diff --git a/.github/workflows/test_riscv64.yaml b/.github/workflows/test_riscv64.yaml
index 5024177..fc56d0f 100644
--- a/.github/workflows/test_riscv64.yaml
+++ b/.github/workflows/test_riscv64.yaml
@@ -14,7 +14,7 @@ jobs:
   test:
     strategy:
       matrix:
-        go-version: [1.18.x]
+        go-version: [1.22.x]
         arch: [riscv64]  
     runs-on: ubuntu-latest
     steps:
@@ -29,11 +29,8 @@ jobs:
     - name: Check out code
       uses: actions/checkout@v4
 
-    - name: Build
-      run: go build -v ./internal/bigmod/...
-      
     - name: Test
-      run: go test -v -short ./internal/bigmod/...
+      run: go test -v -short ./internal/...
       env:
         GODEBUG: x509sha1=1
         GOARCH: ${{ matrix.arch }}      
diff --git a/internal/bigmod/nat_riscv64.s b/internal/bigmod/nat_riscv64.s
index e105ec0..91dfb22 100644
--- a/internal/bigmod/nat_riscv64.s
+++ b/internal/bigmod/nat_riscv64.s
@@ -85,10 +85,10 @@ loop:
 	MOV	X16, 2*8(X5)	// z[2]
 	MOV	X19, 3*8(X5)	// z[3]
 
-	ADDI	$32, X5
-	ADDI	$32, X7
+	ADD	$32, X5
+	ADD	$32, X7
 
-	ADDI	$-4, X30
+	SUB	$4, X30
 	BNEZ	X30, loop
 
 done:
diff --git a/internal/sm2ec/fiat/sm2p256scalar_test.go b/internal/sm2ec/fiat/sm2p256scalar_test.go
index 1e44e82..80a427a 100644
--- a/internal/sm2ec/fiat/sm2p256scalar_test.go
+++ b/internal/sm2ec/fiat/sm2p256scalar_test.go
@@ -42,16 +42,6 @@ var testValues = [20]string{
 	"c79886c5cd9de1f2a0deee1c76cd8c38da7dcd401f59ec4bebbaf815006f2f71",
 }
 
-func TestGenerateValues(t *testing.T) {
-	p, _ := new(big.Int).SetString("FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFF7203DF6B21C6052B53BBF40939D54123", 16)
-	for i := 0; i < 20; i++ {
-		k, _ := rand.Int(rand.Reader, p)
-		if k.Sign() > 0 {
-			fmt.Printf("%v\n", hex.EncodeToString(k.Bytes()))
-		}
-	}
-}
-
 func p256OrderMulTest(t *testing.T, x, y, n *big.Int) {
 	var scalar1 [32]byte
 	var scalar2 [32]byte
diff --git a/internal/subtle/xor_generic.go b/internal/subtle/xor_generic.go
index c515f53..118244e 100644
--- a/internal/subtle/xor_generic.go
+++ b/internal/subtle/xor_generic.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 //
-//go:build purego || !(amd64 || arm64 || s390x || ppc64 || ppc64le)
+//go:build purego || !(amd64 || arm64 || s390x || ppc64 || ppc64le || riscv64)
 
 package subtle
 
diff --git a/internal/subtle/xor_riscv64.go b/internal/subtle/xor_riscv64.go
new file mode 100644
index 0000000..ea8dd38
--- /dev/null
+++ b/internal/subtle/xor_riscv64.go
@@ -0,0 +1,10 @@
+// Copyright 2024 Sun Yimin. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+//go:build !purego
+
+package subtle
+
+//go:noescape
+func xorBytes(dst, a, b *byte, n int)
diff --git a/internal/subtle/xor_riscv64.s b/internal/subtle/xor_riscv64.s
new file mode 100644
index 0000000..bdf38cb
--- /dev/null
+++ b/internal/subtle/xor_riscv64.s
@@ -0,0 +1,63 @@
+// Copyright 2024 Sun Yimin. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+//go:build !purego
+
+#include "textflag.h"
+
+// func xorBytes(dst, a, b *byte, n int)
+TEXT ·xorBytes(SB), NOSPLIT|NOFRAME, $0
+	MOV	dst+0(FP), X5
+	MOV	a+8(FP), X6
+	MOV	b+16(FP), X7
+	MOV	n+24(FP), X8
+
+	MOV 	$8, X9
+	BLTU	X8, X9, tail
+
+loop:
+	MOV (X6), X10
+	MOV (X7), X11
+	XOR X10, X11, X10
+	MOV X10, (X5)
+	ADD $8, X5
+	ADD $8, X6
+	ADD $8, X7
+	SUB $8, X8
+	BGEU X8, X9, loop
+
+tail:
+	BEQZ	X8, done
+	MOV $4, X9
+	BLTU X8, X9, less_than4
+	MOVWU (X6), X10
+	MOVWU (X7), X11
+	XOR X10, X11, X10
+	MOVW X10, (X5)
+	ADD $4, X5
+	ADD $4, X6
+	ADD $4, X7
+	SUB $4, X8
+
+less_than4:
+	MOV $2, X9
+	BLTU X8, X9, less_than2
+	MOVHU (X6), X10
+	MOVHU (X7), X11
+	XOR X10, X11, X10
+	MOVHU X10, (X5)
+	ADD $2, X5
+	ADD $2, X6
+	ADD $2, X7
+	SUB $2, X8
+
+less_than2:
+	BEQZ	X8, done
+	MOVBU (X6), X10
+	MOVBU (X7), X11
+	XOR X10, X11, X10
+	MOVBU X10, (X5)
+
+done:
+	RET
diff --git a/internal/subtle/xor_s390x.go b/internal/subtle/xor_s390x.go
index 6fbacf9..ea8dd38 100644
--- a/internal/subtle/xor_s390x.go
+++ b/internal/subtle/xor_s390x.go
@@ -1,7 +1,7 @@
-// Copyright 2018 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
+// Copyright 2024 Sun Yimin. All rights reserved.
+// Use of this source code is governed by a MIT-style
 // license that can be found in the LICENSE file.
-//
+
 //go:build !purego
 
 package subtle
diff --git a/internal/subtle/xor_s390x.s b/internal/subtle/xor_s390x.s
index 834385e..a5ad498 100644
--- a/internal/subtle/xor_s390x.s
+++ b/internal/subtle/xor_s390x.s
@@ -1,3 +1,7 @@
+// Copyright 2024 Sun Yimin. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
 //go:build !purego
 
 #include "textflag.h"