1 files changed, 11 insertions, 8 deletions
diff --git a/kernel/riscv.h b/kernel/riscv.h
index adc3e38..af18972 100644
--- a/kernel/riscv.h
+++ b/kernel/riscv.h
@@ -295,14 +295,6 @@ r_sp()
   return x;
 }
 
-static inline uint64
-r_fp()
-{
-  uint64 x;
-  asm volatile("mv %0, s0" : "=r" (x) );
-  return x;
-}
-
 // read and write tp, the thread pointer, which xv6 uses to hold
 // this core's hartid (core number), the index into cpus[].
 static inline uint64
@@ -335,6 +327,15 @@ sfence_vma()
   asm volatile("sfence.vma zero, zero");
 }
 
+// read the frame pointer of currently executing func
+static inline uint64
+r_fp()
+{
+  uint64 x;
+  asm volatile("mv %0, s0" : "=r" (x) );
+  return x;
+}
+
 typedef uint64 pte_t;
 typedef uint64 *pagetable_t; // 512 PTEs
 
@@ -351,6 +352,8 @@ typedef uint64 *pagetable_t; // 512 PTEs
 #define PTE_W (1L << 2)
 #define PTE_X (1L << 3)
 #define PTE_U (1L << 4) // user can access
+#define PTE_A (1L << 6) // riscv access bit                      
+#define PTE_C (1L << 8) // RSW low bit, use it to mark whether a page is COW