uint64_t port_cap_;
+};