kernel: add a temporary syscall dispatch system

include/mango/syscall.h

@@ -0,0 +1,20 @@
+#ifndef MANGO_SYSCALL_H_
+#define MANGO_SYSCALL_H_
+
+#include <mango/handle.h>
+#include <mango/status.h>
+#include <mango/vm.h>
+
+#define SYS_EXIT             1
+#define SYS_VM_OBJECT_CREATE 2
+
+extern kern_status_t sys_exit(int status);
+extern kern_status_t sys_vm_object_create(
+	const char *name,
+	size_t len,
+	enum vm_prot prot,
+	kern_handle_t *out_handle);
+
+extern virt_addr_t syscall_get_func(unsigned int sysid);
+
+#endif