feat(util): add esp_crc8 for efuse check

components/util/include/crc.h

@@ -12,8 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#ifndef ROM_CRC_H
+#ifndef __CRC_H_
-#define ROM_CRC_H
+#define __CRC_H_
 
 #include <stdint.h>
 
@@ -115,6 +115,17 @@ uint8_t crc8_le(uint8_t crc, uint8_t const *buf, uint32_t len);
   */
 uint8_t crc8_be(uint8_t crc, uint8_t const *buf, uint32_t len);
 
+/**
+  * @brief  A crc8 algorithm used in efuse check.
+  *
+  * @param  uint8_t const *p : Pointer to original data.
+  *
+  * @param  uint32_t len : Data length in byte.
+  *
+  * @return uint8_t: Crc value.
+  */
+uint8_t esp_crc8(uint8_t const *p, uint32_t len);
+
 /**
   * @}
   */

components/util/src/crc.c

@@ -1,5 +1,20 @@
+// Copyright 2018 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 #include <stdint.h>
-#include <stdbool.h>
+
+#include "crc.h"
 
 static const uint32_t crc32_le_table[256] = {
     0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L, 0x706af48fL, 0xe963a535L, 0x9e6495a3L,
@@ -43,9 +58,29 @@ uint32_t crc32_le(uint32_t crc, const uint8_t *buf, uint32_t len)
 
     crc = ~crc;
 
-    for (i = 0; i < len; i++){
+    for (i = 0; i < len; i++) {
         crc = crc32_le_table[(crc ^ buf[i]) & 0xff] ^ (crc >> 8);
     }
 
     return ~crc;
 }
+
+uint8_t esp_crc8(uint8_t const *p, uint32_t len)
+{
+    uint8_t i;
+    uint8_t crc = 0;
+
+    while (len--) {
+        crc = crc ^ (*p++);
+
+        for (i = 0; i < 8; i++) {
+            if (crc & 0x01) {
+                crc = (crc >> 1) ^ 0x8c;
+            } else {
+                crc = crc >> 1;
+            }
+        }
+    }
+
+    return crc;
+}