L2_BUCKET_XLOG2
#define L2_BUCKET_XSHIFT (L2_BUCKET_XLOG2 - L1_S_SHIFT)
#define L2_BUCKET_XFRAME (~(vaddr_t)0 << L2_BUCKET_XLOG2)
#define L2_BUCKET_XSIZE (1 << L2_BUCKET_XLOG2)
#define L2_LOG2 (32 - (L2_BUCKET_XLOG2 + L2_BUCKET_LOG2))