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-rw-r--r--kernel/riscv.h11
1 files changed, 11 insertions, 0 deletions
diff --git a/kernel/riscv.h b/kernel/riscv.h
index 20a01db..adc3e38 100644
--- a/kernel/riscv.h
+++ b/kernel/riscv.h
@@ -295,6 +295,14 @@ 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
@@ -344,6 +352,9 @@ typedef uint64 *pagetable_t; // 512 PTEs
#define PTE_X (1L << 3)
#define PTE_U (1L << 4) // user can access
+
+
+
// shift a physical address to the right place for a PTE.
#define PA2PTE(pa) ((((uint64)pa) >> 12) << 10)