[mammoth] Create a method for getting initial caps.

lib/mammoth/src/init.cpp

@@ -0,0 +1,38 @@
+#include "mammoth/init.h"
+
+#include <zinit.h>
+
+#include "mammoth/debug.h"
+#include "mammoth/port.h"
+
+uint64_t gSelfProcCap = 0;
+uint64_t gSelfVmasCap = 0;
+
+uint64_t gBootDenaliVmmoCap = 0;
+
+z_err_t ParseInitPort(uint64_t init_port_cap) {
+  Port port(init_port_cap);
+  z_err_t ret;
+  uint64_t init_sig, init_cap;
+  while ((ret = port.PollForIntCap(&init_sig, &init_cap)) != Z_ERR_EMPTY) {
+    RET_ERR(ret);
+    switch (init_sig) {
+      case Z_INIT_PROC_SELF:
+        dbgln("received proc");
+        gSelfProcCap = init_cap;
+        break;
+      case Z_INIT_VMAS_SELF:
+        dbgln("received vmas");
+        gSelfVmasCap = init_cap;
+        break;
+      case Z_BOOT_DENALI_VMMO:
+        dbgln("received denali");
+        gBootDenaliVmmoCap = init_cap;
+        break;
+      default:
+        dbgln("Unexpected init type %x, continuing.", init_sig);
+    }
+  }
+
+  return Z_OK;
+}