diff --git a/kernel.h b/kernel.h
index e08972d..44ed420 100644
--- a/kernel.h
+++ b/kernel.h
@@ -70,3 +70,10 @@ struct process {
     vaddr_t sp;                 // Stack pointer
     uint8_t stack[8192];        // Kernel stack
 };
+
+#define SATP_SV32 (1u << 32)
+#define PAGE_V (1 << 0) // "Valid" bit (entry is allowed)
+#define PAGE_R (1 << 1) // Readable
+#define PAGE_W (1 << 2) // Writable
+#define PAGE_X (1 << 3) // Executable
+#define PAGE_U (1 << 4) // User (accessible in user mode)